aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/tree-ssa-loop-ivopts.c
blob: c5a5dd48ac38b2c6a64ecfe702905f154dba2e84 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
/* Induction variable optimizations.
   Copyright (C) 2003-2014 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.

GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

/* This pass tries to find the optimal set of induction variables for the loop.
   It optimizes just the basic linear induction variables (although adding
   support for other types should not be too hard).  It includes the
   optimizations commonly known as strength reduction, induction variable
   coalescing and induction variable elimination.  It does it in the
   following steps:

   1) The interesting uses of induction variables are found.  This includes

      -- uses of induction variables in non-linear expressions
      -- addresses of arrays
      -- comparisons of induction variables

   2) Candidates for the induction variables are found.  This includes

      -- old induction variables
      -- the variables defined by expressions derived from the "interesting
	 uses" above

   3) The optimal (w.r. to a cost function) set of variables is chosen.  The
      cost function assigns a cost to sets of induction variables and consists
      of three parts:

      -- The use costs.  Each of the interesting uses chooses the best induction
	 variable in the set and adds its cost to the sum.  The cost reflects
	 the time spent on modifying the induction variables value to be usable
	 for the given purpose (adding base and offset for arrays, etc.).
      -- The variable costs.  Each of the variables has a cost assigned that
	 reflects the costs associated with incrementing the value of the
	 variable.  The original variables are somewhat preferred.
      -- The set cost.  Depending on the size of the set, extra cost may be
	 added to reflect register pressure.

      All the costs are defined in a machine-specific way, using the target
      hooks and machine descriptions to determine them.

   4) The trees are transformed to use the new variables, the dead code is
      removed.

   All of this is done loop by loop.  Doing it globally is theoretically
   possible, it might give a better performance and it might enable us
   to decide costs more precisely, but getting all the interactions right
   would be complicated.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "stor-layout.h"
#include "tm_p.h"
#include "basic-block.h"
#include "gimple-pretty-print.h"
#include "pointer-set.h"
#include "hash-table.h"
#include "tree-ssa-alias.h"
#include "internal-fn.h"
#include "tree-eh.h"
#include "gimple-expr.h"
#include "is-a.h"
#include "gimple.h"
#include "gimplify.h"
#include "gimple-iterator.h"
#include "gimplify-me.h"
#include "gimple-ssa.h"
#include "cgraph.h"
#include "tree-cfg.h"
#include "tree-phinodes.h"
#include "ssa-iterators.h"
#include "stringpool.h"
#include "tree-ssanames.h"
#include "tree-ssa-loop-ivopts.h"
#include "tree-ssa-loop-manip.h"
#include "tree-ssa-loop-niter.h"
#include "tree-ssa-loop.h"
#include "expr.h"
#include "tree-dfa.h"
#include "tree-ssa.h"
#include "cfgloop.h"
#include "tree-pass.h"
#include "insn-config.h"
#include "tree-chrec.h"
#include "tree-scalar-evolution.h"
#include "cfgloop.h"
#include "params.h"
#include "langhooks.h"
#include "tree-affine.h"
#include "target.h"
#include "tree-inline.h"
#include "tree-ssa-propagate.h"
#include "expmed.h"
#include "tree-ssa-address.h"

/* FIXME: Expressions are expanded to RTL in this pass to determine the
   cost of different addressing modes.  This should be moved to a TBD
   interface between the GIMPLE and RTL worlds.  */
#include "expr.h"
#include "recog.h"

/* The infinite cost.  */
#define INFTY 10000000

#define AVG_LOOP_NITER(LOOP) 5

/* Returns the expected number of loop iterations for LOOP.
   The average trip count is computed from profile data if it
   exists. */

static inline HOST_WIDE_INT
avg_loop_niter (struct loop *loop)
{
  HOST_WIDE_INT niter = estimated_stmt_executions_int (loop);
  if (niter == -1)
    return AVG_LOOP_NITER (loop);

  return niter;
}

/* Representation of the induction variable.  */
struct iv
{
  tree base;		/* Initial value of the iv.  */
  tree base_object;	/* A memory object to that the induction variable points.  */
  tree step;		/* Step of the iv (constant only).  */
  tree ssa_name;	/* The ssa name with the value.  */
  bool biv_p;		/* Is it a biv?  */
  bool have_use_for;	/* Do we already have a use for it?  */
  unsigned use_id;	/* The identifier in the use if it is the case.  */
};

/* Per-ssa version information (induction variable descriptions, etc.).  */
struct version_info
{
  tree name;		/* The ssa name.  */
  struct iv *iv;	/* Induction variable description.  */
  bool has_nonlin_use;	/* For a loop-level invariant, whether it is used in
			   an expression that is not an induction variable.  */
  bool preserve_biv;	/* For the original biv, whether to preserve it.  */
  unsigned inv_id;	/* Id of an invariant.  */
};

/* Types of uses.  */
enum use_type
{
  USE_NONLINEAR_EXPR,	/* Use in a nonlinear expression.  */
  USE_ADDRESS,		/* Use in an address.  */
  USE_COMPARE		/* Use is a compare.  */
};

/* Cost of a computation.  */
typedef struct
{
  int cost;		/* The runtime cost.  */
  unsigned complexity;	/* The estimate of the complexity of the code for
			   the computation (in no concrete units --
			   complexity field should be larger for more
			   complex expressions and addressing modes).  */
} comp_cost;

static const comp_cost no_cost = {0, 0};
static const comp_cost infinite_cost = {INFTY, INFTY};

/* The candidate - cost pair.  */
struct cost_pair
{
  struct iv_cand *cand;	/* The candidate.  */
  comp_cost cost;	/* The cost.  */
  bitmap depends_on;	/* The list of invariants that have to be
			   preserved.  */
  tree value;		/* For final value elimination, the expression for
			   the final value of the iv.  For iv elimination,
			   the new bound to compare with.  */
  enum tree_code comp;	/* For iv elimination, the comparison.  */
  int inv_expr_id;      /* Loop invariant expression id.  */
};

/* Use.  */
struct iv_use
{
  unsigned id;		/* The id of the use.  */
  enum use_type type;	/* Type of the use.  */
  struct iv *iv;	/* The induction variable it is based on.  */
  gimple stmt;		/* Statement in that it occurs.  */
  tree *op_p;		/* The place where it occurs.  */
  bitmap related_cands;	/* The set of "related" iv candidates, plus the common
			   important ones.  */

  unsigned n_map_members; /* Number of candidates in the cost_map list.  */
  struct cost_pair *cost_map;
			/* The costs wrto the iv candidates.  */

  struct iv_cand *selected;
			/* The selected candidate.  */
};

/* The position where the iv is computed.  */
enum iv_position
{
  IP_NORMAL,		/* At the end, just before the exit condition.  */
  IP_END,		/* At the end of the latch block.  */
  IP_BEFORE_USE,	/* Immediately before a specific use.  */
  IP_AFTER_USE,		/* Immediately after a specific use.  */
  IP_ORIGINAL		/* The original biv.  */
};

/* The induction variable candidate.  */
struct iv_cand
{
  unsigned id;		/* The number of the candidate.  */
  bool important;	/* Whether this is an "important" candidate, i.e. such
			   that it should be considered by all uses.  */
  ENUM_BITFIELD(iv_position) pos : 8;	/* Where it is computed.  */
  gimple incremented_at;/* For original biv, the statement where it is
			   incremented.  */
  tree var_before;	/* The variable used for it before increment.  */
  tree var_after;	/* The variable used for it after increment.  */
  struct iv *iv;	/* The value of the candidate.  NULL for
			   "pseudocandidate" used to indicate the possibility
			   to replace the final value of an iv by direct
			   computation of the value.  */
  unsigned cost;	/* Cost of the candidate.  */
  unsigned cost_step;	/* Cost of the candidate's increment operation.  */
  struct iv_use *ainc_use; /* For IP_{BEFORE,AFTER}_USE candidates, the place
			      where it is incremented.  */
  bitmap depends_on;	/* The list of invariants that are used in step of the
			   biv.  */
};

/* Loop invariant expression hashtable entry.  */
struct iv_inv_expr_ent
{
  tree expr;
  int id;
  hashval_t hash;
};

/* The data used by the induction variable optimizations.  */

typedef struct iv_use *iv_use_p;

typedef struct iv_cand *iv_cand_p;

/* Hashtable helpers.  */

struct iv_inv_expr_hasher : typed_free_remove <iv_inv_expr_ent>
{
  typedef iv_inv_expr_ent value_type;
  typedef iv_inv_expr_ent compare_type;
  static inline hashval_t hash (const value_type *);
  static inline bool equal (const value_type *, const compare_type *);
};

/* Hash function for loop invariant expressions.  */

inline hashval_t
iv_inv_expr_hasher::hash (const value_type *expr)
{
  return expr->hash;
}

/* Hash table equality function for expressions.  */

inline bool
iv_inv_expr_hasher::equal (const value_type *expr1, const compare_type *expr2)
{
  return expr1->hash == expr2->hash
	 && operand_equal_p (expr1->expr, expr2->expr, 0);
}

struct ivopts_data
{
  /* The currently optimized loop.  */
  struct loop *current_loop;

  /* Numbers of iterations for all exits of the current loop.  */
  struct pointer_map_t *niters;

  /* Number of registers used in it.  */
  unsigned regs_used;

  /* The size of version_info array allocated.  */
  unsigned version_info_size;

  /* The array of information for the ssa names.  */
  struct version_info *version_info;

  /* The hashtable of loop invariant expressions created
     by ivopt.  */
  hash_table <iv_inv_expr_hasher> inv_expr_tab;

  /* Loop invariant expression id.  */
  int inv_expr_id;

  /* The bitmap of indices in version_info whose value was changed.  */
  bitmap relevant;

  /* The uses of induction variables.  */
  vec<iv_use_p> iv_uses;

  /* The candidates.  */
  vec<iv_cand_p> iv_candidates;

  /* A bitmap of important candidates.  */
  bitmap important_candidates;

  /* The maximum invariant id.  */
  unsigned max_inv_id;

  /* Whether to consider just related and important candidates when replacing a
     use.  */
  bool consider_all_candidates;

  /* Are we optimizing for speed?  */
  bool speed;

  /* Whether the loop body includes any function calls.  */
  bool body_includes_call;

  /* Whether the loop body can only be exited via single exit.  */
  bool loop_single_exit_p;
};

/* An assignment of iv candidates to uses.  */

struct iv_ca
{
  /* The number of uses covered by the assignment.  */
  unsigned upto;

  /* Number of uses that cannot be expressed by the candidates in the set.  */
  unsigned bad_uses;

  /* Candidate assigned to a use, together with the related costs.  */
  struct cost_pair **cand_for_use;

  /* Number of times each candidate is used.  */
  unsigned *n_cand_uses;

  /* The candidates used.  */
  bitmap cands;

  /* The number of candidates in the set.  */
  unsigned n_cands;

  /* Total number of registers needed.  */
  unsigned n_regs;

  /* Total cost of expressing uses.  */
  comp_cost cand_use_cost;

  /* Total cost of candidates.  */
  unsigned cand_cost;

  /* Number of times each invariant is used.  */
  unsigned *n_invariant_uses;

  /* The array holding the number of uses of each loop
     invariant expressions created by ivopt.  */
  unsigned *used_inv_expr;

  /* The number of created loop invariants.  */
  unsigned num_used_inv_expr;

  /* Total cost of the assignment.  */
  comp_cost cost;
};

/* Difference of two iv candidate assignments.  */

struct iv_ca_delta
{
  /* Changed use.  */
  struct iv_use *use;

  /* An old assignment (for rollback purposes).  */
  struct cost_pair *old_cp;

  /* A new assignment.  */
  struct cost_pair *new_cp;

  /* Next change in the list.  */
  struct iv_ca_delta *next_change;
};

/* Bound on number of candidates below that all candidates are considered.  */

#define CONSIDER_ALL_CANDIDATES_BOUND \
  ((unsigned) PARAM_VALUE (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND))

/* If there are more iv occurrences, we just give up (it is quite unlikely that
   optimizing such a loop would help, and it would take ages).  */

#define MAX_CONSIDERED_USES \
  ((unsigned) PARAM_VALUE (PARAM_IV_MAX_CONSIDERED_USES))

/* If there are at most this number of ivs in the set, try removing unnecessary
   ivs from the set always.  */

#define ALWAYS_PRUNE_CAND_SET_BOUND \
  ((unsigned) PARAM_VALUE (PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND))

/* The list of trees for that the decl_rtl field must be reset is stored
   here.  */

static vec<tree> decl_rtl_to_reset;

static comp_cost force_expr_to_var_cost (tree, bool);

/* Number of uses recorded in DATA.  */

static inline unsigned
n_iv_uses (struct ivopts_data *data)
{
  return data->iv_uses.length ();
}

/* Ith use recorded in DATA.  */

static inline struct iv_use *
iv_use (struct ivopts_data *data, unsigned i)
{
  return data->iv_uses[i];
}

/* Number of candidates recorded in DATA.  */

static inline unsigned
n_iv_cands (struct ivopts_data *data)
{
  return data->iv_candidates.length ();
}

/* Ith candidate recorded in DATA.  */

static inline struct iv_cand *
iv_cand (struct ivopts_data *data, unsigned i)
{
  return data->iv_candidates[i];
}

/* The single loop exit if it dominates the latch, NULL otherwise.  */

edge
single_dom_exit (struct loop *loop)
{
  edge exit = single_exit (loop);

  if (!exit)
    return NULL;

  if (!just_once_each_iteration_p (loop, exit->src))
    return NULL;

  return exit;
}

/* Dumps information about the induction variable IV to FILE.  */

void
dump_iv (FILE *file, struct iv *iv)
{
  if (iv->ssa_name)
    {
      fprintf (file, "ssa name ");
      print_generic_expr (file, iv->ssa_name, TDF_SLIM);
      fprintf (file, "\n");
    }

  fprintf (file, "  type ");
  print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM);
  fprintf (file, "\n");

  if (iv->step)
    {
      fprintf (file, "  base ");
      print_generic_expr (file, iv->base, TDF_SLIM);
      fprintf (file, "\n");

      fprintf (file, "  step ");
      print_generic_expr (file, iv->step, TDF_SLIM);
      fprintf (file, "\n");
    }
  else
    {
      fprintf (file, "  invariant ");
      print_generic_expr (file, iv->base, TDF_SLIM);
      fprintf (file, "\n");
    }

  if (iv->base_object)
    {
      fprintf (file, "  base object ");
      print_generic_expr (file, iv->base_object, TDF_SLIM);
      fprintf (file, "\n");
    }

  if (iv->biv_p)
    fprintf (file, "  is a biv\n");
}

/* Dumps information about the USE to FILE.  */

void
dump_use (FILE *file, struct iv_use *use)
{
  fprintf (file, "use %d\n", use->id);

  switch (use->type)
    {
    case USE_NONLINEAR_EXPR:
      fprintf (file, "  generic\n");
      break;

    case USE_ADDRESS:
      fprintf (file, "  address\n");
      break;

    case USE_COMPARE:
      fprintf (file, "  compare\n");
      break;

    default:
      gcc_unreachable ();
    }

  fprintf (file, "  in statement ");
  print_gimple_stmt (file, use->stmt, 0, 0);
  fprintf (file, "\n");

  fprintf (file, "  at position ");
  if (use->op_p)
    print_generic_expr (file, *use->op_p, TDF_SLIM);
  fprintf (file, "\n");

  dump_iv (file, use->iv);

  if (use->related_cands)
    {
      fprintf (file, "  related candidates ");
      dump_bitmap (file, use->related_cands);
    }
}

/* Dumps information about the uses to FILE.  */

void
dump_uses (FILE *file, struct ivopts_data *data)
{
  unsigned i;
  struct iv_use *use;

  for (i = 0; i < n_iv_uses (data); i++)
    {
      use = iv_use (data, i);

      dump_use (file, use);
      fprintf (file, "\n");
    }
}

/* Dumps information about induction variable candidate CAND to FILE.  */

void
dump_cand (FILE *file, struct iv_cand *cand)
{
  struct iv *iv = cand->iv;

  fprintf (file, "candidate %d%s\n",
	   cand->id, cand->important ? " (important)" : "");

  if (cand->depends_on)
    {
      fprintf (file, "  depends on ");
      dump_bitmap (file, cand->depends_on);
    }

  if (!iv)
    {
      fprintf (file, "  final value replacement\n");
      return;
    }

  if (cand->var_before)
    {
      fprintf (file, "  var_before ");
      print_generic_expr (file, cand->var_before, TDF_SLIM);
      fprintf (file, "\n");
    }
  if (cand->var_after)
    {
      fprintf (file, "  var_after ");
      print_generic_expr (file, cand->var_after, TDF_SLIM);
      fprintf (file, "\n");
    }

  switch (cand->pos)
    {
    case IP_NORMAL:
      fprintf (file, "  incremented before exit test\n");
      break;

    case IP_BEFORE_USE:
      fprintf (file, "  incremented before use %d\n", cand->ainc_use->id);
      break;

    case IP_AFTER_USE:
      fprintf (file, "  incremented after use %d\n", cand->ainc_use->id);
      break;

    case IP_END:
      fprintf (file, "  incremented at end\n");
      break;

    case IP_ORIGINAL:
      fprintf (file, "  original biv\n");
      break;
    }

  dump_iv (file, iv);
}

/* Returns the info for ssa version VER.  */

static inline struct version_info *
ver_info (struct ivopts_data *data, unsigned ver)
{
  return data->version_info + ver;
}

/* Returns the info for ssa name NAME.  */

static inline struct version_info *
name_info (struct ivopts_data *data, tree name)
{
  return ver_info (data, SSA_NAME_VERSION (name));
}

/* Returns true if STMT is after the place where the IP_NORMAL ivs will be
   emitted in LOOP.  */

static bool
stmt_after_ip_normal_pos (struct loop *loop, gimple stmt)
{
  basic_block bb = ip_normal_pos (loop), sbb = gimple_bb (stmt);

  gcc_assert (bb);

  if (sbb == loop->latch)
    return true;

  if (sbb != bb)
    return false;

  return stmt == last_stmt (bb);
}

/* Returns true if STMT if after the place where the original induction
   variable CAND is incremented.  If TRUE_IF_EQUAL is set, we return true
   if the positions are identical.  */

static bool
stmt_after_inc_pos (struct iv_cand *cand, gimple stmt, bool true_if_equal)
{
  basic_block cand_bb = gimple_bb (cand->incremented_at);
  basic_block stmt_bb = gimple_bb (stmt);

  if (!dominated_by_p (CDI_DOMINATORS, stmt_bb, cand_bb))
    return false;

  if (stmt_bb != cand_bb)
    return true;

  if (true_if_equal
      && gimple_uid (stmt) == gimple_uid (cand->incremented_at))
    return true;
  return gimple_uid (stmt) > gimple_uid (cand->incremented_at);
}

/* Returns true if STMT if after the place where the induction variable
   CAND is incremented in LOOP.  */

static bool
stmt_after_increment (struct loop *loop, struct iv_cand *cand, gimple stmt)
{
  switch (cand->pos)
    {
    case IP_END:
      return false;

    case IP_NORMAL:
      return stmt_after_ip_normal_pos (loop, stmt);

    case IP_ORIGINAL:
    case IP_AFTER_USE:
      return stmt_after_inc_pos (cand, stmt, false);

    case IP_BEFORE_USE:
      return stmt_after_inc_pos (cand, stmt, true);

    default:
      gcc_unreachable ();
    }
}

/* Returns true if EXP is a ssa name that occurs in an abnormal phi node.  */

static bool
abnormal_ssa_name_p (tree exp)
{
  if (!exp)
    return false;

  if (TREE_CODE (exp) != SSA_NAME)
    return false;

  return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) != 0;
}

/* Returns false if BASE or INDEX contains a ssa name that occurs in an
   abnormal phi node.  Callback for for_each_index.  */

static bool
idx_contains_abnormal_ssa_name_p (tree base, tree *index,
				  void *data ATTRIBUTE_UNUSED)
{
  if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
    {
      if (abnormal_ssa_name_p (TREE_OPERAND (base, 2)))
	return false;
      if (abnormal_ssa_name_p (TREE_OPERAND (base, 3)))
	return false;
    }

  return !abnormal_ssa_name_p (*index);
}

/* Returns true if EXPR contains a ssa name that occurs in an
   abnormal phi node.  */

bool
contains_abnormal_ssa_name_p (tree expr)
{
  enum tree_code code;
  enum tree_code_class codeclass;

  if (!expr)
    return false;

  code = TREE_CODE (expr);
  codeclass = TREE_CODE_CLASS (code);

  if (code == SSA_NAME)
    return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0;

  if (code == INTEGER_CST
      || is_gimple_min_invariant (expr))
    return false;

  if (code == ADDR_EXPR)
    return !for_each_index (&TREE_OPERAND (expr, 0),
			    idx_contains_abnormal_ssa_name_p,
			    NULL);

  if (code == COND_EXPR)
    return contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0))
      || contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1))
      || contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 2));

  switch (codeclass)
    {
    case tcc_binary:
    case tcc_comparison:
      if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1)))
	return true;

      /* Fallthru.  */
    case tcc_unary:
      if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0)))
	return true;

      break;

    default:
      gcc_unreachable ();
    }

  return false;
}

/*  Returns the structure describing number of iterations determined from
    EXIT of DATA->current_loop, or NULL if something goes wrong.  */

static struct tree_niter_desc *
niter_for_exit (struct ivopts_data *data, edge exit)
{
  struct tree_niter_desc *desc;
  void **slot;

  if (!data->niters)
    {
      data->niters = pointer_map_create ();
      slot = NULL;
    }
  else
    slot = pointer_map_contains (data->niters, exit);

  if (!slot)
    {
      /* Try to determine number of iterations.  We cannot safely work with ssa
         names that appear in phi nodes on abnormal edges, so that we do not
         create overlapping life ranges for them (PR 27283).  */
      desc = XNEW (struct tree_niter_desc);
      if (!number_of_iterations_exit (data->current_loop,
				      exit, desc, true)
     	  || contains_abnormal_ssa_name_p (desc->niter))
	{
	  XDELETE (desc);
	  desc = NULL;
	}
      slot = pointer_map_insert (data->niters, exit);
      *slot = desc;
    }
  else
    desc = (struct tree_niter_desc *) *slot;

  return desc;
}

/* Returns the structure describing number of iterations determined from
   single dominating exit of DATA->current_loop, or NULL if something
   goes wrong.  */

static struct tree_niter_desc *
niter_for_single_dom_exit (struct ivopts_data *data)
{
  edge exit = single_dom_exit (data->current_loop);

  if (!exit)
    return NULL;

  return niter_for_exit (data, exit);
}

/* Initializes data structures used by the iv optimization pass, stored
   in DATA.  */

static void
tree_ssa_iv_optimize_init (struct ivopts_data *data)
{
  data->version_info_size = 2 * num_ssa_names;
  data->version_info = XCNEWVEC (struct version_info, data->version_info_size);
  data->relevant = BITMAP_ALLOC (NULL);
  data->important_candidates = BITMAP_ALLOC (NULL);
  data->max_inv_id = 0;
  data->niters = NULL;
  data->iv_uses.create (20);
  data->iv_candidates.create (20);
  data->inv_expr_tab.create (10);
  data->inv_expr_id = 0;
  decl_rtl_to_reset.create (20);
}

/* Returns a memory object to that EXPR points.  In case we are able to
   determine that it does not point to any such object, NULL is returned.  */

static tree
determine_base_object (tree expr)
{
  enum tree_code code = TREE_CODE (expr);
  tree base, obj;

  /* If this is a pointer casted to any type, we need to determine
     the base object for the pointer; so handle conversions before
     throwing away non-pointer expressions.  */
  if (CONVERT_EXPR_P (expr))
    return determine_base_object (TREE_OPERAND (expr, 0));

  if (!POINTER_TYPE_P (TREE_TYPE (expr)))
    return NULL_TREE;

  switch (code)
    {
    case INTEGER_CST:
      return NULL_TREE;

    case ADDR_EXPR:
      obj = TREE_OPERAND (expr, 0);
      base = get_base_address (obj);

      if (!base)
	return expr;

      if (TREE_CODE (base) == MEM_REF)
	return determine_base_object (TREE_OPERAND (base, 0));

      return fold_convert (ptr_type_node,
		           build_fold_addr_expr (base));

    case POINTER_PLUS_EXPR:
      return determine_base_object (TREE_OPERAND (expr, 0));

    case PLUS_EXPR:
    case MINUS_EXPR:
      /* Pointer addition is done solely using POINTER_PLUS_EXPR.  */
      gcc_unreachable ();

    default:
      return fold_convert (ptr_type_node, expr);
    }
}

/* Allocates an induction variable with given initial value BASE and step STEP
   for loop LOOP.  */

static struct iv *
alloc_iv (tree base, tree step)
{
  tree base_object = base;
  struct iv *iv = XCNEW (struct iv);
  gcc_assert (step != NULL_TREE);

  /* Lower all address expressions except ones with DECL_P as operand.
     By doing this:
       1) More accurate cost can be computed for address expressions;
       2) Duplicate candidates won't be created for bases in different
          forms, like &a[0] and &a.  */
  STRIP_NOPS (base_object);
  if (TREE_CODE (base_object) == ADDR_EXPR
      && !DECL_P (TREE_OPERAND (base_object, 0)))
    {
      aff_tree comb;
      double_int size;
      base_object = get_inner_reference_aff (TREE_OPERAND (base_object, 0),
					     &comb, &size);
      gcc_assert (base_object != NULL_TREE);
      base_object = build_fold_addr_expr (base_object);
      base = fold_convert (TREE_TYPE (base), aff_combination_to_tree (&comb));
    }

  iv->base = base;
  iv->base_object = determine_base_object (base_object);
  iv->step = step;
  iv->biv_p = false;
  iv->have_use_for = false;
  iv->use_id = 0;
  iv->ssa_name = NULL_TREE;

  return iv;
}

/* Sets STEP and BASE for induction variable IV.  */

static void
set_iv (struct ivopts_data *data, tree iv, tree base, tree step)
{
  struct version_info *info = name_info (data, iv);

  gcc_assert (!info->iv);

  bitmap_set_bit (data->relevant, SSA_NAME_VERSION (iv));
  info->iv = alloc_iv (base, step);
  info->iv->ssa_name = iv;
}

