about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc64/power7/strncpy.S
blob: d46cfa402d915b6dcccc534caa1dbbc7b0332515 (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
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
/* Copyright (C) 2014-2022 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>

/* Implements the functions

   char * [r3] strncpy (char *dst [r3], const char *src [r4], size_t n [r5])

   AND

   char * [r3] stpncpy (char *dst [r3], const char *src [r4], size_t n [r5])

   The algorithm is as follows:
   > if src and dest are 8 byte aligned, perform double word copy
     else
   > copy byte by byte on unaligned addresses.

   The aligned comparison are made using cmpb instructions.  */

/* The focus on optimization for performance improvements are as follows:
   1. data alignment [gain from aligned memory access on read/write]
   2. POWER7 gains performance with loop unrolling/unwinding
      [gain by reduction of branch penalty].
   3. The final pad with null bytes is done by calling an optimized
      memset.  */

#ifdef USE_AS_STPNCPY
# ifndef STPNCPY
#  define FUNC_NAME __stpncpy
# else
#  define FUNC_NAME STPNCPY
# endif
#else
# ifndef STRNCPY
#  define FUNC_NAME strncpy
# else
#  define FUNC_NAME STRNCPY
# endif
#endif  /* !USE_AS_STPNCPY  */

#define		FRAMESIZE	(FRAME_MIN_SIZE+16)

#ifndef MEMSET
/* For builds with no IFUNC support, local calls should be made to internal
   GLIBC symbol (created by libc_hidden_builtin_def).  */
# ifdef SHARED
#  define MEMSET_is_local
#  define MEMSET   __GI_memset
# else
#  define MEMSET   memset
# endif
#endif

	.machine  power7
#ifdef MEMSET_is_local
ENTRY_TOCLESS (FUNC_NAME, 4)
#else
ENTRY (FUNC_NAME, 4)
#endif
	CALL_MCOUNT 3

	or r10, r3, r4		/* to verify source and destination  */
	rldicl. r8, r10, 0, 61	/* is double word aligned .. ?  */

	std r19, -8(r1)		/* save callers register , r19  */
	std r18, -16(r1)	/* save callers register , r18  */
	cfi_offset(r19, -8)
	cfi_offset(r18, -16)

	mr r9, r3		/* save r3 into r9 for use  */
	mr r18, r3		/* save r3 for retCode of strncpy  */
	bne 0, L(unaligned)

L(aligned):
	srdi r11, r5, 3		/* compute count for CTR ; count = n/8  */
	cmpldi cr7, r11, 3	/* if count > 4 ; perform unrolling 4 times  */
	ble 7, L(update1)

	ld r10, 0(r4)		/* load doubleWord from src  */
	cmpb r8, r10, r8	/* compare src with NULL ,we read just now  */
	cmpdi cr7, r8, 0	/* if cmpb returned NULL ; we continue  */
	bne cr7, L(update3)

	std r10, 0(r3)		/* copy doubleword at offset=0  */
	ld r10, 8(r4)		/* load next doubleword from offset=8  */
	cmpb r8, r10, r8	/* compare src with NULL , we read just now  */
	cmpdi cr7, r8, 0	/* if cmpb returned NULL ; we continue  */
	bne 7,L(HopBy8)

	addi r8, r11, -4
	mr r7, r3
	srdi r8, r8, 2
	mr r6, r4
	addi r8, r8, 1
	li r12, 0
	mtctr r8
	b L(dwordCopy)

	.p2align 4
L(dWordUnroll):
	std r8, 16(r9)
	ld r8, 24(r4)		/* load dword,perform loop unrolling again  */
	cmpb r10, r8, r10
	cmpdi cr7, r10, 0
	bne cr7, L(HopBy24)

	std r8, 24(r7)		/* copy dword at offset=24  */
	addi r9, r9, 32
	addi r4, r4, 32
	bdz  L(leftDwords)	/* continue with loop on counter  */

	ld r3, 32(r6)
	cmpb r8, r3, r10
	cmpdi cr7, r8, 0
	bne cr7, L(update2)

	std r3, 32(r7)
	ld r10, 40(r6)
	cmpb r8, r10, r8
	cmpdi cr7, r8, 0
	bne cr7, L(HopBy40)

	mr r6, r4		/* update values  */
	mr r7, r9
	mr r11, r0
	mr r5, r19

L(dwordCopy):
	std r10, 8(r9)		/* copy dword at offset=8  */
	addi r19, r5, -32
	addi r0, r11, -4
	ld r8, 16(r4)
	cmpb r10, r8, r12
	cmpdi cr7, r10, 0
	beq cr7, L(dWordUnroll)

	addi r9, r9, 16		/* increment dst by 16  */
	addi r4, r4, 16		/* increment src by 16  */
	addi r5, r5, -16	/* decrement length 'n' by 16  */
	addi r0, r11, -2	/* decrement loop counter  */

