[thirdparty/glibc.git] / sysdeps / powerpc / powerpc64 / power7 / memset.S

/* Optimized memset implementation for PowerPC64/POWER7.
   Copyright (C) 2010-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <sysdep.h>

/* void * [r3] memset (void *s [r3], int c [r4], size_t n [r5]));
   Returns 's'.  */

#ifndef MEMSET
# define MEMSET memset
#endif
	.machine power7
ENTRY_TOCLESS (MEMSET, 5)
	CALL_MCOUNT 3

L(_memset):
	cmpldi	cr7,5,31
	cmpldi	cr6,5,8
	mr	10,3

	/* Replicate byte to word.  */
	insrdi	4,4,8,48
	insrdi	4,4,16,32
	ble	cr6,L(small)	/* If length <= 8, use short copy code.  */

	neg	0,3
	ble	cr7,L(medium)	/* If length < 32, use medium copy code.  */

	andi.	11,10,7		/* Check alignment of SRC.  */
	insrdi	4,4,32,0	/* Replicate word to double word.  */

	mr	12,5
	beq	L(big_aligned)

	clrldi	0,0,61
	mtocrf	0x01,0
	subf	5,0,5

	/* Get DST aligned to 8 bytes.  */
1:	bf	31,2f

	stb	4,0(10)
	addi	10,10,1
2:	bf	30,4f

	sth	4,0(10)
	addi	10,10,2
4:	bf	29,L(big_aligned)

	stw	4,0(10)
	addi	10,10,4

	.align	4
L(big_aligned):

	cmpldi	cr5,5,255
	li	0,32
	dcbtst	0,10
	cmpldi	cr6,4,0
	srdi	9,5,3	/* Number of full doublewords remaining.  */
	crand	27,26,21
	mtocrf	0x01,9
	bt	27,L(huge)

	/* From this point on, we'll copy 32+ bytes and the value
	   isn't 0 (so we can't use dcbz).  */

	srdi	8,5,5
	clrldi	11,5,61
	cmpldi	cr6,11,0
	cmpldi	cr1,9,4
	mtctr	8

	/* Copy 1~3 doublewords so the main loop starts
	at a multiple of 32 bytes.  */

	bf	30,1f

	std	4,0(10)
	std	4,8(10)
	addi	10,10,16
	bf	31,L(big_loop)

	std	4,0(10)
	addi	10,10,8
	mr	12,10
	blt	cr1,L(tail_bytes)
	b	L(big_loop)

	.align	4
1:	/* Copy 1 doubleword.  */
	bf	31,L(big_loop)

	std	4,0(10)
	addi	10,10,8

	/* Main aligned copy loop.  Copies 32-bytes at a time and
	   ping-pong through r10 and r12 to avoid AGEN delays.  */
	.align	4
L(big_loop):
	addi	12,10,32
	std	4,0(10)
	std	4,8(10)
	std	4,16(10)
	std	4,24(10)
	bdz	L(tail_bytes)

	addi	10,10,64
	std	4,0(12)
	std	4,8(12)
	std	4,16(12)
	std	4,24(12)
	bdnz	L(big_loop)

	mr	12,10
	b	L(tail_bytes)

	.align	4
L(tail_bytes):

	/* Check for tail bytes.  */
	beqlr	cr6

	clrldi	0,5,61
	mtocrf	0x01,0

	/*  At this point we have a tail of 0-7 bytes and we know that the
	destination is doubleword-aligned.  */
4:	/* Copy 4 bytes.  */
	bf	29,2f

	stw	4,0(12)
	addi	12,12,4
2:	/* Copy 2 bytes.  */
	bf	30,1f

	sth	4,0(12)
	addi	12,12,2
1:	/* Copy 1 byte.  */
	bflr	31

	stb	4,0(12)
	blr

	/* Special case when value is 0 and we have a long length to deal
	   with.  Use dcbz to zero out 128-bytes at a time.  Before using
	   dcbz though, we need to get the destination 128-bytes aligned.  */
	.align	4
L(huge):
	andi.	11,10,127
	neg	0,10
	beq	L(huge_aligned)