/* Finds induction variable declaration for VAR.  */

static struct iv *
get_iv (struct ivopts_data *data, tree var)
{
  basic_block bb;
  tree type = TREE_TYPE (var);

  if (!POINTER_TYPE_P (type)
      && !INTEGRAL_TYPE_P (type))
    return NULL;

  if (!name_info (data, var)->iv)
    {
      bb = gimple_bb (SSA_NAME_DEF_STMT (var));

      if (!bb
	  || !flow_bb_inside_loop_p (data->current_loop, bb))
	set_iv (data, var, var, build_int_cst (type, 0));
    }

  return name_info (data, var)->iv;
}

/* Determines the step of a biv defined in PHI.  Returns NULL if PHI does
   not define a simple affine biv with nonzero step.  */

static tree
determine_biv_step (gimple phi)
{
  struct loop *loop = gimple_bb (phi)->loop_father;
  tree name = PHI_RESULT (phi);
  affine_iv iv;

  if (virtual_operand_p (name))
    return NULL_TREE;

  if (!simple_iv (loop, loop, name, &iv, true))
    return NULL_TREE;

  return integer_zerop (iv.step) ? NULL_TREE : iv.step;
}

/* Finds basic ivs.  */

static bool
find_bivs (struct ivopts_data *data)
{
  gimple phi;
  tree step, type, base;
  bool found = false;
  struct loop *loop = data->current_loop;
  gimple_stmt_iterator psi;

  for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
    {
      phi = gsi_stmt (psi);

      if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
	continue;

      step = determine_biv_step (phi);
      if (!step)
	continue;

      base = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
      base = expand_simple_operations (base);
      if (contains_abnormal_ssa_name_p (base)
	  || contains_abnormal_ssa_name_p (step))
	continue;

      type = TREE_TYPE (PHI_RESULT (phi));
      base = fold_convert (type, base);
      if (step)
	{
	  if (POINTER_TYPE_P (type))
	    step = convert_to_ptrofftype (step);
	  else
	    step = fold_convert (type, step);
	}

      set_iv (data, PHI_RESULT (phi), base, step);
      found = true;
    }

  return found;
}

/* Marks basic ivs.  */

static void
mark_bivs (struct ivopts_data *data)
{
  gimple phi, def;
  tree var;
  struct iv *iv, *incr_iv;
  struct loop *loop = data->current_loop;
  basic_block incr_bb;
  gimple_stmt_iterator psi;

  for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
    {
      phi = gsi_stmt (psi);

      iv = get_iv (data, PHI_RESULT (phi));
      if (!iv)
	continue;

      var = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop));
      def = SSA_NAME_DEF_STMT (var);
      /* Don't mark iv peeled from other one as biv.  */
      if (def
	  && gimple_code (def) == GIMPLE_PHI
	  && gimple_bb (def) == loop->header)
	continue;

      incr_iv = get_iv (data, var);
      if (!incr_iv)
	continue;

      /* If the increment is in the subloop, ignore it.  */
      incr_bb = gimple_bb (SSA_NAME_DEF_STMT (var));
      if (incr_bb->loop_father != data->current_loop
	  || (incr_bb->flags & BB_IRREDUCIBLE_LOOP))
	continue;

      iv->biv_p = true;
      incr_iv->biv_p = true;
    }
}

/* Checks whether STMT defines a linear induction variable and stores its
   parameters to IV.  */

static bool
find_givs_in_stmt_scev (struct ivopts_data *data, gimple stmt, affine_iv *iv)
{
  tree lhs;
  struct loop *loop = data->current_loop;

  iv->base = NULL_TREE;
  iv->step = NULL_TREE;

  if (gimple_code (stmt) != GIMPLE_ASSIGN)
    return false;

  lhs = gimple_assign_lhs (stmt);
  if (TREE_CODE (lhs) != SSA_NAME)
    return false;

  if (!simple_iv (loop, loop_containing_stmt (stmt), lhs, iv, true))
    return false;
  iv->base = expand_simple_operations (iv->base);

  if (contains_abnormal_ssa_name_p (iv->base)
      || contains_abnormal_ssa_name_p (iv->step))
    return false;

  /* If STMT could throw, then do not consider STMT as defining a GIV.  
     While this will suppress optimizations, we can not safely delete this
     GIV and associated statements, even if it appears it is not used.  */
  if (stmt_could_throw_p (stmt))
    return false;

  return true;
}

/* Finds general ivs in statement STMT.  */

static void
find_givs_in_stmt (struct ivopts_data *data, gimple stmt)
{
  affine_iv iv;

  if (!find_givs_in_stmt_scev (data, stmt, &iv))
    return;

  set_iv (data, gimple_assign_lhs (stmt), iv.base, iv.step);
}

/* Finds general ivs in basic block BB.  */

static void
find_givs_in_bb (struct ivopts_data *data, basic_block bb)
{
  gimple_stmt_iterator bsi;

  for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
    find_givs_in_stmt (data, gsi_stmt (bsi));
}

/* Finds general ivs.  */

static void
find_givs (struct ivopts_data *data)
{
  struct loop *loop = data->current_loop;
  basic_block *body = get_loop_body_in_dom_order (loop);
  unsigned i;

  for (i = 0; i < loop->num_nodes; i++)
    find_givs_in_bb (data, body[i]);
  free (body);
}

/* For each ssa name defined in LOOP determines whether it is an induction
   variable and if so, its initial value and step.  */

static bool
find_induction_variables (struct ivopts_data *data)
{
  unsigned i;
  bitmap_iterator bi;

  if (!find_bivs (data))
    return false;

  find_givs (data);
  mark_bivs (data);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      struct tree_niter_desc *niter = niter_for_single_dom_exit (data);

      if (niter)
	{
	  fprintf (dump_file, "  number of iterations ");
	  print_generic_expr (dump_file, niter->niter, TDF_SLIM);
	  if (!integer_zerop (niter->may_be_zero))
	    {
	      fprintf (dump_file, "; zero if ");
	      print_generic_expr (dump_file, niter->may_be_zero, TDF_SLIM);
	    }
	  fprintf (dump_file, "\n\n");
    	};

      fprintf (dump_file, "Induction variables:\n\n");

      EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
	{
	  if (ver_info (data, i)->iv)
	    dump_iv (dump_file, ver_info (data, i)->iv);
	}
    }

  return true;
}

/* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV.  */

static struct iv_use *
record_use (struct ivopts_data *data, tree *use_p, struct iv *iv,
	    gimple stmt, enum use_type use_type)
{
  struct iv_use *use = XCNEW (struct iv_use);

  use->id = n_iv_uses (data);
  use->type = use_type;
  use->iv = iv;
  use->stmt = stmt;
  use->op_p = use_p;
  use->related_cands = BITMAP_ALLOC (NULL);

  /* To avoid showing ssa name in the dumps, if it was not reset by the
     caller.  */
  iv->ssa_name = NULL_TREE;

  if (dump_file && (dump_flags & TDF_DETAILS))
    dump_use (dump_file, use);

  data->iv_uses.safe_push (use);

  return use;
}

/* Checks whether OP is a loop-level invariant and if so, records it.
   NONLINEAR_USE is true if the invariant is used in a way we do not
   handle specially.  */

static void
record_invariant (struct ivopts_data *data, tree op, bool nonlinear_use)
{
  basic_block bb;
  struct version_info *info;

  if (TREE_CODE (op) != SSA_NAME
      || virtual_operand_p (op))
    return;

  bb = gimple_bb (SSA_NAME_DEF_STMT (op));
  if (bb
      && flow_bb_inside_loop_p (data->current_loop, bb))
    return;

  info = name_info (data, op);
  info->name = op;
  info->has_nonlin_use |= nonlinear_use;
  if (!info->inv_id)
    info->inv_id = ++data->max_inv_id;
  bitmap_set_bit (data->relevant, SSA_NAME_VERSION (op));
}

/* Checks whether the use OP is interesting and if so, records it.  */

static struct iv_use *
find_interesting_uses_op (struct ivopts_data *data, tree op)
{
  struct iv *iv;
  struct iv *civ;
  gimple stmt;
  struct iv_use *use;

  if (TREE_CODE (op) != SSA_NAME)
    return NULL;

  iv = get_iv (data, op);
  if (!iv)
    return NULL;

  if (iv->have_use_for)
    {
      use = iv_use (data, iv->use_id);

      gcc_assert (use->type == USE_NONLINEAR_EXPR);
      return use;
    }

  if (integer_zerop (iv->step))
    {
      record_invariant (data, op, true);
      return NULL;
    }
  iv->have_use_for = true;

  civ = XNEW (struct iv);
  *civ = *iv;

  stmt = SSA_NAME_DEF_STMT (op);
  gcc_assert (gimple_code (stmt) == GIMPLE_PHI
	      || is_gimple_assign (stmt));

  use = record_use (data, NULL, civ, stmt, USE_NONLINEAR_EXPR);
  iv->use_id = use->id;

  return use;
}

/* Given a condition in statement STMT, checks whether it is a compare
   of an induction variable and an invariant.  If this is the case,
   CONTROL_VAR is set to location of the iv, BOUND to the location of
   the invariant, IV_VAR and IV_BOUND are set to the corresponding
   induction variable descriptions, and true is returned.  If this is not
   the case, CONTROL_VAR and BOUND are set to the arguments of the
   condition and false is returned.  */

static bool
extract_cond_operands (struct ivopts_data *data, gimple stmt,
		       tree **control_var, tree **bound,
		       struct iv **iv_var, struct iv **iv_bound)
{
  /* The objects returned when COND has constant operands.  */
  static struct iv const_iv;
  static tree zero;
  tree *op0 = &zero, *op1 = &zero, *tmp_op;
  struct iv *iv0 = &const_iv, *iv1 = &const_iv, *tmp_iv;
  bool ret = false;

  if (gimple_code (stmt) == GIMPLE_COND)
    {
      op0 = gimple_cond_lhs_ptr (stmt);
      op1 = gimple_cond_rhs_ptr (stmt);
    }
  else
    {
      op0 = gimple_assign_rhs1_ptr (stmt);
      op1 = gimple_assign_rhs2_ptr (stmt);
    }

  zero = integer_zero_node;
  const_iv.step = integer_zero_node;

  if (TREE_CODE (*op0) == SSA_NAME)
    iv0 = get_iv (data, *op0);
  if (TREE_CODE (*op1) == SSA_NAME)
    iv1 = get_iv (data, *op1);

  /* Exactly one of the compared values must be an iv, and the other one must
     be an invariant.  */
  if (!iv0 || !iv1)
    goto end;

  if (integer_zerop (iv0->step))
    {
      /* Control variable may be on the other side.  */
      tmp_op = op0; op0 = op1; op1 = tmp_op;
      tmp_iv = iv0; iv0 = iv1; iv1 = tmp_iv;
    }
  ret = !integer_zerop (iv0->step) && integer_zerop (iv1->step);

end:
  if (control_var)
    *control_var = op0;;
  if (iv_var)
    *iv_var = iv0;;
  if (bound)
    *bound = op1;
  if (iv_bound)
    *iv_bound = iv1;

  return ret;
}

/* Checks whether the condition in STMT is interesting and if so,
   records it.  */

static void
find_interesting_uses_cond (struct ivopts_data *data, gimple stmt)
{
  tree *var_p, *bound_p;
  struct iv *var_iv, *civ;

  if (!extract_cond_operands (data, stmt, &var_p, &bound_p, &var_iv, NULL))
    {
      find_interesting_uses_op (data, *var_p);
      find_interesting_uses_op (data, *bound_p);
      return;
    }

  civ = XNEW (struct iv);
  *civ = *var_iv;
  record_use (data, NULL, civ, stmt, USE_COMPARE);
}

/* Returns the outermost loop EXPR is obviously invariant in
   relative to the loop LOOP, i.e. if all its operands are defined
   outside of the returned loop.  Returns NULL if EXPR is not
   even obviously invariant in LOOP.  */

struct loop *
outermost_invariant_loop_for_expr (struct loop *loop, tree expr)
{
  basic_block def_bb;
  unsigned i, len;

  if (is_gimple_min_invariant (expr))
    return current_loops->tree_root;

  if (TREE_CODE (expr) == SSA_NAME)
    {
      def_bb = gimple_bb (SSA_NAME_DEF_STMT (expr));
      if (def_bb)
	{
	  if (flow_bb_inside_loop_p (loop, def_bb))
	    return NULL;
	  return superloop_at_depth (loop,
				     loop_depth (def_bb->loop_father) + 1);
	}

      return current_loops->tree_root;
    }

  if (!EXPR_P (expr))
    return NULL;

  unsigned maxdepth = 0;
  len = TREE_OPERAND_LENGTH (expr);
  for (i = 0; i < len; i++)
    {
      struct loop *ivloop;
      if (!TREE_OPERAND (expr, i))
	continue;

      ivloop = outermost_invariant_loop_for_expr (loop, TREE_OPERAND (expr, i));
      if (!ivloop)
	return NULL;
      maxdepth = MAX (maxdepth, loop_depth (ivloop));
    }

  return superloop_at_depth (loop, maxdepth);
}

/* Returns true if expression EXPR is obviously invariant in LOOP,
   i.e. if all its operands are defined outside of the LOOP.  LOOP
   should not be the function body.  */

bool
expr_invariant_in_loop_p (struct loop *loop, tree expr)
{
  basic_block def_bb;
  unsigned i, len;

  gcc_assert (loop_depth (loop) > 0);

  if (is_gimple_min_invariant (expr))
    return true;

  if (TREE_CODE (expr) == SSA_NAME)
    {
      def_bb = gimple_bb (SSA_NAME_DEF_STMT (expr));
      if (def_bb
	  && flow_bb_inside_loop_p (loop, def_bb))
	return false;

      return true;
    }

  if (!EXPR_P (expr))
    return false;

  len = TREE_OPERAND_LENGTH (expr);
  for (i = 0; i < len; i++)
    if (TREE_OPERAND (expr, i)
	&& !expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i)))
      return false;

  return true;
}

/* Cumulates the steps of indices into DATA and replaces their values with the
   initial ones.  Returns false when the value of the index cannot be determined.
   Callback for for_each_index.  */

struct ifs_ivopts_data
{
  struct ivopts_data *ivopts_data;
  gimple stmt;
  tree step;
};

static bool
idx_find_step (tree base, tree *idx, void *data)
{
  struct ifs_ivopts_data *dta = (struct ifs_ivopts_data *) data;
  struct iv *iv;
  tree step, iv_base, iv_step, lbound, off;
  struct loop *loop = dta->ivopts_data->current_loop;

  /* If base is a component ref, require that the offset of the reference
     be invariant.  */
  if (TREE_CODE (base) == COMPONENT_REF)
    {
      off = component_ref_field_offset (base);
      return expr_invariant_in_loop_p (loop, off);
    }

  /* If base is array, first check whether we will be able to move the
     reference out of the loop (in order to take its address in strength
     reduction).  In order for this to work we need both lower bound
     and step to be loop invariants.  */
  if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
    {
      /* Moreover, for a range, the size needs to be invariant as well.  */
      if (TREE_CODE (base) == ARRAY_RANGE_REF
	  && !expr_invariant_in_loop_p (loop, TYPE_SIZE (TREE_TYPE (base))))
	return false;

      step = array_ref_element_size (base);
      lbound = array_ref_low_bound (base);

      if (!expr_invariant_in_loop_p (loop, step)
	  || !expr_invariant_in_loop_p (loop, lbound))
	return false;
    }

  if (TREE_CODE (*idx) != SSA_NAME)
    return true;

  iv = get_iv (dta->ivopts_data, *idx);
  if (!iv)
    return false;

  /* XXX  We produce for a base of *D42 with iv->base being &x[0]
	  *&x[0], which is not folded and does not trigger the
	  ARRAY_REF path below.  */
  *idx = iv->base;

  if (integer_zerop (iv->step))
    return true;

  if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
    {
      step = array_ref_element_size (base);

      /* We only handle addresses whose step is an integer constant.  */
      if (TREE_CODE (step) != INTEGER_CST)
	return false;
    }
  else
    /* The step for pointer arithmetics already is 1 byte.  */
    step = size_one_node;

  iv_base = iv->base;
  iv_step = iv->step;
  if (!convert_affine_scev (dta->ivopts_data->current_loop,
			    sizetype, &iv_base, &iv_step, dta->stmt,
			    false))
    {
      /* The index might wrap.  */
      return false;
    }

  step = fold_build2 (MULT_EXPR, sizetype, step, iv_step);
  dta->step = fold_build2 (PLUS_EXPR, sizetype, dta->step, step);

  return true;
}

/* Records use in index IDX.  Callback for for_each_index.  Ivopts data
   object is passed to it in DATA.  */

static bool
idx_record_use (tree base, tree *idx,
		void *vdata)
{
  struct ivopts_data *data = (struct ivopts_data *) vdata;
  find_interesting_uses_op (data, *idx);
  if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
    {
      find_interesting_uses_op (data, array_ref_element_size (base));
      find_interesting_uses_op (data, array_ref_low_bound (base));
    }
  return true;
}

/* If we can prove that TOP = cst * BOT for some constant cst,
   store cst to MUL and return true.  Otherwise return false.
   The returned value is always sign-extended, regardless of the
   signedness of TOP and BOT.  */

static bool
constant_multiple_of (tree top, tree bot, double_int *mul)
{
  tree mby;
  enum tree_code code;
  double_int res, p0, p1;
  unsigned precision = TYPE_PRECISION (TREE_TYPE (top));

  STRIP_NOPS (top);
  STRIP_NOPS (bot);

  if (operand_equal_p (top, bot, 0))
    {
      *mul = double_int_one;
      return true;
    }

  code = TREE_CODE (top);
  switch (code)
    {
    case MULT_EXPR:
      mby = TREE_OPERAND (top, 1);
      if (TREE_CODE (mby) != INTEGER_CST)
	return false;

      if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &res))
	return false;

      *mul = (res * tree_to_double_int (mby)).sext (precision);
      return true;

    case PLUS_EXPR:
    case MINUS_EXPR:
      if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &p0)
	  || !constant_multiple_of (TREE_OPERAND (top, 1), bot, &p1))
	return false;

      if (code == MINUS_EXPR)
	p1 = -p1;
      *mul = (p0 + p1).sext (precision);
      return true;

    case INTEGER_CST:
      if (TREE_CODE (bot) != INTEGER_CST)
	return false;

      p0 = tree_to_double_int (top).sext (precision);
      p1 = tree_to_double_int (bot).sext (precision);
      if (p1.is_zero ())
	return false;
      *mul = p0.sdivmod (p1, FLOOR_DIV_EXPR, &res).sext (precision);
      return res.is_zero ();

    default:
      return false;
    }
}

/* Return true if memory reference REF with step STEP may be unaligned.  */

static bool
may_be_unaligned_p (tree ref, tree step)
{
  /* TARGET_MEM_REFs are translated directly to valid MEMs on the target,
     thus they are not misaligned.  */
  if (TREE_CODE (ref) == TARGET_MEM_REF)
    return false;

  unsigned int align = TYPE_ALIGN (TREE_TYPE (ref));
  if (GET_MODE_ALIGNMENT (TYPE_MODE (TREE_TYPE (ref))) > align)
    align = GET_MODE_ALIGNMENT (TYPE_MODE (TREE_TYPE (ref)));

  unsigned HOST_WIDE_INT bitpos;
  unsigned int ref_align;
  get_object_alignment_1 (ref, &ref_align, &bitpos);
  if (ref_align < align
      || (bitpos % align) != 0
      || (bitpos % BITS_PER_UNIT) != 0)
    return true;

  unsigned int trailing_zeros = tree_ctz (step);
  if (trailing_zeros < HOST_BITS_PER_INT
      && (1U << trailing_zeros) * BITS_PER_UNIT < align)
    return true;

  return false;
}

/* Return true if EXPR may be non-addressable.   */

bool
may_be_nonaddressable_p (tree expr)
{
  switch (TREE_CODE (expr))
    {
    case TARGET_MEM_REF:
      /* TARGET_MEM_REFs are translated directly to valid MEMs on the
	 target, thus they are always addressable.  */
      return false;

    case COMPONENT_REF:
      return DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1))
	     || may_be_nonaddressable_p (TREE_OPERAND (expr, 0));

    case VIEW_CONVERT_EXPR:
      /* This kind of view-conversions may wrap non-addressable objects
	 and make them look addressable.  After some processing the
	 non-addressability may be uncovered again, causing ADDR_EXPRs
	 of inappropriate objects to be built.  */
      if (is_gimple_reg (TREE_OPERAND (expr, 0))
	  || !is_gimple_addressable (TREE_OPERAND (expr, 0)))
	return true;

      /* ... fall through ... */

    case ARRAY_REF:
    case ARRAY_RANGE_REF:
      return may_be_nonaddressable_p (TREE_OPERAND (expr, 0));

    CASE_CONVERT:
      return true;

    default:
      break;
    }

  return false;
}

/* Finds addresses in *OP_P inside STMT.  */

static void
find_interesting_uses_address (struct ivopts_data *data, gimple stmt, tree *op_p)
{
  tree base = *op_p, step = size_zero_node;
  struct iv *civ;
  struct ifs_ivopts_data ifs_ivopts_data;

  /* Do not play with volatile memory references.  A bit too conservative,
     perhaps, but safe.  */
  if (gimple_has_volatile_ops (stmt))
    goto fail;

  /* Ignore bitfields for now.  Not really something terribly complicated
     to handle.  TODO.  */
  if (TREE_CODE (base) == BIT_FIELD_REF)
    goto fail;

  base = unshare_expr (base);

  if (TREE_CODE (base) == TARGET_MEM_REF)
    {
      tree type = build_pointer_type (TREE_TYPE (base));
      tree astep;

      if (TMR_BASE (base)
	  && TREE_CODE (TMR_BASE (base)) == SSA_NAME)
	{
	  civ = get_iv (data, TMR_BASE (base));
	  if (!civ)
	    goto fail;

	  TMR_BASE (base) = civ->base;
	  step = civ->step;
	}
      if (TMR_INDEX2 (base)
	  && TREE_CODE (TMR_INDEX2 (base)) == SSA_NAME)
	{
	  civ = get_iv (data, TMR_INDEX2 (base));
	  if (!civ)
	    goto fail;

	  TMR_INDEX2 (base) = civ->base;
	  step = civ->step;
	}
      if (TMR_INDEX (base)
	  && TREE_CODE (TMR_INDEX (base)) == SSA_NAME)
	{
	  civ = get_iv (data, TMR_INDEX (base));
	  if (!civ)
	    goto fail;

	  TMR_INDEX (base) = civ->base;
	  astep = civ->step;

	  if (astep)
	    {
	      if (TMR_STEP (base))
		astep = fold_build2 (MULT_EXPR, type, TMR_STEP (base), astep);

	      step = fold_build2 (PLUS_EXPR, type, step, astep);
	    }
	}

      if (integer_zerop (step))
	goto fail;
      base = tree_mem_ref_addr (type, base);
    }
  else
    {
      ifs_ivopts_data.ivopts_data = data;
      ifs_ivopts_data.stmt = stmt;
      ifs_ivopts_data.step = size_zero_node;
      if (!for_each_index (&base, idx_find_step, &ifs_ivopts_data)
	  || integer_zerop (ifs_ivopts_data.step))
	goto fail;
      step = ifs_ivopts_data.step;

      /* Check that the base expression is addressable.  This needs
	 to be done after substituting bases of IVs into it.  */
      if (may_be_nonaddressable_p (base))
	goto fail;

      /* Moreover, on strict alignment platforms, check that it is
	 sufficiently aligned.  */
      if (STRICT_ALIGNMENT && may_be_unaligned_p (base, step))
	goto fail;

      base = build_fold_addr_expr (base);

      /* Substituting bases of IVs into the base expression might
	 have caused folding opportunities.  */
      if (TREE_CODE (base) == ADDR_EXPR)
	{
	  tree *ref = &TREE_OPERAND (base, 0);
	  while (handled_component_p (*ref))
	    ref = &TREE_OPERAND (*ref, 0);
	  if (TREE_CODE (*ref) == MEM_REF)
	    {
	      tree tem = fold_binary (MEM_REF, TREE_TYPE (*ref),
				      TREE_OPERAND (*ref, 0),
				      TREE_OPERAND (*ref, 1));
	      if (tem)
		*ref = tem;
	    }
	}
    }

  civ = alloc_iv (base, step);
  record_use (data, op_p, civ, stmt, USE_ADDRESS);
  return;

fail:
  for_each_index (op_p, idx_record_use, data);
}

/* Finds and records invariants used in STMT.  */

static void
find_invariants_stmt (struct ivopts_data *data, gimple stmt)
{
  ssa_op_iter iter;
  use_operand_p use_p;
  tree op;

  FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
    {
      op = USE_FROM_PTR (use_p);
      record_invariant (data, op, false);
    }
}

/* Finds interesting uses of induction variables in the statement STMT.  */

static void
find_interesting_uses_stmt (struct ivopts_data *data, gimple stmt)
{
  struct iv *iv;
  tree op, *lhs, *rhs;
  ssa_op_iter iter;
  use_operand_p use_p;
  enum tree_code code;

  find_invariants_stmt (data, stmt);

  if (gimple_code (stmt) == GIMPLE_COND)
    {
      find_interesting_uses_cond (data, stmt);
      return;
    }

  if (is_gimple_assign (stmt))
    {
      lhs = gimple_assign_lhs_ptr (stmt);
      rhs = gimple_assign_rhs1_ptr (stmt);

      if (TREE_CODE (*lhs) == SSA_NAME)
	{
	  /* If the statement defines an induction variable, the uses are not
	     interesting by themselves.  */

	  iv = get_iv (data, *lhs);

	  if (iv && !integer_zerop (iv->step))
	    return;
	}

      code = gimple_assign_rhs_code (stmt);
      if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
	  && (REFERENCE_CLASS_P (*rhs)
	      || is_gimple_val (*rhs)))
	{
	  if (REFERENCE_CLASS_P (*rhs))
	    find_interesting_uses_address (data, stmt, rhs);
	  else
	    find_interesting_uses_op (data, *rhs);

	  if (REFERENCE_CLASS_P (*lhs))
	    find_interesting_uses_address (data, stmt, lhs);
	  return;
	}
      else if (TREE_CODE_CLASS (code) == tcc_comparison)
	{
	  find_interesting_uses_cond (data, stmt);
	  return;
	}

