summary refs log tree commit diff
path: root/sysdeps/sparc/sub_n.S
blob: b7a11958e258d406a2b2cfa5e92a1a4f54fba4ab (plain) (blame)
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
! SPARC __mpn_sub_n -- Subtract two limb vectors of the same length > 0 and
! store difference in a third limb vector.

! Copyright (C) 1995, 1996 Free Software Foundation, Inc.

! This file is part of the GNU MP Library.

! The GNU MP Library is free software; you can redistribute it and/or modify
! it under the terms of the GNU Library General Public License as published by
! the Free Software Foundation; either version 2 of the License, or (at your
! option) any later version.

! The GNU MP Library 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 Library General Public
! License for more details.

! You should have received a copy of the GNU Library General Public License
! along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
! the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
! MA 02111-1307, USA.


! INPUT PARAMETERS
#define res_ptr	%o0
#define s1_ptr	%o1
#define s2_ptr	%o2
#define size	%o3

#include "sysdep.h"

	.text
	.align	4
	.global	C_SYMBOL_NAME(__mpn_sub_n)
C_SYMBOL_NAME(__mpn_sub_n):
	xor	s2_ptr,res_ptr,%g1
	andcc	%g1,4,%g0
	bne	L1			! branch if alignment differs
	nop
! **  V1a  **
	andcc	res_ptr,4,%g0		! res_ptr unaligned? Side effect: cy=0
	be	L_v1			! if no, branch
	nop
/* Add least significant limb separately to align res_ptr and s2_ptr */
	ld	[s1_ptr],%g4
	add	s1_ptr,4,s1_ptr
	ld	[s2_ptr],%g2
	add	s2_ptr,4,s2_ptr
	add	size,-1,size
	subcc	%g4,%g2,%o4
	st	%o4,[res_ptr]
	add	res_ptr,4,res_ptr
L_v1:	addx	%g0,%g0,%o4		! save cy in register
	cmp	size,2			! if size < 2 ...
	bl	Lend2			! ... branch to tail code
	subcc	%g0,%o4,%g0		! restore cy

	ld	[s1_ptr+0],%g4
	addcc	size,-10,size
	ld	[s1_ptr+4],%g1
	ldd	[s2_ptr+0],%g2
	blt	Lfin1
	subcc	%g0,%o4,%g0		! restore cy
/* Add blocks of 8 limbs until less than 8 limbs remain */
Loop1:	subxcc	%g4,%g2,%o4
	ld	[s1_ptr+8],%g4
	subxcc	%g1,%g3,%o5
	ld	[s1_ptr+12],%g1
	ldd	[s2_ptr+8],%g2
	std	%o4,[res_ptr+0]
	subxcc	%g4,%g2,%o4
	ld	[s1_ptr+16],%g4
	subxcc	%g1,%g3,%o5
	ld	[s1_ptr+20],%g1
	ldd	[s2_ptr+16],%g2
	std	%o4,[res_ptr+8]
	subxcc	%g4,%g2,%o4
	ld	[s1_ptr+24],%g4
	subxcc	%g1,%g3,%o5
	ld	[s1_ptr+28],%g1
	ldd	[s2_ptr+24],%g2
	std	%o4,[res_ptr+16]
	subxcc	%g4,%g2,%o4
	ld	[s1_ptr+32],%g4
	subxcc	%g1,%g3,%o5
	ld	[s1_ptr+36],%g1
	ldd	[s2_ptr+32],%g2
	std	%o4,[res_ptr+24]
	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-8,size
	add	s1_ptr,32,s1_ptr
	add	s2_ptr,32,s2_ptr
	add	res_ptr,32,res_ptr
	bge	Loop1
	subcc	%g0,%o4,%g0		! restore cy

