aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/cfgrtl.c
blob: ed1c37cd4bdb44ff5e487c3cffdcf6c8834b28a1 (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
/* Control flow graph manipulation code for GNU compiler.
   Copyright (C) 1987-2014 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 file contains low level functions to manipulate the CFG and analyze it
   that are aware of the RTL intermediate language.

   Available functionality:
     - Basic CFG/RTL manipulation API documented in cfghooks.h
     - CFG-aware instruction chain manipulation
	 delete_insn, delete_insn_chain
     - Edge splitting and committing to edges
	 insert_insn_on_edge, commit_edge_insertions
     - CFG updating after insn simplification
	 purge_dead_edges, purge_all_dead_edges
     - CFG fixing after coarse manipulation
	fixup_abnormal_edges

   Functions not supposed for generic use:
     - Infrastructure to determine quickly basic block for insn
	 compute_bb_for_insn, update_bb_for_insn, set_block_for_insn,
     - Edge redirection with updating and optimizing of insn chain
	 block_label, tidy_fallthru_edge, force_nonfallthru  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "bb-reorder.h"
#include "regs.h"
#include "flags.h"
#include "function.h"
#include "except.h"
#include "rtl-error.h"
#include "tm_p.h"
#include "obstack.h"
#include "insn-attr.h"
#include "insn-config.h"
#include "expr.h"
#include "target.h"
#include "common/common-target.h"
#include "cfgloop.h"
#include "ggc.h"
#include "tree-pass.h"
#include "df.h"

/* Holds the interesting leading and trailing notes for the function.
   Only applicable if the CFG is in cfglayout mode.  */
static GTY(()) rtx cfg_layout_function_footer;
static GTY(()) rtx cfg_layout_function_header;

static rtx skip_insns_after_block (basic_block);
static void record_effective_endpoints (void);
static rtx label_for_bb (basic_block);
static void fixup_reorder_chain (void);

void verify_insn_chain (void);
static void fixup_fallthru_exit_predecessor (void);
static int can_delete_note_p (const_rtx);
static int can_delete_label_p (const_rtx);
static basic_block rtl_split_edge (edge);
static bool rtl_move_block_after (basic_block, basic_block);
static int rtl_verify_flow_info (void);
static basic_block cfg_layout_split_block (basic_block, void *);
static edge cfg_layout_redirect_edge_and_branch (edge, basic_block);
static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block);
static void cfg_layout_delete_block (basic_block);
static void rtl_delete_block (basic_block);
static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block);
static edge rtl_redirect_edge_and_branch (edge, basic_block);
static basic_block rtl_split_block (basic_block, void *);
static void rtl_dump_bb (FILE *, basic_block, int, int);
static int rtl_verify_flow_info_1 (void);
static void rtl_make_forwarder_block (edge);

/* Return true if NOTE is not one of the ones that must be kept paired,
   so that we may simply delete it.  */

static int
can_delete_note_p (const_rtx note)
{
  switch (NOTE_KIND (note))
    {
    case NOTE_INSN_DELETED:
    case NOTE_INSN_BASIC_BLOCK:
    case NOTE_INSN_EPILOGUE_BEG:
      return true;

    default:
      return false;
    }
}

/* True if a given label can be deleted.  */

static int
can_delete_label_p (const_rtx label)
{
  return (!LABEL_PRESERVE_P (label)
	  /* User declared labels must be preserved.  */
	  && LABEL_NAME (label) == 0
	  && !in_expr_list_p (forced_labels, label));
}

/* Delete INSN by patching it out.  */

void
delete_insn (rtx insn)
{
  rtx note;
  bool really_delete = true;

  if (LABEL_P (insn))
    {
      /* Some labels can't be directly removed from the INSN chain, as they
	 might be references via variables, constant pool etc.
	 Convert them to the special NOTE_INSN_DELETED_LABEL note.  */
      if (! can_delete_label_p (insn))
	{
	  const char *name = LABEL_NAME (insn);
	  basic_block bb = BLOCK_FOR_INSN (insn);
	  rtx bb_note = NEXT_INSN (insn);

	  really_delete = false;
	  PUT_CODE (insn, NOTE);
	  NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL;
	  NOTE_DELETED_LABEL_NAME (insn) = name;

	  /* If the note following the label starts a basic block, and the
	     label is a member of the same basic block, interchange the two.  */
	  if (bb_note != NULL_RTX
	      && NOTE_INSN_BASIC_BLOCK_P (bb_note)
	      && bb != NULL
	      && bb == BLOCK_FOR_INSN (bb_note))
	    {
	      reorder_insns_nobb (insn, insn, bb_note);
	      BB_HEAD (bb) = bb_note;
	      if (BB_END (bb) == bb_note)
		BB_END (bb) = insn;
	    }
	}

      remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels);
    }

  if (really_delete)
    {
      /* If this insn has already been deleted, something is very wrong.  */
      gcc_assert (!INSN_DELETED_P (insn));
      if (INSN_P (insn))
	df_insn_delete (insn);
      remove_insn (insn);
      INSN_DELETED_P (insn) = 1;
    }

  /* If deleting a jump, decrement the use count of the label.  Deleting
     the label itself should happen in the normal course of block merging.  */
  if (JUMP_P (insn))
    {
      if (JUMP_LABEL (insn)
	  && LABEL_P (JUMP_LABEL (insn)))
	LABEL_NUSES (JUMP_LABEL (insn))--;

      /* If there are more targets, remove them too.  */
      while ((note
	      = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX
	     && LABEL_P (XEXP (note, 0)))
	{
	  LABEL_NUSES (XEXP (note, 0))--;
	  remove_note (insn, note);
	}
    }

  /* Also if deleting any insn that references a label as an operand.  */
  while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX
	 && LABEL_P (XEXP (note, 0)))
    {
      LABEL_NUSES (XEXP (note, 0))--;
      remove_note (insn, note);
    }

  if (JUMP_TABLE_DATA_P (insn))
    {
      rtx pat = PATTERN (insn);
      int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC;
      int len = XVECLEN (pat, diff_vec_p);
      int i;

      for (i = 0; i < len; i++)
	{
	  rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0);

	  /* When deleting code in bulk (e.g. removing many unreachable
	     blocks) we can delete a label that's a target of the vector
	     before deleting the vector itself.  */
	  if (!NOTE_P (label))
	    LABEL_NUSES (label)--;
	}
    }
}

/* Like delete_insn but also purge dead edges from BB.  */

void
delete_insn_and_edges (rtx insn)
{
  bool purge = false;

  if (INSN_P (insn)
      && BLOCK_FOR_INSN (insn)
      && BB_END (BLOCK_FOR_INSN (insn)) == insn)
    purge = true;
  delete_insn (insn);
  if (purge)
    purge_dead_edges (BLOCK_FOR_INSN (insn));
}

/* Unlink a chain of insns between START and FINISH, leaving notes
   that must be paired.  If CLEAR_BB is true, we set bb field for
   insns that cannot be removed to NULL.  */

void
delete_insn_chain (rtx start, rtx finish, bool clear_bb)
{
  rtx prev, current;

  /* Unchain the insns one by one.  It would be quicker to delete all of these
     with a single unchaining, rather than one at a time, but we need to keep
     the NOTE's.  */
  current = finish;
  while (1)
    {
      prev = PREV_INSN (current);
      if (NOTE_P (current) && !can_delete_note_p (current))
	;
      else
	delete_insn (current);

      if (clear_bb && !INSN_DELETED_P (current))
	set_block_for_insn (current, NULL);

      if (current == start)
	break;
      current = prev;
    }
}

/* Create a new basic block consisting of the instructions between HEAD and END
   inclusive.  This function is designed to allow fast BB construction - reuses
   the note and basic block struct in BB_NOTE, if any and do not grow
   BASIC_BLOCK chain and should be used directly only by CFG construction code.
   END can be NULL in to create new empty basic block before HEAD.  Both END
   and HEAD can be NULL to create basic block at the end of INSN chain.
   AFTER is the basic block we should be put after.  */

basic_block
create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after)
{
  basic_block bb;

  if (bb_note
      && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL
      && bb->aux == NULL)
    {
      /* If we found an existing note, thread it back onto the chain.  */

      rtx after;

      if (LABEL_P (head))
	after = head;
      else
	{
	  after = PREV_INSN (head);
	  head = bb_note;
	}

      if (after != bb_note && NEXT_INSN (after) != bb_note)
	reorder_insns_nobb (bb_note, bb_note, after);
    }
  else
    {
      /* Otherwise we must create a note and a basic block structure.  */

      bb = alloc_block ();

      init_rtl_bb_info (bb);
      if (!head && !end)
	head = end = bb_note
	  = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ());
      else if (LABEL_P (head) && end)
	{
	  bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head);
	  if (head == end)
	    end = bb_note;
	}
      else
	{
	  bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head);
	  head = bb_note;
	  if (!end)
	    end = head;
	}

      NOTE_BASIC_BLOCK (bb_note) = bb;
    }

  /* Always include the bb note in the block.  */
  if (NEXT_INSN (end) == bb_note)
    end = bb_note;

  BB_HEAD (bb) = head;
  BB_END (bb) = end;
  bb->index = last_basic_block_for_fn (cfun)++;
  bb->flags = BB_NEW | BB_RTL;
  link_block (bb, after);
  SET_BASIC_BLOCK_FOR_FN (cfun, bb->index, bb);
  df_bb_refs_record (bb->index, false);
  update_bb_for_insn (bb);
  BB_SET_PARTITION (bb, BB_UNPARTITIONED);

  /* Tag the block so that we know it has been used when considering
     other basic block notes.  */
  bb->aux = bb;

  return bb;
}

/* Create new basic block consisting of instructions in between HEAD and END
   and place it to the BB chain after block AFTER.  END can be NULL to
   create a new empty basic block before HEAD.  Both END and HEAD can be
   NULL to create basic block at the end of INSN chain.  */

static basic_block
rtl_create_basic_block (void *headp, void *endp, basic_block after)
{
  rtx head = (rtx) headp, end = (rtx) endp;
  basic_block bb;

  /* Grow the basic block array if needed.  */
  if ((size_t) last_basic_block_for_fn (cfun)
      >= basic_block_info_for_fn (cfun)->length ())
    {
      size_t new_size =
	(last_basic_block_for_fn (cfun)
	 + (last_basic_block_for_fn (cfun) + 3) / 4);
      vec_safe_grow_cleared (basic_block_info_for_fn (cfun), new_size);
    }

  n_basic_blocks_for_fn (cfun)++;

  bb = create_basic_block_structure (head, end, NULL, after);
  bb->aux = NULL;
  return bb;
}

static basic_block
cfg_layout_create_basic_block (void *head, void *end, basic_block after)
{
  basic_block newbb = rtl_create_basic_block (head, end, after);

  return newbb;
}

/* Delete the insns in a (non-live) block.  We physically delete every
   non-deleted-note insn, and update the flow graph appropriately.

   Return nonzero if we deleted an exception handler.  */

/* ??? Preserving all such notes strikes me as wrong.  It would be nice
   to post-process the stream to remove empty blocks, loops, ranges, etc.  */

static void
rtl_delete_block (basic_block b)
{
  rtx insn, end;

  /* If the head of this block is a CODE_LABEL, then it might be the
     label for an exception handler which can't be reached.  We need
     to remove the label from the exception_handler_label list.  */
  insn = BB_HEAD (b);

  end = get_last_bb_insn (b);

  /* Selectively delete the entire chain.  */
  BB_HEAD (b) = NULL;
  delete_insn_chain (insn, end, true);


  if (dump_file)
    fprintf (dump_file, "deleting block %d\n", b->index);
  df_bb_delete (b->index);
}

/* Records the basic block struct in BLOCK_FOR_INSN for every insn.  */

void
compute_bb_for_insn (void)
{
  basic_block bb;

  FOR_EACH_BB_FN (bb, cfun)
    {
      rtx end = BB_END (bb);
      rtx insn;

      for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
	{
	  BLOCK_FOR_INSN (insn) = bb;
	  if (insn == end)
	    break;
	}
    }
}

/* Release the basic_block_for_insn array.  */

unsigned int
free_bb_for_insn (void)
{
  rtx insn;
  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
    if (!BARRIER_P (insn))
      BLOCK_FOR_INSN (insn) = NULL;
  return 0;
}

static unsigned int
rest_of_pass_free_cfg (void)
{
#ifdef DELAY_SLOTS
  /* The resource.c machinery uses DF but the CFG isn't guaranteed to be
     valid at that point so it would be too late to call df_analyze.  */
  if (optimize > 0 && flag_delayed_branch)
    {
      df_note_add_problem ();
      df_analyze ();
    }
#endif

  if (crtl->has_bb_partition)
    insert_section_boundary_note ();

  free_bb_for_insn ();
  return 0;
}

namespace {

const pass_data pass_data_free_cfg =
{
  RTL_PASS, /* type */
  "*free_cfg", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  false, /* has_gate */
  true, /* has_execute */
  TV_NONE, /* tv_id */
  0, /* properties_required */
  0, /* properties_provided */
  PROP_cfg, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_free_cfg : public rtl_opt_pass
{
public:
  pass_free_cfg (gcc::context *ctxt)
    : rtl_opt_pass (pass_data_free_cfg, ctxt)
  {}

  /* opt_pass methods: */
  unsigned int execute () { return rest_of_pass_free_cfg (); }

}; // class pass_free_cfg

} // anon namespace

rtl_opt_pass *
make_pass_free_cfg (gcc::context *ctxt)
{
  return new pass_free_cfg (ctxt);
}

/* Return RTX to emit after when we want to emit code on the entry of function.  */
rtx
entry_of_function (void)
{
  return (n_basic_blocks_for_fn (cfun) > NUM_FIXED_BLOCKS ?
	  BB_HEAD (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) : get_insns ());
}

/* Emit INSN at the entry point of the function, ensuring that it is only
   executed once per function.  */
void
emit_insn_at_entry (rtx insn)
{
  edge_iterator ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs);
  edge e = ei_safe_edge (ei);
  gcc_assert (e->flags & EDGE_FALLTHRU);

  insert_insn_on_edge (insn, e);
  commit_edge_insertions ();
}

/* Update BLOCK_FOR_INSN of insns between BEGIN and END
   (or BARRIER if found) and notify df of the bb change.
   The insn chain range is inclusive
   (i.e. both BEGIN and END will be updated. */

static void
update_bb_for_insn_chain (rtx begin, rtx end, basic_block bb)
{
  rtx insn;

  end = NEXT_INSN (end);
  for (insn = begin; insn != end; insn = NEXT_INSN (insn))
    if (!BARRIER_P (insn))
      df_insn_change_bb (insn, bb);
}

/* Update BLOCK_FOR_INSN of insns in BB to BB,
   and notify df of the change.  */

void
update_bb_for_insn (basic_block bb)
{
  update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb);
}


/* Like active_insn_p, except keep the return value clobber around
   even after reload.  */

static bool
flow_active_insn_p (const_rtx insn)
{
  if (active_insn_p (insn))
    return true;

  /* A clobber of the function return value exists for buggy
     programs that fail to return a value.  Its effect is to
     keep the return value from being live across the entire
     function.  If we allow it to be skipped, we introduce the
     possibility for register lifetime confusion.  */
  if (GET_CODE (PATTERN (insn)) == CLOBBER
      && REG_P (XEXP (PATTERN (insn), 0))
      && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))
    return true;

  return false;
}

/* Return true if the block has no effect and only forwards control flow to
   its single destination.  */

bool
contains_no_active_insn_p (const_basic_block bb)
{
  rtx insn;

  if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)
      || !single_succ_p (bb))
    return false;

  for (insn = BB_HEAD (bb); insn != BB_END (bb); insn = NEXT_INSN (insn))
    if (INSN_P (insn) && flow_active_insn_p (insn))
      return false;

  return (!INSN_P (insn)
	  || (JUMP_P (insn) && simplejump_p (insn))
	  || !flow_active_insn_p (insn));
}

/* Likewise, but protect loop latches, headers and preheaders.  */
/* FIXME: Make this a cfg hook.  */

bool
forwarder_block_p (const_basic_block bb)
{
  if (!contains_no_active_insn_p (bb))
    return false;

  /* Protect loop latches, headers and preheaders.  */
  if (current_loops)
    {
      basic_block dest;
      if (bb->loop_father->header == bb)
	return false;
      dest = EDGE_SUCC (bb, 0)->dest;
      if (dest->loop_father->header == dest)
	return false;
    }

  return true;
}

/* Return nonzero if we can reach target from src by falling through.  */
/* FIXME: Make this a cfg hook, the result is only valid in cfgrtl mode.  */

bool
can_fallthru (basic_block src, basic_block target)
{
  rtx insn = BB_END (src);
  rtx insn2;
  edge e;
  edge_iterator ei;

  if (target == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return true;
  if (src->next_bb != target)
    return false;

  /* ??? Later we may add code to move jump tables offline.  */
  if (tablejump_p (insn, NULL, NULL))
    return false;

  FOR_EACH_EDGE (e, ei, src->succs)
    if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)
	&& e->flags & EDGE_FALLTHRU)
      return false;

  insn2 = BB_HEAD (target);
  if (!active_insn_p (insn2))
    insn2 = next_active_insn (insn2);

  return next_active_insn (insn) == insn2;
}

/* Return nonzero if we could reach target from src by falling through,
   if the target was made adjacent.  If we already have a fall-through
   edge to the exit block, we can't do that.  */
static bool
could_fall_through (basic_block src, basic_block target)
{
  edge e;
  edge_iterator ei;

  if (target == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return true;
  FOR_EACH_EDGE (e, ei, src->succs)
    if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)
	&& e->flags & EDGE_FALLTHRU)
      return 0;
  return true;
}

/* Return the NOTE_INSN_BASIC_BLOCK of BB.  */
rtx
bb_note (basic_block bb)
{
  rtx note;

  note = BB_HEAD (bb);
  if (LABEL_P (note))
    note = NEXT_INSN (note);

  gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note));
  return note;
}

/* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK
   note associated with the BLOCK.  */

static rtx
first_insn_after_basic_block_note (basic_block block)
{
  rtx insn;