      /* TODO -- we should also handle address uses of type

	 memory = call (whatever);

	 and

	 call (memory).  */
    }

  if (gimple_code (stmt) == GIMPLE_PHI
      && gimple_bb (stmt) == data->current_loop->header)
    {
      iv = get_iv (data, PHI_RESULT (stmt));

      if (iv && !integer_zerop (iv->step))
	return;
    }

  FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
    {
      op = USE_FROM_PTR (use_p);

      if (TREE_CODE (op) != SSA_NAME)
	continue;

      iv = get_iv (data, op);
      if (!iv)
	continue;

      find_interesting_uses_op (data, op);
    }
}

/* Finds interesting uses of induction variables outside of loops
   on loop exit edge EXIT.  */

static void
find_interesting_uses_outside (struct ivopts_data *data, edge exit)
{
  gimple phi;
  gimple_stmt_iterator psi;
  tree def;

  for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi))
    {
      phi = gsi_stmt (psi);
      def = PHI_ARG_DEF_FROM_EDGE (phi, exit);
      if (!virtual_operand_p (def))
        find_interesting_uses_op (data, def);
    }
}

/* Finds uses of the induction variables that are interesting.  */

static void
find_interesting_uses (struct ivopts_data *data)
{
  basic_block bb;
  gimple_stmt_iterator bsi;
  basic_block *body = get_loop_body (data->current_loop);
  unsigned i;
  struct version_info *info;
  edge e;

  if (dump_file && (dump_flags & TDF_DETAILS))
    fprintf (dump_file, "Uses:\n\n");

  for (i = 0; i < data->current_loop->num_nodes; i++)
    {
      edge_iterator ei;
      bb = body[i];

      FOR_EACH_EDGE (e, ei, bb->succs)
	if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
	    && !flow_bb_inside_loop_p (data->current_loop, e->dest))
	  find_interesting_uses_outside (data, e);

      for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
	find_interesting_uses_stmt (data, gsi_stmt (bsi));
      for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
	if (!is_gimple_debug (gsi_stmt (bsi)))
	  find_interesting_uses_stmt (data, gsi_stmt (bsi));
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      bitmap_iterator bi;

      fprintf (dump_file, "\n");

      EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
	{
	  info = ver_info (data, i);
	  if (info->inv_id)
	    {
	      fprintf (dump_file, "  ");
	      print_generic_expr (dump_file, info->name, TDF_SLIM);
	      fprintf (dump_file, " is invariant (%d)%s\n",
		       info->inv_id, info->has_nonlin_use ? "" : ", eliminable");
	    }
	}

      fprintf (dump_file, "\n");
    }

  free (body);
}

/* Strips constant offsets from EXPR and stores them to OFFSET.  If INSIDE_ADDR
   is true, assume we are inside an address.  If TOP_COMPREF is true, assume
   we are at the top-level of the processed address.  */

static tree
strip_offset_1 (tree expr, bool inside_addr, bool top_compref,
		HOST_WIDE_INT *offset)
{
  tree op0 = NULL_TREE, op1 = NULL_TREE, tmp, step;
  enum tree_code code;
  tree type, orig_type = TREE_TYPE (expr);
  HOST_WIDE_INT off0, off1, st;
  tree orig_expr = expr;

  STRIP_NOPS (expr);

  type = TREE_TYPE (expr);
  code = TREE_CODE (expr);
  *offset = 0;

  switch (code)
    {
    case INTEGER_CST:
      if (!cst_and_fits_in_hwi (expr)
	  || integer_zerop (expr))
	return orig_expr;

      *offset = int_cst_value (expr);
      return build_int_cst (orig_type, 0);

    case POINTER_PLUS_EXPR:
    case PLUS_EXPR:
    case MINUS_EXPR:
      op0 = TREE_OPERAND (expr, 0);
      op1 = TREE_OPERAND (expr, 1);

      op0 = strip_offset_1 (op0, false, false, &off0);
      op1 = strip_offset_1 (op1, false, false, &off1);

      *offset = (code == MINUS_EXPR ? off0 - off1 : off0 + off1);
      if (op0 == TREE_OPERAND (expr, 0)
	  && op1 == TREE_OPERAND (expr, 1))
	return orig_expr;

      if (integer_zerop (op1))
	expr = op0;
      else if (integer_zerop (op0))
	{
	  if (code == MINUS_EXPR)
	    expr = fold_build1 (NEGATE_EXPR, type, op1);
	  else
	    expr = op1;
	}
      else
	expr = fold_build2 (code, type, op0, op1);

      return fold_convert (orig_type, expr);

    case MULT_EXPR:
      op1 = TREE_OPERAND (expr, 1);
      if (!cst_and_fits_in_hwi (op1))
	return orig_expr;

      op0 = TREE_OPERAND (expr, 0);
      op0 = strip_offset_1 (op0, false, false, &off0);
      if (op0 == TREE_OPERAND (expr, 0))
	return orig_expr;

      *offset = off0 * int_cst_value (op1);
      if (integer_zerop (op0))
	expr = op0;
      else
	expr = fold_build2 (MULT_EXPR, type, op0, op1);

      return fold_convert (orig_type, expr);

    case ARRAY_REF:
    case ARRAY_RANGE_REF:
      if (!inside_addr)
	return orig_expr;

      step = array_ref_element_size (expr);
      if (!cst_and_fits_in_hwi (step))
	break;

      st = int_cst_value (step);
      op1 = TREE_OPERAND (expr, 1);
      op1 = strip_offset_1 (op1, false, false, &off1);
      *offset = off1 * st;

      if (top_compref
	  && integer_zerop (op1))
	{
	  /* Strip the component reference completely.  */
	  op0 = TREE_OPERAND (expr, 0);
	  op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
	  *offset += off0;
	  return op0;
	}
      break;

    case COMPONENT_REF:
      {
	tree field;

	if (!inside_addr)
	  return orig_expr;

	tmp = component_ref_field_offset (expr);
	field = TREE_OPERAND (expr, 1);
	if (top_compref
	    && cst_and_fits_in_hwi (tmp)
	    && cst_and_fits_in_hwi (DECL_FIELD_BIT_OFFSET (field)))
	  {
	    HOST_WIDE_INT boffset, abs_off;

	    /* Strip the component reference completely.  */
	    op0 = TREE_OPERAND (expr, 0);
	    op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
	    boffset = int_cst_value (DECL_FIELD_BIT_OFFSET (field));
	    abs_off = abs_hwi (boffset) / BITS_PER_UNIT;
	    if (boffset < 0)
	      abs_off = -abs_off;

	    *offset = off0 + int_cst_value (tmp) + abs_off;
	    return op0;
	  }
      }
      break;

    case ADDR_EXPR:
      op0 = TREE_OPERAND (expr, 0);
      op0 = strip_offset_1 (op0, true, true, &off0);
      *offset += off0;

      if (op0 == TREE_OPERAND (expr, 0))
	return orig_expr;

      expr = build_fold_addr_expr (op0);
      return fold_convert (orig_type, expr);

    case MEM_REF:
      /* ???  Offset operand?  */
      inside_addr = false;
      break;

    default:
      return orig_expr;
    }

  /* Default handling of expressions for that we want to recurse into
     the first operand.  */
  op0 = TREE_OPERAND (expr, 0);
  op0 = strip_offset_1 (op0, inside_addr, false, &off0);
  *offset += off0;

  if (op0 == TREE_OPERAND (expr, 0)
      && (!op1 || op1 == TREE_OPERAND (expr, 1)))
    return orig_expr;

  expr = copy_node (expr);
  TREE_OPERAND (expr, 0) = op0;
  if (op1)
    TREE_OPERAND (expr, 1) = op1;

  /* Inside address, we might strip the top level component references,
     thus changing type of the expression.  Handling of ADDR_EXPR
     will fix that.  */
  expr = fold_convert (orig_type, expr);

  return expr;
}

/* Strips constant offsets from EXPR and stores them to OFFSET.  */

static tree
strip_offset (tree expr, unsigned HOST_WIDE_INT *offset)
{
  HOST_WIDE_INT off;
  tree core = strip_offset_1 (expr, false, false, &off);
  *offset = off;
  return core;
}

/* Returns variant of TYPE that can be used as base for different uses.
   We return unsigned type with the same precision, which avoids problems
   with overflows.  */

static tree
generic_type_for (tree type)
{
  if (POINTER_TYPE_P (type))
    return unsigned_type_for (type);

  if (TYPE_UNSIGNED (type))
    return type;

  return unsigned_type_for (type);
}

/* Records invariants in *EXPR_P.  Callback for walk_tree.  DATA contains
   the bitmap to that we should store it.  */

static struct ivopts_data *fd_ivopts_data;
static tree
find_depends (tree *expr_p, int *ws ATTRIBUTE_UNUSED, void *data)
{
  bitmap *depends_on = (bitmap *) data;
  struct version_info *info;

  if (TREE_CODE (*expr_p) != SSA_NAME)
    return NULL_TREE;
  info = name_info (fd_ivopts_data, *expr_p);

  if (!info->inv_id || info->has_nonlin_use)
    return NULL_TREE;

  if (!*depends_on)
    *depends_on = BITMAP_ALLOC (NULL);
  bitmap_set_bit (*depends_on, info->inv_id);

  return NULL_TREE;
}

/* Adds a candidate BASE + STEP * i.  Important field is set to IMPORTANT and
   position to POS.  If USE is not NULL, the candidate is set as related to
   it.  If both BASE and STEP are NULL, we add a pseudocandidate for the
   replacement of the final value of the iv by a direct computation.  */

static struct iv_cand *
add_candidate_1 (struct ivopts_data *data,
		 tree base, tree step, bool important, enum iv_position pos,
		 struct iv_use *use, gimple incremented_at)
{
  unsigned i;
  struct iv_cand *cand = NULL;
  tree type, orig_type;

  /* For non-original variables, make sure their values are computed in a type
     that does not invoke undefined behavior on overflows (since in general,
     we cannot prove that these induction variables are non-wrapping).  */
  if (pos != IP_ORIGINAL)
    {
      orig_type = TREE_TYPE (base);
      type = generic_type_for (orig_type);
      if (type != orig_type)
	{
	  base = fold_convert (type, base);
	  step = fold_convert (type, step);
	}
    }

  for (i = 0; i < n_iv_cands (data); i++)
    {
      cand = iv_cand (data, i);

      if (cand->pos != pos)
	continue;

      if (cand->incremented_at != incremented_at
	  || ((pos == IP_AFTER_USE || pos == IP_BEFORE_USE)
	      && cand->ainc_use != use))
	continue;

      if (!cand->iv)
	{
	  if (!base && !step)
	    break;

	  continue;
	}

      if (!base && !step)
	continue;

      if (operand_equal_p (base, cand->iv->base, 0)
	  && operand_equal_p (step, cand->iv->step, 0)
          && (TYPE_PRECISION (TREE_TYPE (base))
              == TYPE_PRECISION (TREE_TYPE (cand->iv->base))))
	break;
    }

  if (i == n_iv_cands (data))
    {
      cand = XCNEW (struct iv_cand);
      cand->id = i;

      if (!base && !step)
	cand->iv = NULL;
      else
	cand->iv = alloc_iv (base, step);

      cand->pos = pos;
      if (pos != IP_ORIGINAL && cand->iv)
	{
	  cand->var_before = create_tmp_var_raw (TREE_TYPE (base), "ivtmp");
	  cand->var_after = cand->var_before;
	}
      cand->important = important;
      cand->incremented_at = incremented_at;
      data->iv_candidates.safe_push (cand);

      if (step
	  && TREE_CODE (step) != INTEGER_CST)
	{
	  fd_ivopts_data = data;
	  walk_tree (&step, find_depends, &cand->depends_on, NULL);
	}

      if (pos == IP_AFTER_USE || pos == IP_BEFORE_USE)
	cand->ainc_use = use;
      else
	cand->ainc_use = NULL;

      if (dump_file && (dump_flags & TDF_DETAILS))
	dump_cand (dump_file, cand);
    }

  if (important && !cand->important)
    {
      cand->important = true;
      if (dump_file && (dump_flags & TDF_DETAILS))
	fprintf (dump_file, "Candidate %d is important\n", cand->id);
    }

  if (use)
    {
      bitmap_set_bit (use->related_cands, i);
      if (dump_file && (dump_flags & TDF_DETAILS))
	fprintf (dump_file, "Candidate %d is related to use %d\n",
		 cand->id, use->id);
    }

  return cand;
}

/* Returns true if incrementing the induction variable at the end of the LOOP
   is allowed.

   The purpose is to avoid splitting latch edge with a biv increment, thus
   creating a jump, possibly confusing other optimization passes and leaving
   less freedom to scheduler.  So we allow IP_END_POS only if IP_NORMAL_POS
   is not available (so we do not have a better alternative), or if the latch
   edge is already nonempty.  */

static bool
allow_ip_end_pos_p (struct loop *loop)
{
  if (!ip_normal_pos (loop))
    return true;

  if (!empty_block_p (ip_end_pos (loop)))
    return true;

  return false;
}

/* If possible, adds autoincrement candidates BASE + STEP * i based on use USE.
   Important field is set to IMPORTANT.  */

static void
add_autoinc_candidates (struct ivopts_data *data, tree base, tree step,
			bool important, struct iv_use *use)
{
  basic_block use_bb = gimple_bb (use->stmt);
  enum machine_mode mem_mode;
  unsigned HOST_WIDE_INT cstepi;

  /* If we insert the increment in any position other than the standard
     ones, we must ensure that it is incremented once per iteration.
     It must not be in an inner nested loop, or one side of an if
     statement.  */
  if (use_bb->loop_father != data->current_loop
      || !dominated_by_p (CDI_DOMINATORS, data->current_loop->latch, use_bb)
      || stmt_could_throw_p (use->stmt)
      || !cst_and_fits_in_hwi (step))
    return;

  cstepi = int_cst_value (step);

  mem_mode = TYPE_MODE (TREE_TYPE (*use->op_p));
  if (((USE_LOAD_PRE_INCREMENT (mem_mode)
	|| USE_STORE_PRE_INCREMENT (mem_mode))
       && GET_MODE_SIZE (mem_mode) == cstepi)
      || ((USE_LOAD_PRE_DECREMENT (mem_mode)
	   || USE_STORE_PRE_DECREMENT (mem_mode))
	  && GET_MODE_SIZE (mem_mode) == -cstepi))
    {
      enum tree_code code = MINUS_EXPR;
      tree new_base;
      tree new_step = step;

      if (POINTER_TYPE_P (TREE_TYPE (base)))
	{
	  new_step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step);
	  code = POINTER_PLUS_EXPR;
	}
      else
	new_step = fold_convert (TREE_TYPE (base), new_step);
      new_base = fold_build2 (code, TREE_TYPE (base), base, new_step);
      add_candidate_1 (data, new_base, step, important, IP_BEFORE_USE, use,
		       use->stmt);
    }
  if (((USE_LOAD_POST_INCREMENT (mem_mode)
	|| USE_STORE_POST_INCREMENT (mem_mode))
       && GET_MODE_SIZE (mem_mode) == cstepi)
      || ((USE_LOAD_POST_DECREMENT (mem_mode)
	   || USE_STORE_POST_DECREMENT (mem_mode))
	  && GET_MODE_SIZE (mem_mode) == -cstepi))
    {
      add_candidate_1 (data, base, step, important, IP_AFTER_USE, use,
		       use->stmt);
    }
}

/* Adds a candidate BASE + STEP * i.  Important field is set to IMPORTANT and
   position to POS.  If USE is not NULL, the candidate is set as related to
   it.  The candidate computation is scheduled on all available positions.  */

static void
add_candidate (struct ivopts_data *data,
	       tree base, tree step, bool important, struct iv_use *use)
{
  if (ip_normal_pos (data->current_loop))
    add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL);
  if (ip_end_pos (data->current_loop)
      && allow_ip_end_pos_p (data->current_loop))
    add_candidate_1 (data, base, step, important, IP_END, use, NULL);

  if (use != NULL && use->type == USE_ADDRESS)
    add_autoinc_candidates (data, base, step, important, use);
}

/* Adds standard iv candidates.  */

static void
add_standard_iv_candidates (struct ivopts_data *data)
{
  add_candidate (data, integer_zero_node, integer_one_node, true, NULL);

  /* The same for a double-integer type if it is still fast enough.  */
  if (TYPE_PRECISION
        (long_integer_type_node) > TYPE_PRECISION (integer_type_node)
      && TYPE_PRECISION (long_integer_type_node) <= BITS_PER_WORD)
    add_candidate (data, build_int_cst (long_integer_type_node, 0),
		   build_int_cst (long_integer_type_node, 1), true, NULL);

  /* The same for a double-integer type if it is still fast enough.  */
  if (TYPE_PRECISION
        (long_long_integer_type_node) > TYPE_PRECISION (long_integer_type_node)
      && TYPE_PRECISION (long_long_integer_type_node) <= BITS_PER_WORD)
    add_candidate (data, build_int_cst (long_long_integer_type_node, 0),
		   build_int_cst (long_long_integer_type_node, 1), true, NULL);
}


/* Adds candidates bases on the old induction variable IV.  */

static void
add_old_iv_candidates (struct ivopts_data *data, struct iv *iv)
{
  gimple phi;
  tree def;
  struct iv_cand *cand;

  add_candidate (data, iv->base, iv->step, true, NULL);

  /* The same, but with initial value zero.  */
  if (POINTER_TYPE_P (TREE_TYPE (iv->base)))
    add_candidate (data, size_int (0), iv->step, true, NULL);
  else
    add_candidate (data, build_int_cst (TREE_TYPE (iv->base), 0),
		   iv->step, true, NULL);

  phi = SSA_NAME_DEF_STMT (iv->ssa_name);
  if (gimple_code (phi) == GIMPLE_PHI)
    {
      /* Additionally record the possibility of leaving the original iv
	 untouched.  */
      def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop));
      /* Don't add candidate if it's from another PHI node because
	 it's an affine iv appearing in the form of PEELED_CHREC.  */
      phi = SSA_NAME_DEF_STMT (def);
      if (gimple_code (phi) != GIMPLE_PHI)
	{
	  cand = add_candidate_1 (data,
				  iv->base, iv->step, true, IP_ORIGINAL, NULL,
				  SSA_NAME_DEF_STMT (def));
	  cand->var_before = iv->ssa_name;
	  cand->var_after = def;
	}
      else
	gcc_assert (gimple_bb (phi) == data->current_loop->header);
    }
}

/* Adds candidates based on the old induction variables.  */

static void
add_old_ivs_candidates (struct ivopts_data *data)
{
  unsigned i;
  struct iv *iv;
  bitmap_iterator bi;

  EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
    {
      iv = ver_info (data, i)->iv;
      if (iv && iv->biv_p && !integer_zerop (iv->step))
	add_old_iv_candidates (data, iv);
    }
}

/* Adds candidates based on the value of the induction variable IV and USE.  */

static void
add_iv_value_candidates (struct ivopts_data *data,
			 struct iv *iv, struct iv_use *use)
{
  unsigned HOST_WIDE_INT offset;
  tree base;
  tree basetype;

  add_candidate (data, iv->base, iv->step, false, use);

  /* The same, but with initial value zero.  Make such variable important,
     since it is generic enough so that possibly many uses may be based
     on it.  */
  basetype = TREE_TYPE (iv->base);
  if (POINTER_TYPE_P (basetype))
    basetype = sizetype;
  add_candidate (data, build_int_cst (basetype, 0),
		 iv->step, true, use);

  /* Third, try removing the constant offset.  Make sure to even
     add a candidate for &a[0] vs. (T *)&a.  */
  base = strip_offset (iv->base, &offset);
  if (offset
      || base != iv->base)
    add_candidate (data, base, iv->step, false, use);
}

/* Adds candidates based on the uses.  */

static void
add_derived_ivs_candidates (struct ivopts_data *data)
{
  unsigned i;

  for (i = 0; i < n_iv_uses (data); i++)
    {
      struct iv_use *use = iv_use (data, i);

      if (!use)
	continue;

      switch (use->type)
	{
	case USE_NONLINEAR_EXPR:
	case USE_COMPARE:
	case USE_ADDRESS:
	  /* Just add the ivs based on the value of the iv used here.  */
	  add_iv_value_candidates (data, use->iv, use);
	  break;

	default:
	  gcc_unreachable ();
	}
    }
}

/* Record important candidates and add them to related_cands bitmaps
   if needed.  */

static void
record_important_candidates (struct ivopts_data *data)
{
  unsigned i;
  struct iv_use *use;

  for (i = 0; i < n_iv_cands (data); i++)
    {
      struct iv_cand *cand = iv_cand (data, i);

      if (cand->important)
	bitmap_set_bit (data->important_candidates, i);
    }

  data->consider_all_candidates = (n_iv_cands (data)
				   <= CONSIDER_ALL_CANDIDATES_BOUND);

  if (data->consider_all_candidates)
    {
      /* We will not need "related_cands" bitmaps in this case,
	 so release them to decrease peak memory consumption.  */
      for (i = 0; i < n_iv_uses (data); i++)
	{
	  use = iv_use (data, i);
	  BITMAP_FREE (use->related_cands);
	}
    }
  else
    {
      /* Add important candidates to the related_cands bitmaps.  */
      for (i = 0; i < n_iv_uses (data); i++)
	bitmap_ior_into (iv_use (data, i)->related_cands,
			 data->important_candidates);
    }
}

/* Allocates the data structure mapping the (use, candidate) pairs to costs.
   If consider_all_candidates is true, we use a two-dimensional array, otherwise
   we allocate a simple list to every use.  */

static void
alloc_use_cost_map (struct ivopts_data *data)
{
  unsigned i, size, s;

  for (i = 0; i < n_iv_uses (data); i++)
    {
      struct iv_use *use = iv_use (data, i);

      if (data->consider_all_candidates)
	size = n_iv_cands (data);
      else
	{
	  s = bitmap_count_bits (use->related_cands);

	  /* Round up to the power of two, so that moduling by it is fast.  */
	  size = s ? (1 << ceil_log2 (s)) : 1;
	}

      use->n_map_members = size;
      use->cost_map = XCNEWVEC (struct cost_pair, size);
    }
}

/* Returns description of computation cost of expression whose runtime
   cost is RUNTIME and complexity corresponds to COMPLEXITY.  */

static comp_cost
new_cost (unsigned runtime, unsigned complexity)
{
  comp_cost cost;

  cost.cost = runtime;
  cost.complexity = complexity;

  return cost;
}

/* Adds costs COST1 and COST2.  */

static comp_cost
add_costs (comp_cost cost1, comp_cost cost2)
{
  cost1.cost += cost2.cost;
  cost1.complexity += cost2.complexity;

  return cost1;
}
/* Subtracts costs COST1 and COST2.  */

static comp_cost
sub_costs (comp_cost cost1, comp_cost cost2)
{
  cost1.cost -= cost2.cost;
  cost1.complexity -= cost2.complexity;

  return cost1;
}

/* Returns a negative number if COST1 < COST2, a positive number if
   COST1 > COST2, and 0 if COST1 = COST2.  */

static int
compare_costs (comp_cost cost1, comp_cost cost2)
{
  if (cost1.cost == cost2.cost)
    return cost1.complexity - cost2.complexity;

  return cost1.cost - cost2.cost;
}

/* Returns true if COST is infinite.  */

static bool
infinite_cost_p (comp_cost cost)
{
  return cost.cost == INFTY;
}

/* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends
   on invariants DEPENDS_ON and that the value used in expressing it
   is VALUE, and in case of iv elimination the comparison operator is COMP.  */

static void
set_use_iv_cost (struct ivopts_data *data,
		 struct iv_use *use, struct iv_cand *cand,
		 comp_cost cost, bitmap depends_on, tree value,
		 enum tree_code comp, int inv_expr_id)
{
  unsigned i, s;

  if (infinite_cost_p (cost))
    {
      BITMAP_FREE (depends_on);
      return;
    }

  if (data->consider_all_candidates)
    {
      use->cost_map[cand->id].cand = cand;
      use->cost_map[cand->id].cost = cost;
      use->cost_map[cand->id].depends_on = depends_on;
      use->cost_map[cand->id].value = value;
      use->cost_map[cand->id].comp = comp;
      use->cost_map[cand->id].inv_expr_id = inv_expr_id;
      return;
    }

  /* n_map_members is a power of two, so this computes modulo.  */
  s = cand->id & (use->n_map_members - 1);
  for (i = s; i < use->n_map_members; i++)
    if (!use->cost_map[i].cand)
      goto found;
  for (i = 0; i < s; i++)
    if (!use->cost_map[i].cand)
      goto found;

  gcc_unreachable ();

found:
  use->cost_map[i].cand = cand;
  use->cost_map[i].cost = cost;
  use->cost_map[i].depends_on = depends_on;
  use->cost_map[i].value = value;
  use->cost_map[i].comp = comp;
  use->cost_map[i].inv_expr_id = inv_expr_id;
}