Lfin1:	addcc	size,8-2,size
	blt	Lend1
	subcc	%g0,%o4,%g0		! restore cy
/* Add blocks of 2 limbs until less than 2 limbs remain */
Loope1:	subxcc	%g4,%g2,%o4
	ld	[s1_ptr+8],%g4
	subxcc	%g1,%g3,%o5
	ld	[s1_ptr+12],%g1
	ldd	[s2_ptr+8],%g2
	std	%o4,[res_ptr+0]
	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-2,size
	add	s1_ptr,8,s1_ptr
	add	s2_ptr,8,s2_ptr
	add	res_ptr,8,res_ptr
	bge	Loope1
	subcc	%g0,%o4,%g0		! restore cy
Lend1:	subxcc	%g4,%g2,%o4
	subxcc	%g1,%g3,%o5
	std	%o4,[res_ptr+0]
	addx	%g0,%g0,%o4		! save cy in register

	andcc	size,1,%g0
	be	Lret1
	subcc	%g0,%o4,%g0		! restore cy
/* Add last limb */
	ld	[s1_ptr+8],%g4
	ld	[s2_ptr+8],%g2
	subxcc	%g4,%g2,%o4
	st	%o4,[res_ptr+8]

Lret1:	retl
	addx	%g0,%g0,%o0	! return carry-out from most sign. limb

L1:	xor	s1_ptr,res_ptr,%g1
	andcc	%g1,4,%g0
	bne	L2
	nop
! **  V1b  **
	andcc	res_ptr,4,%g0		! res_ptr unaligned? Side effect: cy=0
	be	L_v1b			! if no, branch
	nop
/* Add least significant limb separately to align res_ptr and s1_ptr */
	ld	[s2_ptr],%g4
	add	s2_ptr,4,s2_ptr
	ld	[s1_ptr],%g2
	add	s1_ptr,4,s1_ptr
	add	size,-1,size
	subcc	%g2,%g4,%o4
	st	%o4,[res_ptr]
	add	res_ptr,4,res_ptr
L_v1b:	addx	%g0,%g0,%o4		! save cy in register
	cmp	size,2			! if size < 2 ...
	bl	Lend2			! ... branch to tail code
	subcc	%g0,%o4,%g0		! restore cy

	ld	[s2_ptr+0],%g4
	addcc	size,-10,size
	ld	[s2_ptr+4],%g1
	ldd	[s1_ptr+0],%g2
	blt	Lfin1b
	subcc	%g0,%o4,%g0		! restore cy
/* Add blocks of 8 limbs until less than 8 limbs remain */
Loop1b:	subxcc	%g2,%g4,%o4
	ld	[s2_ptr+8],%g4
	subxcc	%g3,%g1,%o5
	ld	[s2_ptr+12],%g1
	ldd	[s1_ptr+8],%g2
	std	%o4,[res_ptr+0]
	subxcc	%g2,%g4,%o4
	ld	[s2_ptr+16],%g4
	subxcc	%g3,%g1,%o5
	ld	[s2_ptr+20],%g1
	ldd	[s1_ptr+16],%g2
	std	%o4,[res_ptr+8]
	subxcc	%g2,%g4,%o4
	ld	[s2_ptr+24],%g4
	subxcc	%g3,%g1,%o5
	ld	[s2_ptr+28],%g1
	ldd	[s1_ptr+24],%g2
	std	%o4,[res_ptr+16]
	subxcc	%g2,%g4,%o4
	ld	[s2_ptr+32],%g4
	subxcc	%g3,%g1,%o5
	ld	[s2_ptr+36],%g1
	ldd	[s1_ptr+32],%g2
	std	%o4,[res_ptr+24]
	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-8,size
	add	s1_ptr,32,s1_ptr
	add	s2_ptr,32,s2_ptr
	add	res_ptr,32,res_ptr
	bge	Loop1b
	subcc	%g0,%o4,%g0		! restore cy

Lfin1b:	addcc	size,8-2,size
	blt	Lend1b
	subcc	%g0,%o4,%g0		! restore cy
/* Add blocks of 2 limbs until less than 2 limbs remain */
Loope1b:subxcc	%g2,%g4,%o4
	ld	[s2_ptr+8],%g4
	subxcc	%g3,%g1,%o5
	ld	[s2_ptr+12],%g1
	ldd	[s1_ptr+8],%g2
	std	%o4,[res_ptr+0]
	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-2,size
	add	s1_ptr,8,s1_ptr
	add	s2_ptr,8,s2_ptr
	add	res_ptr,8,res_ptr
	bge	Loope1b
	subcc	%g0,%o4,%g0		! restore cy
Lend1b:	subxcc	%g2,%g4,%o4
	subxcc	%g3,%g1,%o5
	std	%o4,[res_ptr+0]
	addx	%g0,%g0,%o4		! save cy in register

	andcc	size,1,%g0
	be	Lret1b
	subcc	%g0,%o4,%g0		! restore cy
/* Add last limb */
	ld	[s2_ptr+8],%g4
	ld	[s1_ptr+8],%g2
	subxcc	%g2,%g4,%o4
	st	%o4,[res_ptr+8]