	clrldi	0,0,57
	subf	5,0,5
	srdi	0,0,3
	mtocrf	0x01,0

	/* Get DST aligned to 128 bytes.  */
8:	bf	28,4f

	std	4,0(10)
	std	4,8(10)
	std	4,16(10)
	std	4,24(10)
	std	4,32(10)
	std	4,40(10)
	std	4,48(10)
	std	4,56(10)
	addi	10,10,64
	.align	4
4:	bf	29,2f

	std	4,0(10)
	std	4,8(10)
	std	4,16(10)
	std	4,24(10)
	addi	10,10,32
	.align	4
2:	bf	30,1f

	std	4,0(10)
	std	4,8(10)
	addi	10,10,16
	.align	4
1:	bf	31,L(huge_aligned)

	std	4,0(10)
	addi	10,10,8


L(huge_aligned):
	srdi	8,5,7
	clrldi	11,5,57
	cmpldi	cr6,11,0
	mtctr	8

	.align	4
L(huge_loop):
	dcbz	0,10
	addi	10,10,128
	bdnz	L(huge_loop)

	/* Check how many bytes are still left.  */
	beqlr	cr6

	subf	9,3,10
	subf	5,9,12
	srdi	8,5,3
	cmpldi	cr6,8,0
	mtocrf	0x01,8

	/* We have a tail o 1~127 bytes.  Copy up to 15 doublewords for
	speed.  We'll handle the resulting tail bytes later.  */
	beq	cr6,L(tail)

8:	bf	28,4f

	std	4,0(10)
	std	4,8(10)
	std	4,16(10)
	std	4,24(10)
	std	4,32(10)
	std	4,40(10)
	std	4,48(10)
	std	4,56(10)
	addi	10,10,64
	.align	4
4:	bf	29,2f

	std	4,0(10)
	std	4,8(10)
	std	4,16(10)
	std	4,24(10)
	addi	10,10,32
	.align	4
2:	bf	30,1f

	std	4,0(10)
	std	4,8(10)
	addi	10,10,16
	.align	4
1:	bf	31,L(tail)

	std	4,0(10)
	addi	10,10,8

	/* Handle the rest of the tail bytes here.  */
L(tail):
	mtocrf	0x01,5

	.align	4
4:	bf	29,2f

	stw	4,0(10)
	addi	10,10,4
	.align	4
2:	bf	30,1f

	sth	4,0(10)
	addi	10,10,2
	.align	4
1:	bflr	31

	stb	4,0(10)
	blr

	/* Expanded tree to copy tail bytes without increments.  */
	.align	4
L(copy_tail):
	bf	29,L(FXX)

	stw	4,0(10)
	bf	30,L(TFX)

	sth	4,4(10)
	bflr	31

	stb	4,6(10)
	blr

	.align	4
L(FXX):	bf	30,L(FFX)

	sth	4,0(10)
	bflr	31

	stb	4,2(10)
	blr

	.align	4
L(TFX):	bflr	31

	stb	4,4(10)
	blr

	.align	4
L(FFX):	bflr	31

	stb	4,0(10)
	blr

	/* Handle copies of 9~31 bytes.  */
	.align	4
L(medium):
	/* At least 9 bytes to go.  */
	andi.	11,10,3
	clrldi	0,0,62
	beq	L(medium_aligned)

	/* Force 4-bytes alignment for DST.  */
	mtocrf	0x01,0
	subf	5,0,5
1:	/* Copy 1 byte.  */
	bf	31,2f

	stb	4,0(10)
	addi	10,10,1
2:	/* Copy 2 bytes.  */
	bf	30,L(medium_aligned)

	sth	4,0(10)
	addi	10,10,2

	.align	4
L(medium_aligned):
	/* At least 6 bytes to go, and DST is word-aligned.  */
	cmpldi	cr1,5,16
	mtocrf	0x01,5
	blt	cr1,8f