/* Gets cost of (USE, CANDIDATE) pair.  */

static struct cost_pair *
get_use_iv_cost (struct ivopts_data *data, struct iv_use *use,
		 struct iv_cand *cand)
{
  unsigned i, s;
  struct cost_pair *ret;

  if (!cand)
    return NULL;

  if (data->consider_all_candidates)
    {
      ret = use->cost_map + cand->id;
      if (!ret->cand)
	return NULL;

      return ret;
    }

  /* n_map_members is a power of two, so this computes modulo.  */
  s = cand->id & (use->n_map_members - 1);
  for (i = s; i < use->n_map_members; i++)
    if (use->cost_map[i].cand == cand)
      return use->cost_map + i;
    else if (use->cost_map[i].cand == NULL)
      return NULL;
  for (i = 0; i < s; i++)
    if (use->cost_map[i].cand == cand)
      return use->cost_map + i;
    else if (use->cost_map[i].cand == NULL)
      return NULL;

  return NULL;
}

/* Returns estimate on cost of computing SEQ.  */

static unsigned
seq_cost (rtx seq, bool speed)
{
  unsigned cost = 0;
  rtx set;

  for (; seq; seq = NEXT_INSN (seq))
    {
      set = single_set (seq);
      if (set)
	cost += set_src_cost (SET_SRC (set), speed);
      else
	cost++;
    }

  return cost;
}

/* Produce DECL_RTL for object obj so it looks like it is stored in memory.  */
static rtx
produce_memory_decl_rtl (tree obj, int *regno)
{
  addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (obj));
  enum machine_mode address_mode = targetm.addr_space.address_mode (as);
  rtx x;

  gcc_assert (obj);
  if (TREE_STATIC (obj) || DECL_EXTERNAL (obj))
    {
      const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (obj));
      x = gen_rtx_SYMBOL_REF (address_mode, name);
      SET_SYMBOL_REF_DECL (x, obj);
      x = gen_rtx_MEM (DECL_MODE (obj), x);
      set_mem_addr_space (x, as);
      targetm.encode_section_info (obj, x, true);
    }
  else
    {
      x = gen_raw_REG (address_mode, (*regno)++);
      x = gen_rtx_MEM (DECL_MODE (obj), x);
      set_mem_addr_space (x, as);
    }

  return x;
}

/* Prepares decl_rtl for variables referred in *EXPR_P.  Callback for
   walk_tree.  DATA contains the actual fake register number.  */

static tree
prepare_decl_rtl (tree *expr_p, int *ws, void *data)
{
  tree obj = NULL_TREE;
  rtx x = NULL_RTX;
  int *regno = (int *) data;

  switch (TREE_CODE (*expr_p))
    {
    case ADDR_EXPR:
      for (expr_p = &TREE_OPERAND (*expr_p, 0);
	   handled_component_p (*expr_p);
	   expr_p = &TREE_OPERAND (*expr_p, 0))
	continue;
      obj = *expr_p;
      if (DECL_P (obj) && HAS_RTL_P (obj) && !DECL_RTL_SET_P (obj))
        x = produce_memory_decl_rtl (obj, regno);
      break;

    case SSA_NAME:
      *ws = 0;
      obj = SSA_NAME_VAR (*expr_p);
      /* Defer handling of anonymous SSA_NAMEs to the expander.  */
      if (!obj)
	return NULL_TREE;
      if (!DECL_RTL_SET_P (obj))
	x = gen_raw_REG (DECL_MODE (obj), (*regno)++);
      break;

    case VAR_DECL:
    case PARM_DECL:
    case RESULT_DECL:
      *ws = 0;
      obj = *expr_p;

      if (DECL_RTL_SET_P (obj))
	break;

      if (DECL_MODE (obj) == BLKmode)
	x = produce_memory_decl_rtl (obj, regno);
      else
	x = gen_raw_REG (DECL_MODE (obj), (*regno)++);

      break;

    default:
      break;
    }

  if (x)
    {
      decl_rtl_to_reset.safe_push (obj);
      SET_DECL_RTL (obj, x);
    }

  return NULL_TREE;
}

/* Determines cost of the computation of EXPR.  */

static unsigned
computation_cost (tree expr, bool speed)
{
  rtx seq, rslt;
  tree type = TREE_TYPE (expr);
  unsigned cost;
  /* Avoid using hard regs in ways which may be unsupported.  */
  int regno = LAST_VIRTUAL_REGISTER + 1;
  struct cgraph_node *node = cgraph_get_node (current_function_decl);
  enum node_frequency real_frequency = node->frequency;

  node->frequency = NODE_FREQUENCY_NORMAL;
  crtl->maybe_hot_insn_p = speed;
  walk_tree (&expr, prepare_decl_rtl, &regno, NULL);
  start_sequence ();
  rslt = expand_expr (expr, NULL_RTX, TYPE_MODE (type), EXPAND_NORMAL);
  seq = get_insns ();
  end_sequence ();
  default_rtl_profile ();
  node->frequency = real_frequency;

  cost = seq_cost (seq, speed);
  if (MEM_P (rslt))
    cost += address_cost (XEXP (rslt, 0), TYPE_MODE (type),
			  TYPE_ADDR_SPACE (type), speed);
  else if (!REG_P (rslt))
    cost += set_src_cost (rslt, speed);

  return cost;
}

/* Returns variable containing the value of candidate CAND at statement AT.  */

static tree
var_at_stmt (struct loop *loop, struct iv_cand *cand, gimple stmt)
{
  if (stmt_after_increment (loop, cand, stmt))
    return cand->var_after;
  else
    return cand->var_before;
}

/* If A is (TYPE) BA and B is (TYPE) BB, and the types of BA and BB have the
   same precision that is at least as wide as the precision of TYPE, stores
   BA to A and BB to B, and returns the type of BA.  Otherwise, returns the
   type of A and B.  */

static tree
determine_common_wider_type (tree *a, tree *b)
{
  tree wider_type = NULL;
  tree suba, subb;
  tree atype = TREE_TYPE (*a);

  if (CONVERT_EXPR_P (*a))
    {
      suba = TREE_OPERAND (*a, 0);
      wider_type = TREE_TYPE (suba);
      if (TYPE_PRECISION (wider_type) < TYPE_PRECISION (atype))
	return atype;
    }
  else
    return atype;

  if (CONVERT_EXPR_P (*b))
    {
      subb = TREE_OPERAND (*b, 0);
      if (TYPE_PRECISION (wider_type) != TYPE_PRECISION (TREE_TYPE (subb)))
	return atype;
    }
  else
    return atype;

  *a = suba;
  *b = subb;
  return wider_type;
}

/* Determines the expression by that USE is expressed from induction variable
   CAND at statement AT in LOOP.  The expression is stored in a decomposed
   form into AFF.  Returns false if USE cannot be expressed using CAND.  */

static bool
get_computation_aff (struct loop *loop,
		     struct iv_use *use, struct iv_cand *cand, gimple at,
		     struct aff_tree *aff)
{
  tree ubase = use->iv->base;
  tree ustep = use->iv->step;
  tree cbase = cand->iv->base;
  tree cstep = cand->iv->step, cstep_common;
  tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase);
  tree common_type, var;
  tree uutype;
  aff_tree cbase_aff, var_aff;
  double_int rat;

  if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
    {
      /* We do not have a precision to express the values of use.  */
      return false;
    }

  var = var_at_stmt (loop, cand, at);
  uutype = unsigned_type_for (utype);

  /* If the conversion is not noop, perform it.  */
  if (TYPE_PRECISION (utype) < TYPE_PRECISION (ctype))
    {
      cstep = fold_convert (uutype, cstep);
      cbase = fold_convert (uutype, cbase);
      var = fold_convert (uutype, var);
    }

  if (!constant_multiple_of (ustep, cstep, &rat))
    return false;

  /* In case both UBASE and CBASE are shortened to UUTYPE from some common
     type, we achieve better folding by computing their difference in this
     wider type, and cast the result to UUTYPE.  We do not need to worry about
     overflows, as all the arithmetics will in the end be performed in UUTYPE
     anyway.  */
  common_type = determine_common_wider_type (&ubase, &cbase);

  /* use = ubase - ratio * cbase + ratio * var.  */
  tree_to_aff_combination (ubase, common_type, aff);
  tree_to_aff_combination (cbase, common_type, &cbase_aff);
  tree_to_aff_combination (var, uutype, &var_aff);

  /* We need to shift the value if we are after the increment.  */
  if (stmt_after_increment (loop, cand, at))
    {
      aff_tree cstep_aff;

      if (common_type != uutype)
	cstep_common = fold_convert (common_type, cstep);
      else
	cstep_common = cstep;

      tree_to_aff_combination (cstep_common, common_type, &cstep_aff);
      aff_combination_add (&cbase_aff, &cstep_aff);
    }

  aff_combination_scale (&cbase_aff, -rat);
  aff_combination_add (aff, &cbase_aff);
  if (common_type != uutype)
    aff_combination_convert (aff, uutype);

  aff_combination_scale (&var_aff, rat);
  aff_combination_add (aff, &var_aff);

  return true;
}

/* Return the type of USE.  */

static tree
get_use_type (struct iv_use *use)
{
  tree base_type = TREE_TYPE (use->iv->base);
  tree type;

  if (use->type == USE_ADDRESS)
    {
      /* The base_type may be a void pointer.  Create a pointer type based on
	 the mem_ref instead.  */
      type = build_pointer_type (TREE_TYPE (*use->op_p));
      gcc_assert (TYPE_ADDR_SPACE (TREE_TYPE (type))
		  == TYPE_ADDR_SPACE (TREE_TYPE (base_type)));
    }
  else
    type = base_type;

  return type;
}

/* Determines the expression by that USE is expressed from induction variable
   CAND at statement AT in LOOP.  The computation is unshared.  */

static tree
get_computation_at (struct loop *loop,
		    struct iv_use *use, struct iv_cand *cand, gimple at)
{
  aff_tree aff;
  tree type = get_use_type (use);

  if (!get_computation_aff (loop, use, cand, at, &aff))
    return NULL_TREE;
  unshare_aff_combination (&aff);
  return fold_convert (type, aff_combination_to_tree (&aff));
}

/* Determines the expression by that USE is expressed from induction variable
   CAND in LOOP.  The computation is unshared.  */

static tree
get_computation (struct loop *loop, struct iv_use *use, struct iv_cand *cand)
{
  return get_computation_at (loop, use, cand, use->stmt);
}

/* Adjust the cost COST for being in loop setup rather than loop body.
   If we're optimizing for space, the loop setup overhead is constant;
   if we're optimizing for speed, amortize it over the per-iteration cost.  */
static unsigned
adjust_setup_cost (struct ivopts_data *data, unsigned cost)
{
  if (cost == INFTY)
    return cost;
  else if (optimize_loop_for_speed_p (data->current_loop))
    return cost / avg_loop_niter (data->current_loop);
  else
    return cost;
}

/* Returns true if multiplying by RATIO is allowed in an address.  Test the
   validity for a memory reference accessing memory of mode MODE in
   address space AS.  */


bool
multiplier_allowed_in_address_p (HOST_WIDE_INT ratio, enum machine_mode mode,
				 addr_space_t as)
{
#define MAX_RATIO 128
  unsigned int data_index = (int) as * MAX_MACHINE_MODE + (int) mode;
  static vec<sbitmap> valid_mult_list;
  sbitmap valid_mult;

  if (data_index >= valid_mult_list.length ())
    valid_mult_list.safe_grow_cleared (data_index + 1);

  valid_mult = valid_mult_list[data_index];
  if (!valid_mult)
    {
      enum machine_mode address_mode = targetm.addr_space.address_mode (as);
      rtx reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);
      rtx reg2 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 2);
      rtx addr, scaled;
      HOST_WIDE_INT i;

      valid_mult = sbitmap_alloc (2 * MAX_RATIO + 1);
      bitmap_clear (valid_mult);
      scaled = gen_rtx_fmt_ee (MULT, address_mode, reg1, NULL_RTX);
      addr = gen_rtx_fmt_ee (PLUS, address_mode, scaled, reg2);
      for (i = -MAX_RATIO; i <= MAX_RATIO; i++)
	{
	  XEXP (scaled, 1) = gen_int_mode (i, address_mode);
	  if (memory_address_addr_space_p (mode, addr, as)
	      || memory_address_addr_space_p (mode, scaled, as))
	    bitmap_set_bit (valid_mult, i + MAX_RATIO);
	}

      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "  allowed multipliers:");
	  for (i = -MAX_RATIO; i <= MAX_RATIO; i++)
	    if (bitmap_bit_p (valid_mult, i + MAX_RATIO))
	      fprintf (dump_file, " %d", (int) i);
	  fprintf (dump_file, "\n");
	  fprintf (dump_file, "\n");
	}

      valid_mult_list[data_index] = valid_mult;
    }

  if (ratio > MAX_RATIO || ratio < -MAX_RATIO)
    return false;

  return bitmap_bit_p (valid_mult, ratio + MAX_RATIO);
}

/* Returns cost of address in shape symbol + var + OFFSET + RATIO * index.
   If SYMBOL_PRESENT is false, symbol is omitted.  If VAR_PRESENT is false,
   variable is omitted.  Compute the cost for a memory reference that accesses
   a memory location of mode MEM_MODE in address space AS.

   MAY_AUTOINC is set to true if the autoincrement (increasing index by
   size of MEM_MODE / RATIO) is available.  To make this determination, we
   look at the size of the increment to be made, which is given in CSTEP.
   CSTEP may be zero if the step is unknown.
   STMT_AFTER_INC is true iff the statement we're looking at is after the
   increment of the original biv.

   TODO -- there must be some better way.  This all is quite crude.  */

enum ainc_type
{
  AINC_PRE_INC,		/* Pre increment.  */
  AINC_PRE_DEC,		/* Pre decrement.  */
  AINC_POST_INC,	/* Post increment.  */
  AINC_POST_DEC,	/* Post decrement.  */
  AINC_NONE		/* Also the number of auto increment types.  */
};

typedef struct address_cost_data_s
{
  HOST_WIDE_INT min_offset, max_offset;
  unsigned costs[2][2][2][2];
  unsigned ainc_costs[AINC_NONE];
} *address_cost_data;


static comp_cost
get_address_cost (bool symbol_present, bool var_present,
		  unsigned HOST_WIDE_INT offset, HOST_WIDE_INT ratio,
		  HOST_WIDE_INT cstep, enum machine_mode mem_mode,
		  addr_space_t as, bool speed,
		  bool stmt_after_inc, bool *may_autoinc)
{
  enum machine_mode address_mode = targetm.addr_space.address_mode (as);
  static vec<address_cost_data> address_cost_data_list;
  unsigned int data_index = (int) as * MAX_MACHINE_MODE + (int) mem_mode;
  address_cost_data data;
  static bool has_preinc[MAX_MACHINE_MODE], has_postinc[MAX_MACHINE_MODE];
  static bool has_predec[MAX_MACHINE_MODE], has_postdec[MAX_MACHINE_MODE];
  unsigned cost, acost, complexity;
  enum ainc_type autoinc_type;
  bool offset_p, ratio_p, autoinc;
  HOST_WIDE_INT s_offset, autoinc_offset, msize;
  unsigned HOST_WIDE_INT mask;
  unsigned bits;

  if (data_index >= address_cost_data_list.length ())
    address_cost_data_list.safe_grow_cleared (data_index + 1);

  data = address_cost_data_list[data_index];
  if (!data)
    {
      HOST_WIDE_INT i;
      HOST_WIDE_INT rat, off = 0;
      int old_cse_not_expected, width;
      unsigned sym_p, var_p, off_p, rat_p, add_c;
      rtx seq, addr, base;
      rtx reg0, reg1;

      data = (address_cost_data) xcalloc (1, sizeof (*data));

      reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);

      width = GET_MODE_BITSIZE (address_mode) - 1;
      if (width > (HOST_BITS_PER_WIDE_INT - 1))
	width = HOST_BITS_PER_WIDE_INT - 1;
      addr = gen_rtx_fmt_ee (PLUS, address_mode, reg1, NULL_RTX);

      for (i = width; i >= 0; i--)
	{
	  off = -((unsigned HOST_WIDE_INT) 1 << i);
	  XEXP (addr, 1) = gen_int_mode (off, address_mode);
	  if (memory_address_addr_space_p (mem_mode, addr, as))
	    break;
	}
      data->min_offset = (i == -1? 0 : off);

      for (i = width; i >= 0; i--)
	{
	  off = ((unsigned HOST_WIDE_INT) 1 << i) - 1;
	  XEXP (addr, 1) = gen_int_mode (off, address_mode);
	  if (memory_address_addr_space_p (mem_mode, addr, as))
	    break;
	}
      if (i == -1)
        off = 0;
      data->max_offset = off;

      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "get_address_cost:\n");
	  fprintf (dump_file, "  min offset %s " HOST_WIDE_INT_PRINT_DEC "\n",
		   GET_MODE_NAME (mem_mode),
		   data->min_offset);
	  fprintf (dump_file, "  max offset %s " HOST_WIDE_INT_PRINT_DEC "\n",
		   GET_MODE_NAME (mem_mode),
		   data->max_offset);
	}

      rat = 1;
      for (i = 2; i <= MAX_RATIO; i++)
	if (multiplier_allowed_in_address_p (i, mem_mode, as))
	  {
	    rat = i;
	    break;
	  }

      /* Compute the cost of various addressing modes.  */
      acost = 0;
      reg0 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);
      reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 2);

      if (USE_LOAD_PRE_DECREMENT (mem_mode)
	  || USE_STORE_PRE_DECREMENT (mem_mode))
	{
	  addr = gen_rtx_PRE_DEC (address_mode, reg0);
	  has_predec[mem_mode]
	    = memory_address_addr_space_p (mem_mode, addr, as);

	  if (has_predec[mem_mode])
	    data->ainc_costs[AINC_PRE_DEC]
	      = address_cost (addr, mem_mode, as, speed);
	}
      if (USE_LOAD_POST_DECREMENT (mem_mode)
	  || USE_STORE_POST_DECREMENT (mem_mode))
	{
	  addr = gen_rtx_POST_DEC (address_mode, reg0);
	  has_postdec[mem_mode]
	    = memory_address_addr_space_p (mem_mode, addr, as);

	  if (has_postdec[mem_mode])
	    data->ainc_costs[AINC_POST_DEC]
	      = address_cost (addr, mem_mode, as, speed);
	}
      if (USE_LOAD_PRE_INCREMENT (mem_mode)
	  || USE_STORE_PRE_DECREMENT (mem_mode))
	{
	  addr = gen_rtx_PRE_INC (address_mode, reg0);
	  has_preinc[mem_mode]
	    = memory_address_addr_space_p (mem_mode, addr, as);

	  if (has_preinc[mem_mode])
	    data->ainc_costs[AINC_PRE_INC]
	      = address_cost (addr, mem_mode, as, speed);
	}
      if (USE_LOAD_POST_INCREMENT (mem_mode)
	  || USE_STORE_POST_INCREMENT (mem_mode))
	{
	  addr = gen_rtx_POST_INC (address_mode, reg0);
	  has_postinc[mem_mode]
	    = memory_address_addr_space_p (mem_mode, addr, as);

	  if (has_postinc[mem_mode])
	    data->ainc_costs[AINC_POST_INC]
	      = address_cost (addr, mem_mode, as, speed);
	}
      for (i = 0; i < 16; i++)
	{
	  sym_p = i & 1;
	  var_p = (i >> 1) & 1;
	  off_p = (i >> 2) & 1;
	  rat_p = (i >> 3) & 1;

	  addr = reg0;
	  if (rat_p)
	    addr = gen_rtx_fmt_ee (MULT, address_mode, addr,
				   gen_int_mode (rat, address_mode));

	  if (var_p)
	    addr = gen_rtx_fmt_ee (PLUS, address_mode, addr, reg1);

	  if (sym_p)
	    {
	      base = gen_rtx_SYMBOL_REF (address_mode, ggc_strdup (""));
	      /* ??? We can run into trouble with some backends by presenting
		 it with symbols which haven't been properly passed through
		 targetm.encode_section_info.  By setting the local bit, we
		 enhance the probability of things working.  */
	      SYMBOL_REF_FLAGS (base) = SYMBOL_FLAG_LOCAL;

	      if (off_p)
		base = gen_rtx_fmt_e (CONST, address_mode,
				      gen_rtx_fmt_ee
					(PLUS, address_mode, base,
					 gen_int_mode (off, address_mode)));
	    }
	  else if (off_p)
	    base = gen_int_mode (off, address_mode);
	  else
	    base = NULL_RTX;

	  if (base)
	    addr = gen_rtx_fmt_ee (PLUS, address_mode, addr, base);

	  start_sequence ();
	  /* To avoid splitting addressing modes, pretend that no cse will
	     follow.  */
	  old_cse_not_expected = cse_not_expected;
	  cse_not_expected = true;
	  addr = memory_address_addr_space (mem_mode, addr, as);
	  cse_not_expected = old_cse_not_expected;
	  seq = get_insns ();
	  end_sequence ();

	  acost = seq_cost (seq, speed);
	  acost += address_cost (addr, mem_mode, as, speed);

	  if (!acost)
	    acost = 1;
	  data->costs[sym_p][var_p][off_p][rat_p] = acost;
	}

      /* On some targets, it is quite expensive to load symbol to a register,
	 which makes addresses that contain symbols look much more expensive.
	 However, the symbol will have to be loaded in any case before the
	 loop (and quite likely we have it in register already), so it does not
	 make much sense to penalize them too heavily.  So make some final
         tweaks for the SYMBOL_PRESENT modes:

         If VAR_PRESENT is false, and the mode obtained by changing symbol to
	 var is cheaper, use this mode with small penalty.
	 If VAR_PRESENT is true, try whether the mode with
	 SYMBOL_PRESENT = false is cheaper even with cost of addition, and
	 if this is the case, use it.  */
      add_c = add_cost (speed, address_mode);
      for (i = 0; i < 8; i++)
	{
	  var_p = i & 1;
	  off_p = (i >> 1) & 1;
	  rat_p = (i >> 2) & 1;

	  acost = data->costs[0][1][off_p][rat_p] + 1;
	  if (var_p)
	    acost += add_c;

	  if (acost < data->costs[1][var_p][off_p][rat_p])
	    data->costs[1][var_p][off_p][rat_p] = acost;
	}

      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "Address costs:\n");

	  for (i = 0; i < 16; i++)
	    {
	      sym_p = i & 1;
	      var_p = (i >> 1) & 1;
	      off_p = (i >> 2) & 1;
	      rat_p = (i >> 3) & 1;

	      fprintf (dump_file, "  ");
	      if (sym_p)
		fprintf (dump_file, "sym + ");
	      if (var_p)
		fprintf (dump_file, "var + ");
	      if (off_p)
		fprintf (dump_file, "cst + ");
	      if (rat_p)
		fprintf (dump_file, "rat * ");

	      acost = data->costs[sym_p][var_p][off_p][rat_p];
	      fprintf (dump_file, "index costs %d\n", acost);
	    }
	  if (has_predec[mem_mode] || has_postdec[mem_mode]
	      || has_preinc[mem_mode] || has_postinc[mem_mode])
	    fprintf (dump_file, "  May include autoinc/dec\n");
	  fprintf (dump_file, "\n");
	}

      address_cost_data_list[data_index] = data;
    }

  bits = GET_MODE_BITSIZE (address_mode);
  mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1);
  offset &= mask;
  if ((offset >> (bits - 1) & 1))
    offset |= ~mask;
  s_offset = offset;

  autoinc = false;
  autoinc_type = AINC_NONE;
  msize = GET_MODE_SIZE (mem_mode);
  autoinc_offset = offset;
  if (stmt_after_inc)
    autoinc_offset += ratio * cstep;
  if (symbol_present || var_present || ratio != 1)
    autoinc = false;
  else
    {
      if (has_postinc[mem_mode] && autoinc_offset == 0
	  && msize == cstep)
	autoinc_type = AINC_POST_INC;
      else if (has_postdec[mem_mode] && autoinc_offset == 0
	       && msize == -cstep)
	autoinc_type = AINC_POST_DEC;
      else if (has_preinc[mem_mode] && autoinc_offset == msize
	       && msize == cstep)
	autoinc_type = AINC_PRE_INC;
      else if (has_predec[mem_mode] && autoinc_offset == -msize
	       && msize == -cstep)
	autoinc_type = AINC_PRE_DEC;

      if (autoinc_type != AINC_NONE)
	autoinc = true;
    }

  cost = 0;
  offset_p = (s_offset != 0
	      && data->min_offset <= s_offset
	      && s_offset <= data->max_offset);
  ratio_p = (ratio != 1
	     && multiplier_allowed_in_address_p (ratio, mem_mode, as));

  if (ratio != 1 && !ratio_p)
    cost += mult_by_coeff_cost (ratio, address_mode, speed);

  if (s_offset && !offset_p && !symbol_present)
    cost += add_cost (speed, address_mode);

  if (may_autoinc)
    *may_autoinc = autoinc;
  if (autoinc)
    acost = data->ainc_costs[autoinc_type];
  else
    acost = data->costs[symbol_present][var_present][offset_p][ratio_p];
  complexity = (symbol_present != 0) + (var_present != 0) + offset_p + ratio_p;
  return new_cost (cost + acost, complexity);
}

 /* Calculate the SPEED or size cost of shiftadd EXPR in MODE.  MULT is the
    the EXPR operand holding the shift.  COST0 and COST1 are the costs for
    calculating the operands of EXPR.  Returns true if successful, and returns
    the cost in COST.  */

static bool
get_shiftadd_cost (tree expr, enum machine_mode mode, comp_cost cost0,
                   comp_cost cost1, tree mult, bool speed, comp_cost *cost)
{
  comp_cost res;
  tree op1 = TREE_OPERAND (expr, 1);
  tree cst = TREE_OPERAND (mult, 1);
  tree multop = TREE_OPERAND (mult, 0);
  int m = exact_log2 (int_cst_value (cst));
  int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode));
  int sa_cost;
  bool equal_p = false;

  if (!(m >= 0 && m < maxm))
    return false;

  if (operand_equal_p (op1, mult, 0))
    equal_p = true;

  sa_cost = (TREE_CODE (expr) != MINUS_EXPR
             ? shiftadd_cost (speed, mode, m)
             : (equal_p
                ? shiftsub1_cost (speed, mode, m)
                : shiftsub0_cost (speed, mode, m)));
  res = new_cost (sa_cost, 0);
  res = add_costs (res, equal_p ? cost0 : cost1);

  STRIP_NOPS (multop);
  if (!is_gimple_val (multop))
    res = add_costs (res, force_expr_to_var_cost (multop, speed));

