summaryrefslogtreecommitdiff
path: root/src/pkg/math/big/arith_arm.s
blob: 8d36761c4cd414078f3ea5d233026ff81bcb6542 (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
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "../../../cmd/ld/textflag.h"

// This file provides fast assembly versions for the elementary
// arithmetic operations on vectors implemented in arith.go.

// func addVV(z, x, y []Word) (c Word)
TEXT ·addVV(SB),NOSPLIT,$0
	ADD.S	$0, R0		// clear carry flag
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R4
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3
	ADD	R4<<2, R1, R4
	B E1
L1:
	MOVW.P	4(R2), R5
	MOVW.P	4(R3), R6
	ADC.S	R6, R5
	MOVW.P	R5, 4(R1)
E1:
	TEQ	R1, R4
	BNE L1

	MOVW	$0, R0
	MOVW.CS	$1, R0
	MOVW	R0, c+36(FP)
	RET


// func subVV(z, x, y []Word) (c Word)
// (same as addVV except for SBC instead of ADC and label names)
TEXT ·subVV(SB),NOSPLIT,$0
	SUB.S	$0, R0		// clear borrow flag
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R4
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3
	ADD	R4<<2, R1, R4
	B E2
L2:
	MOVW.P	4(R2), R5
	MOVW.P	4(R3), R6
	SBC.S	R6, R5
	MOVW.P	R5, 4(R1)
E2:
	TEQ	R1, R4
	BNE L2

	MOVW	$0, R0
	MOVW.CC	$1, R0
	MOVW	R0, c+36(FP)
	RET


// func addVW(z, x []Word, y Word) (c Word)
TEXT ·addVW(SB),NOSPLIT,$0
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R4
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3
	ADD	R4<<2, R1, R4
	TEQ	R1, R4
	BNE L3a
	MOVW	R3, c+28(FP)
	RET
L3a:
	MOVW.P	4(R2), R5
	ADD.S	R3, R5
	MOVW.P	R5, 4(R1)
	B	E3
L3:
	MOVW.P	4(R2), R5
	ADC.S	$0, R5
	MOVW.P	R5, 4(R1)
E3:
	TEQ	R1, R4
	BNE	L3

	MOVW	$0, R0
	MOVW.CS	$1, R0
	MOVW	R0, c+28(FP)
	RET


// func subVW(z, x []Word, y Word) (c Word)
TEXT ·subVW(SB),NOSPLIT,$0
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R4
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3
	ADD	R4<<2, R1, R4
	TEQ	R1, R4
	BNE L4a
	MOVW	R3, c+28(FP)
	RET
L4a:
	MOVW.P	4(R2), R5
	SUB.S	R3, R5
	MOVW.P	R5, 4(R1)
	B	E4
L4:
	MOVW.P	4(R2), R5
	SBC.S	$0, R5
	MOVW.P	R5, 4(R1)
E4:
	TEQ	R1, R4
	BNE	L4

	MOVW	$0, R0
	MOVW.CC	$1, R0
	MOVW	R0, c+28(FP)
	RET


// func shlVU(z, x []Word, s uint) (c Word)
TEXT ·shlVU(SB),NOSPLIT,$0
	MOVW	z_len+4(FP), R5
	TEQ	$0, R5
	BEQ	X7
	
	MOVW	z+0(FP), R1
	MOVW	x+12(FP), R2
	ADD	R5<<2, R2, R2
	ADD	R5<<2, R1, R5
	MOVW	s+24(FP), R3
	TEQ	$0, R3	// shift 0 is special
	BEQ	Y7
	ADD	$4, R1	// stop one word early
	MOVW	$32, R4
	SUB	R3, R4
	MOVW	$0, R7
	
	MOVW.W	-4(R2), R6
	MOVW	R6<<R3, R7
	MOVW	R6>>R4, R6
	MOVW	R6, c+28(FP)
	B E7

L7:
	MOVW.W	-4(R2), R6
	ORR	R6>>R4, R7
	MOVW.W	R7, -4(R5)
	MOVW	R6<<R3, R7
E7:
	TEQ	R1, R5
	BNE	L7

	MOVW	R7, -4(R5)
	RET

Y7:	// copy loop, because shift 0 == shift 32
	MOVW.W	-4(R2), R6
	MOVW.W	R6, -4(R5)
	TEQ	R1, R5
	BNE Y7