L(dWordUnrollOFF):
	ld r10, 0(r4)		/* load first dword  */
	li r8, 0		/* load mask  */
	cmpb r8, r10, r8
	cmpdi cr7, r8, 0
	bne cr7, L(byte_by_byte)
	mtctr r0
	li r7, 0
	b L(CopyDword)

	.p2align 4
L(loadDWordandCompare):
	ld r10, 0(r4)
	cmpb r8, r10, r7
	cmpdi cr7, r8, 0
	bne cr7, L(byte_by_byte)

L(CopyDword):
	addi r9, r9, 8
	std r10, -8(r9)
	addi r4, r4, 8
	addi r5, r5, -8
	bdnz L(loadDWordandCompare)

L(byte_by_byte):
	cmpldi cr7, r5, 3
	ble cr7, L(verifyByte)
	srdi r10, r5, 2
	mr r19, r9
	mtctr r10
	b L(firstByteUnroll)

	.p2align 4
L(bytes_unroll):
	lbz r10, 1(r4)		/* load byte from src  */
	cmpdi cr7, r10, 0	/* compare for NULL  */
	stb r10, 1(r19)		/* store byte to dst  */
	beq cr7, L(updtDestComputeN2ndByte)

	addi r4, r4, 4		/* advance src  */

	lbz r10, -2(r4)		/* perform loop unrolling for byte r/w  */
	cmpdi cr7, r10, 0
	stb r10, 2(r19)
	beq cr7, L(updtDestComputeN3rdByte)

	lbz r10, -1(r4)		/* perform loop unrolling for byte r/w  */
	addi r19, r19, 4
	cmpdi cr7, r10, 0
	stb r10, -1(r19)
	beq cr7, L(ComputeNByte)

	bdz L(update0)

L(firstByteUnroll):
	lbz r10, 0(r4)		/* perform loop unrolling for byte r/w  */
	cmpdi cr7, 10, 0
	stb r10, 0(r19)
	bne cr7, L(bytes_unroll)
	addi r19, r19, 1

L(ComputeNByte):
	subf r9, r19, r9	/* compute 'n'n bytes to fill  */
	add r8, r9, r5

L(zeroFill):
	cmpdi cr7, r8, 0	/* compare if length is zero  */
	beq cr7, L(update3return)

	mflr r0			/* load link register LR to r0  */
	std r0, 16(r1)		/* store the link register  */
	stdu r1, -FRAMESIZE(r1)	/* create the stack frame  */
	cfi_adjust_cfa_offset(FRAMESIZE)
	cfi_offset(lr, 16)
	mr r3, r19		/* fill buffer with  */
	li r4, 0		/* zero fill buffer  */
	mr r5, r8		/* how many bytes to fill buffer with  */
	bl MEMSET		/* call optimized memset  */
#ifndef MEMSET_is_local
	nop
#endif
	ld r0, FRAMESIZE+16(r1) /* read the saved link register  */
	addi r1, r1, FRAMESIZE	/* restore stack pointer  */
	cfi_adjust_cfa_offset(-FRAMESIZE)
	mtlr r0
	cfi_restore(lr)

L(update3return):
#ifdef USE_AS_STPNCPY
	addi r3, r19, -1	/* update return value  */
#endif

L(hop2return):
#ifndef USE_AS_STPNCPY
	mr r3, r18		/* set return value  */
#endif
	ld r18, -16(r1)		/* restore callers save register, r18  */
	ld r19, -8(r1)		/* restore callers save register, r19  */
	blr			/* return  */

	.p2align 4
L(update0):
	mr r9, r19

	.p2align 4
L(verifyByte):
	rldicl. r8, r5, 0, 62
#ifdef USE_AS_STPNCPY
	mr r3, r9
#endif
	beq cr0, L(hop2return)
	mtctr r8
	addi r4, r4, -1
	mr r19, r9
	b L(oneBYone)

	.p2align 4
L(proceed):
	bdz L(done)

L(oneBYone):
	lbzu r10, 1(r4)		/* copy byte  */
	addi r19, r19, 1
	addi r8, r8, -1
	cmpdi cr7, r10, 0
	stb r10, -1(r19)
	bne cr7, L(proceed)
	b L(zeroFill)

	.p2align 4
L(done):
#ifdef USE_AS_STPNCPY
	mr r3, r19		/* set the return value  */
#else
	mr r3, r18		/* set the return value  */
#endif
	ld r18, -16(r1)		/* restore callers save register, r18  */
	ld r19, -8(r1)		/* restore callers save register, r19  */
	blr			/* return  */