  *cost = res;
  return true;
}

/* Estimates cost of forcing expression EXPR into a variable.  */

static comp_cost
force_expr_to_var_cost (tree expr, bool speed)
{
  static bool costs_initialized = false;
  static unsigned integer_cost [2];
  static unsigned symbol_cost [2];
  static unsigned address_cost [2];
  tree op0, op1;
  comp_cost cost0, cost1, cost;
  enum machine_mode mode;

  if (!costs_initialized)
    {
      tree type = build_pointer_type (integer_type_node);
      tree var, addr;
      rtx x;
      int i;

      var = create_tmp_var_raw (integer_type_node, "test_var");
      TREE_STATIC (var) = 1;
      x = produce_memory_decl_rtl (var, NULL);
      SET_DECL_RTL (var, x);

      addr = build1 (ADDR_EXPR, type, var);


      for (i = 0; i < 2; i++)
	{
	  integer_cost[i] = computation_cost (build_int_cst (integer_type_node,
							     2000), i);

	  symbol_cost[i] = computation_cost (addr, i) + 1;

	  address_cost[i]
	    = computation_cost (fold_build_pointer_plus_hwi (addr, 2000), i) + 1;
	  if (dump_file && (dump_flags & TDF_DETAILS))
	    {
	      fprintf (dump_file, "force_expr_to_var_cost %s costs:\n", i ? "speed" : "size");
	      fprintf (dump_file, "  integer %d\n", (int) integer_cost[i]);
	      fprintf (dump_file, "  symbol %d\n", (int) symbol_cost[i]);
	      fprintf (dump_file, "  address %d\n", (int) address_cost[i]);
	      fprintf (dump_file, "  other %d\n", (int) target_spill_cost[i]);
	      fprintf (dump_file, "\n");
	    }
	}

      costs_initialized = true;
    }

  STRIP_NOPS (expr);

  if (SSA_VAR_P (expr))
    return no_cost;

  if (is_gimple_min_invariant (expr))
    {
      if (TREE_CODE (expr) == INTEGER_CST)
	return new_cost (integer_cost [speed], 0);

      if (TREE_CODE (expr) == ADDR_EXPR)
	{
	  tree obj = TREE_OPERAND (expr, 0);

	  if (TREE_CODE (obj) == VAR_DECL
	      || TREE_CODE (obj) == PARM_DECL
	      || TREE_CODE (obj) == RESULT_DECL)
	    return new_cost (symbol_cost [speed], 0);
	}

      return new_cost (address_cost [speed], 0);
    }

  switch (TREE_CODE (expr))
    {
    case POINTER_PLUS_EXPR:
    case PLUS_EXPR:
    case MINUS_EXPR:
    case MULT_EXPR:
      op0 = TREE_OPERAND (expr, 0);
      op1 = TREE_OPERAND (expr, 1);
      STRIP_NOPS (op0);
      STRIP_NOPS (op1);
      break;

    CASE_CONVERT:
    case NEGATE_EXPR:
      op0 = TREE_OPERAND (expr, 0);
      STRIP_NOPS (op0);
      op1 = NULL_TREE;
      break;

    default:
      /* Just an arbitrary value, FIXME.  */
      return new_cost (target_spill_cost[speed], 0);
    }

  if (op0 == NULL_TREE
      || TREE_CODE (op0) == SSA_NAME || CONSTANT_CLASS_P (op0))
    cost0 = no_cost;
  else
    cost0 = force_expr_to_var_cost (op0, speed);

  if (op1 == NULL_TREE
      || TREE_CODE (op1) == SSA_NAME || CONSTANT_CLASS_P (op1))
    cost1 = no_cost;
  else
    cost1 = force_expr_to_var_cost (op1, speed);

  mode = TYPE_MODE (TREE_TYPE (expr));
  switch (TREE_CODE (expr))
    {
    case POINTER_PLUS_EXPR:
    case PLUS_EXPR:
    case MINUS_EXPR:
    case NEGATE_EXPR:
      cost = new_cost (add_cost (speed, mode), 0);
      if (TREE_CODE (expr) != NEGATE_EXPR)
        {
          tree mult = NULL_TREE;
          comp_cost sa_cost;
          if (TREE_CODE (op1) == MULT_EXPR)
            mult = op1;
          else if (TREE_CODE (op0) == MULT_EXPR)
            mult = op0;

          if (mult != NULL_TREE
              && cst_and_fits_in_hwi (TREE_OPERAND (mult, 1))
              && get_shiftadd_cost (expr, mode, cost0, cost1, mult,
                                    speed, &sa_cost))
            return sa_cost;
        }
      break;

    CASE_CONVERT:
      {
	tree inner_mode, outer_mode;
	outer_mode = TREE_TYPE (expr);
	inner_mode = TREE_TYPE (op0);
	cost = new_cost (convert_cost (TYPE_MODE (outer_mode),
				       TYPE_MODE (inner_mode), speed), 0);
      }
      break;

    case MULT_EXPR:
      if (cst_and_fits_in_hwi (op0))
	cost = new_cost (mult_by_coeff_cost (int_cst_value (op0),
					     mode, speed), 0);
      else if (cst_and_fits_in_hwi (op1))
	cost = new_cost (mult_by_coeff_cost (int_cst_value (op1),
					     mode, speed), 0);
      else
	return new_cost (target_spill_cost [speed], 0);
      break;

    default:
      gcc_unreachable ();
    }

  cost = add_costs (cost, cost0);
  cost = add_costs (cost, cost1);

  /* Bound the cost by target_spill_cost.  The parts of complicated
     computations often are either loop invariant or at least can
     be shared between several iv uses, so letting this grow without
     limits would not give reasonable results.  */
  if (cost.cost > (int) target_spill_cost [speed])
    cost.cost = target_spill_cost [speed];

  return cost;
}

/* Estimates cost of forcing EXPR into a variable.  DEPENDS_ON is a set of the
   invariants the computation depends on.  */

static comp_cost
force_var_cost (struct ivopts_data *data,
		tree expr, bitmap *depends_on)
{
  if (depends_on)
    {
      fd_ivopts_data = data;
      walk_tree (&expr, find_depends, depends_on, NULL);
    }

  return force_expr_to_var_cost (expr, data->speed);
}

/* Estimates cost of expressing address ADDR  as var + symbol + offset.  The
   value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set
   to false if the corresponding part is missing.  DEPENDS_ON is a set of the
   invariants the computation depends on.  */

static comp_cost
split_address_cost (struct ivopts_data *data,
		    tree addr, bool *symbol_present, bool *var_present,
		    unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
{
  tree core;
  HOST_WIDE_INT bitsize;
  HOST_WIDE_INT bitpos;
  tree toffset;
  enum machine_mode mode;
  int unsignedp, volatilep;

  core = get_inner_reference (addr, &bitsize, &bitpos, &toffset, &mode,
			      &unsignedp, &volatilep, false);

  if (toffset != 0
      || bitpos % BITS_PER_UNIT != 0
      || TREE_CODE (core) != VAR_DECL)
    {
      *symbol_present = false;
      *var_present = true;
      fd_ivopts_data = data;
      walk_tree (&addr, find_depends, depends_on, NULL);
      return new_cost (target_spill_cost[data->speed], 0);
    }

  *offset += bitpos / BITS_PER_UNIT;
  if (TREE_STATIC (core)
      || DECL_EXTERNAL (core))
    {
      *symbol_present = true;
      *var_present = false;
      return no_cost;
    }

  *symbol_present = false;
  *var_present = true;
  return no_cost;
}

/* Estimates cost of expressing difference of addresses E1 - E2 as
   var + symbol + offset.  The value of offset is added to OFFSET,
   SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding
   part is missing.  DEPENDS_ON is a set of the invariants the computation
   depends on.  */

static comp_cost
ptr_difference_cost (struct ivopts_data *data,
		     tree e1, tree e2, bool *symbol_present, bool *var_present,
		     unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
{
  HOST_WIDE_INT diff = 0;
  aff_tree aff_e1, aff_e2;
  tree type;

  gcc_assert (TREE_CODE (e1) == ADDR_EXPR);

  if (ptr_difference_const (e1, e2, &diff))
    {
      *offset += diff;
      *symbol_present = false;
      *var_present = false;
      return no_cost;
    }

  if (integer_zerop (e2))
    return split_address_cost (data, TREE_OPERAND (e1, 0),
			       symbol_present, var_present, offset, depends_on);

  *symbol_present = false;
  *var_present = true;

  type = signed_type_for (TREE_TYPE (e1));
  tree_to_aff_combination (e1, type, &aff_e1);
  tree_to_aff_combination (e2, type, &aff_e2);
  aff_combination_scale (&aff_e2, double_int_minus_one);
  aff_combination_add (&aff_e1, &aff_e2);

  return force_var_cost (data, aff_combination_to_tree (&aff_e1), depends_on);
}

/* Estimates cost of expressing difference E1 - E2 as
   var + symbol + offset.  The value of offset is added to OFFSET,
   SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding
   part is missing.  DEPENDS_ON is a set of the invariants the computation
   depends on.  */

static comp_cost
difference_cost (struct ivopts_data *data,
		 tree e1, tree e2, bool *symbol_present, bool *var_present,
		 unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
{
  enum machine_mode mode = TYPE_MODE (TREE_TYPE (e1));
  unsigned HOST_WIDE_INT off1, off2;
  aff_tree aff_e1, aff_e2;
  tree type;

  e1 = strip_offset (e1, &off1);
  e2 = strip_offset (e2, &off2);
  *offset += off1 - off2;

  STRIP_NOPS (e1);
  STRIP_NOPS (e2);

  if (TREE_CODE (e1) == ADDR_EXPR)
    return ptr_difference_cost (data, e1, e2, symbol_present, var_present,
				offset, depends_on);
  *symbol_present = false;

  if (operand_equal_p (e1, e2, 0))
    {
      *var_present = false;
      return no_cost;
    }

  *var_present = true;

  if (integer_zerop (e2))
    return force_var_cost (data, e1, depends_on);

  if (integer_zerop (e1))
    {
      comp_cost cost = force_var_cost (data, e2, depends_on);
      cost.cost += mult_by_coeff_cost (-1, mode, data->speed);
      return cost;
    }

  type = signed_type_for (TREE_TYPE (e1));
  tree_to_aff_combination (e1, type, &aff_e1);
  tree_to_aff_combination (e2, type, &aff_e2);
  aff_combination_scale (&aff_e2, double_int_minus_one);
  aff_combination_add (&aff_e1, &aff_e2);

  return force_var_cost (data, aff_combination_to_tree (&aff_e1), depends_on);
}

/* Returns true if AFF1 and AFF2 are identical.  */

static bool
compare_aff_trees (aff_tree *aff1, aff_tree *aff2)
{
  unsigned i;

  if (aff1->n != aff2->n)
    return false;

  for (i = 0; i < aff1->n; i++)
    {
      if (aff1->elts[i].coef != aff2->elts[i].coef)
        return false;

      if (!operand_equal_p (aff1->elts[i].val, aff2->elts[i].val, 0))
        return false;
    }
  return true;
}

/* Stores EXPR in DATA->inv_expr_tab, and assigns it an inv_expr_id.  */

static int
get_expr_id (struct ivopts_data *data, tree expr)
{
  struct iv_inv_expr_ent ent;
  struct iv_inv_expr_ent **slot;

  ent.expr = expr;
  ent.hash = iterative_hash_expr (expr, 0);
  slot = data->inv_expr_tab.find_slot (&ent, INSERT);
  if (*slot)
    return (*slot)->id;

  *slot = XNEW (struct iv_inv_expr_ent);
  (*slot)->expr = expr;
  (*slot)->hash = ent.hash;
  (*slot)->id = data->inv_expr_id++;
  return (*slot)->id;
}

/* Returns the pseudo expr id if expression UBASE - RATIO * CBASE
   requires a new compiler generated temporary.  Returns -1 otherwise.
   ADDRESS_P is a flag indicating if the expression is for address
   computation.  */

static int
get_loop_invariant_expr_id (struct ivopts_data *data, tree ubase,
                            tree cbase, HOST_WIDE_INT ratio,
                            bool address_p)
{
  aff_tree ubase_aff, cbase_aff;
  tree expr, ub, cb;

  STRIP_NOPS (ubase);
  STRIP_NOPS (cbase);
  ub = ubase;
  cb = cbase;

  if ((TREE_CODE (ubase) == INTEGER_CST)
      && (TREE_CODE (cbase) == INTEGER_CST))
    return -1;

  /* Strips the constant part. */
  if (TREE_CODE (ubase) == PLUS_EXPR
      || TREE_CODE (ubase) == MINUS_EXPR
      || TREE_CODE (ubase) == POINTER_PLUS_EXPR)
    {
      if (TREE_CODE (TREE_OPERAND (ubase, 1)) == INTEGER_CST)
        ubase = TREE_OPERAND (ubase, 0);
    }

  /* Strips the constant part. */
  if (TREE_CODE (cbase) == PLUS_EXPR
      || TREE_CODE (cbase) == MINUS_EXPR
      || TREE_CODE (cbase) == POINTER_PLUS_EXPR)
    {
      if (TREE_CODE (TREE_OPERAND (cbase, 1)) == INTEGER_CST)
        cbase = TREE_OPERAND (cbase, 0);
    }

  if (address_p)
    {
      if (((TREE_CODE (ubase) == SSA_NAME)
           || (TREE_CODE (ubase) == ADDR_EXPR
               && is_gimple_min_invariant (ubase)))
          && (TREE_CODE (cbase) == INTEGER_CST))
        return -1;

      if (((TREE_CODE (cbase) == SSA_NAME)
           || (TREE_CODE (cbase) == ADDR_EXPR
               && is_gimple_min_invariant (cbase)))
          && (TREE_CODE (ubase) == INTEGER_CST))
        return -1;
    }

  if (ratio == 1)
    {
      if (operand_equal_p (ubase, cbase, 0))
        return -1;

      if (TREE_CODE (ubase) == ADDR_EXPR
          && TREE_CODE (cbase) == ADDR_EXPR)
        {
          tree usym, csym;

          usym = TREE_OPERAND (ubase, 0);
          csym = TREE_OPERAND (cbase, 0);
          if (TREE_CODE (usym) == ARRAY_REF)
            {
              tree ind = TREE_OPERAND (usym, 1);
              if (TREE_CODE (ind) == INTEGER_CST
                  && tree_fits_shwi_p (ind)
                  && tree_to_shwi (ind) == 0)
                usym = TREE_OPERAND (usym, 0);
            }
          if (TREE_CODE (csym) == ARRAY_REF)
            {
              tree ind = TREE_OPERAND (csym, 1);
              if (TREE_CODE (ind) == INTEGER_CST
                  && tree_fits_shwi_p (ind)
                  && tree_to_shwi (ind) == 0)
                csym = TREE_OPERAND (csym, 0);
            }
          if (operand_equal_p (usym, csym, 0))
            return -1;
        }
      /* Now do more complex comparison  */
      tree_to_aff_combination (ubase, TREE_TYPE (ubase), &ubase_aff);
      tree_to_aff_combination (cbase, TREE_TYPE (cbase), &cbase_aff);
      if (compare_aff_trees (&ubase_aff, &cbase_aff))
        return -1;
    }

  tree_to_aff_combination (ub, TREE_TYPE (ub), &ubase_aff);
  tree_to_aff_combination (cb, TREE_TYPE (cb), &cbase_aff);

  aff_combination_scale (&cbase_aff, double_int::from_shwi (-1 * ratio));
  aff_combination_add (&ubase_aff, &cbase_aff);
  expr = aff_combination_to_tree (&ubase_aff);
  return get_expr_id (data, expr);
}



/* Determines the cost of the computation by that USE is expressed
   from induction variable CAND.  If ADDRESS_P is true, we just need
   to create an address from it, otherwise we want to get it into
   register.  A set of invariants we depend on is stored in
   DEPENDS_ON.  AT is the statement at that the value is computed.
   If CAN_AUTOINC is nonnull, use it to record whether autoinc
   addressing is likely.  */

static comp_cost
get_computation_cost_at (struct ivopts_data *data,
			 struct iv_use *use, struct iv_cand *cand,
			 bool address_p, bitmap *depends_on, gimple at,
			 bool *can_autoinc,
                         int *inv_expr_id)
{
  tree ubase = use->iv->base, ustep = use->iv->step;
  tree cbase, cstep;
  tree utype = TREE_TYPE (ubase), ctype;
  unsigned HOST_WIDE_INT cstepi, offset = 0;
  HOST_WIDE_INT ratio, aratio;
  bool var_present, symbol_present, stmt_is_after_inc;
  comp_cost cost;
  double_int rat;
  bool speed = optimize_bb_for_speed_p (gimple_bb (at));
  enum machine_mode mem_mode = (address_p
				? TYPE_MODE (TREE_TYPE (*use->op_p))
				: VOIDmode);

  *depends_on = NULL;

  /* Only consider real candidates.  */
  if (!cand->iv)
    return infinite_cost;

  cbase = cand->iv->base;
  cstep = cand->iv->step;
  ctype = TREE_TYPE (cbase);

  if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
    {
      /* We do not have a precision to express the values of use.  */
      return infinite_cost;
    }

  if (address_p
      || (use->iv->base_object
	  && cand->iv->base_object
	  && POINTER_TYPE_P (TREE_TYPE (use->iv->base_object))
	  && POINTER_TYPE_P (TREE_TYPE (cand->iv->base_object))))
    {
      /* Do not try to express address of an object with computation based
	 on address of a different object.  This may cause problems in rtl
	 level alias analysis (that does not expect this to be happening,
	 as this is illegal in C), and would be unlikely to be useful
	 anyway.  */
      if (use->iv->base_object
	  && cand->iv->base_object
	  && !operand_equal_p (use->iv->base_object, cand->iv->base_object, 0))
	return infinite_cost;
    }

  if (TYPE_PRECISION (utype) < TYPE_PRECISION (ctype))
    {
      /* TODO -- add direct handling of this case.  */
      goto fallback;
    }

  /* CSTEPI is removed from the offset in case statement is after the
     increment.  If the step is not constant, we use zero instead.
     This is a bit imprecise (there is the extra addition), but
     redundancy elimination is likely to transform the code so that
     it uses value of the variable before increment anyway,
     so it is not that much unrealistic.  */
  if (cst_and_fits_in_hwi (cstep))
    cstepi = int_cst_value (cstep);
  else
    cstepi = 0;

  if (!constant_multiple_of (ustep, cstep, &rat))
    return infinite_cost;

  if (rat.fits_shwi ())
    ratio = rat.to_shwi ();
  else
    return infinite_cost;

  STRIP_NOPS (cbase);
  ctype = TREE_TYPE (cbase);

  stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);

  /* use = ubase + ratio * (var - cbase).  If either cbase is a constant
     or ratio == 1, it is better to handle this like

     ubase - ratio * cbase + ratio * var

     (also holds in the case ratio == -1, TODO.  */

  if (cst_and_fits_in_hwi (cbase))
    {
      offset = - ratio * int_cst_value (cbase);
      cost = difference_cost (data,
			      ubase, build_int_cst (utype, 0),
			      &symbol_present, &var_present, &offset,
			      depends_on);
      cost.cost /= avg_loop_niter (data->current_loop);
    }
  else if (ratio == 1)
    {
      tree real_cbase = cbase;

      /* Check to see if any adjustment is needed.  */
      if (cstepi == 0 && stmt_is_after_inc)
        {
          aff_tree real_cbase_aff;
          aff_tree cstep_aff;

          tree_to_aff_combination (cbase, TREE_TYPE (real_cbase),
                                   &real_cbase_aff);
          tree_to_aff_combination (cstep, TREE_TYPE (cstep), &cstep_aff);

          aff_combination_add (&real_cbase_aff, &cstep_aff);
          real_cbase = aff_combination_to_tree (&real_cbase_aff);
        }

      cost = difference_cost (data,
			      ubase, real_cbase,
			      &symbol_present, &var_present, &offset,
			      depends_on);
      cost.cost /= avg_loop_niter (data->current_loop);
    }
  else if (address_p
	   && !POINTER_TYPE_P (ctype)
	   && multiplier_allowed_in_address_p
		(ratio, mem_mode,
			TYPE_ADDR_SPACE (TREE_TYPE (utype))))
    {
      cbase
	= fold_build2 (MULT_EXPR, ctype, cbase, build_int_cst (ctype, ratio));
      cost = difference_cost (data,
			      ubase, cbase,
			      &symbol_present, &var_present, &offset,
			      depends_on);
      cost.cost /= avg_loop_niter (data->current_loop);
    }
  else
    {
      cost = force_var_cost (data, cbase, depends_on);
      cost = add_costs (cost,
			difference_cost (data,
					 ubase, build_int_cst (utype, 0),
					 &symbol_present, &var_present,
					 &offset, depends_on));
      cost.cost /= avg_loop_niter (data->current_loop);
      cost.cost += add_cost (data->speed, TYPE_MODE (ctype));
    }

  if (inv_expr_id)
    {
      *inv_expr_id =
          get_loop_invariant_expr_id (data, ubase, cbase, ratio, address_p);
      /* Clear depends on.  */
      if (*inv_expr_id != -1 && depends_on && *depends_on)
        bitmap_clear (*depends_on);
    }

  /* If we are after the increment, the value of the candidate is higher by
     one iteration.  */
  if (stmt_is_after_inc)
    offset -= ratio * cstepi;

  /* Now the computation is in shape symbol + var1 + const + ratio * var2.
     (symbol/var1/const parts may be omitted).  If we are looking for an
     address, find the cost of addressing this.  */
  if (address_p)
    return add_costs (cost,
		      get_address_cost (symbol_present, var_present,
					offset, ratio, cstepi,
					mem_mode,
					TYPE_ADDR_SPACE (TREE_TYPE (utype)),
					speed, stmt_is_after_inc,
					can_autoinc));

  /* Otherwise estimate the costs for computing the expression.  */
  if (!symbol_present && !var_present && !offset)
    {
      if (ratio != 1)
	cost.cost += mult_by_coeff_cost (ratio, TYPE_MODE (ctype), speed);
      return cost;
    }

  /* Symbol + offset should be compile-time computable so consider that they
      are added once to the variable, if present.  */
  if (var_present && (symbol_present || offset))
    cost.cost += adjust_setup_cost (data,
				    add_cost (speed, TYPE_MODE (ctype)));

  /* Having offset does not affect runtime cost in case it is added to
     symbol, but it increases complexity.  */
  if (offset)
    cost.complexity++;

  cost.cost += add_cost (speed, TYPE_MODE (ctype));

  aratio = ratio > 0 ? ratio : -ratio;
  if (aratio != 1)
    cost.cost += mult_by_coeff_cost (aratio, TYPE_MODE (ctype), speed);
  return cost;

fallback:
  if (can_autoinc)
    *can_autoinc = false;

  {
    /* Just get the expression, expand it and measure the cost.  */
    tree comp = get_computation_at (data->current_loop, use, cand, at);

    if (!comp)
      return infinite_cost;

    if (address_p)
      comp = build_simple_mem_ref (comp);

    return new_cost (computation_cost (comp, speed), 0);
  }
}

/* Determines the cost of the computation by that USE is expressed
   from induction variable CAND.  If ADDRESS_P is true, we just need
   to create an address from it, otherwise we want to get it into
   register.  A set of invariants we depend on is stored in
   DEPENDS_ON.  If CAN_AUTOINC is nonnull, use it to record whether
   autoinc addressing is likely.  */

static comp_cost
get_computation_cost (struct ivopts_data *data,
		      struct iv_use *use, struct iv_cand *cand,
		      bool address_p, bitmap *depends_on,
                      bool *can_autoinc, int *inv_expr_id)
{
  return get_computation_cost_at (data,
				  use, cand, address_p, depends_on, use->stmt,
				  can_autoinc, inv_expr_id);
}

/* Determines cost of basing replacement of USE on CAND in a generic
   expression.  */

static bool
determine_use_iv_cost_generic (struct ivopts_data *data,
			       struct iv_use *use, struct iv_cand *cand)
{
  bitmap depends_on;
  comp_cost cost;
  int inv_expr_id = -1;

  /* The simple case first -- if we need to express value of the preserved
     original biv, the cost is 0.  This also prevents us from counting the
     cost of increment twice -- once at this use and once in the cost of
     the candidate.  */
  if (cand->pos == IP_ORIGINAL
      && cand->incremented_at == use->stmt)
    {
      set_use_iv_cost (data, use, cand, no_cost, NULL, NULL_TREE,
                       ERROR_MARK, -1);
      return true;
    }

  cost = get_computation_cost (data, use, cand, false, &depends_on,
                               NULL, &inv_expr_id);

  set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE, ERROR_MARK,
                   inv_expr_id);

  return !infinite_cost_p (cost);
}

/* Determines cost of basing replacement of USE on CAND in an address.  */

static bool
determine_use_iv_cost_address (struct ivopts_data *data,
			       struct iv_use *use, struct iv_cand *cand)
{
  bitmap depends_on;
  bool can_autoinc;
  int inv_expr_id = -1;
  comp_cost cost = get_computation_cost (data, use, cand, true, &depends_on,
					 &can_autoinc, &inv_expr_id);

  if (cand->ainc_use == use)
    {
      if (can_autoinc)
	cost.cost -= cand->cost_step;
      /* If we generated the candidate solely for exploiting autoincrement
	 opportunities, and it turns out it can't be used, set the cost to
	 infinity to make sure we ignore it.  */
      else if (cand->pos == IP_AFTER_USE || cand->pos == IP_BEFORE_USE)
	cost = infinite_cost;
    }
  set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE, ERROR_MARK,
                   inv_expr_id);

  return !infinite_cost_p (cost);
}

/* Computes value of candidate CAND at position AT in iteration NITER, and
   stores it to VAL.  */

static void
cand_value_at (struct loop *loop, struct iv_cand *cand, gimple at, tree niter,
	       aff_tree *val)
{
  aff_tree step, delta, nit;
  struct iv *iv = cand->iv;
  tree type = TREE_TYPE (iv->base);
  tree steptype = type;
  if (POINTER_TYPE_P (type))
    steptype = sizetype;
  steptype = unsigned_type_for (type);

  tree_to_aff_combination (iv->step, TREE_TYPE (iv->step), &step);
  aff_combination_convert (&step, steptype);
  tree_to_aff_combination (niter, TREE_TYPE (niter), &nit);
  aff_combination_convert (&nit, steptype);
  aff_combination_mult (&nit, &step, &delta);
  if (stmt_after_increment (loop, cand, at))
    aff_combination_add (&delta, &step);

  tree_to_aff_combination (iv->base, type, val);
  if (!POINTER_TYPE_P (type))
    aff_combination_convert (val, steptype);
  aff_combination_add (val, &delta);
}

/* Returns period of induction variable iv.  */

static tree
iv_period (struct iv *iv)
{
  tree step = iv->step, period, type;
  tree pow2div;

  gcc_assert (step && TREE_CODE (step) == INTEGER_CST);

  type = unsigned_type_for (TREE_TYPE (step));
  /* Period of the iv is lcm (step, type_range)/step -1,
     i.e., N*type_range/step - 1. Since type range is power
     of two, N == (step >> num_of_ending_zeros_binary (step),
     so the final result is

       (type_range >> num_of_ending_zeros_binary (step)) - 1

  */
  pow2div = num_ending_zeros (step);

  period = build_low_bits_mask (type,
                                (TYPE_PRECISION (type)
                                 - tree_to_uhwi (pow2div)));

  return period;
}

/* Returns the comparison operator used when eliminating the iv USE.  */

static enum tree_code
iv_elimination_compare (struct ivopts_data *data, struct iv_use *use)
{
  struct loop *loop = data->current_loop;
  basic_block ex_bb;
  edge exit;

  ex_bb = gimple_bb (use->stmt);
  exit = EDGE_SUCC (ex_bb, 0);
  if (flow_bb_inside_loop_p (loop, exit->dest))
    exit = EDGE_SUCC (ex_bb, 1);

  return (exit->flags & EDGE_TRUE_VALUE ? EQ_EXPR : NE_EXPR);
}

static tree
strip_wrap_conserving_type_conversions (tree exp)
{
  while (tree_ssa_useless_type_conversion (exp)
	 && (nowrap_type_p (TREE_TYPE (exp))
	     == nowrap_type_p (TREE_TYPE (TREE_OPERAND (exp, 0)))))
    exp = TREE_OPERAND (exp, 0);
  return exp;
}

/* Walk the SSA form and check whether E == WHAT.  Fairly simplistic, we
   check for an exact match.  */

static bool
expr_equal_p (tree e, tree what)
{
  gimple stmt;
  enum tree_code code;

  e = strip_wrap_conserving_type_conversions (e);
  what = strip_wrap_conserving_type_conversions (what);

  code = TREE_CODE (what);
  if (TREE_TYPE (e) != TREE_TYPE (what))
    return false;

  if (operand_equal_p (e, what, 0))
    return true;

  if (TREE_CODE (e) != SSA_NAME)
    return false;

  stmt = SSA_NAME_DEF_STMT (e);
  if (gimple_code (stmt) != GIMPLE_ASSIGN
      || gimple_assign_rhs_code (stmt) != code)
    return false;

  switch (get_gimple_rhs_class (code))
    {
    case GIMPLE_BINARY_RHS:
      if (!expr_equal_p (gimple_assign_rhs2 (stmt), TREE_OPERAND (what, 1)))
	return false;
      /* Fallthru.  */

    case GIMPLE_UNARY_RHS:
    case GIMPLE_SINGLE_RHS:
      return expr_equal_p (gimple_assign_rhs1 (stmt), TREE_OPERAND (what, 0));
    default:
      return false;
    }
}

/* Returns true if we can prove that BASE - OFFSET does not overflow.  For now,
   we only detect the situation that BASE = SOMETHING + OFFSET, where the
   calculation is performed in non-wrapping type.