	/* Copy 16 bytes.  */
	stw	4,0(10)
	stw	4,4(10)
	stw	4,8(10)
	stw	4,12(10)
	addi	10,10,16
8:	/* Copy 8 bytes.  */
	bf	28,4f

	stw	4,0(10)
	stw	4,4(10)
	addi	10,10,8
4:	/* Copy 4 bytes.  */
	bf	29,2f

	stw	4,0(10)
	addi	10,10,4
2:	/* Copy 2-3 bytes.  */
	bf	30,1f

	sth	4,0(10)
	addi	10,10,2
1:	/* Copy 1 byte.  */
	bflr	31

	stb	4,0(10)
	blr

	/* Handles copies of 0~8 bytes.  */
	.align	4
L(small):
	mtocrf	0x01,5
	bne	cr6,L(copy_tail)

	stw	4,0(10)
	stw	4,4(10)
	blr

END_GEN_TB (MEMSET,TB_TOCLESS)
libc_hidden_builtin_def (memset)

/* Copied from bzero.S to prevent the linker from inserting a stub
   between bzero and memset.  */
ENTRY_TOCLESS (__bzero)
	CALL_MCOUNT 3
	mr	r5,r4
	li	r4,0
	b	L(_memset)
END (__bzero)
#ifndef __bzero
weak_alias (__bzero, bzero)
#endif
Commit	Line	Data
33b8d90a	1	/* Optimized memset implementation for PowerPC64/POWER7.
2b778ceb	2	Copyright (C) 2010-2021 Free Software Foundation, Inc.
33b8d90a LM	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
59ba27a6	16	License along with the GNU C Library; if not, see
5a82c748	17	<https://www.gnu.org/licenses/>. */
33b8d90a LM	18
33b8d90a LM	19	#include <sysdep.h>
33b8d90a	20
f17a4233	21	/* void * [r3] memset (void *s [r3], int c [r4], size_t n [r5]));
33b8d90a LM	22	Returns 's'. */
33b8d90a LM	23
18e0054b WSM	24	#ifndef MEMSET
	25	# define MEMSET memset
	26	#endif
33b8d90a	27	.machine power7
d5b41185	28	ENTRY_TOCLESS (MEMSET, 5)
33b8d90a LM	29	CALL_MCOUNT 3
	30
	31	L(_memset):
	32	cmpldi cr7,5,31
	33	cmpldi cr6,5,8
	34	mr 10,3
	35
	36	/* Replicate byte to word. */
3be87c77 AM	37	insrdi 4,4,8,48
3be87c77 AM	38	insrdi 4,4,16,32
33b8d90a LM	39	ble cr6,L(small) /* If length <= 8, use short copy code. */
	40
	41	neg 0,3
	42	ble cr7,L(medium) /* If length < 32, use medium copy code. */
	43
	44	andi. 11,10,7 /* Check alignment of SRC. */
	45	insrdi 4,4,32,0 /* Replicate word to double word. */
	46
	47	mr 12,5
	48	beq L(big_aligned)
	49
	50	clrldi 0,0,61
	51	mtocrf 0x01,0
	52	subf 5,0,5
	53
	54	/* Get DST aligned to 8 bytes. */
	55	1: bf 31,2f
	56
	57	stb 4,0(10)
	58	addi 10,10,1
	59	2: bf 30,4f
	60
	61	sth 4,0(10)
	62	addi 10,10,2
	63	4: bf 29,L(big_aligned)
	64
	65	stw 4,0(10)
	66	addi 10,10,4
	67
	68	.align 4
	69	L(big_aligned):
	70
	71	cmpldi cr5,5,255
	72	li 0,32
	73	dcbtst 0,10
	74	cmpldi cr6,4,0
	75	srdi 9,5,3 /* Number of full doublewords remaining. */
	76	crand 27,26,21
	77	mtocrf 0x01,9
	78	bt 27,L(huge)
	79
	80	/* From this point on, we'll copy 32+ bytes and the value
	81	isn't 0 (so we can't use dcbz). */
	82
	83	srdi 8,5,5
	84	clrldi 11,5,61
	85	cmpldi cr6,11,0
	86	cmpldi cr1,9,4
	87	mtctr 8
	88
	89	/* Copy 1~3 doublewords so the main loop starts