  /* Get the first instruction in the block.  */
  insn = BB_HEAD (block);

  if (insn == NULL_RTX)
    return NULL_RTX;
  if (LABEL_P (insn))
    insn = NEXT_INSN (insn);
  gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn));

  return NEXT_INSN (insn);
}

/* Creates a new basic block just after basic block B by splitting
   everything after specified instruction I.  */

static basic_block
rtl_split_block (basic_block bb, void *insnp)
{
  basic_block new_bb;
  rtx insn = (rtx) insnp;
  edge e;
  edge_iterator ei;

  if (!insn)
    {
      insn = first_insn_after_basic_block_note (bb);

      if (insn)
	{
	  rtx next = insn;

	  insn = PREV_INSN (insn);

	  /* If the block contains only debug insns, insn would have
	     been NULL in a non-debug compilation, and then we'd end
	     up emitting a DELETED note.  For -fcompare-debug
	     stability, emit the note too.  */
	  if (insn != BB_END (bb)
	      && DEBUG_INSN_P (next)
	      && DEBUG_INSN_P (BB_END (bb)))
	    {
	      while (next != BB_END (bb) && DEBUG_INSN_P (next))
		next = NEXT_INSN (next);

	      if (next == BB_END (bb))
		emit_note_after (NOTE_INSN_DELETED, next);
	    }
	}
      else
	insn = get_last_insn ();
    }

  /* We probably should check type of the insn so that we do not create
     inconsistent cfg.  It is checked in verify_flow_info anyway, so do not
     bother.  */
  if (insn == BB_END (bb))
    emit_note_after (NOTE_INSN_DELETED, insn);

  /* Create the new basic block.  */
  new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb);
  BB_COPY_PARTITION (new_bb, bb);
  BB_END (bb) = insn;

  /* Redirect the outgoing edges.  */
  new_bb->succs = bb->succs;
  bb->succs = NULL;
  FOR_EACH_EDGE (e, ei, new_bb->succs)
    e->src = new_bb;

  /* The new block starts off being dirty.  */
  df_set_bb_dirty (bb);
  return new_bb;
}

/* Return true if the single edge between blocks A and B is the only place
   in RTL which holds some unique locus.  */

static bool
unique_locus_on_edge_between_p (basic_block a, basic_block b)
{
  const location_t goto_locus = EDGE_SUCC (a, 0)->goto_locus;
  rtx insn, end;

  if (LOCATION_LOCUS (goto_locus) == UNKNOWN_LOCATION)
    return false;

  /* First scan block A backward.  */
  insn = BB_END (a);
  end = PREV_INSN (BB_HEAD (a));
  while (insn != end && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn)))
    insn = PREV_INSN (insn);

  if (insn != end && INSN_LOCATION (insn) == goto_locus)
    return false;

  /* Then scan block B forward.  */
  insn = BB_HEAD (b);
  if (insn)
    {
      end = NEXT_INSN (BB_END (b));
      while (insn != end && !NONDEBUG_INSN_P (insn))
	insn = NEXT_INSN (insn);

      if (insn != end && INSN_HAS_LOCATION (insn)
	  && INSN_LOCATION (insn) == goto_locus)
	return false;
    }

  return true;
}

/* If the single edge between blocks A and B is the only place in RTL which
   holds some unique locus, emit a nop with that locus between the blocks.  */

static void
emit_nop_for_unique_locus_between (basic_block a, basic_block b)
{
  if (!unique_locus_on_edge_between_p (a, b))
    return;

  BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a);
  INSN_LOCATION (BB_END (a)) = EDGE_SUCC (a, 0)->goto_locus;
}

/* Blocks A and B are to be merged into a single block A.  The insns
   are already contiguous.  */

static void
rtl_merge_blocks (basic_block a, basic_block b)
{
  rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a);
  rtx del_first = NULL_RTX, del_last = NULL_RTX;
  rtx b_debug_start = b_end, b_debug_end = b_end;
  bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0;
  int b_empty = 0;

  if (dump_file)
    fprintf (dump_file, "Merging block %d into block %d...\n", b->index,
	     a->index);

  while (DEBUG_INSN_P (b_end))
    b_end = PREV_INSN (b_debug_start = b_end);

  /* If there was a CODE_LABEL beginning B, delete it.  */
  if (LABEL_P (b_head))
    {
      /* Detect basic blocks with nothing but a label.  This can happen
	 in particular at the end of a function.  */
      if (b_head == b_end)
	b_empty = 1;

      del_first = del_last = b_head;
      b_head = NEXT_INSN (b_head);
    }

  /* Delete the basic block note and handle blocks containing just that
     note.  */
  if (NOTE_INSN_BASIC_BLOCK_P (b_head))
    {
      if (b_head == b_end)
	b_empty = 1;
      if (! del_last)
	del_first = b_head;

      del_last = b_head;
      b_head = NEXT_INSN (b_head);
    }

  /* If there was a jump out of A, delete it.  */
  if (JUMP_P (a_end))
    {
      rtx prev;

      for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev))
	if (!NOTE_P (prev)
	    || NOTE_INSN_BASIC_BLOCK_P (prev)
	    || prev == BB_HEAD (a))
	  break;

      del_first = a_end;

#ifdef HAVE_cc0
      /* If this was a conditional jump, we need to also delete
	 the insn that set cc0.  */
      if (only_sets_cc0_p (prev))
	{
	  rtx tmp = prev;

	  prev = prev_nonnote_insn (prev);
	  if (!prev)
	    prev = BB_HEAD (a);
	  del_first = tmp;
	}
#endif

      a_end = PREV_INSN (del_first);
    }
  else if (BARRIER_P (NEXT_INSN (a_end)))
    del_first = NEXT_INSN (a_end);

  /* Delete everything marked above as well as crap that might be
     hanging out between the two blocks.  */
  BB_END (a) = a_end;
  BB_HEAD (b) = b_empty ? NULL_RTX : b_head;
  delete_insn_chain (del_first, del_last, true);

  /* When not optimizing CFG and the edge is the only place in RTL which holds
     some unique locus, emit a nop with that locus in between.  */
  if (!optimize)
    {
      emit_nop_for_unique_locus_between (a, b);
      a_end = BB_END (a);
    }

  /* Reassociate the insns of B with A.  */
  if (!b_empty)
    {
      update_bb_for_insn_chain (a_end, b_debug_end, a);

      BB_END (a) = b_debug_end;
      BB_HEAD (b) = NULL_RTX;
    }
  else if (b_end != b_debug_end)
    {
      /* Move any deleted labels and other notes between the end of A
	 and the debug insns that make up B after the debug insns,
	 bringing the debug insns into A while keeping the notes after
	 the end of A.  */
      if (NEXT_INSN (a_end) != b_debug_start)
	reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start),
			    b_debug_end);
      update_bb_for_insn_chain (b_debug_start, b_debug_end, a);
      BB_END (a) = b_debug_end;
    }

  df_bb_delete (b->index);

  /* If B was a forwarder block, propagate the locus on the edge.  */
  if (forwarder_p
      && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION)
    EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus;

  if (dump_file)
    fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index);
}


/* Return true when block A and B can be merged.  */

static bool
rtl_can_merge_blocks (basic_block a, basic_block b)
{
  /* If we are partitioning hot/cold basic blocks, we don't want to
     mess up unconditional or indirect jumps that cross between hot
     and cold sections.

     Basic block partitioning may result in some jumps that appear to
     be optimizable (or blocks that appear to be mergeable), but which really
     must be left untouched (they are required to make it safely across
     partition boundaries).  See  the comments at the top of
     bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */

  if (BB_PARTITION (a) != BB_PARTITION (b))
    return false;

  /* Protect the loop latches.  */
  if (current_loops && b->loop_father->latch == b)
    return false;

  /* There must be exactly one edge in between the blocks.  */
  return (single_succ_p (a)
	  && single_succ (a) == b
	  && single_pred_p (b)
	  && a != b
	  /* Must be simple edge.  */
	  && !(single_succ_edge (a)->flags & EDGE_COMPLEX)
	  && a->next_bb == b
	  && a != ENTRY_BLOCK_PTR_FOR_FN (cfun)
	  && b != EXIT_BLOCK_PTR_FOR_FN (cfun)
	  /* If the jump insn has side effects,
	     we can't kill the edge.  */
	  && (!JUMP_P (BB_END (a))
	      || (reload_completed
		  ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
}

/* Return the label in the head of basic block BLOCK.  Create one if it doesn't
   exist.  */

rtx
block_label (basic_block block)
{
  if (block == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return NULL_RTX;

  if (!LABEL_P (BB_HEAD (block)))
    {
      BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block));
    }

  return BB_HEAD (block);
}

/* Attempt to perform edge redirection by replacing possibly complex jump
   instruction by unconditional jump or removing jump completely.  This can
   apply only if all edges now point to the same block.  The parameters and
   return values are equivalent to redirect_edge_and_branch.  */

edge
try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout)
{
  basic_block src = e->src;
  rtx insn = BB_END (src), kill_from;
  rtx set;
  int fallthru = 0;

  /* If we are partitioning hot/cold basic blocks, we don't want to
     mess up unconditional or indirect jumps that cross between hot
     and cold sections.

     Basic block partitioning may result in some jumps that appear to
     be optimizable (or blocks that appear to be mergeable), but which really
     must be left untouched (they are required to make it safely across
     partition boundaries).  See  the comments at the top of
     bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */

  if (BB_PARTITION (src) != BB_PARTITION (target))
    return NULL;

  /* We can replace or remove a complex jump only when we have exactly
     two edges.  Also, if we have exactly one outgoing edge, we can
     redirect that.  */
  if (EDGE_COUNT (src->succs) >= 3
      /* Verify that all targets will be TARGET.  Specifically, the
	 edge that is not E must also go to TARGET.  */
      || (EDGE_COUNT (src->succs) == 2
	  && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target))
    return NULL;

  if (!onlyjump_p (insn))
    return NULL;
  if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL))
    return NULL;

  /* Avoid removing branch with side effects.  */
  set = single_set (insn);
  if (!set || side_effects_p (set))
    return NULL;

  /* In case we zap a conditional jump, we'll need to kill
     the cc0 setter too.  */
  kill_from = insn;
#ifdef HAVE_cc0
  if (reg_mentioned_p (cc0_rtx, PATTERN (insn))
      && only_sets_cc0_p (PREV_INSN (insn)))
    kill_from = PREV_INSN (insn);
#endif

  /* See if we can create the fallthru edge.  */
  if (in_cfglayout || can_fallthru (src, target))
    {
      if (dump_file)
	fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn));
      fallthru = 1;

      /* Selectively unlink whole insn chain.  */
      if (in_cfglayout)
	{
	  rtx insn = BB_FOOTER (src);

	  delete_insn_chain (kill_from, BB_END (src), false);

	  /* Remove barriers but keep jumptables.  */
	  while (insn)
	    {
	      if (BARRIER_P (insn))
		{
		  if (PREV_INSN (insn))
		    NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
		  else
		    BB_FOOTER (src) = NEXT_INSN (insn);
		  if (NEXT_INSN (insn))
		    PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
		}
	      if (LABEL_P (insn))
		break;
	      insn = NEXT_INSN (insn);
	    }
	}
      else
	delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)),
			   false);
    }

  /* If this already is simplejump, redirect it.  */
  else if (simplejump_p (insn))
    {
      if (e->dest == target)
	return NULL;
      if (dump_file)
	fprintf (dump_file, "Redirecting jump %i from %i to %i.\n",
		 INSN_UID (insn), e->dest->index, target->index);
      if (!redirect_jump (insn, block_label (target), 0))
	{
	  gcc_assert (target == EXIT_BLOCK_PTR_FOR_FN (cfun));
	  return NULL;
	}
    }

  /* Cannot do anything for target exit block.  */
  else if (target == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return NULL;

  /* Or replace possibly complicated jump insn by simple jump insn.  */
  else
    {
      rtx target_label = block_label (target);
      rtx barrier, label, table;

      emit_jump_insn_after_noloc (gen_jump (target_label), insn);
      JUMP_LABEL (BB_END (src)) = target_label;
      LABEL_NUSES (target_label)++;
      if (dump_file)
	fprintf (dump_file, "Replacing insn %i by jump %i\n",
		 INSN_UID (insn), INSN_UID (BB_END (src)));


      delete_insn_chain (kill_from, insn, false);

      /* Recognize a tablejump that we are converting to a
	 simple jump and remove its associated CODE_LABEL
	 and ADDR_VEC or ADDR_DIFF_VEC.  */
      if (tablejump_p (insn, &label, &table))
	delete_insn_chain (label, table, false);

      barrier = next_nonnote_insn (BB_END (src));
      if (!barrier || !BARRIER_P (barrier))
	emit_barrier_after (BB_END (src));
      else
	{
	  if (barrier != NEXT_INSN (BB_END (src)))
	    {
	      /* Move the jump before barrier so that the notes
		 which originally were or were created before jump table are
		 inside the basic block.  */
	      rtx new_insn = BB_END (src);

	      update_bb_for_insn_chain (NEXT_INSN (BB_END (src)),
				        PREV_INSN (barrier), src);

	      NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn);
	      PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn);

	      NEXT_INSN (new_insn) = barrier;
	      NEXT_INSN (PREV_INSN (barrier)) = new_insn;

	      PREV_INSN (new_insn) = PREV_INSN (barrier);
	      PREV_INSN (barrier) = new_insn;
	    }
	}
    }

  /* Keep only one edge out and set proper flags.  */
  if (!single_succ_p (src))
    remove_edge (e);
  gcc_assert (single_succ_p (src));

  e = single_succ_edge (src);
  if (fallthru)
    e->flags = EDGE_FALLTHRU;
  else
    e->flags = 0;

  e->probability = REG_BR_PROB_BASE;
  e->count = src->count;

  if (e->dest != target)
    redirect_edge_succ (e, target);
  return e;
}

/* Subroutine of redirect_branch_edge that tries to patch the jump
   instruction INSN so that it reaches block NEW.  Do this
   only when it originally reached block OLD.  Return true if this
   worked or the original target wasn't OLD, return false if redirection
   doesn't work.  */

static bool
patch_jump_insn (rtx insn, rtx old_label, basic_block new_bb)
{
  rtx tmp;
  /* Recognize a tablejump and adjust all matching cases.  */
  if (tablejump_p (insn, NULL, &tmp))
    {
      rtvec vec;
      int j;
      rtx new_label = block_label (new_bb);

      if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
	return false;
      if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
	vec = XVEC (PATTERN (tmp), 0);
      else
	vec = XVEC (PATTERN (tmp), 1);

      for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j)
	if (XEXP (RTVEC_ELT (vec, j), 0) == old_label)
	  {
	    RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label);
	    --LABEL_NUSES (old_label);
	    ++LABEL_NUSES (new_label);
	  }

      /* Handle casesi dispatch insns.  */
      if ((tmp = single_set (insn)) != NULL
	  && SET_DEST (tmp) == pc_rtx
	  && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
	  && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF
	  && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label)
	{
	  XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode,
						       new_label);
	  --LABEL_NUSES (old_label);
	  ++LABEL_NUSES (new_label);
	}
    }
  else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL)
    {
      int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp);
      rtx new_label, note;

      if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
	return false;
      new_label = block_label (new_bb);

      for (i = 0; i < n; ++i)
	{
	  rtx old_ref = ASM_OPERANDS_LABEL (tmp, i);
	  gcc_assert (GET_CODE (old_ref) == LABEL_REF);
	  if (XEXP (old_ref, 0) == old_label)
	    {
	      ASM_OPERANDS_LABEL (tmp, i)
		= gen_rtx_LABEL_REF (Pmode, new_label);
	      --LABEL_NUSES (old_label);
	      ++LABEL_NUSES (new_label);
	    }
	}

      if (JUMP_LABEL (insn) == old_label)
	{
	  JUMP_LABEL (insn) = new_label;
	  note = find_reg_note (insn, REG_LABEL_TARGET, new_label);
	  if (note)
	    remove_note (insn, note);
	}
      else
	{
	  note = find_reg_note (insn, REG_LABEL_TARGET, old_label);
	  if (note)
	    remove_note (insn, note);
	  if (JUMP_LABEL (insn) != new_label
	      && !find_reg_note (insn, REG_LABEL_TARGET, new_label))
	    add_reg_note (insn, REG_LABEL_TARGET, new_label);
	}
      while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label))
	     != NULL_RTX)
	XEXP (note, 0) = new_label;
    }
  else
    {
      /* ?? We may play the games with moving the named labels from
	 one basic block to the other in case only one computed_jump is
	 available.  */
      if (computed_jump_p (insn)
	  /* A return instruction can't be redirected.  */
	  || returnjump_p (insn))
	return false;

      if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label)
	{
	  /* If the insn doesn't go where we think, we're confused.  */
	  gcc_assert (JUMP_LABEL (insn) == old_label);

	  /* If the substitution doesn't succeed, die.  This can happen
	     if the back end emitted unrecognizable instructions or if
	     target is exit block on some arches.  */
	  if (!redirect_jump (insn, block_label (new_bb), 0))
	    {
	      gcc_assert (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun));
	      return false;
	    }
	}
    }
  return true;
}


/* Redirect edge representing branch of (un)conditional jump or tablejump,
   NULL on failure  */
static edge
redirect_branch_edge (edge e, basic_block target)
{
  rtx old_label = BB_HEAD (e->dest);
  basic_block src = e->src;
  rtx insn = BB_END (src);

  /* We can only redirect non-fallthru edges of jump insn.  */
  if (e->flags & EDGE_FALLTHRU)
    return NULL;
  else if (!JUMP_P (insn) && !currently_expanding_to_rtl)
    return NULL;

  if (!currently_expanding_to_rtl)
    {
      if (!patch_jump_insn (insn, old_label, target))
	return NULL;
    }
  else
    /* When expanding this BB might actually contain multiple
       jumps (i.e. not yet split by find_many_sub_basic_blocks).
       Redirect all of those that match our label.  */
    FOR_BB_INSNS (src, insn)
      if (JUMP_P (insn) && !patch_jump_insn (insn, old_label, target))
	return NULL;

  if (dump_file)
    fprintf (dump_file, "Edge %i->%i redirected to %i\n",
	     e->src->index, e->dest->index, target->index);

  if (e->dest != target)
    e = redirect_edge_succ_nodup (e, target);

  return e;
}

/* Called when edge E has been redirected to a new destination,
   in order to update the region crossing flag on the edge and
   jump.  */

static void
fixup_partition_crossing (edge e)
{
  rtx note;

  if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || e->dest
      == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return;
  /* If we redirected an existing edge, it may already be marked
     crossing, even though the new src is missing a reg crossing note.
     But make sure reg crossing note doesn't already exist before
     inserting.  */
  if (BB_PARTITION (e->src) != BB_PARTITION (e->dest))
    {
      e->flags |= EDGE_CROSSING;
      note = find_reg_note (BB_END (e->src), REG_CROSSING_JUMP, NULL_RTX);
      if (JUMP_P (BB_END (e->src))
          && !note)
        add_reg_note (BB_END (e->src), REG_CROSSING_JUMP, NULL_RTX);
    }
  else if (BB_PARTITION (e->src) == BB_PARTITION (e->dest))
    {
      e->flags &= ~EDGE_CROSSING;
      /* Remove the section crossing note from jump at end of
         src if it exists, and if no other successors are
         still crossing.  */
      note = find_reg_note (BB_END (e->src), REG_CROSSING_JUMP, NULL_RTX);
      if (note)
        {
          bool has_crossing_succ = false;
          edge e2;
          edge_iterator ei;
          FOR_EACH_EDGE (e2, ei, e->src->succs)
            {
              has_crossing_succ |= (e2->flags & EDGE_CROSSING);
              if (has_crossing_succ)
                break;
            }
          if (!has_crossing_succ)
            remove_note (BB_END (e->src), note);
        }
    }
}

/* Called when block BB has been reassigned to the cold partition,
   because it is now dominated by another cold block,
   to ensure that the region crossing attributes are updated.  */

static void
fixup_new_cold_bb (basic_block bb)
{
  edge e;
  edge_iterator ei;

  /* This is called when a hot bb is found to now be dominated
     by a cold bb and therefore needs to become cold. Therefore,
     its preds will no longer be region crossing. Any non-dominating
     preds that were previously hot would also have become cold
     in the caller for the same region. Any preds that were previously
     region-crossing will be adjusted in fixup_partition_crossing.  */
  FOR_EACH_EDGE (e, ei, bb->preds)
    {
      fixup_partition_crossing (e);
    }

  /* Possibly need to make bb's successor edges region crossing,
     or remove stale region crossing.  */
  FOR_EACH_EDGE (e, ei, bb->succs)
    {
      /* We can't have fall-through edges across partition boundaries.
         Note that force_nonfallthru will do any necessary partition
         boundary fixup by calling fixup_partition_crossing itself.  */
      if ((e->flags & EDGE_FALLTHRU)
          && BB_PARTITION (bb) != BB_PARTITION (e->dest)
	  && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
        force_nonfallthru (e);
      else
        fixup_partition_crossing (e);
    }
}

/* Attempt to change code to redirect edge E to TARGET.  Don't do that on
   expense of adding new instructions or reordering basic blocks.