   TODO: More generally, we could test for the situation that
	 BASE = SOMETHING + OFFSET' and OFFSET is between OFFSET' and zero.
	 This would require knowing the sign of OFFSET.

	 Also, we only look for the first addition in the computation of BASE.
	 More complex analysis would be better, but introducing it just for
	 this optimization seems like an overkill.  */

static bool
difference_cannot_overflow_p (tree base, tree offset)
{
  enum tree_code code;
  tree e1, e2;

  if (!nowrap_type_p (TREE_TYPE (base)))
    return false;

  base = expand_simple_operations (base);

  if (TREE_CODE (base) == SSA_NAME)
    {
      gimple stmt = SSA_NAME_DEF_STMT (base);

      if (gimple_code (stmt) != GIMPLE_ASSIGN)
	return false;

      code = gimple_assign_rhs_code (stmt);
      if (get_gimple_rhs_class (code) != GIMPLE_BINARY_RHS)
	return false;

      e1 = gimple_assign_rhs1 (stmt);
      e2 = gimple_assign_rhs2 (stmt);
    }
  else
    {
      code = TREE_CODE (base);
      if (get_gimple_rhs_class (code) != GIMPLE_BINARY_RHS)
	return false;
      e1 = TREE_OPERAND (base, 0);
      e2 = TREE_OPERAND (base, 1);
    }

  /* TODO: deeper inspection may be necessary to prove the equality.  */
  switch (code)
    {
    case PLUS_EXPR:
      return expr_equal_p (e1, offset) || expr_equal_p (e2, offset);
    case POINTER_PLUS_EXPR:
      return expr_equal_p (e2, offset);

    default:
      return false;
    }
}

/* Tries to replace loop exit by one formulated in terms of a LT_EXPR
   comparison with CAND.  NITER describes the number of iterations of
   the loops.  If successful, the comparison in COMP_P is altered accordingly.

   We aim to handle the following situation:

   sometype *base, *p;
   int a, b, i;

   i = a;
   p = p_0 = base + a;

   do
     {
       bla (*p);
       p++;
       i++;
     }
   while (i < b);

   Here, the number of iterations of the loop is (a + 1 > b) ? 0 : b - a - 1.
   We aim to optimize this to

   p = p_0 = base + a;
   do
     {
       bla (*p);
       p++;
     }
   while (p < p_0 - a + b);

   This preserves the correctness, since the pointer arithmetics does not
   overflow.  More precisely:

   1) if a + 1 <= b, then p_0 - a + b is the final value of p, hence there is no
      overflow in computing it or the values of p.
   2) if a + 1 > b, then we need to verify that the expression p_0 - a does not
      overflow.  To prove this, we use the fact that p_0 = base + a.  */

static bool
iv_elimination_compare_lt (struct ivopts_data *data,
                           struct iv_cand *cand, enum tree_code *comp_p,
			   struct tree_niter_desc *niter)
{
  tree cand_type, a, b, mbz, nit_type = TREE_TYPE (niter->niter), offset;
  struct aff_tree nit, tmpa, tmpb;
  enum tree_code comp;
  HOST_WIDE_INT step;

  /* We need to know that the candidate induction variable does not overflow.
     While more complex analysis may be used to prove this, for now just
     check that the variable appears in the original program and that it
     is computed in a type that guarantees no overflows.  */
  cand_type = TREE_TYPE (cand->iv->base);
  if (cand->pos != IP_ORIGINAL || !nowrap_type_p (cand_type))
    return false;

  /* Make sure that the loop iterates till the loop bound is hit, as otherwise
     the calculation of the BOUND could overflow, making the comparison
     invalid.  */
  if (!data->loop_single_exit_p)
    return false;

  /* We need to be able to decide whether candidate is increasing or decreasing
     in order to choose the right comparison operator.  */
  if (!cst_and_fits_in_hwi (cand->iv->step))
    return false;
  step = int_cst_value (cand->iv->step);

  /* Check that the number of iterations matches the expected pattern:
     a + 1 > b ? 0 : b - a - 1.  */
  mbz = niter->may_be_zero;
  if (TREE_CODE (mbz) == GT_EXPR)
    {
      /* Handle a + 1 > b.  */
      tree op0 = TREE_OPERAND (mbz, 0);
      if (TREE_CODE (op0) == PLUS_EXPR && integer_onep (TREE_OPERAND (op0, 1)))
	{
	  a = TREE_OPERAND (op0, 0);
	  b = TREE_OPERAND (mbz, 1);
	}
      else
	return false;
    }
  else if (TREE_CODE (mbz) == LT_EXPR)
    {
      tree op1 = TREE_OPERAND (mbz, 1);

      /* Handle b < a + 1.  */
      if (TREE_CODE (op1) == PLUS_EXPR && integer_onep (TREE_OPERAND (op1, 1)))
        {
          a = TREE_OPERAND (op1, 0);
          b = TREE_OPERAND (mbz, 0);
        }
      else
	return false;
    }
  else
    return false;

  /* Expected number of iterations is B - A - 1.  Check that it matches
     the actual number, i.e., that B - A - NITER = 1.  */
  tree_to_aff_combination (niter->niter, nit_type, &nit);
  tree_to_aff_combination (fold_convert (nit_type, a), nit_type, &tmpa);
  tree_to_aff_combination (fold_convert (nit_type, b), nit_type, &tmpb);
  aff_combination_scale (&nit, double_int_minus_one);
  aff_combination_scale (&tmpa, double_int_minus_one);
  aff_combination_add (&tmpb, &tmpa);
  aff_combination_add (&tmpb, &nit);
  if (tmpb.n != 0 || tmpb.offset != double_int_one)
    return false;

  /* Finally, check that CAND->IV->BASE - CAND->IV->STEP * A does not
     overflow.  */
  offset = fold_build2 (MULT_EXPR, TREE_TYPE (cand->iv->step),
			cand->iv->step,
			fold_convert (TREE_TYPE (cand->iv->step), a));
  if (!difference_cannot_overflow_p (cand->iv->base, offset))
    return false;

  /* Determine the new comparison operator.  */
  comp = step < 0 ? GT_EXPR : LT_EXPR;
  if (*comp_p == NE_EXPR)
    *comp_p = comp;
  else if (*comp_p == EQ_EXPR)
    *comp_p = invert_tree_comparison (comp, false);
  else
    gcc_unreachable ();

  return true;
}

/* Check whether it is possible to express the condition in USE by comparison
   of candidate CAND.  If so, store the value compared with to BOUND, and the
   comparison operator to COMP.  */

static bool
may_eliminate_iv (struct ivopts_data *data,
		  struct iv_use *use, struct iv_cand *cand, tree *bound,
		  enum tree_code *comp)
{
  basic_block ex_bb;
  edge exit;
  tree period;
  struct loop *loop = data->current_loop;
  aff_tree bnd;
  struct tree_niter_desc *desc = NULL;

  if (TREE_CODE (cand->iv->step) != INTEGER_CST)
    return false;

  /* For now works only for exits that dominate the loop latch.
     TODO: extend to other conditions inside loop body.  */
  ex_bb = gimple_bb (use->stmt);
  if (use->stmt != last_stmt (ex_bb)
      || gimple_code (use->stmt) != GIMPLE_COND
      || !dominated_by_p (CDI_DOMINATORS, loop->latch, ex_bb))
    return false;

  exit = EDGE_SUCC (ex_bb, 0);
  if (flow_bb_inside_loop_p (loop, exit->dest))
    exit = EDGE_SUCC (ex_bb, 1);
  if (flow_bb_inside_loop_p (loop, exit->dest))
    return false;

  desc = niter_for_exit (data, exit);
  if (!desc)
    return false;

  /* Determine whether we can use the variable to test the exit condition.
     This is the case iff the period of the induction variable is greater
     than the number of iterations for which the exit condition is true.  */
  period = iv_period (cand->iv);

  /* If the number of iterations is constant, compare against it directly.  */
  if (TREE_CODE (desc->niter) == INTEGER_CST)
    {
      /* See cand_value_at.  */
      if (stmt_after_increment (loop, cand, use->stmt))
        {
          if (!tree_int_cst_lt (desc->niter, period))
            return false;
        }
      else
        {
          if (tree_int_cst_lt (period, desc->niter))
            return false;
        }
    }

  /* If not, and if this is the only possible exit of the loop, see whether
     we can get a conservative estimate on the number of iterations of the
     entire loop and compare against that instead.  */
  else
    {
      double_int period_value, max_niter;

      max_niter = desc->max;
      if (stmt_after_increment (loop, cand, use->stmt))
        max_niter += double_int_one;
      period_value = tree_to_double_int (period);
      if (max_niter.ugt (period_value))
        {
          /* See if we can take advantage of inferred loop bound information.  */
          if (data->loop_single_exit_p)
            {
              if (!max_loop_iterations (loop, &max_niter))
                return false;
              /* The loop bound is already adjusted by adding 1.  */
              if (max_niter.ugt (period_value))
                return false;
            }
          else
            return false;
        }
    }

  cand_value_at (loop, cand, use->stmt, desc->niter, &bnd);

  *bound = fold_convert (TREE_TYPE (cand->iv->base),
			 aff_combination_to_tree (&bnd));
  *comp = iv_elimination_compare (data, use);

  /* It is unlikely that computing the number of iterations using division
     would be more profitable than keeping the original induction variable.  */
  if (expression_expensive_p (*bound))
    return false;

  /* Sometimes, it is possible to handle the situation that the number of
     iterations may be zero unless additional assumtions by using <
     instead of != in the exit condition.

     TODO: we could also calculate the value MAY_BE_ZERO ? 0 : NITER and
	   base the exit condition on it.  However, that is often too
	   expensive.  */
  if (!integer_zerop (desc->may_be_zero))
    return iv_elimination_compare_lt (data, cand, comp, desc);

  return true;
}

 /* Calculates the cost of BOUND, if it is a PARM_DECL.  A PARM_DECL must
    be copied, if is is used in the loop body and DATA->body_includes_call.  */

static int
parm_decl_cost (struct ivopts_data *data, tree bound)
{
  tree sbound = bound;
  STRIP_NOPS (sbound);

  if (TREE_CODE (sbound) == SSA_NAME
      && SSA_NAME_IS_DEFAULT_DEF (sbound)
      && TREE_CODE (SSA_NAME_VAR (sbound)) == PARM_DECL
      && data->body_includes_call)
    return COSTS_N_INSNS (1);

  return 0;
}

/* Determines cost of basing replacement of USE on CAND in a condition.  */

static bool
determine_use_iv_cost_condition (struct ivopts_data *data,
				 struct iv_use *use, struct iv_cand *cand)
{
  tree bound = NULL_TREE;
  struct iv *cmp_iv;
  bitmap depends_on_elim = NULL, depends_on_express = NULL, depends_on;
  comp_cost elim_cost, express_cost, cost, bound_cost;
  bool ok;
  int elim_inv_expr_id = -1, express_inv_expr_id = -1, inv_expr_id;
  tree *control_var, *bound_cst;
  enum tree_code comp = ERROR_MARK;

  /* Only consider real candidates.  */
  if (!cand->iv)
    {
      set_use_iv_cost (data, use, cand, infinite_cost, NULL, NULL_TREE,
		       ERROR_MARK, -1);
      return false;
    }

  /* Try iv elimination.  */
  if (may_eliminate_iv (data, use, cand, &bound, &comp))
    {
      elim_cost = force_var_cost (data, bound, &depends_on_elim);
      if (elim_cost.cost == 0)
        elim_cost.cost = parm_decl_cost (data, bound);
      else if (TREE_CODE (bound) == INTEGER_CST)
        elim_cost.cost = 0;
      /* If we replace a loop condition 'i < n' with 'p < base + n',
	 depends_on_elim will have 'base' and 'n' set, which implies
	 that both 'base' and 'n' will be live during the loop.	 More likely,
	 'base + n' will be loop invariant, resulting in only one live value
	 during the loop.  So in that case we clear depends_on_elim and set
        elim_inv_expr_id instead.  */
      if (depends_on_elim && bitmap_count_bits (depends_on_elim) > 1)
	{
	  elim_inv_expr_id = get_expr_id (data, bound);
	  bitmap_clear (depends_on_elim);
	}
      /* The bound is a loop invariant, so it will be only computed
	 once.  */
      elim_cost.cost = adjust_setup_cost (data, elim_cost.cost);
    }
  else
    elim_cost = infinite_cost;

  /* Try expressing the original giv.  If it is compared with an invariant,
     note that we cannot get rid of it.  */
  ok = extract_cond_operands (data, use->stmt, &control_var, &bound_cst,
			      NULL, &cmp_iv);
  gcc_assert (ok);

  /* When the condition is a comparison of the candidate IV against
     zero, prefer this IV.

     TODO: The constant that we're subtracting from the cost should
     be target-dependent.  This information should be added to the
     target costs for each backend.  */
  if (!infinite_cost_p (elim_cost) /* Do not try to decrease infinite! */
      && integer_zerop (*bound_cst)
      && (operand_equal_p (*control_var, cand->var_after, 0)
	  || operand_equal_p (*control_var, cand->var_before, 0)))
    elim_cost.cost -= 1;

  express_cost = get_computation_cost (data, use, cand, false,
				       &depends_on_express, NULL,
                                       &express_inv_expr_id);
  fd_ivopts_data = data;
  walk_tree (&cmp_iv->base, find_depends, &depends_on_express, NULL);

  /* Count the cost of the original bound as well.  */
  bound_cost = force_var_cost (data, *bound_cst, NULL);
  if (bound_cost.cost == 0)
    bound_cost.cost = parm_decl_cost (data, *bound_cst);
  else if (TREE_CODE (*bound_cst) == INTEGER_CST)
    bound_cost.cost = 0;
  express_cost.cost += bound_cost.cost;

  /* Choose the better approach, preferring the eliminated IV. */
  if (compare_costs (elim_cost, express_cost) <= 0)
    {
      cost = elim_cost;
      depends_on = depends_on_elim;
      depends_on_elim = NULL;
      inv_expr_id = elim_inv_expr_id;
    }
  else
    {
      cost = express_cost;
      depends_on = depends_on_express;
      depends_on_express = NULL;
      bound = NULL_TREE;
      comp = ERROR_MARK;
      inv_expr_id = express_inv_expr_id;
    }

  set_use_iv_cost (data, use, cand, cost, depends_on, bound, comp, inv_expr_id);

  if (depends_on_elim)
    BITMAP_FREE (depends_on_elim);
  if (depends_on_express)
    BITMAP_FREE (depends_on_express);

  return !infinite_cost_p (cost);
}

/* Determines cost of basing replacement of USE on CAND.  Returns false
   if USE cannot be based on CAND.  */

static bool
determine_use_iv_cost (struct ivopts_data *data,
		       struct iv_use *use, struct iv_cand *cand)
{
  switch (use->type)
    {
    case USE_NONLINEAR_EXPR:
      return determine_use_iv_cost_generic (data, use, cand);

    case USE_ADDRESS:
      return determine_use_iv_cost_address (data, use, cand);

    case USE_COMPARE:
      return determine_use_iv_cost_condition (data, use, cand);

    default:
      gcc_unreachable ();
    }
}

/* Return true if get_computation_cost indicates that autoincrement is
   a possibility for the pair of USE and CAND, false otherwise.  */

static bool
autoinc_possible_for_pair (struct ivopts_data *data, struct iv_use *use,
			   struct iv_cand *cand)
{
  bitmap depends_on;
  bool can_autoinc;
  comp_cost cost;

  if (use->type != USE_ADDRESS)
    return false;

  cost = get_computation_cost (data, use, cand, true, &depends_on,
			       &can_autoinc, NULL);

  BITMAP_FREE (depends_on);

  return !infinite_cost_p (cost) && can_autoinc;
}

/* Examine IP_ORIGINAL candidates to see if they are incremented next to a
   use that allows autoincrement, and set their AINC_USE if possible.  */

static void
set_autoinc_for_original_candidates (struct ivopts_data *data)
{
  unsigned i, j;

  for (i = 0; i < n_iv_cands (data); i++)
    {
      struct iv_cand *cand = iv_cand (data, i);
      struct iv_use *closest_before = NULL;
      struct iv_use *closest_after = NULL;
      if (cand->pos != IP_ORIGINAL)
	continue;

      for (j = 0; j < n_iv_uses (data); j++)
	{
	  struct iv_use *use = iv_use (data, j);
	  unsigned uid = gimple_uid (use->stmt);

	  if (gimple_bb (use->stmt) != gimple_bb (cand->incremented_at))
	    continue;

	  if (uid < gimple_uid (cand->incremented_at)
	      && (closest_before == NULL
		  || uid > gimple_uid (closest_before->stmt)))
	    closest_before = use;

	  if (uid > gimple_uid (cand->incremented_at)
	      && (closest_after == NULL
		  || uid < gimple_uid (closest_after->stmt)))
	    closest_after = use;
	}

      if (closest_before != NULL
	  && autoinc_possible_for_pair (data, closest_before, cand))
	cand->ainc_use = closest_before;
      else if (closest_after != NULL
	       && autoinc_possible_for_pair (data, closest_after, cand))
	cand->ainc_use = closest_after;
    }
}

/* Finds the candidates for the induction variables.  */

static void
find_iv_candidates (struct ivopts_data *data)
{
  /* Add commonly used ivs.  */
  add_standard_iv_candidates (data);

  /* Add old induction variables.  */
  add_old_ivs_candidates (data);

  /* Add induction variables derived from uses.  */
  add_derived_ivs_candidates (data);

  set_autoinc_for_original_candidates (data);

  /* Record the important candidates.  */
  record_important_candidates (data);
}

/* Determines costs of basing the use of the iv on an iv candidate.  */

static void
determine_use_iv_costs (struct ivopts_data *data)
{
  unsigned i, j;
  struct iv_use *use;
  struct iv_cand *cand;
  bitmap to_clear = BITMAP_ALLOC (NULL);

  alloc_use_cost_map (data);

  for (i = 0; i < n_iv_uses (data); i++)
    {
      use = iv_use (data, i);

      if (data->consider_all_candidates)
	{
	  for (j = 0; j < n_iv_cands (data); j++)
	    {
	      cand = iv_cand (data, j);
	      determine_use_iv_cost (data, use, cand);
	    }
	}
      else
	{
	  bitmap_iterator bi;

	  EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi)
	    {
	      cand = iv_cand (data, j);
	      if (!determine_use_iv_cost (data, use, cand))
		bitmap_set_bit (to_clear, j);
	    }

	  /* Remove the candidates for that the cost is infinite from
	     the list of related candidates.  */
	  bitmap_and_compl_into (use->related_cands, to_clear);
	  bitmap_clear (to_clear);
	}
    }

  BITMAP_FREE (to_clear);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Use-candidate costs:\n");

      for (i = 0; i < n_iv_uses (data); i++)
	{
	  use = iv_use (data, i);

	  fprintf (dump_file, "Use %d:\n", i);
	  fprintf (dump_file, "  cand\tcost\tcompl.\tdepends on\n");
	  for (j = 0; j < use->n_map_members; j++)
	    {
	      if (!use->cost_map[j].cand
		  || infinite_cost_p (use->cost_map[j].cost))
		continue;

	      fprintf (dump_file, "  %d\t%d\t%d\t",
		       use->cost_map[j].cand->id,
		       use->cost_map[j].cost.cost,
		       use->cost_map[j].cost.complexity);
	      if (use->cost_map[j].depends_on)
		bitmap_print (dump_file,
			      use->cost_map[j].depends_on, "","");
              if (use->cost_map[j].inv_expr_id != -1)
                fprintf (dump_file, " inv_expr:%d", use->cost_map[j].inv_expr_id);
	      fprintf (dump_file, "\n");
	    }

	  fprintf (dump_file, "\n");
	}
      fprintf (dump_file, "\n");
    }
}

/* Determines cost of the candidate CAND.  */

static void
determine_iv_cost (struct ivopts_data *data, struct iv_cand *cand)
{
  comp_cost cost_base;
  unsigned cost, cost_step;
  tree base;

  if (!cand->iv)
    {
      cand->cost = 0;
      return;
    }

  /* There are two costs associated with the candidate -- its increment
     and its initialization.  The second is almost negligible for any loop
     that rolls enough, so we take it just very little into account.  */

  base = cand->iv->base;
  cost_base = force_var_cost (data, base, NULL);
  /* It will be exceptional that the iv register happens to be initialized with
     the proper value at no cost.  In general, there will at least be a regcopy
     or a const set.  */
  if (cost_base.cost == 0)
    cost_base.cost = COSTS_N_INSNS (1);
  cost_step = add_cost (data->speed, TYPE_MODE (TREE_TYPE (base)));

  cost = cost_step + adjust_setup_cost (data, cost_base.cost);

  /* Prefer the original ivs unless we may gain something by replacing it.
     The reason is to make debugging simpler; so this is not relevant for
     artificial ivs created by other optimization passes.  */
  if (cand->pos != IP_ORIGINAL
      || !SSA_NAME_VAR (cand->var_before)
      || DECL_ARTIFICIAL (SSA_NAME_VAR (cand->var_before)))
    cost++;

  /* Prefer not to insert statements into latch unless there are some
     already (so that we do not create unnecessary jumps).  */
  if (cand->pos == IP_END
      && empty_block_p (ip_end_pos (data->current_loop)))
    cost++;

  cand->cost = cost;
  cand->cost_step = cost_step;
}

/* Determines costs of computation of the candidates.  */

static void
determine_iv_costs (struct ivopts_data *data)
{
  unsigned i;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Candidate costs:\n");
      fprintf (dump_file, "  cand\tcost\n");
    }

  for (i = 0; i < n_iv_cands (data); i++)
    {
      struct iv_cand *cand = iv_cand (data, i);

      determine_iv_cost (data, cand);

      if (dump_file && (dump_flags & TDF_DETAILS))
	fprintf (dump_file, "  %d\t%d\n", i, cand->cost);
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    fprintf (dump_file, "\n");
}

/* Calculates cost for having SIZE induction variables.  */

static unsigned
ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size)
{
  /* We add size to the cost, so that we prefer eliminating ivs
     if possible.  */
  return size + estimate_reg_pressure_cost (size, data->regs_used, data->speed,
					    data->body_includes_call);
}

/* For each size of the induction variable set determine the penalty.  */

static void
determine_set_costs (struct ivopts_data *data)
{
  unsigned j, n;
  gimple phi;
  gimple_stmt_iterator psi;
  tree op;
  struct loop *loop = data->current_loop;
  bitmap_iterator bi;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Global costs:\n");
      fprintf (dump_file, "  target_avail_regs %d\n", target_avail_regs);
      fprintf (dump_file, "  target_clobbered_regs %d\n", target_clobbered_regs);
      fprintf (dump_file, "  target_reg_cost %d\n", target_reg_cost[data->speed]);
      fprintf (dump_file, "  target_spill_cost %d\n", target_spill_cost[data->speed]);
    }

  n = 0;
  for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
    {
      phi = gsi_stmt (psi);
      op = PHI_RESULT (phi);

      if (virtual_operand_p (op))
	continue;

      if (get_iv (data, op))
	continue;

      n++;
    }

  EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
    {
      struct version_info *info = ver_info (data, j);

      if (info->inv_id && info->has_nonlin_use)
	n++;
    }

  data->regs_used = n;
  if (dump_file && (dump_flags & TDF_DETAILS))
    fprintf (dump_file, "  regs_used %d\n", n);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "  cost for size:\n");
      fprintf (dump_file, "  ivs\tcost\n");
      for (j = 0; j <= 2 * target_avail_regs; j++)
	fprintf (dump_file, "  %d\t%d\n", j,
		 ivopts_global_cost_for_size (data, j));
      fprintf (dump_file, "\n");
    }
}

