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
|
/* libgcc functions for Blackfin.
Copyright (C) 2005-2014 Free Software Foundation, Inc.
Contributed by Analog Devices.
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.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifdef L_divsi3
.text
.align 2
.global ___divsi3;
.type ___divsi3, STT_FUNC;
___divsi3:
[--SP]= RETS;
[--SP] = R7;
R2 = -R0;
CC = R0 < 0;
IF CC R0 = R2;
R7 = CC;
R2 = -R1;
CC = R1 < 0;
IF CC R1 = R2;
R2 = CC;
R7 = R7 ^ R2;
CALL ___udivsi3;
CC = R7;
R1 = -R0;
IF CC R0 = R1;
R7 = [SP++];
RETS = [SP++];
RTS;
#endif
#ifdef L_modsi3
.align 2
.global ___modsi3;
.type ___modsi3, STT_FUNC;
___modsi3:
[--SP] = RETS;
[--SP] = R0;
[--SP] = R1;
CALL ___divsi3;
R2 = [SP++];
R1 = [SP++];
R2 *= R0;
R0 = R1 - R2;
RETS = [SP++];
RTS;
#endif
#ifdef L_udivsi3
.align 2
.global ___udivsi3;
.type ___udivsi3, STT_FUNC;
___udivsi3:
P0 = 32;
LSETUP (0f, 1f) LC0 = P0;
/* upper half of dividend */
R3 = 0;
0:
/* The first time round in the loop we shift in garbage, but since we
perform 33 shifts, it doesn't matter. */
R0 = ROT R0 BY 1;
R3 = ROT R3 BY 1;
R2 = R3 - R1;
CC = R3 < R1 (IU);
1:
/* Last instruction of the loop. */
IF ! CC R3 = R2;
/* Shift in the last bit. */
R0 = ROT R0 BY 1;
/* R0 is the result, R3 contains the remainder. */
R0 = ~ R0;
RTS;
#endif
#ifdef L_umodsi3
.align 2
.global ___umodsi3;
.type ___umodsi3, STT_FUNC;
___umodsi3:
[--SP] = RETS;
CALL ___udivsi3;
R0 = R3;
RETS = [SP++];
RTS;
#endif
#ifdef L_umulsi3_highpart
.align 2
.global ___umulsi3_highpart;
.type ___umulsi3_highpart, STT_FUNC;
___umulsi3_highpart:
A1 = R1.L * R0.L (FU);
A1 = A1 >> 16;
A0 = R1.H * R0.H, A1 += R1.L * R0.H (FU);
A1 += R0.L * R1.H (FU);
A1 = A1 >> 16;
A0 += A1;
R0 = A0 (FU);
RTS;
#endif
#ifdef L_smulsi3_highpart
.align 2
.global ___smulsi3_highpart;
.type ___smulsi3_highpart, STT_FUNC;
___smulsi3_highpart:
A1 = R1.L * R0.L (FU);
A1 = A1 >> 16;
A0 = R0.H * R1.H, A1 += R0.H * R1.L (IS,M);
A1 += R1.H * R0.L (IS,M);
A1 = A1 >>> 16;
R0 = (A0 += A1);
RTS;
#endif
#ifdef L_muldi3
.align 2
.global ___muldi3;
.type ___muldi3, STT_FUNC;
/*
R1:R0 * R3:R2
= R1.h:R1.l:R0.h:R0.l * R3.h:R3.l:R2.h:R2.l
[X] = (R1.h * R3.h) * 2^96
[X] + (R1.h * R3.l + R1.l * R3.h) * 2^80
[X] + (R1.h * R2.h + R1.l * R3.l + R3.h * R0.h) * 2^64
[T1] + (R1.h * R2.l + R3.h * R0.l + R1.l * R2.h + R3.l * R0.h) * 2^48
[T2] + (R1.l * R2.l + R3.l * R0.l + R0.h * R2.h) * 2^32
[T3] + (R0.l * R2.h + R2.l * R0.h) * 2^16
[T4] + (R0.l * R2.l)
We can discard the first three lines marked "X" since we produce
only a 64 bit result. So, we need ten 16-bit multiplies.
Individual mul-acc results:
[E1] = R1.h * R2.l + R3.h * R0.l + R1.l * R2.h + R3.l * R0.h
[E2] = R1.l * R2.l + R3.l * R0.l + R0.h * R2.h
[E3] = R0.l * R2.h + R2.l * R0.h
[E4] = R0.l * R2.l
We also need to add high parts from lower-level results to higher ones:
E[n]c = E[n] + (E[n+1]c >> 16), where E4c := E4
One interesting property is that all parts of the result that depend
on the sign of the multiplication are discarded. Those would be the
multiplications involving R1.h and R3.h, but only the top 16 bit of
the 32 bit result depend on the sign, and since R1.h and R3.h only
occur in E1, the top half of these results is cut off.
So, we can just use FU mode for all of the 16-bit multiplies, and
ignore questions of when to use mixed mode. */
___muldi3:
/* [SP] technically is part of the caller's frame, but we can
use it as scratch space. */
A0 = R2.H * R1.L, A1 = R2.L * R1.H (FU) || R3 = [SP + 12]; /* E1 */
A0 += R3.H * R0.L, A1 += R3.L * R0.H (FU) || [SP] = R4; /* E1 */
A0 += A1; /* E1 */
R4 = A0.w;
A0 = R0.l * R3.l (FU); /* E2 */
A0 += R2.l * R1.l (FU); /* E2 */
A1 = R2.L * R0.L (FU); /* E4 */
R3 = A1.w;
A1 = A1 >> 16; /* E3c */
A0 += R2.H * R0.H, A1 += R2.L * R0.H (FU); /* E2, E3c */
A1 += R0.L * R2.H (FU); /* E3c */
R0 = A1.w;
A1 = A1 >> 16; /* E2c */
A0 += A1; /* E2c */
R1 = A0.w;
/* low(result) = low(E3c):low(E4) */
R0 = PACK (R0.l, R3.l);
/* high(result) = E2c + (E1 << 16) */
R1.h = R1.h + R4.l (NS) || R4 = [SP];
RTS;
.size ___muldi3, .-___muldi3
#endif
|