   Function can be also called with edge destination equivalent to the TARGET.
   Then it should try the simplifications and do nothing if none is possible.

   Return edge representing the branch if transformation succeeded.  Return NULL
   on failure.
   We still return NULL in case E already destinated TARGET and we didn't
   managed to simplify instruction stream.  */

static edge
rtl_redirect_edge_and_branch (edge e, basic_block target)
{
  edge ret;
  basic_block src = e->src;
  basic_block dest = e->dest;

  if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
    return NULL;

  if (dest == target)
    return e;

  if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL)
    {
      df_set_bb_dirty (src);
      fixup_partition_crossing (ret);
      return ret;
    }

  ret = redirect_branch_edge (e, target);
  if (!ret)
    return NULL;

  df_set_bb_dirty (src);
  fixup_partition_crossing (ret);
  return ret;
}

/* Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode.  */

void
emit_barrier_after_bb (basic_block bb)
{
  rtx barrier = emit_barrier_after (BB_END (bb));
  gcc_assert (current_ir_type () == IR_RTL_CFGRTL
              || current_ir_type () == IR_RTL_CFGLAYOUT);
  if (current_ir_type () == IR_RTL_CFGLAYOUT)
    {
      rtx insn = unlink_insn_chain (barrier, barrier);

      if (BB_FOOTER (bb))
        { 
          rtx footer_tail = BB_FOOTER (bb);

          while (NEXT_INSN (footer_tail))
            footer_tail = NEXT_INSN (footer_tail);
          if (!BARRIER_P (footer_tail))
            {
              NEXT_INSN (footer_tail) = insn;
              PREV_INSN (insn) = footer_tail;
            }
        }
      else
        BB_FOOTER (bb) = insn;
    }
}

/* Like force_nonfallthru below, but additionally performs redirection
   Used by redirect_edge_and_branch_force.  JUMP_LABEL is used only
   when redirecting to the EXIT_BLOCK, it is either ret_rtx or
   simple_return_rtx, indicating which kind of returnjump to create.
   It should be NULL otherwise.  */

basic_block
force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label)
{
  basic_block jump_block, new_bb = NULL, src = e->src;
  rtx note;
  edge new_edge;
  int abnormal_edge_flags = 0;
  bool asm_goto_edge = false;
  int loc;

  /* In the case the last instruction is conditional jump to the next
     instruction, first redirect the jump itself and then continue
     by creating a basic block afterwards to redirect fallthru edge.  */
  if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)
      && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
      && any_condjump_p (BB_END (e->src))
      && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest))
    {
      rtx note;
      edge b = unchecked_make_edge (e->src, target, 0);
      bool redirected;

      redirected = redirect_jump (BB_END (e->src), block_label (target), 0);
      gcc_assert (redirected);

      note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX);
      if (note)
	{
	  int prob = XINT (note, 0);

	  b->probability = prob;
          /* Update this to use GCOV_COMPUTE_SCALE.  */
	  b->count = e->count * prob / REG_BR_PROB_BASE;
	  e->probability -= e->probability;
	  e->count -= b->count;
	  if (e->probability < 0)
	    e->probability = 0;
	  if (e->count < 0)
	    e->count = 0;
	}
    }

  if (e->flags & EDGE_ABNORMAL)
    {
      /* Irritating special case - fallthru edge to the same block as abnormal
	 edge.
	 We can't redirect abnormal edge, but we still can split the fallthru
	 one and create separate abnormal edge to original destination.
	 This allows bb-reorder to make such edge non-fallthru.  */
      gcc_assert (e->dest == target);
      abnormal_edge_flags = e->flags & ~EDGE_FALLTHRU;
      e->flags &= EDGE_FALLTHRU;
    }
  else
    {
      gcc_assert (e->flags & EDGE_FALLTHRU);
      if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun))
	{
	  /* We can't redirect the entry block.  Create an empty block
	     at the start of the function which we use to add the new
	     jump.  */
	  edge tmp;
	  edge_iterator ei;
	  bool found = false;

	  basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL,
					       ENTRY_BLOCK_PTR_FOR_FN (cfun));

	  /* Change the existing edge's source to be the new block, and add
	     a new edge from the entry block to the new block.  */
	  e->src = bb;
	  for (ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs);
	       (tmp = ei_safe_edge (ei)); )
	    {
	      if (tmp == e)
		{
		  ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs->unordered_remove (ei.index);
		  found = true;
		  break;
		}
	      else
		ei_next (&ei);
	    }

	  gcc_assert (found);

	  vec_safe_push (bb->succs, e);
	  make_single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb,
				 EDGE_FALLTHRU);
	}
    }

  /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs
     don't point to the target or fallthru label.  */
  if (JUMP_P (BB_END (e->src))
      && target != EXIT_BLOCK_PTR_FOR_FN (cfun)
      && (e->flags & EDGE_FALLTHRU)
      && (note = extract_asm_operands (PATTERN (BB_END (e->src)))))
    {
      int i, n = ASM_OPERANDS_LABEL_LENGTH (note);
      bool adjust_jump_target = false;

      for (i = 0; i < n; ++i)
	{
	  if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (e->dest))
	    {
	      LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))--;
	      XEXP (ASM_OPERANDS_LABEL (note, i), 0) = block_label (target);
	      LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))++;
	      adjust_jump_target = true;
	    }
	  if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (target))
	    asm_goto_edge = true;
	}
      if (adjust_jump_target)
	{
	  rtx insn = BB_END (e->src), note;
	  rtx old_label = BB_HEAD (e->dest);
	  rtx new_label = BB_HEAD (target);

	  if (JUMP_LABEL (insn) == old_label)
	    {
	      JUMP_LABEL (insn) = new_label;
	      note = find_reg_note (insn, REG_LABEL_TARGET, new_label);
	      if (note)
		remove_note (insn, note);
	    }
	  else
	    {
	      note = find_reg_note (insn, REG_LABEL_TARGET, old_label);
	      if (note)
		remove_note (insn, note);
	      if (JUMP_LABEL (insn) != new_label
		  && !find_reg_note (insn, REG_LABEL_TARGET, new_label))
		add_reg_note (insn, REG_LABEL_TARGET, new_label);
	    }
	  while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label))
		 != NULL_RTX)
	    XEXP (note, 0) = new_label;
	}
    }

  if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags || asm_goto_edge)
    {
      gcov_type count = e->count;
      int probability = e->probability;
      /* Create the new structures.  */

      /* If the old block ended with a tablejump, skip its table
	 by searching forward from there.  Otherwise start searching
	 forward from the last instruction of the old block.  */
      if (!tablejump_p (BB_END (e->src), NULL, &note))
	note = BB_END (e->src);
      note = NEXT_INSN (note);

      jump_block = create_basic_block (note, NULL, e->src);
      jump_block->count = count;
      jump_block->frequency = EDGE_FREQUENCY (e);

      /* Make sure new block ends up in correct hot/cold section.  */

      BB_COPY_PARTITION (jump_block, e->src);

      /* Wire edge in.  */
      new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU);
      new_edge->probability = probability;
      new_edge->count = count;

      /* Redirect old edge.  */
      redirect_edge_pred (e, jump_block);
      e->probability = REG_BR_PROB_BASE;

      /* If e->src was previously region crossing, it no longer is
         and the reg crossing note should be removed.  */
      fixup_partition_crossing (new_edge);

      /* If asm goto has any label refs to target's label,
	 add also edge from asm goto bb to target.  */
      if (asm_goto_edge)
	{
	  new_edge->probability /= 2;
	  new_edge->count /= 2;
	  jump_block->count /= 2;
	  jump_block->frequency /= 2;
	  new_edge = make_edge (new_edge->src, target,
				e->flags & ~EDGE_FALLTHRU);
	  new_edge->probability = probability - probability / 2;
	  new_edge->count = count - count / 2;
	}

      new_bb = jump_block;
    }
  else
    jump_block = e->src;

  loc = e->goto_locus;
  e->flags &= ~EDGE_FALLTHRU;
  if (target == EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      if (jump_label == ret_rtx)
	{
#ifdef HAVE_return
	  emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block), loc);
#else
	  gcc_unreachable ();
#endif
	}
      else
	{
	  gcc_assert (jump_label == simple_return_rtx);
#ifdef HAVE_simple_return
	  emit_jump_insn_after_setloc (gen_simple_return (),
				       BB_END (jump_block), loc);
#else
	  gcc_unreachable ();
#endif
	}
      set_return_jump_label (BB_END (jump_block));
    }
  else
    {
      rtx label = block_label (target);
      emit_jump_insn_after_setloc (gen_jump (label), BB_END (jump_block), loc);
      JUMP_LABEL (BB_END (jump_block)) = label;
      LABEL_NUSES (label)++;
    }

  /* We might be in cfg layout mode, and if so, the following routine will
     insert the barrier correctly.  */
  emit_barrier_after_bb (jump_block);
  redirect_edge_succ_nodup (e, target);

  if (abnormal_edge_flags)
    make_edge (src, target, abnormal_edge_flags);

  df_mark_solutions_dirty ();
  fixup_partition_crossing (e);
  return new_bb;
}

/* Edge E is assumed to be fallthru edge.  Emit needed jump instruction
   (and possibly create new basic block) to make edge non-fallthru.
   Return newly created BB or NULL if none.  */

static basic_block
rtl_force_nonfallthru (edge e)
{
  return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX);
}

/* Redirect edge even at the expense of creating new jump insn or
   basic block.  Return new basic block if created, NULL otherwise.
   Conversion must be possible.  */

static basic_block
rtl_redirect_edge_and_branch_force (edge e, basic_block target)
{
  if (redirect_edge_and_branch (e, target)
      || e->dest == target)
    return NULL;

  /* In case the edge redirection failed, try to force it to be non-fallthru
     and redirect newly created simplejump.  */
  df_set_bb_dirty (e->src);
  return force_nonfallthru_and_redirect (e, target, NULL_RTX);
}

/* The given edge should potentially be a fallthru edge.  If that is in
   fact true, delete the jump and barriers that are in the way.  */

static void
rtl_tidy_fallthru_edge (edge e)
{
  rtx q;
  basic_block b = e->src, c = b->next_bb;

  /* ??? In a late-running flow pass, other folks may have deleted basic
     blocks by nopping out blocks, leaving multiple BARRIERs between here
     and the target label. They ought to be chastised and fixed.

     We can also wind up with a sequence of undeletable labels between
     one block and the next.

     So search through a sequence of barriers, labels, and notes for
     the head of block C and assert that we really do fall through.  */

  for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q))
    if (INSN_P (q))
      return;

  /* Remove what will soon cease being the jump insn from the source block.
     If block B consisted only of this single jump, turn it into a deleted
     note.  */
  q = BB_END (b);
  if (JUMP_P (q)
      && onlyjump_p (q)
      && (any_uncondjump_p (q)
	  || single_succ_p (b)))
    {
      rtx label, table;

      if (tablejump_p (q, &label, &table))
	{
	  /* The label is likely mentioned in some instruction before
	     the tablejump and might not be DCEd, so turn it into
	     a note instead and move before the tablejump that is going to
	     be deleted.  */
	  const char *name = LABEL_NAME (label);
	  PUT_CODE (label, NOTE);
	  NOTE_KIND (label) = NOTE_INSN_DELETED_LABEL;
	  NOTE_DELETED_LABEL_NAME (label) = name;
	  reorder_insns (label, label, PREV_INSN (q));
	  delete_insn (table);
	}

#ifdef HAVE_cc0
      /* If this was a conditional jump, we need to also delete
	 the insn that set cc0.  */
      if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q)))
	q = PREV_INSN (q);
#endif

      q = PREV_INSN (q);
    }

  /* Selectively unlink the sequence.  */
  if (q != PREV_INSN (BB_HEAD (c)))
    delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false);

  e->flags |= EDGE_FALLTHRU;
}

/* Should move basic block BB after basic block AFTER.  NIY.  */

static bool
rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED,
		      basic_block after ATTRIBUTE_UNUSED)
{
  return false;
}

/* Locate the last bb in the same partition as START_BB.  */

static basic_block
last_bb_in_partition (basic_block start_bb)
{
  basic_block bb;
  FOR_BB_BETWEEN (bb, start_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb)
    {
      if (BB_PARTITION (start_bb) != BB_PARTITION (bb->next_bb))
        return bb;
    }
  /* Return bb before the exit block.  */
  return bb->prev_bb;
}

/* Split a (typically critical) edge.  Return the new block.
   The edge must not be abnormal.

   ??? The code generally expects to be called on critical edges.
   The case of a block ending in an unconditional jump to a
   block with multiple predecessors is not handled optimally.  */

static basic_block
rtl_split_edge (edge edge_in)
{
  basic_block bb, new_bb;
  rtx before;

  /* Abnormal edges cannot be split.  */
  gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));

  /* We are going to place the new block in front of edge destination.
     Avoid existence of fallthru predecessors.  */
  if ((edge_in->flags & EDGE_FALLTHRU) == 0)
    {
      edge e = find_fallthru_edge (edge_in->dest->preds);

      if (e)
	force_nonfallthru (e);
    }

  /* Create the basic block note.  */
  if (edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
    before = BB_HEAD (edge_in->dest);
  else
    before = NULL_RTX;

  /* If this is a fall through edge to the exit block, the blocks might be
     not adjacent, and the right place is after the source.  */
  if ((edge_in->flags & EDGE_FALLTHRU)
      && edge_in->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      before = NEXT_INSN (BB_END (edge_in->src));
      bb = create_basic_block (before, NULL, edge_in->src);
      BB_COPY_PARTITION (bb, edge_in->src);
    }
  else
    {
      if (edge_in->src == ENTRY_BLOCK_PTR_FOR_FN (cfun))
        {
          bb = create_basic_block (before, NULL, edge_in->dest->prev_bb);
          BB_COPY_PARTITION (bb, edge_in->dest);
        }
      else
        {
          basic_block after = edge_in->dest->prev_bb;
          /* If this is post-bb reordering, and the edge crosses a partition
             boundary, the new block needs to be inserted in the bb chain
             at the end of the src partition (since we put the new bb into
             that partition, see below). Otherwise we may end up creating
             an extra partition crossing in the chain, which is illegal.
             It can't go after the src, because src may have a fall-through
             to a different block.  */
          if (crtl->bb_reorder_complete
              && (edge_in->flags & EDGE_CROSSING))
            {
              after = last_bb_in_partition (edge_in->src);
              before = NEXT_INSN (BB_END (after));
              /* The instruction following the last bb in partition should
                 be a barrier, since it cannot end in a fall-through.  */
              gcc_checking_assert (BARRIER_P (before));
              before = NEXT_INSN (before);
            }
          bb = create_basic_block (before, NULL, after);
          /* Put the split bb into the src partition, to avoid creating
             a situation where a cold bb dominates a hot bb, in the case
             where src is cold and dest is hot. The src will dominate
             the new bb (whereas it might not have dominated dest).  */
          BB_COPY_PARTITION (bb, edge_in->src);
        }
    }

  make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU);

  /* Can't allow a region crossing edge to be fallthrough.  */
  if (BB_PARTITION (bb) != BB_PARTITION (edge_in->dest)
      && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      new_bb = force_nonfallthru (single_succ_edge (bb));
      gcc_assert (!new_bb);
    }

  /* For non-fallthru edges, we must adjust the predecessor's
     jump instruction to target our new block.  */
  if ((edge_in->flags & EDGE_FALLTHRU) == 0)
    {
      edge redirected = redirect_edge_and_branch (edge_in, bb);
      gcc_assert (redirected);
    }
  else
    {
      if (edge_in->src != ENTRY_BLOCK_PTR_FOR_FN (cfun))
	{
	  /* For asm goto even splitting of fallthru edge might
	     need insn patching, as other labels might point to the
	     old label.  */
	  rtx last = BB_END (edge_in->src);
	  if (last
	      && JUMP_P (last)
	      && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
	      && extract_asm_operands (PATTERN (last)) != NULL_RTX
	      && patch_jump_insn (last, before, bb))
	    df_set_bb_dirty (edge_in->src);
	}
      redirect_edge_succ (edge_in, bb);
    }

  return bb;
}

/* Queue instructions for insertion on an edge between two basic blocks.
   The new instructions and basic blocks (if any) will not appear in the
   CFG until commit_edge_insertions is called.  */

void
insert_insn_on_edge (rtx pattern, edge e)
{
  /* We cannot insert instructions on an abnormal critical edge.
     It will be easier to find the culprit if we die now.  */
  gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)));

  if (e->insns.r == NULL_RTX)
    start_sequence ();
  else
    push_to_sequence (e->insns.r);

  emit_insn (pattern);

  e->insns.r = get_insns ();
  end_sequence ();
}

/* Update the CFG for the instructions queued on edge E.  */

void
commit_one_edge_insertion (edge e)
{
  rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
  basic_block bb;

  /* Pull the insns off the edge now since the edge might go away.  */
  insns = e->insns.r;
  e->insns.r = NULL_RTX;

  /* Figure out where to put these insns.  If the destination has
     one predecessor, insert there.  Except for the exit block.  */
  if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      bb = e->dest;

      /* Get the location correct wrt a code label, and "nice" wrt
	 a basic block note, and before everything else.  */
      tmp = BB_HEAD (bb);
      if (LABEL_P (tmp))
	tmp = NEXT_INSN (tmp);
      if (NOTE_INSN_BASIC_BLOCK_P (tmp))
	tmp = NEXT_INSN (tmp);
      if (tmp == BB_HEAD (bb))
	before = tmp;
      else if (tmp)
	after = PREV_INSN (tmp);
      else
	after = get_last_insn ();
    }

  /* If the source has one successor and the edge is not abnormal,
     insert there.  Except for the entry block.
     Don't do this if the predecessor ends in a jump other than
     unconditional simple jump.  E.g. for asm goto that points all
     its labels at the fallthru basic block, we can't insert instructions
     before the asm goto, as the asm goto can have various of side effects,
     and can't emit instructions after the asm goto, as it must end
     the basic block.  */
  else if ((e->flags & EDGE_ABNORMAL) == 0
	   && single_succ_p (e->src)
	   && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)
	   && (!JUMP_P (BB_END (e->src))
	       || simplejump_p (BB_END (e->src))))
    {
      bb = e->src;

      /* It is possible to have a non-simple jump here.  Consider a target
	 where some forms of unconditional jumps clobber a register.  This
	 happens on the fr30 for example.