/* Returns true if A is a cheaper cost pair than B.  */

static bool
cheaper_cost_pair (struct cost_pair *a, struct cost_pair *b)
{
  int cmp;

  if (!a)
    return false;

  if (!b)
    return true;

  cmp = compare_costs (a->cost, b->cost);
  if (cmp < 0)
    return true;

  if (cmp > 0)
    return false;

  /* In case the costs are the same, prefer the cheaper candidate.  */
  if (a->cand->cost < b->cand->cost)
    return true;

  return false;
}


/* Returns candidate by that USE is expressed in IVS.  */

static struct cost_pair *
iv_ca_cand_for_use (struct iv_ca *ivs, struct iv_use *use)
{
  return ivs->cand_for_use[use->id];
}

/* Computes the cost field of IVS structure.  */

static void
iv_ca_recount_cost (struct ivopts_data *data, struct iv_ca *ivs)
{
  comp_cost cost = ivs->cand_use_cost;

  cost.cost += ivs->cand_cost;

  cost.cost += ivopts_global_cost_for_size (data,
                                            ivs->n_regs + ivs->num_used_inv_expr);

  ivs->cost = cost;
}

/* Remove invariants in set INVS to set IVS.  */

static void
iv_ca_set_remove_invariants (struct iv_ca *ivs, bitmap invs)
{
  bitmap_iterator bi;
  unsigned iid;

  if (!invs)
    return;

  EXECUTE_IF_SET_IN_BITMAP (invs, 0, iid, bi)
    {
      ivs->n_invariant_uses[iid]--;
      if (ivs->n_invariant_uses[iid] == 0)
        ivs->n_regs--;
    }
}

/* Set USE not to be expressed by any candidate in IVS.  */

static void
iv_ca_set_no_cp (struct ivopts_data *data, struct iv_ca *ivs,
		 struct iv_use *use)
{
  unsigned uid = use->id, cid;
  struct cost_pair *cp;

  cp = ivs->cand_for_use[uid];
  if (!cp)
    return;
  cid = cp->cand->id;

  ivs->bad_uses++;
  ivs->cand_for_use[uid] = NULL;
  ivs->n_cand_uses[cid]--;

  if (ivs->n_cand_uses[cid] == 0)
    {
      bitmap_clear_bit (ivs->cands, cid);
      /* Do not count the pseudocandidates.  */
      if (cp->cand->iv)
	ivs->n_regs--;
      ivs->n_cands--;
      ivs->cand_cost -= cp->cand->cost;

      iv_ca_set_remove_invariants (ivs, cp->cand->depends_on);
    }

  ivs->cand_use_cost = sub_costs (ivs->cand_use_cost, cp->cost);

  iv_ca_set_remove_invariants (ivs, cp->depends_on);

  if (cp->inv_expr_id != -1)
    {
      ivs->used_inv_expr[cp->inv_expr_id]--;
      if (ivs->used_inv_expr[cp->inv_expr_id] == 0)
        ivs->num_used_inv_expr--;
    }
  iv_ca_recount_cost (data, ivs);
}

/* Add invariants in set INVS to set IVS.  */

static void
iv_ca_set_add_invariants (struct iv_ca *ivs, bitmap invs)
{
  bitmap_iterator bi;
  unsigned iid;

  if (!invs)
    return;

  EXECUTE_IF_SET_IN_BITMAP (invs, 0, iid, bi)
    {
      ivs->n_invariant_uses[iid]++;
      if (ivs->n_invariant_uses[iid] == 1)
        ivs->n_regs++;
    }
}

/* Set cost pair for USE in set IVS to CP.  */

static void
iv_ca_set_cp (struct ivopts_data *data, struct iv_ca *ivs,
	      struct iv_use *use, struct cost_pair *cp)
{
  unsigned uid = use->id, cid;

  if (ivs->cand_for_use[uid] == cp)
    return;

  if (ivs->cand_for_use[uid])
    iv_ca_set_no_cp (data, ivs, use);

  if (cp)
    {
      cid = cp->cand->id;

      ivs->bad_uses--;
      ivs->cand_for_use[uid] = cp;
      ivs->n_cand_uses[cid]++;
      if (ivs->n_cand_uses[cid] == 1)
	{
	  bitmap_set_bit (ivs->cands, cid);
	  /* Do not count the pseudocandidates.  */
	  if (cp->cand->iv)
	    ivs->n_regs++;
	  ivs->n_cands++;
	  ivs->cand_cost += cp->cand->cost;

	  iv_ca_set_add_invariants (ivs, cp->cand->depends_on);
	}

      ivs->cand_use_cost = add_costs (ivs->cand_use_cost, cp->cost);
      iv_ca_set_add_invariants (ivs, cp->depends_on);

      if (cp->inv_expr_id != -1)
        {
          ivs->used_inv_expr[cp->inv_expr_id]++;
          if (ivs->used_inv_expr[cp->inv_expr_id] == 1)
            ivs->num_used_inv_expr++;
        }
      iv_ca_recount_cost (data, ivs);
    }
}

/* Extend set IVS by expressing USE by some of the candidates in it
   if possible. All important candidates will be considered
   if IMPORTANT_CANDIDATES is true.  */

static void
iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs,
	       struct iv_use *use, bool important_candidates)
{
  struct cost_pair *best_cp = NULL, *cp;
  bitmap_iterator bi;
  bitmap cands;
  unsigned i;

  gcc_assert (ivs->upto >= use->id);

  if (ivs->upto == use->id)
    {
      ivs->upto++;
      ivs->bad_uses++;
    }

  cands = (important_candidates ? data->important_candidates : ivs->cands);
  EXECUTE_IF_SET_IN_BITMAP (cands, 0, i, bi)
    {
      struct iv_cand *cand = iv_cand (data, i);

      cp = get_use_iv_cost (data, use, cand);

      if (cheaper_cost_pair (cp, best_cp))
	best_cp = cp;
    }

  iv_ca_set_cp (data, ivs, use, best_cp);
}

/* Get cost for assignment IVS.  */

static comp_cost
iv_ca_cost (struct iv_ca *ivs)
{
  /* This was a conditional expression but it triggered a bug in
     Sun C 5.5.  */
  if (ivs->bad_uses)
    return infinite_cost;
  else
    return ivs->cost;
}

/* Returns true if all dependences of CP are among invariants in IVS.  */

static bool
iv_ca_has_deps (struct iv_ca *ivs, struct cost_pair *cp)
{
  unsigned i;
  bitmap_iterator bi;

  if (!cp->depends_on)
    return true;

  EXECUTE_IF_SET_IN_BITMAP (cp->depends_on, 0, i, bi)
    {
      if (ivs->n_invariant_uses[i] == 0)
	return false;
    }

  return true;
}

/* Creates change of expressing USE by NEW_CP instead of OLD_CP and chains
   it before NEXT_CHANGE.  */

static struct iv_ca_delta *
iv_ca_delta_add (struct iv_use *use, struct cost_pair *old_cp,
		 struct cost_pair *new_cp, struct iv_ca_delta *next_change)
{
  struct iv_ca_delta *change = XNEW (struct iv_ca_delta);

  change->use = use;
  change->old_cp = old_cp;
  change->new_cp = new_cp;
  change->next_change = next_change;

  return change;
}

/* Joins two lists of changes L1 and L2.  Destructive -- old lists
   are rewritten.  */

static struct iv_ca_delta *
iv_ca_delta_join (struct iv_ca_delta *l1, struct iv_ca_delta *l2)
{
  struct iv_ca_delta *last;

  if (!l2)
    return l1;

  if (!l1)
    return l2;

  for (last = l1; last->next_change; last = last->next_change)
    continue;
  last->next_change = l2;

  return l1;
}

/* Reverse the list of changes DELTA, forming the inverse to it.  */

static struct iv_ca_delta *
iv_ca_delta_reverse (struct iv_ca_delta *delta)
{
  struct iv_ca_delta *act, *next, *prev = NULL;
  struct cost_pair *tmp;

  for (act = delta; act; act = next)
    {
      next = act->next_change;
      act->next_change = prev;
      prev = act;

      tmp = act->old_cp;
      act->old_cp = act->new_cp;
      act->new_cp = tmp;
    }

  return prev;
}

/* Commit changes in DELTA to IVS.  If FORWARD is false, the changes are
   reverted instead.  */

static void
iv_ca_delta_commit (struct ivopts_data *data, struct iv_ca *ivs,
		    struct iv_ca_delta *delta, bool forward)
{
  struct cost_pair *from, *to;
  struct iv_ca_delta *act;

  if (!forward)
    delta = iv_ca_delta_reverse (delta);

  for (act = delta; act; act = act->next_change)
    {
      from = act->old_cp;
      to = act->new_cp;
      gcc_assert (iv_ca_cand_for_use (ivs, act->use) == from);
      iv_ca_set_cp (data, ivs, act->use, to);
    }

  if (!forward)
    iv_ca_delta_reverse (delta);
}

/* Returns true if CAND is used in IVS.  */

static bool
iv_ca_cand_used_p (struct iv_ca *ivs, struct iv_cand *cand)
{
  return ivs->n_cand_uses[cand->id] > 0;
}

/* Returns number of induction variable candidates in the set IVS.  */

static unsigned
iv_ca_n_cands (struct iv_ca *ivs)
{
  return ivs->n_cands;
}

/* Free the list of changes DELTA.  */

static void
iv_ca_delta_free (struct iv_ca_delta **delta)
{
  struct iv_ca_delta *act, *next;

  for (act = *delta; act; act = next)
    {
      next = act->next_change;
      free (act);
    }

  *delta = NULL;
}

/* Allocates new iv candidates assignment.  */

static struct iv_ca *
iv_ca_new (struct ivopts_data *data)
{
  struct iv_ca *nw = XNEW (struct iv_ca);

  nw->upto = 0;
  nw->bad_uses = 0;
  nw->cand_for_use = XCNEWVEC (struct cost_pair *, n_iv_uses (data));
  nw->n_cand_uses = XCNEWVEC (unsigned, n_iv_cands (data));
  nw->cands = BITMAP_ALLOC (NULL);
  nw->n_cands = 0;
  nw->n_regs = 0;
  nw->cand_use_cost = no_cost;
  nw->cand_cost = 0;
  nw->n_invariant_uses = XCNEWVEC (unsigned, data->max_inv_id + 1);
  nw->cost = no_cost;
  nw->used_inv_expr = XCNEWVEC (unsigned, data->inv_expr_id + 1);
  nw->num_used_inv_expr = 0;

  return nw;
}

/* Free memory occupied by the set IVS.  */

static void
iv_ca_free (struct iv_ca **ivs)
{
  free ((*ivs)->cand_for_use);
  free ((*ivs)->n_cand_uses);
  BITMAP_FREE ((*ivs)->cands);
  free ((*ivs)->n_invariant_uses);
  free ((*ivs)->used_inv_expr);
  free (*ivs);
  *ivs = NULL;
}

/* Dumps IVS to FILE.  */

static void
iv_ca_dump (struct ivopts_data *data, FILE *file, struct iv_ca *ivs)
{
  const char *pref = "  invariants ";
  unsigned i;
  comp_cost cost = iv_ca_cost (ivs);

  fprintf (file, "  cost: %d (complexity %d)\n", cost.cost, cost.complexity);
  fprintf (file, "  cand_cost: %d\n  cand_use_cost: %d (complexity %d)\n",
           ivs->cand_cost, ivs->cand_use_cost.cost, ivs->cand_use_cost.complexity);
  bitmap_print (file, ivs->cands, "  candidates: ","\n");

   for (i = 0; i < ivs->upto; i++)
    {
      struct iv_use *use = iv_use (data, i);
      struct cost_pair *cp = iv_ca_cand_for_use (ivs, use);
      if (cp)
        fprintf (file, "   use:%d --> iv_cand:%d, cost=(%d,%d)\n",
                 use->id, cp->cand->id, cp->cost.cost, cp->cost.complexity);
      else
        fprintf (file, "   use:%d --> ??\n", use->id);
    }

  for (i = 1; i <= data->max_inv_id; i++)
    if (ivs->n_invariant_uses[i])
      {
	fprintf (file, "%s%d", pref, i);
	pref = ", ";
      }
  fprintf (file, "\n\n");
}

/* Try changing candidate in IVS to CAND for each use.  Return cost of the
   new set, and store differences in DELTA.  Number of induction variables
   in the new set is stored to N_IVS. MIN_NCAND is a flag. When it is true
   the function will try to find a solution with mimimal iv candidates.  */

static comp_cost
iv_ca_extend (struct ivopts_data *data, struct iv_ca *ivs,
	      struct iv_cand *cand, struct iv_ca_delta **delta,
	      unsigned *n_ivs, bool min_ncand)
{
  unsigned i;
  comp_cost cost;
  struct iv_use *use;
  struct cost_pair *old_cp, *new_cp;

  *delta = NULL;
  for (i = 0; i < ivs->upto; i++)
    {
      use = iv_use (data, i);
      old_cp = iv_ca_cand_for_use (ivs, use);

      if (old_cp
	  && old_cp->cand == cand)
	continue;

      new_cp = get_use_iv_cost (data, use, cand);
      if (!new_cp)
	continue;

      if (!min_ncand && !iv_ca_has_deps (ivs, new_cp))
	continue;

      if (!min_ncand && !cheaper_cost_pair (new_cp, old_cp))
        continue;

      *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta);
    }

  iv_ca_delta_commit (data, ivs, *delta, true);
  cost = iv_ca_cost (ivs);
  if (n_ivs)
    *n_ivs = iv_ca_n_cands (ivs);
  iv_ca_delta_commit (data, ivs, *delta, false);

  return cost;
}

/* Try narrowing set IVS by removing CAND.  Return the cost of
   the new set and store the differences in DELTA.  START is
   the candidate with which we start narrowing.  */

static comp_cost
iv_ca_narrow (struct ivopts_data *data, struct iv_ca *ivs,
	      struct iv_cand *cand, struct iv_cand *start,
	      struct iv_ca_delta **delta)
{
  unsigned i, ci;
  struct iv_use *use;
  struct cost_pair *old_cp, *new_cp, *cp;
  bitmap_iterator bi;
  struct iv_cand *cnd;
  comp_cost cost, best_cost, acost;

  *delta = NULL;
  for (i = 0; i < n_iv_uses (data); i++)
    {
      use = iv_use (data, i);

      old_cp = iv_ca_cand_for_use (ivs, use);
      if (old_cp->cand != cand)
	continue;

      best_cost = iv_ca_cost (ivs);
      /* Start narrowing with START.  */
      new_cp = get_use_iv_cost (data, use, start);

      if (data->consider_all_candidates)
	{
	  EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, ci, bi)
	    {
	      if (ci == cand->id || (start && ci == start->id))
		continue;

	      cnd = iv_cand (data, ci);

	      cp = get_use_iv_cost (data, use, cnd);
	      if (!cp)
		continue;

	      iv_ca_set_cp (data, ivs, use, cp);
	      acost = iv_ca_cost (ivs);

	      if (compare_costs (acost, best_cost) < 0)
		{
		  best_cost = acost;
		  new_cp = cp;
		}
	    }
	}
      else
	{
	  EXECUTE_IF_AND_IN_BITMAP (use->related_cands, ivs->cands, 0, ci, bi)
	    {
	      if (ci == cand->id || (start && ci == start->id))
		continue;

	      cnd = iv_cand (data, ci);

	      cp = get_use_iv_cost (data, use, cnd);
	      if (!cp)
		continue;

	      iv_ca_set_cp (data, ivs, use, cp);
	      acost = iv_ca_cost (ivs);

	      if (compare_costs (acost, best_cost) < 0)
		{
		  best_cost = acost;
		  new_cp = cp;
		}
	    }
	}
      /* Restore to old cp for use.  */
      iv_ca_set_cp (data, ivs, use, old_cp);

      if (!new_cp)
	{
	  iv_ca_delta_free (delta);
	  return infinite_cost;
	}

      *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta);
    }

  iv_ca_delta_commit (data, ivs, *delta, true);
  cost = iv_ca_cost (ivs);
  iv_ca_delta_commit (data, ivs, *delta, false);

  return cost;
}

/* Try optimizing the set of candidates IVS by removing candidates different
   from to EXCEPT_CAND from it.  Return cost of the new set, and store
   differences in DELTA.  */

static comp_cost
iv_ca_prune (struct ivopts_data *data, struct iv_ca *ivs,
	     struct iv_cand *except_cand, struct iv_ca_delta **delta)
{
  bitmap_iterator bi;
  struct iv_ca_delta *act_delta, *best_delta;
  unsigned i;
  comp_cost best_cost, acost;
  struct iv_cand *cand;

  best_delta = NULL;
  best_cost = iv_ca_cost (ivs);

  EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi)
    {
      cand = iv_cand (data, i);

      if (cand == except_cand)
	continue;

      acost = iv_ca_narrow (data, ivs, cand, except_cand, &act_delta);

      if (compare_costs (acost, best_cost) < 0)
	{
	  best_cost = acost;
	  iv_ca_delta_free (&best_delta);
	  best_delta = act_delta;
	}
      else
	iv_ca_delta_free (&act_delta);
    }

  if (!best_delta)
    {
      *delta = NULL;
      return best_cost;
    }

  /* Recurse to possibly remove other unnecessary ivs.  */
  iv_ca_delta_commit (data, ivs, best_delta, true);
  best_cost = iv_ca_prune (data, ivs, except_cand, delta);
  iv_ca_delta_commit (data, ivs, best_delta, false);
  *delta = iv_ca_delta_join (best_delta, *delta);
  return best_cost;
}

/* Check if CAND_IDX is a candidate other than OLD_CAND and has
   cheaper local cost for USE than BEST_CP.  Return pointer to
   the corresponding cost_pair, otherwise just return BEST_CP.  */

static struct cost_pair*
cheaper_cost_with_cand (struct ivopts_data *data, struct iv_use *use,
			unsigned int cand_idx, struct iv_cand *old_cand,
			struct cost_pair *best_cp)
{
  struct iv_cand *cand;
  struct cost_pair *cp;

  gcc_assert (old_cand != NULL && best_cp != NULL);
  if (cand_idx == old_cand->id)
    return best_cp;

  cand = iv_cand (data, cand_idx);
  cp = get_use_iv_cost (data, use, cand);
  if (cp != NULL && cheaper_cost_pair (cp, best_cp))
    return cp;

  return best_cp;
}

/* Try breaking local optimal fixed-point for IVS by replacing candidates
   which are used by more than one iv uses.  For each of those candidates,
   this function tries to represent iv uses under that candidate using
   other ones with lower local cost, then tries to prune the new set.
   If the new set has lower cost, It returns the new cost after recording
   candidate replacement in list DELTA.  */

static comp_cost
iv_ca_replace (struct ivopts_data *data, struct iv_ca *ivs,
	       struct iv_ca_delta **delta)
{
  bitmap_iterator bi, bj;
  unsigned int i, j, k;
  struct iv_use *use;
  struct iv_cand *cand;
  comp_cost orig_cost, acost;
  struct iv_ca_delta *act_delta, *tmp_delta;
  struct cost_pair *old_cp, *best_cp = NULL;

  *delta = NULL;
  orig_cost = iv_ca_cost (ivs);

  EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi)
    {
      if (ivs->n_cand_uses[i] == 1
	  || ivs->n_cand_uses[i] > ALWAYS_PRUNE_CAND_SET_BOUND)
	continue;

      cand = iv_cand (data, i);
  
      act_delta = NULL;
      /*  Represent uses under current candidate using other ones with
	  lower local cost.  */
      for (j = 0; j < ivs->upto; j++)
	{
	  use = iv_use (data, j);
	  old_cp = iv_ca_cand_for_use (ivs, use);

	  if (old_cp->cand != cand)
	    continue;

	  best_cp = old_cp;
	  if (data->consider_all_candidates)
	    for (k = 0; k < n_iv_cands (data); k++)
	      best_cp = cheaper_cost_with_cand (data, use, k,
						old_cp->cand, best_cp);
	  else
	    EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, k, bj)
	      best_cp = cheaper_cost_with_cand (data, use, k,
						old_cp->cand, best_cp);

	  if (best_cp == old_cp)
	    continue;

	  act_delta = iv_ca_delta_add (use, old_cp, best_cp, act_delta);
	}
      /* No need for further prune.  */
      if (!act_delta)
	continue;

      /* Prune the new candidate set.  */
      iv_ca_delta_commit (data, ivs, act_delta, true);
      acost = iv_ca_prune (data, ivs, NULL, &tmp_delta);
      iv_ca_delta_commit (data, ivs, act_delta, false);
      act_delta = iv_ca_delta_join (act_delta, tmp_delta);

      if (compare_costs (acost, orig_cost) < 0)
	{
	  *delta = act_delta;
	  return acost;
	}
      else
	iv_ca_delta_free (&act_delta);
    }

  return orig_cost;
}

/* Tries to extend the sets IVS in the best possible way in order
   to express the USE.  If ORIGINALP is true, prefer candidates from
   the original set of IVs, otherwise favor important candidates not
   based on any memory object.  */

static bool
try_add_cand_for (struct ivopts_data *data, struct iv_ca *ivs,
		  struct iv_use *use, bool originalp)
{
  comp_cost best_cost, act_cost;
  unsigned i;
  bitmap_iterator bi;
  struct iv_cand *cand;
  struct iv_ca_delta *best_delta = NULL, *act_delta;
  struct cost_pair *cp;

  iv_ca_add_use (data, ivs, use, false);
  best_cost = iv_ca_cost (ivs);

  cp = iv_ca_cand_for_use (ivs, use);
  if (!cp)
    {
      ivs->upto--;
      ivs->bad_uses--;
      iv_ca_add_use (data, ivs, use, true);
      best_cost = iv_ca_cost (ivs);
      cp = iv_ca_cand_for_use (ivs, use);
    }
  if (cp)
    {
      best_delta = iv_ca_delta_add (use, NULL, cp, NULL);
      iv_ca_set_no_cp (data, ivs, use);
    }

  /* If ORIGINALP is true, try to find the original IV for the use.  Otherwise
     first try important candidates not based on any memory object.  Only if
     this fails, try the specific ones.  Rationale -- in loops with many
     variables the best choice often is to use just one generic biv.  If we
     added here many ivs specific to the uses, the optimization algorithm later
     would be likely to get stuck in a local minimum, thus causing us to create
     too many ivs.  The approach from few ivs to more seems more likely to be
     successful -- starting from few ivs, replacing an expensive use by a
     specific iv should always be a win.  */
  EXECUTE_IF_SET_IN_BITMAP (data->important_candidates, 0, i, bi)
    {
      cand = iv_cand (data, i);

      if (originalp && cand->pos !=IP_ORIGINAL)
	continue;

      if (!originalp && cand->iv->base_object != NULL_TREE)
	continue;

      if (iv_ca_cand_used_p (ivs, cand))
        continue;

      cp = get_use_iv_cost (data, use, cand);
      if (!cp)
	continue;

      iv_ca_set_cp (data, ivs, use, cp);
      act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL,
                               true);
      iv_ca_set_no_cp (data, ivs, use);
      act_delta = iv_ca_delta_add (use, NULL, cp, act_delta);

      if (compare_costs (act_cost, best_cost) < 0)
	{
	  best_cost = act_cost;

	  iv_ca_delta_free (&best_delta);
	  best_delta = act_delta;
	}
      else
	iv_ca_delta_free (&act_delta);
    }

  if (infinite_cost_p (best_cost))
    {
      for (i = 0; i < use->n_map_members; i++)
	{
	  cp = use->cost_map + i;
	  cand = cp->cand;
	  if (!cand)
	    continue;

	  /* Already tried this.  */
	  if (cand->important)
	    {
	      if (originalp && cand->pos == IP_ORIGINAL)
		continue;
	      if (!originalp && cand->iv->base_object == NULL_TREE)
		continue;
	    }

	  if (iv_ca_cand_used_p (ivs, cand))
	    continue;

	  act_delta = NULL;
	  iv_ca_set_cp (data, ivs, use, cp);
	  act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL, true);
	  iv_ca_set_no_cp (data, ivs, use);
	  act_delta = iv_ca_delta_add (use, iv_ca_cand_for_use (ivs, use),
				       cp, act_delta);

	  if (compare_costs (act_cost, best_cost) < 0)
	    {
	      best_cost = act_cost;

	      if (best_delta)
		iv_ca_delta_free (&best_delta);
	      best_delta = act_delta;
	    }
	  else
	    iv_ca_delta_free (&act_delta);
	}
    }

  iv_ca_delta_commit (data, ivs, best_delta, true);
  iv_ca_delta_free (&best_delta);

  return !infinite_cost_p (best_cost);
}

/* Finds an initial assignment of candidates to uses.  */

static struct iv_ca *
get_initial_solution (struct ivopts_data *data, bool originalp)
{
  struct iv_ca *ivs = iv_ca_new (data);
  unsigned i;

  for (i = 0; i < n_iv_uses (data); i++)
    if (!try_add_cand_for (data, ivs, iv_use (data, i), originalp))
      {
	iv_ca_free (&ivs);
	return NULL;
      }

  return ivs;
}

/* Tries to improve set of induction variables IVS.  TRY_REPLACE_P
   points to a bool variable, this function tries to break local
   optimal fixed-point by replacing candidates in IVS if it's true.  */

static bool
try_improve_iv_set (struct ivopts_data *data,
		    struct iv_ca *ivs, bool *try_replace_p)
{
  unsigned i, n_ivs;
  comp_cost acost, best_cost = iv_ca_cost (ivs);
  struct iv_ca_delta *best_delta = NULL, *act_delta, *tmp_delta;
  struct iv_cand *cand;

  /* Try extending the set of induction variables by one.  */
  for (i = 0; i < n_iv_cands (data); i++)
    {
      cand = iv_cand (data, i);

      if (iv_ca_cand_used_p (ivs, cand))
	continue;

      acost = iv_ca_extend (data, ivs, cand, &act_delta, &n_ivs, false);
      if (!act_delta)
	continue;