	90	at a multiple of 32 bytes. */
	91
	92	bf 30,1f
	93
	94	std 4,0(10)
	95	std 4,8(10)
	96	addi 10,10,16
	97	bf 31,L(big_loop)
	98
	99	std 4,0(10)
	100	addi 10,10,8
	101	mr 12,10
	102	blt cr1,L(tail_bytes)
103	b L(big_loop)
104
105	.align 4
106	1: /* Copy 1 doubleword. */
107	bf 31,L(big_loop)
108
109	std 4,0(10)
110	addi 10,10,8
111
112	/* Main aligned copy loop. Copies 32-bytes at a time and
113	ping-pong through r10 and r12 to avoid AGEN delays. */
114	.align 4
115	L(big_loop):
116	addi 12,10,32
117	std 4,0(10)
118	std 4,8(10)
119	std 4,16(10)
120	std 4,24(10)
121	bdz L(tail_bytes)
122
123	addi 10,10,64
124	std 4,0(12)
125	std 4,8(12)
126	std 4,16(12)
127	std 4,24(12)
128	bdnz L(big_loop)
129
130	mr 12,10
131	b L(tail_bytes)
132
133	.align 4
134	L(tail_bytes):
135
136	/* Check for tail bytes. */
137	beqlr cr6
138
139	clrldi 0,5,61
140	mtocrf 0x01,0
141
142	/* At this point we have a tail of 0-7 bytes and we know that the
143	destination is doubleword-aligned. */
144	4: /* Copy 4 bytes. */
145	bf 29,2f
146
147	stw 4,0(12)
148	addi 12,12,4
149	2: /* Copy 2 bytes. */
150	bf 30,1f
151
152	sth 4,0(12)
153	addi 12,12,2
154	1: /* Copy 1 byte. */
155	bflr 31
156
157	stb 4,0(12)
158	blr
159
160	/* Special case when value is 0 and we have a long length to deal
161	with. Use dcbz to zero out 128-bytes at a time. Before using
162	dcbz though, we need to get the destination 128-bytes aligned. */
163	.align 4
164	L(huge):
165	andi. 11,10,127
166	neg 0,10
167	beq L(huge_aligned)
168
169	clrldi 0,0,57
170	subf 5,0,5
171	srdi 0,0,3
172	mtocrf 0x01,0
173
174	/* Get DST aligned to 128 bytes. */
175	8: bf 28,4f
176
177	std 4,0(10)
178	std 4,8(10)
179	std 4,16(10)
180	std 4,24(10)
181	std 4,32(10)
182	std 4,40(10)
183	std 4,48(10)
184	std 4,56(10)
185	addi 10,10,64
186	.align 4
187	4: bf 29,2f
188
189	std 4,0(10)
190	std 4,8(10)
191	std 4,16(10)
192	std 4,24(10)
193	addi 10,10,32
194	.align 4
195	2: bf 30,1f
196
197	std 4,0(10)
198	std 4,8(10)
199	addi 10,10,16
200	.align 4
201	1: bf 31,L(huge_aligned)
202
203	std 4,0(10)
204	addi 10,10,8
205
206
207	L(huge_aligned):
208	srdi 8,5,7
209	clrldi 11,5,57
210	cmpldi cr6,11,0
211	mtctr 8
212
213	.align 4
214	L(huge_loop):
215	dcbz 0,10
216	addi 10,10,128
217	bdnz L(huge_loop)
218
219	/* Check how many bytes are still left. */
220	beqlr cr6
221
222	subf 9,3,10
223	subf 5,9,12
224	srdi 8,5,3
225	cmpldi cr6,8,0
226	mtocrf 0x01,8
227
228	/* We have a tail o 1~127 bytes. Copy up to 15 doublewords for
229	speed. We'll handle the resulting tail bytes later. */
230	beq cr6,L(tail)
231
232	8: bf 28,4f
233
234	std 4,0(10)
235	std 4,8(10)
236	std 4,16(10)
237	std 4,24(10)
238	std 4,32(10)
239	std 4,40(10)
240	std 4,48(10)
241	std 4,56(10)