	 We know this block has a single successor, so we can just emit
	 the queued insns before the jump.  */
      if (JUMP_P (BB_END (bb)))
	before = BB_END (bb);
      else
	{
	  /* We'd better be fallthru, or we've lost track of what's what.  */
	  gcc_assert (e->flags & EDGE_FALLTHRU);

	  after = BB_END (bb);
	}
    }

  /* Otherwise we must split the edge.  */
  else
    {
      bb = split_edge (e);

      /* If E crossed a partition boundary, we needed to make bb end in
         a region-crossing jump, even though it was originally fallthru.  */
      if (JUMP_P (BB_END (bb)))
	before = BB_END (bb);
      else
        after = BB_END (bb);
    }

  /* Now that we've found the spot, do the insertion.  */
  if (before)
    {
      emit_insn_before_noloc (insns, before, bb);
      last = prev_nonnote_insn (before);
    }
  else
    last = emit_insn_after_noloc (insns, after, bb);

  if (returnjump_p (last))
    {
      /* ??? Remove all outgoing edges from BB and add one for EXIT.
	 This is not currently a problem because this only happens
	 for the (single) epilogue, which already has a fallthru edge
	 to EXIT.  */

      e = single_succ_edge (bb);
      gcc_assert (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)
		  && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU));

      e->flags &= ~EDGE_FALLTHRU;
      emit_barrier_after (last);

      if (before)
	delete_insn (before);
    }
  else
    gcc_assert (!JUMP_P (last));
}

/* Update the CFG for all queued instructions.  */

void
commit_edge_insertions (void)
{
  basic_block bb;

  /* Optimization passes that invoke this routine can cause hot blocks
     previously reached by both hot and cold blocks to become dominated only
     by cold blocks. This will cause the verification below to fail,
     and lead to now cold code in the hot section. In some cases this
     may only be visible after newly unreachable blocks are deleted,
     which will be done by fixup_partitions.  */
  fixup_partitions ();

#ifdef ENABLE_CHECKING
  verify_flow_info ();
#endif

  FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun),
		  EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb)
    {
      edge e;
      edge_iterator ei;

      FOR_EACH_EDGE (e, ei, bb->succs)
	if (e->insns.r)
	  commit_one_edge_insertion (e);
    }
}


/* Print out RTL-specific basic block information (live information
   at start and end with TDF_DETAILS).  FLAGS are the TDF_* masks
   documented in dumpfile.h.  */

static void
rtl_dump_bb (FILE *outf, basic_block bb, int indent, int flags)
{
  rtx insn;
  rtx last;
  char *s_indent;

  s_indent = (char *) alloca ((size_t) indent + 1);
  memset (s_indent, ' ', (size_t) indent);
  s_indent[indent] = '\0';

  if (df && (flags & TDF_DETAILS))
    {
      df_dump_top (bb, outf);
      putc ('\n', outf);
    }

  if (bb->index != ENTRY_BLOCK && bb->index != EXIT_BLOCK)
    for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last;
	 insn = NEXT_INSN (insn))
      {
	if (flags & TDF_DETAILS)
	  df_dump_insn_top (insn, outf);
	if (! (flags & TDF_SLIM))
	  print_rtl_single (outf, insn);
	else
	  dump_insn_slim (outf, insn);
	if (flags & TDF_DETAILS)
	  df_dump_insn_bottom (insn, outf);
      }

  if (df && (flags & TDF_DETAILS))
    {
      df_dump_bottom (bb, outf);
      putc ('\n', outf);
    }

}

/* Like dump_function_to_file, but for RTL.  Print out dataflow information
   for the start of each basic block.  FLAGS are the TDF_* masks documented
   in dumpfile.h.  */

void
print_rtl_with_bb (FILE *outf, const_rtx rtx_first, int flags)
{
  const_rtx tmp_rtx;
  if (rtx_first == 0)
    fprintf (outf, "(nil)\n");
  else
    {
      enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB };
      int max_uid = get_max_uid ();
      basic_block *start = XCNEWVEC (basic_block, max_uid);
      basic_block *end = XCNEWVEC (basic_block, max_uid);
      enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid);
      basic_block bb;

      /* After freeing the CFG, we still have BLOCK_FOR_INSN set on most
	 insns, but the CFG is not maintained so the basic block info
	 is not reliable.  Therefore it's omitted from the dumps.  */
      if (! (cfun->curr_properties & PROP_cfg))
        flags &= ~TDF_BLOCKS;

      if (df)
	df_dump_start (outf);

      if (flags & TDF_BLOCKS)
	{
	  FOR_EACH_BB_REVERSE_FN (bb, cfun)
	    {
	      rtx x;

	      start[INSN_UID (BB_HEAD (bb))] = bb;
	      end[INSN_UID (BB_END (bb))] = bb;
	      for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x))
		{
		  enum bb_state state = IN_MULTIPLE_BB;

		  if (in_bb_p[INSN_UID (x)] == NOT_IN_BB)
		    state = IN_ONE_BB;
		  in_bb_p[INSN_UID (x)] = state;

		  if (x == BB_END (bb))
		    break;
		}
	    }
	}

      for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx))
	{
	  if (flags & TDF_BLOCKS)
	    {
	      bb = start[INSN_UID (tmp_rtx)];
	      if (bb != NULL)
		{
		  dump_bb_info (outf, bb, 0, dump_flags | TDF_COMMENT, true, false);
		  if (df && (flags & TDF_DETAILS))
		    df_dump_top (bb, outf);
		}

	      if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB
		  && !NOTE_P (tmp_rtx)
		  && !BARRIER_P (tmp_rtx))
		fprintf (outf, ";; Insn is not within a basic block\n");
	      else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB)
		fprintf (outf, ";; Insn is in multiple basic blocks\n");
	    }

	  if (flags & TDF_DETAILS)
	    df_dump_insn_top (tmp_rtx, outf);
	  if (! (flags & TDF_SLIM))
	    print_rtl_single (outf, tmp_rtx);
	  else
	    dump_insn_slim (outf, tmp_rtx);
	  if (flags & TDF_DETAILS)
	    df_dump_insn_bottom (tmp_rtx, outf);

	  if (flags & TDF_BLOCKS)
	    {
	      bb = end[INSN_UID (tmp_rtx)];
	      if (bb != NULL)
		{
		  dump_bb_info (outf, bb, 0, dump_flags | TDF_COMMENT, false, true);
		  if (df && (flags & TDF_DETAILS))
		    df_dump_bottom (bb, outf);
		  putc ('\n', outf);
		}
	    }
	}

      free (start);
      free (end);
      free (in_bb_p);
    }
}

/* Update the branch probability of BB if a REG_BR_PROB is present.  */

void
update_br_prob_note (basic_block bb)
{
  rtx note;
  if (!JUMP_P (BB_END (bb)))
    return;
  note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX);
  if (!note || XINT (note, 0) == BRANCH_EDGE (bb)->probability)
    return;
  XINT (note, 0) = BRANCH_EDGE (bb)->probability;
}

/* Get the last insn associated with block BB (that includes barriers and
   tablejumps after BB).  */
rtx
get_last_bb_insn (basic_block bb)
{
  rtx tmp;
  rtx end = BB_END (bb);

  /* Include any jump table following the basic block.  */
  if (tablejump_p (end, NULL, &tmp))
    end = tmp;

  /* Include any barriers that may follow the basic block.  */
  tmp = next_nonnote_insn_bb (end);
  while (tmp && BARRIER_P (tmp))
    {
      end = tmp;
      tmp = next_nonnote_insn_bb (end);
    }

  return end;
}

/* Sanity check partition hotness to ensure that basic blocks in
   the cold partition don't dominate basic blocks in the hot partition.
   If FLAG_ONLY is true, report violations as errors. Otherwise
   re-mark the dominated blocks as cold, since this is run after
   cfg optimizations that may make hot blocks previously reached
   by both hot and cold blocks now only reachable along cold paths.  */

static vec<basic_block>
find_partition_fixes (bool flag_only)
{
  basic_block bb;
  vec<basic_block> bbs_in_cold_partition = vNULL;
  vec<basic_block> bbs_to_fix = vNULL;

  /* Callers check this.  */
  gcc_checking_assert (crtl->has_bb_partition);

  FOR_EACH_BB_FN (bb, cfun)
    if ((BB_PARTITION (bb) == BB_COLD_PARTITION))
      bbs_in_cold_partition.safe_push (bb);

  if (bbs_in_cold_partition.is_empty ())
    return vNULL;

  bool dom_calculated_here = !dom_info_available_p (CDI_DOMINATORS);

  if (dom_calculated_here)
    calculate_dominance_info (CDI_DOMINATORS);

  while (! bbs_in_cold_partition.is_empty  ())
    {
      bb = bbs_in_cold_partition.pop ();
      /* Any blocks dominated by a block in the cold section
         must also be cold.  */
      basic_block son;
      for (son = first_dom_son (CDI_DOMINATORS, bb);
           son;
           son = next_dom_son (CDI_DOMINATORS, son))
        {
          /* If son is not yet cold, then mark it cold here and
             enqueue it for further processing.  */
          if ((BB_PARTITION (son) != BB_COLD_PARTITION))
            {
              if (flag_only)
                error ("non-cold basic block %d dominated "
                       "by a block in the cold partition (%d)", son->index, bb->index);
              else
                BB_SET_PARTITION (son, BB_COLD_PARTITION);
              bbs_to_fix.safe_push (son);
              bbs_in_cold_partition.safe_push (son);
            }
        }
    }

  if (dom_calculated_here)
    free_dominance_info (CDI_DOMINATORS);

  return bbs_to_fix;
}

/* Perform cleanup on the hot/cold bb partitioning after optimization
   passes that modify the cfg.  */

void
fixup_partitions (void)
{
  basic_block bb;

  if (!crtl->has_bb_partition)
    return;

  /* Delete any blocks that became unreachable and weren't
     already cleaned up, for example during edge forwarding
     and convert_jumps_to_returns. This will expose more
     opportunities for fixing the partition boundaries here.
     Also, the calculation of the dominance graph during verification
     will assert if there are unreachable nodes.  */
  delete_unreachable_blocks ();

  /* If there are partitions, do a sanity check on them: A basic block in
     a cold partition cannot dominate a basic block in a hot partition.
     Fixup any that now violate this requirement, as a result of edge
     forwarding and unreachable block deletion.  */
  vec<basic_block> bbs_to_fix = find_partition_fixes (false);

  /* Do the partition fixup after all necessary blocks have been converted to
     cold, so that we only update the region crossings the minimum number of
     places, which can require forcing edges to be non fallthru.  */
  while (! bbs_to_fix.is_empty ())
    {
      bb = bbs_to_fix.pop ();
      fixup_new_cold_bb (bb);
    }
}

/* Verify, in the basic block chain, that there is at most one switch
   between hot/cold partitions. This condition will not be true until
   after reorder_basic_blocks is called.  */

static int
verify_hot_cold_block_grouping (void)
{
  basic_block bb;
  int err = 0;
  bool switched_sections = false;
  int current_partition = BB_UNPARTITIONED;

  /* Even after bb reordering is complete, we go into cfglayout mode
     again (in compgoto). Ensure we don't call this before going back
     into linearized RTL when any layout fixes would have been committed.  */
  if (!crtl->bb_reorder_complete
      || current_ir_type () != IR_RTL_CFGRTL)
    return err;

  FOR_EACH_BB_FN (bb, cfun)
    {
      if (current_partition != BB_UNPARTITIONED
          && BB_PARTITION (bb) != current_partition)
	{
	  if (switched_sections)
	    {
	      error ("multiple hot/cold transitions found (bb %i)",
		     bb->index);
	      err = 1;
	    }
	  else
            switched_sections = true;

          if (!crtl->has_bb_partition)
            error ("partition found but function partition flag not set");
	}
      current_partition = BB_PARTITION (bb);
    }

  return err;
}


/* Perform several checks on the edges out of each block, such as
   the consistency of the branch probabilities, the correctness
   of hot/cold partition crossing edges, and the number of expected
   successor edges.  Also verify that the dominance relationship
   between hot/cold blocks is sane.  */

static int
rtl_verify_edges (void)
{
  int err = 0;
  basic_block bb;

  FOR_EACH_BB_REVERSE_FN (bb, cfun)
    {
      int n_fallthru = 0, n_branch = 0, n_abnormal_call = 0, n_sibcall = 0;
      int n_eh = 0, n_abnormal = 0;
      edge e, fallthru = NULL;
      edge_iterator ei;
      rtx note;
      bool has_crossing_edge = false;

      if (JUMP_P (BB_END (bb))
	  && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX))
	  && EDGE_COUNT (bb->succs) >= 2
	  && any_condjump_p (BB_END (bb)))
	{
	  if (XINT (note, 0) != BRANCH_EDGE (bb)->probability
	      && profile_status_for_fn (cfun) != PROFILE_ABSENT)
	    {
	      error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i",
		     XINT (note, 0), BRANCH_EDGE (bb)->probability);
	      err = 1;
	    }
	}

      FOR_EACH_EDGE (e, ei, bb->succs)
	{
	  bool is_crossing;

	  if (e->flags & EDGE_FALLTHRU)
	    n_fallthru++, fallthru = e;

	  is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest)
			 && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)
			 && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun));
          has_crossing_edge |= is_crossing;
	  if (e->flags & EDGE_CROSSING)
	    {
	      if (!is_crossing)
		{
		  error ("EDGE_CROSSING incorrectly set across same section");
		  err = 1;
		}
	      if (e->flags & EDGE_FALLTHRU)
		{
		  error ("fallthru edge crosses section boundary in bb %i",
			 e->src->index);
		  err = 1;
		}
	      if (e->flags & EDGE_EH)
		{
		  error ("EH edge crosses section boundary in bb %i",
			 e->src->index);
		  err = 1;
		}
              if (JUMP_P (BB_END (bb))
                  && !find_reg_note (BB_END (bb), REG_CROSSING_JUMP, NULL_RTX))
		{
		  error ("No region crossing jump at section boundary in bb %i",
			 bb->index);
		  err = 1;
		}
	    }
	  else if (is_crossing)
	    {
	      error ("EDGE_CROSSING missing across section boundary");
	      err = 1;
	    }

	  if ((e->flags & ~(EDGE_DFS_BACK
			    | EDGE_CAN_FALLTHRU
			    | EDGE_IRREDUCIBLE_LOOP
			    | EDGE_LOOP_EXIT
			    | EDGE_CROSSING
			    | EDGE_PRESERVE
			    | EDGE_PREDICTED_BY_EXPECT)) == 0)
	    n_branch++;

	  if (e->flags & EDGE_ABNORMAL_CALL)
	    n_abnormal_call++;

	  if (e->flags & EDGE_SIBCALL)
	    n_sibcall++;

	  if (e->flags & EDGE_EH)
	    n_eh++;

	  if (e->flags & EDGE_ABNORMAL)
	    n_abnormal++;
	}

        if (!has_crossing_edge
            && find_reg_note (BB_END (bb), REG_CROSSING_JUMP, NULL_RTX))
          {
            print_rtl_with_bb (stderr, get_insns (), TDF_RTL | TDF_BLOCKS | TDF_DETAILS);
            error ("Region crossing jump across same section in bb %i",
                   bb->index);
            err = 1;
          }

      if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX))
	{
	  error ("missing REG_EH_REGION note at the end of bb %i", bb->index);
	  err = 1;
	}
      if (n_eh > 1)
	{
	  error ("too many exception handling edges in bb %i", bb->index);
	  err = 1;
	}
      if (n_branch
	  && (!JUMP_P (BB_END (bb))
	      || (n_branch > 1 && (any_uncondjump_p (BB_END (bb))
				   || any_condjump_p (BB_END (bb))))))
	{
	  error ("too many outgoing branch edges from bb %i", bb->index);
	  err = 1;
	}
      if (n_fallthru && any_uncondjump_p (BB_END (bb)))
	{
	  error ("fallthru edge after unconditional jump in bb %i", bb->index);
	  err = 1;
	}
      if (n_branch != 1 && any_uncondjump_p (BB_END (bb)))
	{
	  error ("wrong number of branch edges after unconditional jump"
		 " in bb %i", bb->index);
	  err = 1;
	}
      if (n_branch != 1 && any_condjump_p (BB_END (bb))
	  && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest))
	{
	  error ("wrong amount of branch edges after conditional jump"
		 " in bb %i", bb->index);
	  err = 1;
	}
      if (n_abnormal_call && !CALL_P (BB_END (bb)))
	{
	  error ("abnormal call edges for non-call insn in bb %i", bb->index);
	  err = 1;
	}
      if (n_sibcall && !CALL_P (BB_END (bb)))
	{
	  error ("sibcall edges for non-call insn in bb %i", bb->index);
	  err = 1;
	}
      if (n_abnormal > n_eh
	  && !(CALL_P (BB_END (bb))
	       && n_abnormal == n_abnormal_call + n_sibcall)
	  && (!JUMP_P (BB_END (bb))
	      || any_condjump_p (BB_END (bb))
	      || any_uncondjump_p (BB_END (bb))))
	{
	  error ("abnormal edges for no purpose in bb %i", bb->index);
	  err = 1;
	}
    }