X7:
	MOVW	$0, R1
	MOVW	R1, c+28(FP)
	RET


// func shrVU(z, x []Word, s uint) (c Word)
TEXT ·shrVU(SB),NOSPLIT,$0
	MOVW	z_len+4(FP), R5
	TEQ	$0, R5
	BEQ	X6

	MOVW	z+0(FP), R1
	MOVW	x+12(FP), R2
	ADD	R5<<2, R1, R5
	MOVW	s+24(FP), R3
	TEQ	$0, R3	// shift 0 is special
	BEQ Y6
	SUB	$4, R5	// stop one word early
	MOVW	$32, R4
	SUB	R3, R4
	MOVW	$0, R7

	// first word
	MOVW.P	4(R2), R6
	MOVW	R6>>R3, R7
	MOVW	R6<<R4, R6
	MOVW	R6, c+28(FP)
	B E6

	// word loop
L6:
	MOVW.P	4(R2), R6
	ORR	R6<<R4, R7
	MOVW.P	R7, 4(R1)
	MOVW	R6>>R3, R7
E6:
	TEQ	R1, R5
	BNE	L6

	MOVW	R7, 0(R1)
	RET

Y6:	// copy loop, because shift 0 == shift 32
	MOVW.P	4(R2), R6
	MOVW.P	R6, 4(R1)
	TEQ R1, R5
	BNE Y6

X6:
	MOVW	$0, R1
	MOVW	R1, c+28(FP)
	RET


// func mulAddVWW(z, x []Word, y, r Word) (c Word)
TEXT ·mulAddVWW(SB),NOSPLIT,$0
	MOVW	$0, R0
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R5
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3
	MOVW	r+28(FP), R4
	ADD	R5<<2, R1, R5
	B E8

	// word loop
L8:
	MOVW.P	4(R2), R6
	MULLU	R6, R3, (R7, R6)
	ADD.S	R4, R6
	ADC	R0, R7
	MOVW.P	R6, 4(R1)
	MOVW	R7, R4
E8:
	TEQ	R1, R5
	BNE	L8

	MOVW	R4, c+32(FP)
	RET


// func addMulVVW(z, x []Word, y Word) (c Word)
TEXT ·addMulVVW(SB),NOSPLIT,$0
	MOVW	$0, R0
	MOVW	z+0(FP), R1
	MOVW	z_len+4(FP), R5
	MOVW	x+12(FP), R2
	MOVW	y+24(FP), R3
	ADD	R5<<2, R1, R5
	MOVW	$0, R4
	B E9

	// word loop
L9:
	MOVW.P	4(R2), R6
	MULLU	R6, R3, (R7, R6)
	ADD.S	R4, R6
	ADC	R0, R7
	MOVW	0(R1), R4
	ADD.S	R4, R6
	ADC	R0, R7
	MOVW.P	R6, 4(R1)
	MOVW	R7, R4
E9:
	TEQ	R1, R5
	BNE	L9

	MOVW	R4, c+28(FP)
	RET


// func divWVW(z* Word, xn Word, x []Word, y Word) (r Word)
TEXT ·divWVW(SB),NOSPLIT,$0
	// ARM has no multiword division, so use portable code.
	B ·divWVW_g(SB)


// func divWW(x1, x0, y Word) (q, r Word)
TEXT ·divWW(SB),NOSPLIT,$0
	// ARM has no multiword division, so use portable code.
	B ·divWW_g(SB)


// func mulWW(x, y Word) (z1, z0 Word)
TEXT ·mulWW(SB),NOSPLIT,$0
	MOVW	x+0(FP), R1
	MOVW	y+4(FP), R2
	MULLU	R1, R2, (R4, R3)
	MOVW	R4, z1+8(FP)
	MOVW	R3, z0+12(FP)
	RET

// func bitLen(x Word) (n int)
TEXT ·bitLen(SB),NOSPLIT,$0
	MOVW	x+0(FP), R0
	CLZ 	R0, R0
	RSB	$32, R0
	MOVW	R0, n+4(FP)
	RET