242	addi 10,10,64
243	.align 4
244	4: bf 29,2f
245
246	std 4,0(10)
247	std 4,8(10)
248	std 4,16(10)
249	std 4,24(10)
250	addi 10,10,32
251	.align 4
252	2: bf 30,1f
253
254	std 4,0(10)
255	std 4,8(10)
256	addi 10,10,16
257	.align 4
258	1: bf 31,L(tail)
259
260	std 4,0(10)
261	addi 10,10,8
262
263	/* Handle the rest of the tail bytes here. */
264	L(tail):
265	mtocrf 0x01,5
266
267	.align 4
268	4: bf 29,2f
269
270	stw 4,0(10)
271	addi 10,10,4
272	.align 4
273	2: bf 30,1f
274
275	sth 4,0(10)
276	addi 10,10,2
277	.align 4
278	1: bflr 31
279
280	stb 4,0(10)
281	blr
282
283	/* Expanded tree to copy tail bytes without increments. */
284	.align 4
285	L(copy_tail):
286	bf 29,L(FXX)
287
288	stw 4,0(10)
289	bf 30,L(TFX)
290
291	sth 4,4(10)
292	bflr 31
293
294	stb 4,6(10)
295	blr
296
297	.align 4
298	L(FXX): bf 30,L(FFX)
299
300	sth 4,0(10)
301	bflr 31
302
303	stb 4,2(10)
304	blr
305
306	.align 4
307	L(TFX): bflr 31
308
309	stb 4,4(10)
310	blr
311
312	.align 4
313	L(FFX): bflr 31
314
315	stb 4,0(10)
316	blr
317
318	/* Handle copies of 9~31 bytes. */
319	.align 4
320	L(medium):
321	/* At least 9 bytes to go. */
322	andi. 11,10,3
323	clrldi 0,0,62
324	beq L(medium_aligned)
325
3be87c77	326	/* Force 4-bytes alignment for DST. */
33b8d90a LM	327	mtocrf 0x01,0
	328	subf 5,0,5
	329	1: /* Copy 1 byte. */
	330	bf 31,2f
	331
	332	stb 4,0(10)
	333	addi 10,10,1
	334	2: /* Copy 2 bytes. */
	335	bf 30,L(medium_aligned)
	336
	337	sth 4,0(10)
	338	addi 10,10,2
	339
	340	.align 4
	341	L(medium_aligned):
	342	/* At least 6 bytes to go, and DST is word-aligned. */
	343	cmpldi cr1,5,16
	344	mtocrf 0x01,5
	345	blt cr1,8f
	346
	347	/* Copy 16 bytes. */
	348	stw 4,0(10)
	349	stw 4,4(10)
	350	stw 4,8(10)
	351	stw 4,12(10)
	352	addi 10,10,16
	353	8: /* Copy 8 bytes. */
	354	bf 28,4f
	355
	356	stw 4,0(10)
	357	stw 4,4(10)
	358	addi 10,10,8
	359	4: /* Copy 4 bytes. */
	360	bf 29,2f
	361
	362	stw 4,0(10)
	363	addi 10,10,4
	364	2: /* Copy 2-3 bytes. */
	365	bf 30,1f
	366
	367	sth 4,0(10)
	368	addi 10,10,2
	369	1: /* Copy 1 byte. */
	370	bflr 31
	371
	372	stb 4,0(10)
	373	blr
	374
	375	/* Handles copies of 0~8 bytes. */
	376	.align 4
	377	L(small):
	378	mtocrf 0x01,5
	379	bne cr6,L(copy_tail)
	380
	381	stw 4,0(10)
	382	stw 4,4(10)
	383	blr
	384
18e0054b	385	END_GEN_TB (MEMSET,TB_TOCLESS)
33b8d90a LM	386	libc_hidden_builtin_def (memset)
	387
	388	/* Copied from bzero.S to prevent the linker from inserting a stub
	389	between bzero and memset. */
d5b41185	390	ENTRY_TOCLESS (__bzero)
33b8d90a LM	391	CALL_MCOUNT 3
	392	mr r5,r4
	393	li r4,0
	394	b L(_memset)
3b473fec AZ	395	END (__bzero)
3b473fec AZ	396	#ifndef __bzero
2d67d91a	397	weak_alias (__bzero, bzero)
8a29a3d0	398	#endif