  /* If there are partitions, do a sanity check on them: A basic block in
     a cold partition cannot dominate a basic block in a hot partition.  */
  if (crtl->has_bb_partition && !err)
    {
      vec<basic_block> bbs_to_fix = find_partition_fixes (true);
      err = !bbs_to_fix.is_empty ();
    }

  /* Clean up.  */
  return err;
}

/* Checks on the instructions within blocks. Currently checks that each
   block starts with a basic block note, and that basic block notes and
   control flow jumps are not found in the middle of the block.  */

static int
rtl_verify_bb_insns (void)
{
  rtx x;
  int err = 0;
  basic_block bb;

  FOR_EACH_BB_REVERSE_FN (bb, cfun)
    {
      /* Now check the header of basic
	 block.  It ought to contain optional CODE_LABEL followed
	 by NOTE_BASIC_BLOCK.  */
      x = BB_HEAD (bb);
      if (LABEL_P (x))
	{
	  if (BB_END (bb) == x)
	    {
	      error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
		     bb->index);
	      err = 1;
	    }

	  x = NEXT_INSN (x);
	}

      if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb)
	{
	  error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
		 bb->index);
	  err = 1;
	}

      if (BB_END (bb) == x)
	/* Do checks for empty blocks here.  */
	;
      else
	for (x = NEXT_INSN (x); x; x = NEXT_INSN (x))
	  {
	    if (NOTE_INSN_BASIC_BLOCK_P (x))
	      {
		error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d",
		       INSN_UID (x), bb->index);
		err = 1;
	      }

	    if (x == BB_END (bb))
	      break;

	    if (control_flow_insn_p (x))
	      {
		error ("in basic block %d:", bb->index);
		fatal_insn ("flow control insn inside a basic block", x);
	      }
	  }
    }

  /* Clean up.  */
  return err;
}

/* Verify that block pointers for instructions in basic blocks, headers and
   footers are set appropriately.  */

static int
rtl_verify_bb_pointers (void)
{
  int err = 0;
  basic_block bb;

  /* Check the general integrity of the basic blocks.  */
  FOR_EACH_BB_REVERSE_FN (bb, cfun)
    {
      rtx insn;

      if (!(bb->flags & BB_RTL))
	{
	  error ("BB_RTL flag not set for block %d", bb->index);
	  err = 1;
	}

      FOR_BB_INSNS (bb, insn)
	if (BLOCK_FOR_INSN (insn) != bb)
	  {
	    error ("insn %d basic block pointer is %d, should be %d",
		   INSN_UID (insn),
		   BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0,
		   bb->index);
	    err = 1;
	  }

      for (insn = BB_HEADER (bb); insn; insn = NEXT_INSN (insn))
	if (!BARRIER_P (insn)
	    && BLOCK_FOR_INSN (insn) != NULL)
	  {
	    error ("insn %d in header of bb %d has non-NULL basic block",
		   INSN_UID (insn), bb->index);
	    err = 1;
	  }
      for (insn = BB_FOOTER (bb); insn; insn = NEXT_INSN (insn))
	if (!BARRIER_P (insn)
	    && BLOCK_FOR_INSN (insn) != NULL)
	  {
	    error ("insn %d in footer of bb %d has non-NULL basic block",
		   INSN_UID (insn), bb->index);
	    err = 1;
	  }
    }

  /* Clean up.  */
  return err;
}

/* Verify the CFG and RTL consistency common for both underlying RTL and
   cfglayout RTL.

   Currently it does following checks:

   - overlapping of basic blocks
   - insns with wrong BLOCK_FOR_INSN pointers
   - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
   - tails of basic blocks (ensure that boundary is necessary)
   - scans body of the basic block for JUMP_INSN, CODE_LABEL
     and NOTE_INSN_BASIC_BLOCK
   - verify that no fall_thru edge crosses hot/cold partition boundaries
   - verify that there are no pending RTL branch predictions
   - verify that hot blocks are not dominated by cold blocks

   In future it can be extended check a lot of other stuff as well
   (reachability of basic blocks, life information, etc. etc.).  */

static int
rtl_verify_flow_info_1 (void)
{
  int err = 0;

  err |= rtl_verify_bb_pointers ();

  err |= rtl_verify_bb_insns ();

  err |= rtl_verify_edges ();

  return err;
}

/* Walk the instruction chain and verify that bb head/end pointers
  are correct, and that instructions are in exactly one bb and have
  correct block pointers.  */

static int
rtl_verify_bb_insn_chain (void)
{
  basic_block bb;
  int err = 0;
  rtx x;
  rtx last_head = get_last_insn ();
  basic_block *bb_info;
  const int max_uid = get_max_uid ();

  bb_info = XCNEWVEC (basic_block, max_uid);

  FOR_EACH_BB_REVERSE_FN (bb, cfun)
    {
      rtx head = BB_HEAD (bb);
      rtx end = BB_END (bb);

      for (x = last_head; x != NULL_RTX; x = PREV_INSN (x))
	{
	  /* Verify the end of the basic block is in the INSN chain.  */
	  if (x == end)
	    break;

            /* And that the code outside of basic blocks has NULL bb field.  */
          if (!BARRIER_P (x)
              && BLOCK_FOR_INSN (x) != NULL)
            {
              error ("insn %d outside of basic blocks has non-NULL bb field",
                     INSN_UID (x));
              err = 1;
            }
	}

      if (!x)
	{
	  error ("end insn %d for block %d not found in the insn stream",
		 INSN_UID (end), bb->index);
	  err = 1;
	}

      /* Work backwards from the end to the head of the basic block
	 to verify the head is in the RTL chain.  */
      for (; x != NULL_RTX; x = PREV_INSN (x))
	{
	  /* While walking over the insn chain, verify insns appear
	     in only one basic block.  */
	  if (bb_info[INSN_UID (x)] != NULL)
	    {
	      error ("insn %d is in multiple basic blocks (%d and %d)",
		     INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index);
	      err = 1;
	    }

	  bb_info[INSN_UID (x)] = bb;

	  if (x == head)
	    break;
	}
      if (!x)
	{
	  error ("head insn %d for block %d not found in the insn stream",
		 INSN_UID (head), bb->index);
	  err = 1;
	}

      last_head = PREV_INSN (x);
    }

  for (x = last_head; x != NULL_RTX; x = PREV_INSN (x))
    {
      /* Check that the code before the first basic block has NULL
	 bb field.  */
      if (!BARRIER_P (x)
	  && BLOCK_FOR_INSN (x) != NULL)
	{
	  error ("insn %d outside of basic blocks has non-NULL bb field",
		 INSN_UID (x));
	  err = 1;
	}
    }
  free (bb_info);

  return err;
}

/* Verify that fallthru edges point to adjacent blocks in layout order and
   that barriers exist after non-fallthru blocks.  */

static int
rtl_verify_fallthru (void)
{
  basic_block bb;
  int err = 0;

  FOR_EACH_BB_REVERSE_FN (bb, cfun)
    {
      edge e;

      e = find_fallthru_edge (bb->succs);
      if (!e)
	{
	  rtx insn;

	  /* Ensure existence of barrier in BB with no fallthru edges.  */
	  for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn))
	    {
	      if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn))
		{
		  error ("missing barrier after block %i", bb->index);
		  err = 1;
		  break;
		}
	      if (BARRIER_P (insn))
		break;
	    }
	}
      else if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)
	       && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun))
	{
	  rtx insn;

	  if (e->src->next_bb != e->dest)
	    {
	      error
		("verify_flow_info: Incorrect blocks for fallthru %i->%i",
		 e->src->index, e->dest->index);
	      err = 1;
	    }
	  else
	    for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest);
		 insn = NEXT_INSN (insn))
	      if (BARRIER_P (insn) || INSN_P (insn))
		{
		  error ("verify_flow_info: Incorrect fallthru %i->%i",
			 e->src->index, e->dest->index);
		  fatal_insn ("wrong insn in the fallthru edge", insn);
		  err = 1;
		}
	}
    }

   return err;
}

/* Verify that blocks are laid out in consecutive order. While walking the
   instructions, verify that all expected instructions are inside the basic
   blocks, and that all returns are followed by barriers.  */

static int
rtl_verify_bb_layout (void)
{
  basic_block bb;
  int err = 0;
  rtx x;
  int num_bb_notes;
  const rtx rtx_first = get_insns ();
  basic_block last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun), curr_bb = NULL;

  num_bb_notes = 0;
  last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun);

  for (x = rtx_first; x; x = NEXT_INSN (x))
    {
      if (NOTE_INSN_BASIC_BLOCK_P (x))
	{
	  bb = NOTE_BASIC_BLOCK (x);

	  num_bb_notes++;
	  if (bb != last_bb_seen->next_bb)
	    internal_error ("basic blocks not laid down consecutively");

	  curr_bb = last_bb_seen = bb;
	}

      if (!curr_bb)
	{
	  switch (GET_CODE (x))
	    {
	    case BARRIER:
	    case NOTE:
	      break;

	    case CODE_LABEL:
	      /* An ADDR_VEC is placed outside any basic block.  */
	      if (NEXT_INSN (x)
		  && JUMP_TABLE_DATA_P (NEXT_INSN (x)))
		x = NEXT_INSN (x);

	      /* But in any case, non-deletable labels can appear anywhere.  */
	      break;

	    default:
	      fatal_insn ("insn outside basic block", x);
	    }
	}

      if (JUMP_P (x)
	  && returnjump_p (x) && ! condjump_p (x)
	  && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x))))
	    fatal_insn ("return not followed by barrier", x);

      if (curr_bb && x == BB_END (curr_bb))
	curr_bb = NULL;
    }

  if (num_bb_notes != n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS)
    internal_error
      ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
       num_bb_notes, n_basic_blocks_for_fn (cfun));

   return err;
}

/* Verify the CFG and RTL consistency common for both underlying RTL and
   cfglayout RTL, plus consistency checks specific to linearized RTL mode.

   Currently it does following checks:
   - all checks of rtl_verify_flow_info_1
   - test head/end pointers
   - check that blocks are laid out in consecutive order
   - check that all insns are in the basic blocks
     (except the switch handling code, barriers and notes)
   - check that all returns are followed by barriers
   - check that all fallthru edge points to the adjacent blocks
   - verify that there is a single hot/cold partition boundary after bbro  */

static int
rtl_verify_flow_info (void)
{
  int err = 0;

  err |= rtl_verify_flow_info_1 ();

  err |= rtl_verify_bb_insn_chain ();

  err |= rtl_verify_fallthru ();

  err |= rtl_verify_bb_layout ();

  err |= verify_hot_cold_block_grouping ();

  return err;
}

/* Assume that the preceding pass has possibly eliminated jump instructions
   or converted the unconditional jumps.  Eliminate the edges from CFG.
   Return true if any edges are eliminated.  */

bool
purge_dead_edges (basic_block bb)
{
  edge e;
  rtx insn = BB_END (bb), note;
  bool purged = false;
  bool found;
  edge_iterator ei;

  if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb))
    do
      insn = PREV_INSN (insn);
    while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb));

  /* If this instruction cannot trap, remove REG_EH_REGION notes.  */
  if (NONJUMP_INSN_P (insn)
      && (note = find_reg_note (insn, REG_EH_REGION, NULL)))
    {
      rtx eqnote;

      if (! may_trap_p (PATTERN (insn))
	  || ((eqnote = find_reg_equal_equiv_note (insn))
	      && ! may_trap_p (XEXP (eqnote, 0))))
	remove_note (insn, note);
    }

  /* Cleanup abnormal edges caused by exceptions or non-local gotos.  */
  for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
    {
      bool remove = false;

      /* There are three types of edges we need to handle correctly here: EH
	 edges, abnormal call EH edges, and abnormal call non-EH edges.  The
	 latter can appear when nonlocal gotos are used.  */
      if (e->flags & EDGE_ABNORMAL_CALL)
	{
	  if (!CALL_P (insn))
	    remove = true;
	  else if (can_nonlocal_goto (insn))
	    ;
	  else if ((e->flags & EDGE_EH) && can_throw_internal (insn))
	    ;
	  else if (flag_tm && find_reg_note (insn, REG_TM, NULL))
	    ;
	  else
	    remove = true;
	}
      else if (e->flags & EDGE_EH)
	remove = !can_throw_internal (insn);

      if (remove)
	{
	  remove_edge (e);
	  df_set_bb_dirty (bb);
	  purged = true;
	}
      else
	ei_next (&ei);
    }

  if (JUMP_P (insn))
    {
      rtx note;
      edge b,f;
      edge_iterator ei;

      /* We do care only about conditional jumps and simplejumps.  */
      if (!any_condjump_p (insn)
	  && !returnjump_p (insn)
	  && !simplejump_p (insn))
	return purged;

      /* Branch probability/prediction notes are defined only for
	 condjumps.  We've possibly turned condjump into simplejump.  */
      if (simplejump_p (insn))
	{
	  note = find_reg_note (insn, REG_BR_PROB, NULL);
	  if (note)
	    remove_note (insn, note);
	  while ((note = find_reg_note (insn, REG_BR_PRED, NULL)))
	    remove_note (insn, note);
	}

      for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
	{
	  /* Avoid abnormal flags to leak from computed jumps turned
	     into simplejumps.  */

	  e->flags &= ~EDGE_ABNORMAL;

	  /* See if this edge is one we should keep.  */
	  if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn))
	    /* A conditional jump can fall through into the next
	       block, so we should keep the edge.  */
	    {
	      ei_next (&ei);
	      continue;
	    }
	  else if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)
		   && BB_HEAD (e->dest) == JUMP_LABEL (insn))
	    /* If the destination block is the target of the jump,
	       keep the edge.  */
	    {
	      ei_next (&ei);
	      continue;
	    }
	  else if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)
		   && returnjump_p (insn))
	    /* If the destination block is the exit block, and this
	       instruction is a return, then keep the edge.  */
	    {
	      ei_next (&ei);
	      continue;
	    }
	  else if ((e->flags & EDGE_EH) && can_throw_internal (insn))
	    /* Keep the edges that correspond to exceptions thrown by
	       this instruction and rematerialize the EDGE_ABNORMAL
	       flag we just cleared above.  */
	    {
	      e->flags |= EDGE_ABNORMAL;
	      ei_next (&ei);
	      continue;
	    }

	  /* We do not need this edge.  */
	  df_set_bb_dirty (bb);
	  purged = true;
	  remove_edge (e);
	}

      if (EDGE_COUNT (bb->succs) == 0 || !purged)
	return purged;

      if (dump_file)
	fprintf (dump_file, "Purged edges from bb %i\n", bb->index);

      if (!optimize)
	return purged;

      /* Redistribute probabilities.  */
      if (single_succ_p (bb))
	{
	  single_succ_edge (bb)->probability = REG_BR_PROB_BASE;
	  single_succ_edge (bb)->count = bb->count;
	}
      else
	{
	  note = find_reg_note (insn, REG_BR_PROB, NULL);
	  if (!note)
	    return purged;

	  b = BRANCH_EDGE (bb);
	  f = FALLTHRU_EDGE (bb);
	  b->probability = XINT (note, 0);
	  f->probability = REG_BR_PROB_BASE - b->probability;
          /* Update these to use GCOV_COMPUTE_SCALE.  */
	  b->count = bb->count * b->probability / REG_BR_PROB_BASE;
	  f->count = bb->count * f->probability / REG_BR_PROB_BASE;
	}

      return purged;
    }
  else if (CALL_P (insn) && SIBLING_CALL_P (insn))
    {
      /* First, there should not be any EH or ABCALL edges resulting
	 from non-local gotos and the like.  If there were, we shouldn't
	 have created the sibcall in the first place.  Second, there
	 should of course never have been a fallthru edge.  */
      gcc_assert (single_succ_p (bb));
      gcc_assert (single_succ_edge (bb)->flags
		  == (EDGE_SIBCALL | EDGE_ABNORMAL));

      return 0;
    }

  /* If we don't see a jump insn, we don't know exactly why the block would
     have been broken at this point.  Look for a simple, non-fallthru edge,
     as these are only created by conditional branches.  If we find such an
     edge we know that there used to be a jump here and can then safely
     remove all non-fallthru edges.  */
  found = false;
  FOR_EACH_EDGE (e, ei, bb->succs)
    if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)))
      {
	found = true;
	break;
      }

  if (!found)
    return purged;

  /* Remove all but the fake and fallthru edges.  The fake edge may be
     the only successor for this block in the case of noreturn
     calls.  */
  for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
    {
      if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE)))
	{
	  df_set_bb_dirty (bb);
	  remove_edge (e);
	  purged = true;
	}
      else
	ei_next (&ei);
    }

  gcc_assert (single_succ_p (bb));

  single_succ_edge (bb)->probability = REG_BR_PROB_BASE;
  single_succ_edge (bb)->count = bb->count;

  if (dump_file)
    fprintf (dump_file, "Purged non-fallthru edges from bb %i\n",
	     bb->index);
  return purged;
}

/* Search all basic blocks for potentially dead edges and purge them.  Return
   true if some edge has been eliminated.  */

bool
purge_all_dead_edges (void)
{
  int purged = false;
  basic_block bb;

  FOR_EACH_BB_FN (bb, cfun)
    {
      bool purged_here = purge_dead_edges (bb);

      purged |= purged_here;
    }

  return purged;
}

/* This is used by a few passes that emit some instructions after abnormal
   calls, moving the basic block's end, while they in fact do want to emit
   them on the fallthru edge.  Look for abnormal call edges, find backward
   the call in the block and insert the instructions on the edge instead.