      /* If we successfully added the candidate and the set is small enough,
	 try optimizing it by removing other candidates.  */
      if (n_ivs <= ALWAYS_PRUNE_CAND_SET_BOUND)
      	{
	  iv_ca_delta_commit (data, ivs, act_delta, true);
	  acost = iv_ca_prune (data, ivs, cand, &tmp_delta);
	  iv_ca_delta_commit (data, ivs, act_delta, false);
	  act_delta = iv_ca_delta_join (act_delta, tmp_delta);
	}

      if (compare_costs (acost, best_cost) < 0)
	{
	  best_cost = acost;
	  iv_ca_delta_free (&best_delta);
	  best_delta = act_delta;
	}
      else
	iv_ca_delta_free (&act_delta);
    }

  if (!best_delta)
    {
      /* Try removing the candidates from the set instead.  */
      best_cost = iv_ca_prune (data, ivs, NULL, &best_delta);

      if (!best_delta && *try_replace_p)
	{
	  *try_replace_p = false;
	  /* So far candidate selecting algorithm tends to choose fewer IVs
	     so that it can handle cases in which loops have many variables
	     but the best choice is often to use only one general biv.  One
	     weakness is it can't handle opposite cases, in which different
	     candidates should be chosen with respect to each use.  To solve
	     the problem, we replace candidates in a manner described by the
	     comments of iv_ca_replace, thus give general algorithm a chance
	     to break local optimal fixed-point in these cases.  */
	  best_cost = iv_ca_replace (data, ivs, &best_delta);
	}

      if (!best_delta)
	return false;
    }

  iv_ca_delta_commit (data, ivs, best_delta, true);
  gcc_assert (compare_costs (best_cost, iv_ca_cost (ivs)) == 0);
  iv_ca_delta_free (&best_delta);
  return true;
}

/* Attempts to find the optimal set of induction variables.  We do simple
   greedy heuristic -- we try to replace at most one candidate in the selected
   solution and remove the unused ivs while this improves the cost.  */

static struct iv_ca *
find_optimal_iv_set_1 (struct ivopts_data *data, bool originalp)
{
  struct iv_ca *set;
  bool try_replace_p = true;

  /* Get the initial solution.  */
  set = get_initial_solution (data, originalp);
  if (!set)
    {
      if (dump_file && (dump_flags & TDF_DETAILS))
	fprintf (dump_file, "Unable to substitute for ivs, failed.\n");
      return NULL;
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Initial set of candidates:\n");
      iv_ca_dump (data, dump_file, set);
    }

  while (try_improve_iv_set (data, set, &try_replace_p))
    {
      if (dump_file && (dump_flags & TDF_DETAILS))
	{
	  fprintf (dump_file, "Improved to:\n");
	  iv_ca_dump (data, dump_file, set);
	}
    }

  return set;
}

static struct iv_ca *
find_optimal_iv_set (struct ivopts_data *data)
{
  unsigned i;
  struct iv_ca *set, *origset;
  struct iv_use *use;
  comp_cost cost, origcost;

  /* Determine the cost based on a strategy that starts with original IVs,
     and try again using a strategy that prefers candidates not based
     on any IVs.  */
  origset = find_optimal_iv_set_1 (data, true);
  set = find_optimal_iv_set_1 (data, false);

  if (!origset && !set)
    return NULL;

  origcost = origset ? iv_ca_cost (origset) : infinite_cost;
  cost = set ? iv_ca_cost (set) : infinite_cost;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Original cost %d (complexity %d)\n\n",
	       origcost.cost, origcost.complexity);
      fprintf (dump_file, "Final cost %d (complexity %d)\n\n",
	       cost.cost, cost.complexity);
    }

  /* Choose the one with the best cost.  */
  if (compare_costs (origcost, cost) <= 0)
    {
      if (set)
	iv_ca_free (&set);
      set = origset;
    }
  else if (origset)
    iv_ca_free (&origset);

  for (i = 0; i < n_iv_uses (data); i++)
    {
      use = iv_use (data, i);
      use->selected = iv_ca_cand_for_use (set, use)->cand;
    }

  return set;
}

/* Creates a new induction variable corresponding to CAND.  */

static void
create_new_iv (struct ivopts_data *data, struct iv_cand *cand)
{
  gimple_stmt_iterator incr_pos;
  tree base;
  bool after = false;

  if (!cand->iv)
    return;

  switch (cand->pos)
    {
    case IP_NORMAL:
      incr_pos = gsi_last_bb (ip_normal_pos (data->current_loop));
      break;

    case IP_END:
      incr_pos = gsi_last_bb (ip_end_pos (data->current_loop));
      after = true;
      break;

    case IP_AFTER_USE:
      after = true;
      /* fall through */
    case IP_BEFORE_USE:
      incr_pos = gsi_for_stmt (cand->incremented_at);
      break;

    case IP_ORIGINAL:
      /* Mark that the iv is preserved.  */
      name_info (data, cand->var_before)->preserve_biv = true;
      name_info (data, cand->var_after)->preserve_biv = true;

      /* Rewrite the increment so that it uses var_before directly.  */
      find_interesting_uses_op (data, cand->var_after)->selected = cand;
      return;
    }

  gimple_add_tmp_var (cand->var_before);

  base = unshare_expr (cand->iv->base);

  create_iv (base, unshare_expr (cand->iv->step),
	     cand->var_before, data->current_loop,
	     &incr_pos, after, &cand->var_before, &cand->var_after);
}

/* Creates new induction variables described in SET.  */

static void
create_new_ivs (struct ivopts_data *data, struct iv_ca *set)
{
  unsigned i;
  struct iv_cand *cand;
  bitmap_iterator bi;

  EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi)
    {
      cand = iv_cand (data, i);
      create_new_iv (data, cand);
    }

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "\nSelected IV set: \n");
      EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi)
        {
          cand = iv_cand (data, i);
          dump_cand (dump_file, cand);
        }
      fprintf (dump_file, "\n");
    }
}

/* Rewrites USE (definition of iv used in a nonlinear expression)
   using candidate CAND.  */

static void
rewrite_use_nonlinear_expr (struct ivopts_data *data,
			    struct iv_use *use, struct iv_cand *cand)
{
  tree comp;
  tree op, tgt;
  gimple ass;
  gimple_stmt_iterator bsi;

  /* An important special case -- if we are asked to express value of
     the original iv by itself, just exit; there is no need to
     introduce a new computation (that might also need casting the
     variable to unsigned and back).  */
  if (cand->pos == IP_ORIGINAL
      && cand->incremented_at == use->stmt)
    {
      enum tree_code stmt_code;

      gcc_assert (is_gimple_assign (use->stmt));
      gcc_assert (gimple_assign_lhs (use->stmt) == cand->var_after);

      /* Check whether we may leave the computation unchanged.
	 This is the case only if it does not rely on other
	 computations in the loop -- otherwise, the computation
	 we rely upon may be removed in remove_unused_ivs,
	 thus leading to ICE.  */
      stmt_code = gimple_assign_rhs_code (use->stmt);
      if (stmt_code == PLUS_EXPR
	  || stmt_code == MINUS_EXPR
	  || stmt_code == POINTER_PLUS_EXPR)
	{
	  if (gimple_assign_rhs1 (use->stmt) == cand->var_before)
	    op = gimple_assign_rhs2 (use->stmt);
	  else if (gimple_assign_rhs2 (use->stmt) == cand->var_before)
	    op = gimple_assign_rhs1 (use->stmt);
	  else
	    op = NULL_TREE;
	}
      else
	op = NULL_TREE;

      if (op && expr_invariant_in_loop_p (data->current_loop, op))
	return;
    }

  comp = get_computation (data->current_loop, use, cand);
  gcc_assert (comp != NULL_TREE);

  switch (gimple_code (use->stmt))
    {
    case GIMPLE_PHI:
      tgt = PHI_RESULT (use->stmt);

      /* If we should keep the biv, do not replace it.  */
      if (name_info (data, tgt)->preserve_biv)
	return;

      bsi = gsi_after_labels (gimple_bb (use->stmt));
      break;

    case GIMPLE_ASSIGN:
      tgt = gimple_assign_lhs (use->stmt);
      bsi = gsi_for_stmt (use->stmt);
      break;

    default:
      gcc_unreachable ();
    }

  if (!valid_gimple_rhs_p (comp)
      || (gimple_code (use->stmt) != GIMPLE_PHI
	  /* We can't allow re-allocating the stmt as it might be pointed
	     to still.  */
	  && (get_gimple_rhs_num_ops (TREE_CODE (comp))
	      >= gimple_num_ops (gsi_stmt (bsi)))))
    {
      comp = force_gimple_operand_gsi (&bsi, comp, true, NULL_TREE,
				       true, GSI_SAME_STMT);
      if (POINTER_TYPE_P (TREE_TYPE (tgt)))
	{
	  duplicate_ssa_name_ptr_info (comp, SSA_NAME_PTR_INFO (tgt));
	  /* As this isn't a plain copy we have to reset alignment
	     information.  */
	  if (SSA_NAME_PTR_INFO (comp))
	    mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (comp));
	}
    }

  if (gimple_code (use->stmt) == GIMPLE_PHI)
    {
      ass = gimple_build_assign (tgt, comp);
      gsi_insert_before (&bsi, ass, GSI_SAME_STMT);

      bsi = gsi_for_stmt (use->stmt);
      remove_phi_node (&bsi, false);
    }
  else
    {
      gimple_assign_set_rhs_from_tree (&bsi, comp);
      use->stmt = gsi_stmt (bsi);
    }
}

/* Performs a peephole optimization to reorder the iv update statement with
   a mem ref to enable instruction combining in later phases. The mem ref uses
   the iv value before the update, so the reordering transformation requires
   adjustment of the offset. CAND is the selected IV_CAND.

   Example:

   t = MEM_REF (base, iv1, 8, 16);  // base, index, stride, offset
   iv2 = iv1 + 1;

   if (t < val)      (1)
     goto L;
   goto Head;


   directly propagating t over to (1) will introduce overlapping live range
   thus increase register pressure. This peephole transform it into:


   iv2 = iv1 + 1;
   t = MEM_REF (base, iv2, 8, 8);
   if (t < val)
     goto L;
   goto Head;
*/

static void
adjust_iv_update_pos (struct iv_cand *cand, struct iv_use *use)
{
  tree var_after;
  gimple iv_update, stmt;
  basic_block bb;
  gimple_stmt_iterator gsi, gsi_iv;

  if (cand->pos != IP_NORMAL)
    return;

  var_after = cand->var_after;
  iv_update = SSA_NAME_DEF_STMT (var_after);

  bb = gimple_bb (iv_update);
  gsi = gsi_last_nondebug_bb (bb);
  stmt = gsi_stmt (gsi);

  /* Only handle conditional statement for now.  */
  if (gimple_code (stmt) != GIMPLE_COND)
    return;

  gsi_prev_nondebug (&gsi);
  stmt = gsi_stmt (gsi);
  if (stmt != iv_update)
    return;

  gsi_prev_nondebug (&gsi);
  if (gsi_end_p (gsi))
    return;

  stmt = gsi_stmt (gsi);
  if (gimple_code (stmt) != GIMPLE_ASSIGN)
    return;

  if (stmt != use->stmt)
    return;

  if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
    return;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Reordering \n");
      print_gimple_stmt (dump_file, iv_update, 0, 0);
      print_gimple_stmt (dump_file, use->stmt, 0, 0);
      fprintf (dump_file, "\n");
    }

  gsi = gsi_for_stmt (use->stmt);
  gsi_iv = gsi_for_stmt (iv_update);
  gsi_move_before (&gsi_iv, &gsi);

  cand->pos = IP_BEFORE_USE;
  cand->incremented_at = use->stmt;
}

/* Rewrites USE (address that is an iv) using candidate CAND.  */

static void
rewrite_use_address (struct ivopts_data *data,
		     struct iv_use *use, struct iv_cand *cand)
{
  aff_tree aff;
  gimple_stmt_iterator bsi = gsi_for_stmt (use->stmt);
  tree base_hint = NULL_TREE;
  tree ref, iv;
  bool ok;

  adjust_iv_update_pos (cand, use);
  ok = get_computation_aff (data->current_loop, use, cand, use->stmt, &aff);
  gcc_assert (ok);
  unshare_aff_combination (&aff);

  /* To avoid undefined overflow problems, all IV candidates use unsigned
     integer types.  The drawback is that this makes it impossible for
     create_mem_ref to distinguish an IV that is based on a memory object
     from one that represents simply an offset.

     To work around this problem, we pass a hint to create_mem_ref that
     indicates which variable (if any) in aff is an IV based on a memory
     object.  Note that we only consider the candidate.  If this is not
     based on an object, the base of the reference is in some subexpression
     of the use -- but these will use pointer types, so they are recognized
     by the create_mem_ref heuristics anyway.  */
  if (cand->iv->base_object)
    base_hint = var_at_stmt (data->current_loop, cand, use->stmt);

  iv = var_at_stmt (data->current_loop, cand, use->stmt);
  ref = create_mem_ref (&bsi, TREE_TYPE (*use->op_p), &aff,
			reference_alias_ptr_type (*use->op_p),
			iv, base_hint, data->speed);
  copy_ref_info (ref, *use->op_p);
  *use->op_p = ref;
}

/* Rewrites USE (the condition such that one of the arguments is an iv) using
   candidate CAND.  */

static void
rewrite_use_compare (struct ivopts_data *data,
		     struct iv_use *use, struct iv_cand *cand)
{
  tree comp, *var_p, op, bound;
  gimple_stmt_iterator bsi = gsi_for_stmt (use->stmt);
  enum tree_code compare;
  struct cost_pair *cp = get_use_iv_cost (data, use, cand);
  bool ok;

  bound = cp->value;
  if (bound)
    {
      tree var = var_at_stmt (data->current_loop, cand, use->stmt);
      tree var_type = TREE_TYPE (var);
      gimple_seq stmts;

      if (dump_file && (dump_flags & TDF_DETAILS))
        {
          fprintf (dump_file, "Replacing exit test: ");
          print_gimple_stmt (dump_file, use->stmt, 0, TDF_SLIM);
        }
      compare = cp->comp;
      bound = unshare_expr (fold_convert (var_type, bound));
      op = force_gimple_operand (bound, &stmts, true, NULL_TREE);
      if (stmts)
	gsi_insert_seq_on_edge_immediate (
		loop_preheader_edge (data->current_loop),
		stmts);

      gimple_cond_set_lhs (use->stmt, var);
      gimple_cond_set_code (use->stmt, compare);
      gimple_cond_set_rhs (use->stmt, op);
      return;
    }

  /* The induction variable elimination failed; just express the original
     giv.  */
  comp = get_computation (data->current_loop, use, cand);
  gcc_assert (comp != NULL_TREE);

  ok = extract_cond_operands (data, use->stmt, &var_p, NULL, NULL, NULL);
  gcc_assert (ok);

  *var_p = force_gimple_operand_gsi (&bsi, comp, true, SSA_NAME_VAR (*var_p),
				     true, GSI_SAME_STMT);
}

/* Rewrites USE using candidate CAND.  */

static void
rewrite_use (struct ivopts_data *data, struct iv_use *use, struct iv_cand *cand)
{
  switch (use->type)
    {
      case USE_NONLINEAR_EXPR:
	rewrite_use_nonlinear_expr (data, use, cand);
	break;

      case USE_ADDRESS:
	rewrite_use_address (data, use, cand);
	break;

      case USE_COMPARE:
	rewrite_use_compare (data, use, cand);
	break;

      default:
	gcc_unreachable ();
    }

  update_stmt (use->stmt);
}

/* Rewrite the uses using the selected induction variables.  */

static void
rewrite_uses (struct ivopts_data *data)
{
  unsigned i;
  struct iv_cand *cand;
  struct iv_use *use;

  for (i = 0; i < n_iv_uses (data); i++)
    {
      use = iv_use (data, i);
      cand = use->selected;
      gcc_assert (cand);

      rewrite_use (data, use, cand);
    }
}

/* Removes the ivs that are not used after rewriting.  */

static void
remove_unused_ivs (struct ivopts_data *data)
{
  unsigned j;
  bitmap_iterator bi;
  bitmap toremove = BITMAP_ALLOC (NULL);

  /* Figure out an order in which to release SSA DEFs so that we don't
     release something that we'd have to propagate into a debug stmt
     afterwards.  */
  EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
    {
      struct version_info *info;

      info = ver_info (data, j);
      if (info->iv
	  && !integer_zerop (info->iv->step)
	  && !info->inv_id
	  && !info->iv->have_use_for
	  && !info->preserve_biv)
	{
	  bitmap_set_bit (toremove, SSA_NAME_VERSION (info->iv->ssa_name));
	  
	  tree def = info->iv->ssa_name;

	  if (MAY_HAVE_DEBUG_STMTS && SSA_NAME_DEF_STMT (def))
	    {
	      imm_use_iterator imm_iter;
	      use_operand_p use_p;
	      gimple stmt;
	      int count = 0;

	      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, def)
		{
		  if (!gimple_debug_bind_p (stmt))
		    continue;

		  /* We just want to determine whether to do nothing
		     (count == 0), to substitute the computed
		     expression into a single use of the SSA DEF by
		     itself (count == 1), or to use a debug temp
		     because the SSA DEF is used multiple times or as
		     part of a larger expression (count > 1). */
		  count++;
		  if (gimple_debug_bind_get_value (stmt) != def)
		    count++;

		  if (count > 1)
		    BREAK_FROM_IMM_USE_STMT (imm_iter);
		}

	      if (!count)
		continue;

	      struct iv_use dummy_use;
	      struct iv_cand *best_cand = NULL, *cand;
	      unsigned i, best_pref = 0, cand_pref;

	      memset (&dummy_use, 0, sizeof (dummy_use));
	      dummy_use.iv = info->iv;
	      for (i = 0; i < n_iv_uses (data) && i < 64; i++)
		{
		  cand = iv_use (data, i)->selected;
		  if (cand == best_cand)
		    continue;
		  cand_pref = operand_equal_p (cand->iv->step,
					       info->iv->step, 0)
		    ? 4 : 0;
		  cand_pref
		    += TYPE_MODE (TREE_TYPE (cand->iv->base))
		    == TYPE_MODE (TREE_TYPE (info->iv->base))
		    ? 2 : 0;
		  cand_pref
		    += TREE_CODE (cand->iv->base) == INTEGER_CST
		    ? 1 : 0;
		  if (best_cand == NULL || best_pref < cand_pref)
		    {
		      best_cand = cand;
		      best_pref = cand_pref;
		    }
		}

	      if (!best_cand)
		continue;

	      tree comp = get_computation_at (data->current_loop,
					      &dummy_use, best_cand,
					      SSA_NAME_DEF_STMT (def));
	      if (!comp)
		continue;

	      if (count > 1)
		{
		  tree vexpr = make_node (DEBUG_EXPR_DECL);
		  DECL_ARTIFICIAL (vexpr) = 1;
		  TREE_TYPE (vexpr) = TREE_TYPE (comp);
		  if (SSA_NAME_VAR (def))
		    DECL_MODE (vexpr) = DECL_MODE (SSA_NAME_VAR (def));
		  else
		    DECL_MODE (vexpr) = TYPE_MODE (TREE_TYPE (vexpr));
		  gimple def_temp = gimple_build_debug_bind (vexpr, comp, NULL);
		  gimple_stmt_iterator gsi;

		  if (gimple_code (SSA_NAME_DEF_STMT (def)) == GIMPLE_PHI)
		    gsi = gsi_after_labels (gimple_bb
					    (SSA_NAME_DEF_STMT (def)));
		  else
		    gsi = gsi_for_stmt (SSA_NAME_DEF_STMT (def));

		  gsi_insert_before (&gsi, def_temp, GSI_SAME_STMT);
		  comp = vexpr;
		}

	      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, def)
		{
		  if (!gimple_debug_bind_p (stmt))
		    continue;

		  FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
		    SET_USE (use_p, comp);

		  update_stmt (stmt);
		}
	    }
	}
    }

  release_defs_bitset (toremove);

  BITMAP_FREE (toremove);
}

/* Frees memory occupied by struct tree_niter_desc in *VALUE. Callback
   for pointer_map_traverse.  */

static bool
free_tree_niter_desc (const void *key ATTRIBUTE_UNUSED, void **value,
                      void *data ATTRIBUTE_UNUSED)
{
  struct tree_niter_desc *const niter = (struct tree_niter_desc *) *value;

  free (niter);
  return true;
}

/* Frees data allocated by the optimization of a single loop.  */

static void
free_loop_data (struct ivopts_data *data)
{
  unsigned i, j;
  bitmap_iterator bi;
  tree obj;

  if (data->niters)
    {
      pointer_map_traverse (data->niters, free_tree_niter_desc, NULL);
      pointer_map_destroy (data->niters);
      data->niters = NULL;
    }

  EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
    {
      struct version_info *info;

      info = ver_info (data, i);
      free (info->iv);
      info->iv = NULL;
      info->has_nonlin_use = false;
      info->preserve_biv = false;
      info->inv_id = 0;
    }
  bitmap_clear (data->relevant);
  bitmap_clear (data->important_candidates);

  for (i = 0; i < n_iv_uses (data); i++)
    {
      struct iv_use *use = iv_use (data, i);

      free (use->iv);
      BITMAP_FREE (use->related_cands);
      for (j = 0; j < use->n_map_members; j++)
	if (use->cost_map[j].depends_on)
	  BITMAP_FREE (use->cost_map[j].depends_on);
      free (use->cost_map);
      free (use);
    }
  data->iv_uses.truncate (0);

  for (i = 0; i < n_iv_cands (data); i++)
    {
      struct iv_cand *cand = iv_cand (data, i);

      free (cand->iv);
      if (cand->depends_on)
	BITMAP_FREE (cand->depends_on);
      free (cand);
    }
  data->iv_candidates.truncate (0);

  if (data->version_info_size < num_ssa_names)
    {
      data->version_info_size = 2 * num_ssa_names;
      free (data->version_info);
      data->version_info = XCNEWVEC (struct version_info, data->version_info_size);
    }

  data->max_inv_id = 0;

  FOR_EACH_VEC_ELT (decl_rtl_to_reset, i, obj)
    SET_DECL_RTL (obj, NULL_RTX);

  decl_rtl_to_reset.truncate (0);

  data->inv_expr_tab.empty ();
  data->inv_expr_id = 0;
}

/* Finalizes data structures used by the iv optimization pass.  LOOPS is the
   loop tree.  */

static void
tree_ssa_iv_optimize_finalize (struct ivopts_data *data)
{
  free_loop_data (data);
  free (data->version_info);
  BITMAP_FREE (data->relevant);
  BITMAP_FREE (data->important_candidates);

  decl_rtl_to_reset.release ();
  data->iv_uses.release ();
  data->iv_candidates.release ();
  data->inv_expr_tab.dispose ();
}

/* Returns true if the loop body BODY includes any function calls.  */

static bool
loop_body_includes_call (basic_block *body, unsigned num_nodes)
{
  gimple_stmt_iterator gsi;
  unsigned i;

  for (i = 0; i < num_nodes; i++)
    for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
      {
	gimple stmt = gsi_stmt (gsi);
	if (is_gimple_call (stmt)
	    && !is_inexpensive_builtin (gimple_call_fndecl (stmt)))
	  return true;
      }
  return false;
}

/* Optimizes the LOOP.  Returns true if anything changed.  */

static bool
tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop)
{
  bool changed = false;
  struct iv_ca *iv_ca;
  edge exit = single_dom_exit (loop);
  basic_block *body;

  gcc_assert (!data->niters);
  data->current_loop = loop;
  data->speed = optimize_loop_for_speed_p (loop);

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file, "Processing loop %d\n", loop->num);

      if (exit)
	{
	  fprintf (dump_file, "  single exit %d -> %d, exit condition ",
		   exit->src->index, exit->dest->index);
	  print_gimple_stmt (dump_file, last_stmt (exit->src), 0, TDF_SLIM);
	  fprintf (dump_file, "\n");
	}

      fprintf (dump_file, "\n");
    }

  body = get_loop_body (loop);
  data->body_includes_call = loop_body_includes_call (body, loop->num_nodes);
  renumber_gimple_stmt_uids_in_blocks (body, loop->num_nodes);
  free (body);

  data->loop_single_exit_p = exit != NULL && loop_only_exit_p (loop, exit);

  /* For each ssa name determines whether it behaves as an induction variable
     in some loop.  */
  if (!find_induction_variables (data))
    goto finish;

  /* Finds interesting uses (item 1).  */
  find_interesting_uses (data);
  if (n_iv_uses (data) > MAX_CONSIDERED_USES)
    goto finish;

  /* Finds candidates for the induction variables (item 2).  */
  find_iv_candidates (data);

  /* Calculates the costs (item 3, part 1).  */
  determine_iv_costs (data);
  determine_use_iv_costs (data);
  determine_set_costs (data);

  /* Find the optimal set of induction variables (item 3, part 2).  */
  iv_ca = find_optimal_iv_set (data);
  if (!iv_ca)
    goto finish;
  changed = true;

  /* Create the new induction variables (item 4, part 1).  */
  create_new_ivs (data, iv_ca);
  iv_ca_free (&iv_ca);

  /* Rewrite the uses (item 4, part 2).  */
  rewrite_uses (data);

  /* Remove the ivs that are unused after rewriting.  */
  remove_unused_ivs (data);

  /* We have changed the structure of induction variables; it might happen
     that definitions in the scev database refer to some of them that were
     eliminated.  */
  scev_reset ();

finish:
  free_loop_data (data);

  return changed;
}

/* Main entry point.  Optimizes induction variables in loops.  */

void
tree_ssa_iv_optimize (void)
{
  struct loop *loop;
  struct ivopts_data data;

  tree_ssa_iv_optimize_init (&data);

  /* Optimize the loops starting with the innermost ones.  */
  FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
    {
      if (dump_file && (dump_flags & TDF_DETAILS))
	flow_loop_dump (loop, dump_file, NULL, 1);

      tree_ssa_iv_optimize_loop (&data, loop);
    }

  tree_ssa_iv_optimize_finalize (&data);
}