Lret1b:	retl
	addx	%g0,%g0,%o0	! return carry-out from most sign. limb

! **  V2  **
/* If we come here, the alignment of s1_ptr and res_ptr as well as the
   alignment of s2_ptr and res_ptr differ.  Since there are only two ways
   things can be aligned (that we care about) we now know that the alignment
   of s1_ptr and s2_ptr are the same.  */

L2:	cmp	size,1
	be	Ljone
	nop
	andcc	s1_ptr,4,%g0		! s1_ptr unaligned? Side effect: cy=0
	be	L_v2			! if no, branch
	nop
/* Add least significant limb separately to align s1_ptr and s2_ptr */
	ld	[s1_ptr],%g4
	add	s1_ptr,4,s1_ptr
	ld	[s2_ptr],%g2
	add	s2_ptr,4,s2_ptr
	add	size,-1,size
	subcc	%g4,%g2,%o4
	st	%o4,[res_ptr]
	add	res_ptr,4,res_ptr

L_v2:	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-8,size
	blt	Lfin2
	subcc	%g0,%o4,%g0		! restore cy
/* Add blocks of 8 limbs until less than 8 limbs remain */
Loop2:	ldd	[s1_ptr+0],%g2
	ldd	[s2_ptr+0],%o4
	subxcc	%g2,%o4,%g2
	st	%g2,[res_ptr+0]
	subxcc	%g3,%o5,%g3
	st	%g3,[res_ptr+4]
	ldd	[s1_ptr+8],%g2
	ldd	[s2_ptr+8],%o4
	subxcc	%g2,%o4,%g2
	st	%g2,[res_ptr+8]
	subxcc	%g3,%o5,%g3
	st	%g3,[res_ptr+12]
	ldd	[s1_ptr+16],%g2
	ldd	[s2_ptr+16],%o4
	subxcc	%g2,%o4,%g2
	st	%g2,[res_ptr+16]
	subxcc	%g3,%o5,%g3
	st	%g3,[res_ptr+20]
	ldd	[s1_ptr+24],%g2
	ldd	[s2_ptr+24],%o4
	subxcc	%g2,%o4,%g2
	st	%g2,[res_ptr+24]
	subxcc	%g3,%o5,%g3
	st	%g3,[res_ptr+28]
	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-8,size
	add	s1_ptr,32,s1_ptr
	add	s2_ptr,32,s2_ptr
	add	res_ptr,32,res_ptr
	bge	Loop2
	subcc	%g0,%o4,%g0		! restore cy

Lfin2:	addcc	size,8-2,size
	blt	Lend2
	subcc	%g0,%o4,%g0		! restore cy
Loope2:	ldd	[s1_ptr+0],%g2
	ldd	[s2_ptr+0],%o4
	subxcc	%g2,%o4,%g2
	st	%g2,[res_ptr+0]
	subxcc	%g3,%o5,%g3
	st	%g3,[res_ptr+4]
	addx	%g0,%g0,%o4		! save cy in register
	addcc	size,-2,size
	add	s1_ptr,8,s1_ptr
	add	s2_ptr,8,s2_ptr
	add	res_ptr,8,res_ptr
	bge	Loope2
	subcc	%g0,%o4,%g0		! restore cy
Lend2:	andcc	size,1,%g0
	be	Lret2
	subcc	%g0,%o4,%g0		! restore cy
/* Add last limb */
Ljone:	ld	[s1_ptr],%g4
	ld	[s2_ptr],%g2
	subxcc	%g4,%g2,%o4
	st	%o4,[res_ptr]

Lret2:	retl
	addx	%g0,%g0,%o0	! return carry-out from most sign. limb