   Similarly, handle instructions throwing exceptions internally.

   Return true when instructions have been found and inserted on edges.  */

bool
fixup_abnormal_edges (void)
{
  bool inserted = false;
  basic_block bb;

  FOR_EACH_BB_FN (bb, cfun)
    {
      edge e;
      edge_iterator ei;

      /* Look for cases we are interested in - calls or instructions causing
         exceptions.  */
      FOR_EACH_EDGE (e, ei, bb->succs)
	if ((e->flags & EDGE_ABNORMAL_CALL)
	    || ((e->flags & (EDGE_ABNORMAL | EDGE_EH))
		== (EDGE_ABNORMAL | EDGE_EH)))
	  break;

      if (e && !CALL_P (BB_END (bb)) && !can_throw_internal (BB_END (bb)))
	{
	  rtx insn;

	  /* Get past the new insns generated.  Allow notes, as the insns
	     may be already deleted.  */
	  insn = BB_END (bb);
	  while ((NONJUMP_INSN_P (insn) || NOTE_P (insn))
		 && !can_throw_internal (insn)
		 && insn != BB_HEAD (bb))
	    insn = PREV_INSN (insn);

	  if (CALL_P (insn) || can_throw_internal (insn))
	    {
	      rtx stop, next;

	      e = find_fallthru_edge (bb->succs);

	      stop = NEXT_INSN (BB_END (bb));
	      BB_END (bb) = insn;

	      for (insn = NEXT_INSN (insn); insn != stop; insn = next)
		{
		  next = NEXT_INSN (insn);
		  if (INSN_P (insn))
		    {
		      delete_insn (insn);

		      /* Sometimes there's still the return value USE.
			 If it's placed after a trapping call (i.e. that
			 call is the last insn anyway), we have no fallthru
			 edge.  Simply delete this use and don't try to insert
			 on the non-existent edge.  */
		      if (GET_CODE (PATTERN (insn)) != USE)
			{
			  /* We're not deleting it, we're moving it.  */
			  INSN_DELETED_P (insn) = 0;
			  PREV_INSN (insn) = NULL_RTX;
			  NEXT_INSN (insn) = NULL_RTX;

			  insert_insn_on_edge (insn, e);
			  inserted = true;
			}
		    }
		  else if (!BARRIER_P (insn))
		    set_block_for_insn (insn, NULL);
		}
	    }

	  /* It may be that we don't find any trapping insn.  In this
	     case we discovered quite late that the insn that had been
	     marked as can_throw_internal in fact couldn't trap at all.
	     So we should in fact delete the EH edges out of the block.  */
	  else
	    purge_dead_edges (bb);
	}
    }

  return inserted;
}

/* Cut the insns from FIRST to LAST out of the insns stream.  */

rtx
unlink_insn_chain (rtx first, rtx last)
{
  rtx prevfirst = PREV_INSN (first);
  rtx nextlast = NEXT_INSN (last);

  PREV_INSN (first) = NULL;
  NEXT_INSN (last) = NULL;
  if (prevfirst)
    NEXT_INSN (prevfirst) = nextlast;
  if (nextlast)
    PREV_INSN (nextlast) = prevfirst;
  else
    set_last_insn (prevfirst);
  if (!prevfirst)
    set_first_insn (nextlast);
  return first;
}

/* Skip over inter-block insns occurring after BB which are typically
   associated with BB (e.g., barriers). If there are any such insns,
   we return the last one. Otherwise, we return the end of BB.  */

static rtx
skip_insns_after_block (basic_block bb)
{
  rtx insn, last_insn, next_head, prev;

  next_head = NULL_RTX;
  if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
    next_head = BB_HEAD (bb->next_bb);

  for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; )
    {
      if (insn == next_head)
	break;

      switch (GET_CODE (insn))
	{
	case BARRIER:
	  last_insn = insn;
	  continue;

	case NOTE:
	  switch (NOTE_KIND (insn))
	    {
	    case NOTE_INSN_BLOCK_END:
	      gcc_unreachable ();
	      continue;
	    default:
	      continue;
	      break;
	    }
	  break;

	case CODE_LABEL:
	  if (NEXT_INSN (insn)
	      && JUMP_TABLE_DATA_P (NEXT_INSN (insn)))
	    {
	      insn = NEXT_INSN (insn);
	      last_insn = insn;
	      continue;
	    }
	  break;

	default:
	  break;
	}

      break;
    }

  /* It is possible to hit contradictory sequence.  For instance:

     jump_insn
     NOTE_INSN_BLOCK_BEG
     barrier

     Where barrier belongs to jump_insn, but the note does not.  This can be
     created by removing the basic block originally following
     NOTE_INSN_BLOCK_BEG.  In such case reorder the notes.  */

  for (insn = last_insn; insn != BB_END (bb); insn = prev)
    {
      prev = PREV_INSN (insn);
      if (NOTE_P (insn))
	switch (NOTE_KIND (insn))
	  {
	  case NOTE_INSN_BLOCK_END:
	    gcc_unreachable ();
	    break;
	  case NOTE_INSN_DELETED:
	  case NOTE_INSN_DELETED_LABEL:
	  case NOTE_INSN_DELETED_DEBUG_LABEL:
	    continue;
	  default:
	    reorder_insns (insn, insn, last_insn);
	  }
    }

  return last_insn;
}

/* Locate or create a label for a given basic block.  */

static rtx
label_for_bb (basic_block bb)
{
  rtx label = BB_HEAD (bb);

  if (!LABEL_P (label))
    {
      if (dump_file)
	fprintf (dump_file, "Emitting label for block %d\n", bb->index);

      label = block_label (bb);
    }

  return label;
}

/* Locate the effective beginning and end of the insn chain for each
   block, as defined by skip_insns_after_block above.  */

static void
record_effective_endpoints (void)
{
  rtx next_insn;
  basic_block bb;
  rtx insn;

  for (insn = get_insns ();
       insn
       && NOTE_P (insn)
       && NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK;
       insn = NEXT_INSN (insn))
    continue;
  /* No basic blocks at all?  */
  gcc_assert (insn);

  if (PREV_INSN (insn))
    cfg_layout_function_header =
	    unlink_insn_chain (get_insns (), PREV_INSN (insn));
  else
    cfg_layout_function_header = NULL_RTX;

  next_insn = get_insns ();
  FOR_EACH_BB_FN (bb, cfun)
    {
      rtx end;

      if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb))
	BB_HEADER (bb) = unlink_insn_chain (next_insn,
					      PREV_INSN (BB_HEAD (bb)));
      end = skip_insns_after_block (bb);
      if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end)
	BB_FOOTER (bb) = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end);
      next_insn = NEXT_INSN (BB_END (bb));
    }

  cfg_layout_function_footer = next_insn;
  if (cfg_layout_function_footer)
    cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ());
}

static unsigned int
into_cfg_layout_mode (void)
{
  cfg_layout_initialize (0);
  return 0;
}

static unsigned int
outof_cfg_layout_mode (void)
{
  basic_block bb;

  FOR_EACH_BB_FN (bb, cfun)
    if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
      bb->aux = bb->next_bb;

  cfg_layout_finalize ();

  return 0;
}

namespace {

const pass_data pass_data_into_cfg_layout_mode =
{
  RTL_PASS, /* type */
  "into_cfglayout", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  false, /* has_gate */
  true, /* has_execute */
  TV_CFG, /* tv_id */
  0, /* properties_required */
  PROP_cfglayout, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_into_cfg_layout_mode : public rtl_opt_pass
{
public:
  pass_into_cfg_layout_mode (gcc::context *ctxt)
    : rtl_opt_pass (pass_data_into_cfg_layout_mode, ctxt)
  {}

  /* opt_pass methods: */
  unsigned int execute () { return into_cfg_layout_mode (); }

}; // class pass_into_cfg_layout_mode

} // anon namespace

rtl_opt_pass *
make_pass_into_cfg_layout_mode (gcc::context *ctxt)
{
  return new pass_into_cfg_layout_mode (ctxt);
}

namespace {

const pass_data pass_data_outof_cfg_layout_mode =
{
  RTL_PASS, /* type */
  "outof_cfglayout", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  false, /* has_gate */
  true, /* has_execute */
  TV_CFG, /* tv_id */
  0, /* properties_required */
  0, /* properties_provided */
  PROP_cfglayout, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_outof_cfg_layout_mode : public rtl_opt_pass
{
public:
  pass_outof_cfg_layout_mode (gcc::context *ctxt)
    : rtl_opt_pass (pass_data_outof_cfg_layout_mode, ctxt)
  {}

  /* opt_pass methods: */
  unsigned int execute () { return outof_cfg_layout_mode (); }

}; // class pass_outof_cfg_layout_mode

} // anon namespace

rtl_opt_pass *
make_pass_outof_cfg_layout_mode (gcc::context *ctxt)
{
  return new pass_outof_cfg_layout_mode (ctxt);
}


/* Link the basic blocks in the correct order, compacting the basic
   block queue while at it.  If STAY_IN_CFGLAYOUT_MODE is false, this
   function also clears the basic block header and footer fields.

   This function is usually called after a pass (e.g. tracer) finishes
   some transformations while in cfglayout mode.  The required sequence
   of the basic blocks is in a linked list along the bb->aux field.
   This functions re-links the basic block prev_bb and next_bb pointers
   accordingly, and it compacts and renumbers the blocks.

   FIXME: This currently works only for RTL, but the only RTL-specific
   bits are the STAY_IN_CFGLAYOUT_MODE bits.  The tracer pass was moved
   to GIMPLE a long time ago, but it doesn't relink the basic block
   chain.  It could do that (to give better initial RTL) if this function
   is made IR-agnostic (and moved to cfganal.c or cfg.c while at it).  */

void
relink_block_chain (bool stay_in_cfglayout_mode)
{
  basic_block bb, prev_bb;
  int index;

  /* Maybe dump the re-ordered sequence.  */
  if (dump_file)
    {
      fprintf (dump_file, "Reordered sequence:\n");
      for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb, index =
	   NUM_FIXED_BLOCKS;
	   bb;
	   bb = (basic_block) bb->aux, index++)
	{
	  fprintf (dump_file, " %i ", index);
	  if (get_bb_original (bb))
	    fprintf (dump_file, "duplicate of %i ",
		     get_bb_original (bb)->index);
	  else if (forwarder_block_p (bb)
		   && !LABEL_P (BB_HEAD (bb)))
	    fprintf (dump_file, "compensation ");
	  else
	    fprintf (dump_file, "bb %i ", bb->index);
	  fprintf (dump_file, " [%i]\n", bb->frequency);
	}
    }

  /* Now reorder the blocks.  */
  prev_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun);
  bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb;
  for (; bb; prev_bb = bb, bb = (basic_block) bb->aux)
    {
      bb->prev_bb = prev_bb;
      prev_bb->next_bb = bb;
    }
  prev_bb->next_bb = EXIT_BLOCK_PTR_FOR_FN (cfun);
  EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb = prev_bb;

  /* Then, clean up the aux fields.  */
  FOR_ALL_BB_FN (bb, cfun)
    {
      bb->aux = NULL;
      if (!stay_in_cfglayout_mode)
	BB_HEADER (bb) = BB_FOOTER (bb) = NULL;
    }

  /* Maybe reset the original copy tables, they are not valid anymore
     when we renumber the basic blocks in compact_blocks.  If we are
     are going out of cfglayout mode, don't re-allocate the tables.  */
  free_original_copy_tables ();
  if (stay_in_cfglayout_mode)
    initialize_original_copy_tables ();

  /* Finally, put basic_block_info in the new order.  */
  compact_blocks ();
}


/* Given a reorder chain, rearrange the code to match.  */

static void
fixup_reorder_chain (void)
{
  basic_block bb;
  rtx insn = NULL;

  if (cfg_layout_function_header)
    {
      set_first_insn (cfg_layout_function_header);
      insn = cfg_layout_function_header;
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
    }

  /* First do the bulk reordering -- rechain the blocks without regard to
     the needed changes to jumps and labels.  */

  for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb; bb = (basic_block)
       bb->aux)
    {
      if (BB_HEADER (bb))
	{
	  if (insn)
	    NEXT_INSN (insn) = BB_HEADER (bb);
	  else
	    set_first_insn (BB_HEADER (bb));
	  PREV_INSN (BB_HEADER (bb)) = insn;
	  insn = BB_HEADER (bb);
	  while (NEXT_INSN (insn))
	    insn = NEXT_INSN (insn);
	}
      if (insn)
	NEXT_INSN (insn) = BB_HEAD (bb);
      else
	set_first_insn (BB_HEAD (bb));
      PREV_INSN (BB_HEAD (bb)) = insn;
      insn = BB_END (bb);
      if (BB_FOOTER (bb))
	{
	  NEXT_INSN (insn) = BB_FOOTER (bb);
	  PREV_INSN (BB_FOOTER (bb)) = insn;
	  while (NEXT_INSN (insn))
	    insn = NEXT_INSN (insn);
	}
    }

  NEXT_INSN (insn) = cfg_layout_function_footer;
  if (cfg_layout_function_footer)
    PREV_INSN (cfg_layout_function_footer) = insn;

  while (NEXT_INSN (insn))
    insn = NEXT_INSN (insn);

  set_last_insn (insn);
#ifdef ENABLE_CHECKING
  verify_insn_chain ();
#endif

  /* Now add jumps and labels as needed to match the blocks new
     outgoing edges.  */

  for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb ; bb = (basic_block)
       bb->aux)
    {
      edge e_fall, e_taken, e;
      rtx bb_end_insn;
      rtx ret_label = NULL_RTX;
      basic_block nb;
      edge_iterator ei;

      if (EDGE_COUNT (bb->succs) == 0)
	continue;

      /* Find the old fallthru edge, and another non-EH edge for
	 a taken jump.  */
      e_taken = e_fall = NULL;

      FOR_EACH_EDGE (e, ei, bb->succs)
	if (e->flags & EDGE_FALLTHRU)
	  e_fall = e;
	else if (! (e->flags & EDGE_EH))
	  e_taken = e;

      bb_end_insn = BB_END (bb);
      if (JUMP_P (bb_end_insn))
	{
	  ret_label = JUMP_LABEL (bb_end_insn);
	  if (any_condjump_p (bb_end_insn))
	    {
	      /* This might happen if the conditional jump has side
		 effects and could therefore not be optimized away.
		 Make the basic block to end with a barrier in order
		 to prevent rtl_verify_flow_info from complaining.  */
	      if (!e_fall)
		{
		  gcc_assert (!onlyjump_p (bb_end_insn)
			      || returnjump_p (bb_end_insn)
                              || (e_taken->flags & EDGE_CROSSING));
		  emit_barrier_after (bb_end_insn);
		  continue;
		}

	      /* If the old fallthru is still next, nothing to do.  */
	      if (bb->aux == e_fall->dest
		  || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
		continue;

	      /* The degenerated case of conditional jump jumping to the next
		 instruction can happen for jumps with side effects.  We need
		 to construct a forwarder block and this will be done just
		 fine by force_nonfallthru below.  */
	      if (!e_taken)
		;

	      /* There is another special case: if *neither* block is next,
		 such as happens at the very end of a function, then we'll
		 need to add a new unconditional jump.  Choose the taken
		 edge based on known or assumed probability.  */
	      else if (bb->aux != e_taken->dest)
		{
		  rtx note = find_reg_note (bb_end_insn, REG_BR_PROB, 0);

		  if (note
		      && XINT (note, 0) < REG_BR_PROB_BASE / 2
		      && invert_jump (bb_end_insn,
				      (e_fall->dest
				       == EXIT_BLOCK_PTR_FOR_FN (cfun)
				       ? NULL_RTX
				       : label_for_bb (e_fall->dest)), 0))
		    {
		      e_fall->flags &= ~EDGE_FALLTHRU;
		      gcc_checking_assert (could_fall_through
					   (e_taken->src, e_taken->dest));
		      e_taken->flags |= EDGE_FALLTHRU;
		      update_br_prob_note (bb);
		      e = e_fall, e_fall = e_taken, e_taken = e;
		    }
		}

	      /* If the "jumping" edge is a crossing edge, and the fall
		 through edge is non-crossing, leave things as they are.  */
	      else if ((e_taken->flags & EDGE_CROSSING)
		       && !(e_fall->flags & EDGE_CROSSING))
		continue;

	      /* Otherwise we can try to invert the jump.  This will
		 basically never fail, however, keep up the pretense.  */
	      else if (invert_jump (bb_end_insn,
				    (e_fall->dest
				     == EXIT_BLOCK_PTR_FOR_FN (cfun)
				     ? NULL_RTX
				     : label_for_bb (e_fall->dest)), 0))
		{
		  e_fall->flags &= ~EDGE_FALLTHRU;
		  gcc_checking_assert (could_fall_through
				       (e_taken->src, e_taken->dest));
		  e_taken->flags |= EDGE_FALLTHRU;
		  update_br_prob_note (bb);
		  if (LABEL_NUSES (ret_label) == 0
		      && single_pred_p (e_taken->dest))
		    delete_insn (ret_label);
		  continue;
		}
	    }
	  else if (extract_asm_operands (PATTERN (bb_end_insn)) != NULL)
	    {
	      /* If the old fallthru is still next or if
		 asm goto doesn't have a fallthru (e.g. when followed by
		 __builtin_unreachable ()), nothing to do.  */
	      if (! e_fall
		  || bb->aux == e_fall->dest
		  || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
		continue;

	      /* Otherwise we'll have to use the fallthru fixup below.  */
	    }
	  else
	    {
	      /* Otherwise we have some return, switch or computed
		 jump.  In the 99% case, there should not have been a
		 fallthru edge.  */
	      gcc_assert (returnjump_p (bb_end_insn) || !e_fall);
	      continue;
	    }
	}
      else
	{
	  /* No fallthru implies a noreturn function with EH edges, or
	     something similarly bizarre.  In any case, we don't need to
	     do anything.  */
	  if (! e_fall)
	    continue;

	  /* If the fallthru block is still next, nothing to do.  */
	  if (bb->aux == e_fall->dest)
	    continue;

	  /* A fallthru to exit block.  */
	  if (e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
	    continue;
	}

      /* We got here if we need to add a new jump insn. 
	 Note force_nonfallthru can delete E_FALL and thus we have to
	 save E_FALL->src prior to the call to force_nonfallthru.  */
      nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest, ret_label);
      if (nb)
	{
	  nb->aux = bb->aux;
	  bb->aux = nb;
	  /* Don't process this new block.  */
	  bb = nb;
	}
    }

  relink_block_chain (/*stay_in_cfglayout_mode=*/false);

  /* Annoying special case - jump around dead jumptables left in the code.  */
  FOR_EACH_BB_FN (bb, cfun)
    {
      edge e = find_fallthru_edge (bb->succs);

      if (e && !can_fallthru (e->src, e->dest))
	force_nonfallthru (e);
    }

  /* Ensure goto_locus from edges has some instructions with that locus
     in RTL.  */
  if (!optimize)
    FOR_EACH_BB_FN (bb, cfun)
      {
        edge e;
        edge_iterator ei;

        FOR_EACH_EDGE (e, ei, bb->succs)
	  if (LOCATION_LOCUS (e->goto_locus) != UNKNOWN_LOCATION
	      && !(e->flags & EDGE_ABNORMAL))
	    {
	      edge e2;
	      edge_iterator ei2;
	      basic_block dest, nb;
	      rtx end;

	      insn = BB_END (e->src);
	      end = PREV_INSN (BB_HEAD (e->src));
	      while (insn != end
		     && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn)))
		insn = PREV_INSN (insn);
	      if (insn != end
		  && INSN_LOCATION (insn) == e->goto_locus)
		continue;
	      if (simplejump_p (BB_END (e->src))
		  && !INSN_HAS_LOCATION (BB_END (e->src)))
		{
		  INSN_LOCATION (BB_END (e->src)) = e->goto_locus;
		  continue;
		}
	      dest = e->dest;
	      if (dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
		{
		  /* Non-fallthru edges to the exit block cannot be split.  */
		  if (!(e->flags & EDGE_FALLTHRU))
		    continue;
		}
	      else
		{
		  insn = BB_HEAD (dest);
		  end = NEXT_INSN (BB_END (dest));
		  while (insn != end && !NONDEBUG_INSN_P (insn))
		    insn = NEXT_INSN (insn);
		  if (insn != end && INSN_HAS_LOCATION (insn)
		      && INSN_LOCATION (insn) == e->goto_locus)
		    continue;
		}
	      nb = split_edge (e);
	      if (!INSN_P (BB_END (nb)))
		BB_END (nb) = emit_insn_after_noloc (gen_nop (), BB_END (nb),
						     nb);
	      INSN_LOCATION (BB_END (nb)) = e->goto_locus;

	      /* If there are other incoming edges to the destination block
		 with the same goto locus, redirect them to the new block as
		 well, this can prevent other such blocks from being created
		 in subsequent iterations of the loop.  */
	      for (ei2 = ei_start (dest->preds); (e2 = ei_safe_edge (ei2)); )
		if (LOCATION_LOCUS (e2->goto_locus) != UNKNOWN_LOCATION
		    && !(e2->flags & (EDGE_ABNORMAL | EDGE_FALLTHRU))
		    && e->goto_locus == e2->goto_locus)
		  redirect_edge_and_branch (e2, nb);
		else
		  ei_next (&ei2);
	    }
      }
}

/* Perform sanity checks on the insn chain.
   1. Check that next/prev pointers are consistent in both the forward and
      reverse direction.
   2. Count insns in chain, going both directions, and check if equal.
   3. Check that get_last_insn () returns the actual end of chain.  */

DEBUG_FUNCTION void
verify_insn_chain (void)
{
  rtx x, prevx, nextx;
  int insn_cnt1, insn_cnt2;

  for (prevx = NULL, insn_cnt1 = 1, x = get_insns ();
       x != 0;
       prevx = x, insn_cnt1++, x = NEXT_INSN (x))
    gcc_assert (PREV_INSN (x) == prevx);

  gcc_assert (prevx == get_last_insn ());

  for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn ();
       x != 0;
       nextx = x, insn_cnt2++, x = PREV_INSN (x))
    gcc_assert (NEXT_INSN (x) == nextx);

  gcc_assert (insn_cnt1 == insn_cnt2);
}

/* If we have assembler epilogues, the block falling through to exit must
   be the last one in the reordered chain when we reach final.  Ensure
   that this condition is met.  */
static void
fixup_fallthru_exit_predecessor (void)
{
  edge e;
  basic_block bb = NULL;

  /* This transformation is not valid before reload, because we might
     separate a call from the instruction that copies the return
     value.  */
  gcc_assert (reload_completed);

  e = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
  if (e)
    bb = e->src;

  if (bb && bb->aux)
    {
      basic_block c = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb;

      /* If the very first block is the one with the fall-through exit
	 edge, we have to split that block.  */
      if (c == bb)
	{
	  bb = split_block (bb, NULL)->dest;
	  bb->aux = c->aux;
	  c->aux = bb;
	  BB_FOOTER (bb) = BB_FOOTER (c);
	  BB_FOOTER (c) = NULL;
	}

      while (c->aux != bb)
	c = (basic_block) c->aux;

      c->aux = bb->aux;
      while (c->aux)
	c = (basic_block) c->aux;

      c->aux = bb;
      bb->aux = NULL;
    }
}

/* In case there are more than one fallthru predecessors of exit, force that
   there is only one.  */

static void
force_one_exit_fallthru (void)
{
  edge e, predecessor = NULL;
  bool more = false;
  edge_iterator ei;
  basic_block forwarder, bb;

  FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
    if (e->flags & EDGE_FALLTHRU)
      {
	if (predecessor == NULL)
	  predecessor = e;
	else
	  {
	    more = true;
	    break;
	  }
      }

  if (!more)
    return;

  /* Exit has several fallthru predecessors.  Create a forwarder block for
     them.  */
  forwarder = split_edge (predecessor);
  for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
       (e = ei_safe_edge (ei)); )
    {
      if (e->src == forwarder
	  || !(e->flags & EDGE_FALLTHRU))
	ei_next (&ei);
      else
	redirect_edge_and_branch_force (e, forwarder);
    }

  /* Fix up the chain of blocks -- make FORWARDER immediately precede the
     exit block.  */
  FOR_EACH_BB_FN (bb, cfun)
    {
      if (bb->aux == NULL && bb != forwarder)
	{
	  bb->aux = forwarder;
	  break;
	}
    }
}

/* Return true in case it is possible to duplicate the basic block BB.  */

static bool
cfg_layout_can_duplicate_bb_p (const_basic_block bb)
{
  /* Do not attempt to duplicate tablejumps, as we need to unshare
     the dispatch table.  This is difficult to do, as the instructions
     computing jump destination may be hoisted outside the basic block.  */
  if (tablejump_p (BB_END (bb), NULL, NULL))
    return false;

  /* Do not duplicate blocks containing insns that can't be copied.  */
  if (targetm.cannot_copy_insn_p)
    {
      rtx insn = BB_HEAD (bb);
      while (1)
	{
	  if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn))
	    return false;
	  if (insn == BB_END (bb))
	    break;
	  insn = NEXT_INSN (insn);
	}
    }

  return true;
}

rtx
duplicate_insn_chain (rtx from, rtx to)
{
  rtx insn, next, last, copy;

  /* Avoid updating of boundaries of previous basic block.  The
     note will get removed from insn stream in fixup.  */
  last = emit_note (NOTE_INSN_DELETED);

  /* Create copy at the end of INSN chain.  The chain will
     be reordered later.  */
  for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn))
    {
      switch (GET_CODE (insn))
	{
	case DEBUG_INSN:
	  /* Don't duplicate label debug insns.  */
	  if (TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL)
	    break;
	  /* FALLTHRU */
	case INSN:
	case CALL_INSN:
	case JUMP_INSN:
	  copy = emit_copy_of_insn_after (insn, get_last_insn ());
	  if (JUMP_P (insn) && JUMP_LABEL (insn) != NULL_RTX
	      && ANY_RETURN_P (JUMP_LABEL (insn)))
	    JUMP_LABEL (copy) = JUMP_LABEL (insn);
          maybe_copy_prologue_epilogue_insn (insn, copy);
	  break;

	case JUMP_TABLE_DATA:
	  /* Avoid copying of dispatch tables.  We never duplicate
	     tablejumps, so this can hit only in case the table got
	     moved far from original jump.
	     Avoid copying following barrier as well if any
	     (and debug insns in between).  */
	  for (next = NEXT_INSN (insn);
	       next != NEXT_INSN (to);
	       next = NEXT_INSN (next))
	    if (!DEBUG_INSN_P (next))
	      break;
	  if (next != NEXT_INSN (to) && BARRIER_P (next))
	    insn = next;
	  break;

	case CODE_LABEL:
	  break;

	case BARRIER:
	  emit_barrier ();
	  break;

	case NOTE:
	  switch (NOTE_KIND (insn))
	    {
	      /* In case prologue is empty and function contain label
		 in first BB, we may want to copy the block.  */
	    case NOTE_INSN_PROLOGUE_END:

	    case NOTE_INSN_DELETED:
	    case NOTE_INSN_DELETED_LABEL:
	    case NOTE_INSN_DELETED_DEBUG_LABEL:
	      /* No problem to strip these.  */
	    case NOTE_INSN_FUNCTION_BEG:
	      /* There is always just single entry to function.  */
	    case NOTE_INSN_BASIC_BLOCK:
              /* We should only switch text sections once.  */
	    case NOTE_INSN_SWITCH_TEXT_SECTIONS:
	      break;

	    case NOTE_INSN_EPILOGUE_BEG:
	      emit_note_copy (insn);
	      break;

	    default:
	      /* All other notes should have already been eliminated.  */
	      gcc_unreachable ();
	    }
	  break;
	default:
	  gcc_unreachable ();
	}
    }
  insn = NEXT_INSN (last);
  delete_insn (last);
  return insn;
}

/* Create a duplicate of the basic block BB.  */

static basic_block
cfg_layout_duplicate_bb (basic_block bb)
{
  rtx insn;
  basic_block new_bb;

  insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb));
  new_bb = create_basic_block (insn,
			       insn ? get_last_insn () : NULL,
			       EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb);

  BB_COPY_PARTITION (new_bb, bb);
  if (BB_HEADER (bb))
    {
      insn = BB_HEADER (bb);
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
      insn = duplicate_insn_chain (BB_HEADER (bb), insn);
      if (insn)
	BB_HEADER (new_bb) = unlink_insn_chain (insn, get_last_insn ());
    }

  if (BB_FOOTER (bb))
    {
      insn = BB_FOOTER (bb);
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
      insn = duplicate_insn_chain (BB_FOOTER (bb), insn);
      if (insn)
	BB_FOOTER (new_bb) = unlink_insn_chain (insn, get_last_insn ());
    }

  return new_bb;
}


/* Main entry point to this module - initialize the datastructures for
   CFG layout changes.  It keeps LOOPS up-to-date if not null.

   FLAGS is a set of additional flags to pass to cleanup_cfg().  */

void
cfg_layout_initialize (unsigned int flags)
{
  rtx x;
  basic_block bb;

  /* Once bb reordering is complete, cfg layout mode should not be re-entered.
     Entering cfg layout mode will perform optimizations on the cfg that
     could affect the bb layout negatively or even require fixups. An
     example of the latter is if edge forwarding performed when optimizing
     the cfg layout required moving a block from the hot to the cold section
     under -freorder-blocks-and-partition. This would create an illegal
     partitioning unless some manual fixup was performed.  */
  gcc_assert (!crtl->bb_reorder_complete);

  initialize_original_copy_tables ();

  cfg_layout_rtl_register_cfg_hooks ();

  record_effective_endpoints ();

  /* Make sure that the targets of non local gotos are marked.  */
  for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1))
    {
      bb = BLOCK_FOR_INSN (XEXP (x, 0));
      bb->flags |= BB_NON_LOCAL_GOTO_TARGET;
    }

  cleanup_cfg (CLEANUP_CFGLAYOUT | flags);
}

/* Splits superblocks.  */
void
break_superblocks (void)
{
  sbitmap superblocks;
  bool need = false;
  basic_block bb;

  superblocks = sbitmap_alloc (last_basic_block_for_fn (cfun));
  bitmap_clear (superblocks);

  FOR_EACH_BB_FN (bb, cfun)
    if (bb->flags & BB_SUPERBLOCK)
      {
	bb->flags &= ~BB_SUPERBLOCK;
	bitmap_set_bit (superblocks, bb->index);
	need = true;
      }

  if (need)
    {
      rebuild_jump_labels (get_insns ());
      find_many_sub_basic_blocks (superblocks);
    }

  free (superblocks);
}

/* Finalize the changes: reorder insn list according to the sequence specified
   by aux pointers, enter compensation code, rebuild scope forest.  */

void
cfg_layout_finalize (void)
{
#ifdef ENABLE_CHECKING
  verify_flow_info ();
#endif
  force_one_exit_fallthru ();
  rtl_register_cfg_hooks ();
  if (reload_completed
#ifdef HAVE_epilogue
      && !HAVE_epilogue
#endif
      )
    fixup_fallthru_exit_predecessor ();
  fixup_reorder_chain ();

  rebuild_jump_labels (get_insns ());
  delete_dead_jumptables ();

#ifdef ENABLE_CHECKING
  verify_insn_chain ();
  verify_flow_info ();
#endif
}


/* Same as split_block but update cfg_layout structures.  */

static basic_block
cfg_layout_split_block (basic_block bb, void *insnp)
{
  rtx insn = (rtx) insnp;
  basic_block new_bb = rtl_split_block (bb, insn);

  BB_FOOTER (new_bb) = BB_FOOTER (bb);
  BB_FOOTER (bb) = NULL;

  return new_bb;
}

/* Redirect Edge to DEST.  */
static edge
cfg_layout_redirect_edge_and_branch (edge e, basic_block dest)
{
  basic_block src = e->src;
  edge ret;

  if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
    return NULL;

  if (e->dest == dest)
    return e;

  if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)
      && (ret = try_redirect_by_replacing_jump (e, dest, true)))
    {
      df_set_bb_dirty (src);
      return ret;
    }

  if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)
      && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX))
    {
      if (dump_file)
	fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n",
		 e->src->index, dest->index);

      df_set_bb_dirty (e->src);
      redirect_edge_succ (e, dest);
      return e;
    }

  /* Redirect_edge_and_branch may decide to turn branch into fallthru edge
     in the case the basic block appears to be in sequence.  Avoid this
     transformation.  */

  if (e->flags & EDGE_FALLTHRU)
    {
      /* Redirect any branch edges unified with the fallthru one.  */
      if (JUMP_P (BB_END (src))
	  && label_is_jump_target_p (BB_HEAD (e->dest),
				     BB_END (src)))
	{
	  edge redirected;

	  if (dump_file)
	    fprintf (dump_file, "Fallthru edge unified with branch "
		     "%i->%i redirected to %i\n",
		     e->src->index, e->dest->index, dest->index);
	  e->flags &= ~EDGE_FALLTHRU;
	  redirected = redirect_branch_edge (e, dest);
	  gcc_assert (redirected);
	  redirected->flags |= EDGE_FALLTHRU;
	  df_set_bb_dirty (redirected->src);
	  return redirected;
	}
      /* In case we are redirecting fallthru edge to the branch edge
	 of conditional jump, remove it.  */
      if (EDGE_COUNT (src->succs) == 2)
	{
	  /* Find the edge that is different from E.  */
	  edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e);

	  if (s->dest == dest
	      && any_condjump_p (BB_END (src))
	      && onlyjump_p (BB_END (src)))
	    delete_insn (BB_END (src));
	}
      if (dump_file)
	fprintf (dump_file, "Redirecting fallthru edge %i->%i to %i\n",
		 e->src->index, e->dest->index, dest->index);
      ret = redirect_edge_succ_nodup (e, dest);
    }
  else
    ret = redirect_branch_edge (e, dest);

  /* We don't want simplejumps in the insn stream during cfglayout.  */
  gcc_assert (!simplejump_p (BB_END (src)));

  df_set_bb_dirty (src);
  return ret;
}

/* Simple wrapper as we always can redirect fallthru edges.  */
static basic_block
cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest)
{
  edge redirected = cfg_layout_redirect_edge_and_branch (e, dest);

  gcc_assert (redirected);
  return NULL;
}

/* Same as delete_basic_block but update cfg_layout structures.  */

static void
cfg_layout_delete_block (basic_block bb)
{
  rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints;

  if (BB_HEADER (bb))
    {
      next = BB_HEAD (bb);
      if (prev)
	NEXT_INSN (prev) = BB_HEADER (bb);
      else
	set_first_insn (BB_HEADER (bb));
      PREV_INSN (BB_HEADER (bb)) = prev;
      insn = BB_HEADER (bb);
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
      NEXT_INSN (insn) = next;
      PREV_INSN (next) = insn;
    }
  next = NEXT_INSN (BB_END (bb));
  if (BB_FOOTER (bb))
    {
      insn = BB_FOOTER (bb);
      while (insn)
	{
	  if (BARRIER_P (insn))
	    {
	      if (PREV_INSN (insn))
		NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
	      else
		BB_FOOTER (bb) = NEXT_INSN (insn);
	      if (NEXT_INSN (insn))
		PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
	    }
	  if (LABEL_P (insn))
	    break;
	  insn = NEXT_INSN (insn);
	}
      if (BB_FOOTER (bb))
	{
	  insn = BB_END (bb);
	  NEXT_INSN (insn) = BB_FOOTER (bb);
	  PREV_INSN (BB_FOOTER (bb)) = insn;
	  while (NEXT_INSN (insn))
	    insn = NEXT_INSN (insn);
	  NEXT_INSN (insn) = next;
	  if (next)
	    PREV_INSN (next) = insn;
	  else
	    set_last_insn (insn);
	}
    }
  if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
    to = &BB_HEADER (bb->next_bb);
  else
    to = &cfg_layout_function_footer;

  rtl_delete_block (bb);

  if (prev)
    prev = NEXT_INSN (prev);
  else
    prev = get_insns ();
  if (next)
    next = PREV_INSN (next);
  else
    next = get_last_insn ();

  if (next && NEXT_INSN (next) != prev)
    {
      remaints = unlink_insn_chain (prev, next);
      insn = remaints;
      while (NEXT_INSN (insn))
	insn = NEXT_INSN (insn);
      NEXT_INSN (insn) = *to;
      if (*to)
	PREV_INSN (*to) = insn;
      *to = remaints;
    }
}

/* Return true when blocks A and B can be safely merged.  */

static bool
cfg_layout_can_merge_blocks_p (basic_block a, basic_block b)
{
  /* If we are partitioning hot/cold basic blocks, we don't want to
     mess up unconditional or indirect jumps that cross between hot
     and cold sections.

     Basic block partitioning may result in some jumps that appear to
     be optimizable (or blocks that appear to be mergeable), but which really
     must be left untouched (they are required to make it safely across
     partition boundaries).  See  the comments at the top of
     bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */

  if (BB_PARTITION (a) != BB_PARTITION (b))
    return false;

  /* Protect the loop latches.  */
  if (current_loops && b->loop_father->latch == b)
    return false;

  /* If we would end up moving B's instructions, make sure it doesn't fall
     through into the exit block, since we cannot recover from a fallthrough
     edge into the exit block occurring in the middle of a function.  */
  if (NEXT_INSN (BB_END (a)) != BB_HEAD (b))
    {
      edge e = find_fallthru_edge (b->succs);
      if (e && e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
	return false;
    }

  /* There must be exactly one edge in between the blocks.  */
  return (single_succ_p (a)
	  && single_succ (a) == b
	  && single_pred_p (b) == 1
	  && a != b
	  /* Must be simple edge.  */
	  && !(single_succ_edge (a)->flags & EDGE_COMPLEX)
	  && a != ENTRY_BLOCK_PTR_FOR_FN (cfun)
	  && b != EXIT_BLOCK_PTR_FOR_FN (cfun)
	  /* If the jump insn has side effects, we can't kill the edge.
	     When not optimizing, try_redirect_by_replacing_jump will
	     not allow us to redirect an edge by replacing a table jump.  */
	  && (!JUMP_P (BB_END (a))
	      || ((!optimize || reload_completed)
		  ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
}

/* Merge block A and B.  The blocks must be mergeable.  */

static void
cfg_layout_merge_blocks (basic_block a, basic_block b)
{
  bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0;
  rtx insn;

  gcc_checking_assert (cfg_layout_can_merge_blocks_p (a, b));

  if (dump_file)
    fprintf (dump_file, "Merging block %d into block %d...\n", b->index,
			 a->index);

  /* If there was a CODE_LABEL beginning B, delete it.  */
  if (LABEL_P (BB_HEAD (b)))
    {
      delete_insn (BB_HEAD (b));
    }

  /* We should have fallthru edge in a, or we can do dummy redirection to get
     it cleaned up.  */
  if (JUMP_P (BB_END (a)))
    try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true);
  gcc_assert (!JUMP_P (BB_END (a)));

  /* When not optimizing CFG and the edge is the only place in RTL which holds
     some unique locus, emit a nop with that locus in between.  */
  if (!optimize)
    emit_nop_for_unique_locus_between (a, b);

  /* Move things from b->footer after a->footer.  */
  if (BB_FOOTER (b))
    {
      if (!BB_FOOTER (a))
	BB_FOOTER (a) = BB_FOOTER (b);
      else
	{
	  rtx last = BB_FOOTER (a);

	  while (NEXT_INSN (last))
	    last = NEXT_INSN (last);
	  NEXT_INSN (last) = BB_FOOTER (b);
	  PREV_INSN (BB_FOOTER (b)) = last;
	}
      BB_FOOTER (b) = NULL;
    }

  /* Move things from b->header before a->footer.
     Note that this may include dead tablejump data, but we don't clean
     those up until we go out of cfglayout mode.  */
   if (BB_HEADER (b))
     {
      if (! BB_FOOTER (a))
	BB_FOOTER (a) = BB_HEADER (b);
      else
	{
	  rtx last = BB_HEADER (b);
 
	  while (NEXT_INSN (last))
	    last = NEXT_INSN (last);
	  NEXT_INSN (last) = BB_FOOTER (a);
	  PREV_INSN (BB_FOOTER (a)) = last;
	  BB_FOOTER (a) = BB_HEADER (b);
	}
      BB_HEADER (b) = NULL;
    }

  /* In the case basic blocks are not adjacent, move them around.  */
  if (NEXT_INSN (BB_END (a)) != BB_HEAD (b))
    {
      insn = unlink_insn_chain (BB_HEAD (b), BB_END (b));

      emit_insn_after_noloc (insn, BB_END (a), a);
    }
  /* Otherwise just re-associate the instructions.  */
  else
    {
      insn = BB_HEAD (b);
      BB_END (a) = BB_END (b);
    }

  /* emit_insn_after_noloc doesn't call df_insn_change_bb.
     We need to explicitly call. */
  update_bb_for_insn_chain (insn, BB_END (b), a);

  /* Skip possible DELETED_LABEL insn.  */
  if (!NOTE_INSN_BASIC_BLOCK_P (insn))
    insn = NEXT_INSN (insn);
  gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn));
  BB_HEAD (b) = BB_END (b) = NULL;
  delete_insn (insn);

  df_bb_delete (b->index);

  /* If B was a forwarder block, propagate the locus on the edge.  */
  if (forwarder_p
      && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION)
    EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus;

  if (dump_file)
    fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index);
}

/* Split edge E.  */

static basic_block
cfg_layout_split_edge (edge e)
{
  basic_block new_bb =
    create_basic_block (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)
			? NEXT_INSN (BB_END (e->src)) : get_insns (),
			NULL_RTX, e->src);

  if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
    BB_COPY_PARTITION (new_bb, e->src);
  else
    BB_COPY_PARTITION (new_bb, e->dest);
  make_edge (new_bb, e->dest, EDGE_FALLTHRU);
  redirect_edge_and_branch_force (e, new_bb);

  return new_bb;
}

/* Do postprocessing after making a forwarder block joined by edge FALLTHRU.  */

static void
rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED)
{
}

/* Return true if BB contains only labels or non-executable
   instructions.  */

static bool
rtl_block_empty_p (basic_block bb)
{
  rtx insn;

  if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)
      || bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return true;

  FOR_BB_INSNS (bb, insn)
    if (NONDEBUG_INSN_P (insn) && !any_uncondjump_p (insn))
      return false;

  return true;
}

/* Split a basic block if it ends with a conditional branch and if
   the other part of the block is not empty.  */

static basic_block
rtl_split_block_before_cond_jump (basic_block bb)
{
  rtx insn;
  rtx split_point = NULL;
  rtx last = NULL;
  bool found_code = false;

  FOR_BB_INSNS (bb, insn)
    {
      if (any_condjump_p (insn))
	split_point = last;
      else if (NONDEBUG_INSN_P (insn))
	found_code = true;
      last = insn;
    }

  /* Did not find everything.  */ 
  if (found_code && split_point)
    return split_block (bb, split_point)->dest;
  else 
    return NULL;
}

/* Return 1 if BB ends with a call, possibly followed by some
   instructions that must stay with the call, 0 otherwise.  */

static bool
rtl_block_ends_with_call_p (basic_block bb)
{
  rtx insn = BB_END (bb);

  while (!CALL_P (insn)
	 && insn != BB_HEAD (bb)
	 && (keep_with_call_p (insn)
	     || NOTE_P (insn)
	     || DEBUG_INSN_P (insn)))
    insn = PREV_INSN (insn);
  return (CALL_P (insn));
}

/* Return 1 if BB ends with a conditional branch, 0 otherwise.  */

static bool
rtl_block_ends_with_condjump_p (const_basic_block bb)
{
  return any_condjump_p (BB_END (bb));
}

/* Return true if we need to add fake edge to exit.
   Helper function for rtl_flow_call_edges_add.  */

static bool
need_fake_edge_p (const_rtx insn)
{
  if (!INSN_P (insn))
    return false;

  if ((CALL_P (insn)
       && !SIBLING_CALL_P (insn)
       && !find_reg_note (insn, REG_NORETURN, NULL)
       && !(RTL_CONST_OR_PURE_CALL_P (insn))))
    return true;

  return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS
	   && MEM_VOLATILE_P (PATTERN (insn)))
	  || (GET_CODE (PATTERN (insn)) == PARALLEL
	      && asm_noperands (insn) != -1
	      && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0)))
	  || GET_CODE (PATTERN (insn)) == ASM_INPUT);
}

/* Add fake edges to the function exit for any non constant and non noreturn
   calls, volatile inline assembly in the bitmap of blocks specified by
   BLOCKS or to the whole CFG if BLOCKS is zero.  Return the number of blocks
   that were split.

   The goal is to expose cases in which entering a basic block does not imply
   that all subsequent instructions must be executed.  */

static int
rtl_flow_call_edges_add (sbitmap blocks)
{
  int i;
  int blocks_split = 0;
  int last_bb = last_basic_block_for_fn (cfun);
  bool check_last_block = false;

  if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS)
    return 0;

  if (! blocks)
    check_last_block = true;
  else
    check_last_block = bitmap_bit_p (blocks,
				     EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb->index);

  /* In the last basic block, before epilogue generation, there will be
     a fallthru edge to EXIT.  Special care is required if the last insn
     of the last basic block is a call because make_edge folds duplicate
     edges, which would result in the fallthru edge also being marked
     fake, which would result in the fallthru edge being removed by
     remove_fake_edges, which would result in an invalid CFG.

     Moreover, we can't elide the outgoing fake edge, since the block
     profiler needs to take this into account in order to solve the minimal
     spanning tree in the case that the call doesn't return.

     Handle this by adding a dummy instruction in a new last basic block.  */
  if (check_last_block)
    {
      basic_block bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb;
      rtx insn = BB_END (bb);

      /* Back up past insns that must be kept in the same block as a call.  */
      while (insn != BB_HEAD (bb)
	     && keep_with_call_p (insn))
	insn = PREV_INSN (insn);

      if (need_fake_edge_p (insn))
	{
	  edge e;

	  e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun));
	  if (e)
	    {
	      insert_insn_on_edge (gen_use (const0_rtx), e);
	      commit_edge_insertions ();
	    }
	}
    }

  /* Now add fake edges to the function exit for any non constant
     calls since there is no way that we can determine if they will
     return or not...  */

  for (i = NUM_FIXED_BLOCKS; i < last_bb; i++)
    {
      basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i);
      rtx insn;
      rtx prev_insn;

      if (!bb)
	continue;

      if (blocks && !bitmap_bit_p (blocks, i))
	continue;

      for (insn = BB_END (bb); ; insn = prev_insn)
	{
	  prev_insn = PREV_INSN (insn);
	  if (need_fake_edge_p (insn))
	    {
	      edge e;
	      rtx split_at_insn = insn;

	      /* Don't split the block between a call and an insn that should
		 remain in the same block as the call.  */
	      if (CALL_P (insn))
		while (split_at_insn != BB_END (bb)
		       && keep_with_call_p (NEXT_INSN (split_at_insn)))
		  split_at_insn = NEXT_INSN (split_at_insn);

	      /* The handling above of the final block before the epilogue
		 should be enough to verify that there is no edge to the exit
		 block in CFG already.  Calling make_edge in such case would
		 cause us to mark that edge as fake and remove it later.  */

#ifdef ENABLE_CHECKING
	      if (split_at_insn == BB_END (bb))
		{
		  e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun));
		  gcc_assert (e == NULL);
		}
#endif

	      /* Note that the following may create a new basic block
		 and renumber the existing basic blocks.  */
	      if (split_at_insn != BB_END (bb))
		{
		  e = split_block (bb, split_at_insn);
		  if (e)
		    blocks_split++;
		}

	      make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FAKE);
	    }

	  if (insn == BB_HEAD (bb))
	    break;
	}
    }

  if (blocks_split)
    verify_flow_info ();

  return blocks_split;
}

/* Add COMP_RTX as a condition at end of COND_BB.  FIRST_HEAD is
   the conditional branch target, SECOND_HEAD should be the fall-thru
   there is no need to handle this here the loop versioning code handles
   this.  the reason for SECON_HEAD is that it is needed for condition
   in trees, and this should be of the same type since it is a hook.  */
static void
rtl_lv_add_condition_to_bb (basic_block first_head ,
			    basic_block second_head ATTRIBUTE_UNUSED,
			    basic_block cond_bb, void *comp_rtx)
{
  rtx label, seq, jump;
  rtx op0 = XEXP ((rtx)comp_rtx, 0);
  rtx op1 = XEXP ((rtx)comp_rtx, 1);
  enum rtx_code comp = GET_CODE ((rtx)comp_rtx);
  enum machine_mode mode;


  label = block_label (first_head);
  mode = GET_MODE (op0);
  if (mode == VOIDmode)
    mode = GET_MODE (op1);

  start_sequence ();
  op0 = force_operand (op0, NULL_RTX);
  op1 = force_operand (op1, NULL_RTX);
  do_compare_rtx_and_jump (op0, op1, comp, 0,
			   mode, NULL_RTX, NULL_RTX, label, -1);
  jump = get_last_insn ();
  JUMP_LABEL (jump) = label;
  LABEL_NUSES (label)++;
  seq = get_insns ();
  end_sequence ();

  /* Add the new cond , in the new head.  */
  emit_insn_after (seq, BB_END (cond_bb));
}


/* Given a block B with unconditional branch at its end, get the
   store the return the branch edge and the fall-thru edge in
   BRANCH_EDGE and FALLTHRU_EDGE respectively.  */
static void
rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge,
			   edge *fallthru_edge)
{
  edge e = EDGE_SUCC (b, 0);

  if (e->flags & EDGE_FALLTHRU)
    {
      *fallthru_edge = e;
      *branch_edge = EDGE_SUCC (b, 1);
    }
  else
    {
      *branch_edge = e;
      *fallthru_edge = EDGE_SUCC (b, 1);
    }
}

void
init_rtl_bb_info (basic_block bb)
{
  gcc_assert (!bb->il.x.rtl);
  bb->il.x.head_ = NULL;
  bb->il.x.rtl = ggc_alloc_cleared_rtl_bb_info ();
}

/* Returns true if it is possible to remove edge E by redirecting
   it to the destination of the other edge from E->src.  */

static bool
rtl_can_remove_branch_p (const_edge e)
{
  const_basic_block src = e->src;
  const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest;
  const_rtx insn = BB_END (src), set;

  /* The conditions are taken from try_redirect_by_replacing_jump.  */
  if (target == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return false;

  if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
    return false;

  if (BB_PARTITION (src) != BB_PARTITION (target))
    return false;

  if (!onlyjump_p (insn)
      || tablejump_p (insn, NULL, NULL))
    return false;

  set = single_set (insn);
  if (!set || side_effects_p (set))
    return false;

  return true;
}

static basic_block
rtl_duplicate_bb (basic_block bb)
{
  bb = cfg_layout_duplicate_bb (bb);
  bb->aux = NULL;
  return bb;
}

/* Do book-keeping of basic block BB for the profile consistency checker.
   If AFTER_PASS is 0, do pre-pass accounting, or if AFTER_PASS is 1
   then do post-pass accounting.  Store the counting in RECORD.  */
static void
rtl_account_profile_record (basic_block bb, int after_pass,
			    struct profile_record *record)
{
  rtx insn;
  FOR_BB_INSNS (bb, insn)
    if (INSN_P (insn))
      {
	record->size[after_pass]
	  += insn_rtx_cost (PATTERN (insn), false);
	if (profile_status_for_fn (cfun) == PROFILE_READ)
	  record->time[after_pass]
	    += insn_rtx_cost (PATTERN (insn), true) * bb->count;
	else if (profile_status_for_fn (cfun) == PROFILE_GUESSED)
	  record->time[after_pass]
	    += insn_rtx_cost (PATTERN (insn), true) * bb->frequency;
      }
}

/* Implementation of CFG manipulation for linearized RTL.  */
struct cfg_hooks rtl_cfg_hooks = {
  "rtl",
  rtl_verify_flow_info,
  rtl_dump_bb,
  rtl_dump_bb_for_graph,
  rtl_create_basic_block,
  rtl_redirect_edge_and_branch,
  rtl_redirect_edge_and_branch_force,
  rtl_can_remove_branch_p,
  rtl_delete_block,
  rtl_split_block,
  rtl_move_block_after,
  rtl_can_merge_blocks,  /* can_merge_blocks_p */
  rtl_merge_blocks,
  rtl_predict_edge,
  rtl_predicted_by_p,
  cfg_layout_can_duplicate_bb_p,
  rtl_duplicate_bb,
  rtl_split_edge,
  rtl_make_forwarder_block,
  rtl_tidy_fallthru_edge,
  rtl_force_nonfallthru,
  rtl_block_ends_with_call_p,
  rtl_block_ends_with_condjump_p,
  rtl_flow_call_edges_add,
  NULL, /* execute_on_growing_pred */
  NULL, /* execute_on_shrinking_pred */
  NULL, /* duplicate loop for trees */
  NULL, /* lv_add_condition_to_bb */
  NULL, /* lv_adjust_loop_header_phi*/
  NULL, /* extract_cond_bb_edges */
  NULL, /* flush_pending_stmts */
  rtl_block_empty_p, /* block_empty_p */
  rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */
  rtl_account_profile_record,
};

/* Implementation of CFG manipulation for cfg layout RTL, where
   basic block connected via fallthru edges does not have to be adjacent.
   This representation will hopefully become the default one in future
   version of the compiler.  */

struct cfg_hooks cfg_layout_rtl_cfg_hooks = {
  "cfglayout mode",
  rtl_verify_flow_info_1,
  rtl_dump_bb,
  rtl_dump_bb_for_graph,
  cfg_layout_create_basic_block,
  cfg_layout_redirect_edge_and_branch,
  cfg_layout_redirect_edge_and_branch_force,
  rtl_can_remove_branch_p,
  cfg_layout_delete_block,
  cfg_layout_split_block,
  rtl_move_block_after,
  cfg_layout_can_merge_blocks_p,
  cfg_layout_merge_blocks,
  rtl_predict_edge,
  rtl_predicted_by_p,
  cfg_layout_can_duplicate_bb_p,
  cfg_layout_duplicate_bb,
  cfg_layout_split_edge,
  rtl_make_forwarder_block,
  NULL, /* tidy_fallthru_edge */
  rtl_force_nonfallthru,
  rtl_block_ends_with_call_p,
  rtl_block_ends_with_condjump_p,
  rtl_flow_call_edges_add,
  NULL, /* execute_on_growing_pred */
  NULL, /* execute_on_shrinking_pred */
  duplicate_loop_to_header_edge, /* duplicate loop for trees */
  rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */
  NULL, /* lv_adjust_loop_header_phi*/
  rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */
  NULL, /* flush_pending_stmts */  
  rtl_block_empty_p, /* block_empty_p */
  rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */
  rtl_account_profile_record,
};

#include "gt-cfgrtl.h"