L(update1):
	mr r0, r11
	mr r19, r5

	.p2align 4
L(leftDwords):
	cmpdi cr7, r0, 0
	mr r5, r19
	bne cr7, L(dWordUnrollOFF)
	b L(byte_by_byte)

	.p2align 4
L(updtDestComputeN2ndByte):
	addi r19, r19, 2	/* update dst by 2  */
	subf r9, r19, r9	/* compute distance covered  */
	add r8, r9, r5
	b L(zeroFill)

	.p2align 4
L(updtDestComputeN3rdByte):
	addi r19, r19, 3	/* update dst by 3  */
	subf r9, r19, r9	/* compute distance covered  */
	add r8, r9, r5
	b L(zeroFill)

	.p2align 4
L(HopBy24):
	addi r9, r9, 24		/* increment dst by 24  */
	addi r4, r4, 24		/* increment src by 24  */
	addi r5, r5, -24	/* decrement length 'n' by 24  */
	addi r0, r11, -3	/* decrement loop counter  */
	b L(dWordUnrollOFF)

	.p2align 4
L(update2):
	mr r5, r19
	b L(dWordUnrollOFF)

	.p2align 4
L(HopBy40):
	addi r9, r7, 40		/* increment dst by 40  */
	addi r4, r6, 40		/* increment src by 40  */
	addi r5, r5, -40	/* decrement length 'n' by 40  */
	addi r0, r11, -5	/* decrement loop counter  */
	b L(dWordUnrollOFF)

L(update3):
	mr r0, r11
	b L(dWordUnrollOFF)

L(HopBy8):
	addi r9, r3, 8		/* increment dst by 8  */
	addi r4, r4, 8		/* increment src by 8  */
	addi r5, r5, -8		/* decrement length 'n' by 8  */
	addi r0, r11, -1	/* decrement loop counter  */
	b L(dWordUnrollOFF)

L(unaligned):
	cmpdi	r5, 16		/* Proceed byte by byte for less than 16  */
	ble	L(byte_by_byte)
	rldicl	r7, r3, 0, 61
	rldicl	r6, r4, 0, 61
	cmpdi	r6, 0	/* Check src alignment */
	beq	L(srcaligndstunalign)
	/* src is unaligned */
	rlwinm	r10, r4, 3,26,28	/* Calculate padding.  */
	clrrdi	r4, r4, 3	/* Align the addr to dw boundary */
	ld	r8, 0(r4)	/* Load doubleword from memory.  */
	li	r0, 0
	/* Discard bits not part of the string */
#ifdef __LITTLE_ENDIAN__
	srd	r7, r8, r10
#else
	sld	r7, r8, r10
#endif
	cmpb	r0, r7, r0	/* Compare each byte against null */
	/* Discard bits not part of the string */
#ifdef __LITTLE_ENDIAN__
	sld	r0, r0, r10
#else
	srd	r0, r0, r10
#endif
	cmpdi	r0, 0
	bne     L(bytebybyte)	/* if it has null, copy byte by byte */
	subfic	r6, r6, 8
	rlwinm	r12, r3, 3,26,28	/* Calculate padding in bits.  */
	rldicl	r9, r3, 0, 61	/* Calculate padding in bytes. */
	addi	r3, r3, -1

	cmpdi	r12, 0	/* check dest alignment */
	beq     L(srcunaligndstalign)

	/* both src and dst unaligned */
#ifdef __LITTLE_ENDIAN__
	sld	r8, r7, r10
	mr	r11, r10
	addi	r11, r11, -8	/* Adjust byte pointer on loaded dw */
#else
	srd	r8, r7, r10
	subfic	r11, r10, 64
#endif
	/* dst alignment is greater then src alignment? */
	cmpd    cr7, r12, r10
	ble     cr7, L(dst_align_small)
	/* src alignment is less than dst */

	/* Calculate the dst alignment difference  */
	subfic	r7, r9, 8
	mtctr	r7

	/* Write until dst is aligned  */
	cmpdi	r0, r7, 4
	blt     L(storebyte1)	/* less than 4, store byte by byte  */
	beq     L(equal1)	/* if its 4, store word  */
	addi	r0, r7, -4	/* greater than 4, so stb and stw  */
	mtctr	r0
L(storebyte1):
#ifdef __LITTLE_ENDIAN__
	addi	r11, r11, 8	/* Adjust byte pointer on loaded dw  */
#else
	addi	r11, r11, -8
#endif
	srd	r7, r8, r11
	stbu	r7, 1(r3)
	addi	r5, r5, -1
	bdnz    L(storebyte1)

	subfic	r7, r9, 8	/* Check the remaining bytes  */
	cmpdi	r0, r7, 4
	blt     L(proceed1)

	.align 4
L(equal1):
#ifdef __LITTLE_ENDIAN__
	addi	r11, r11, 8	/* Adjust byte pointer on loaded dw  */
	srd	r7, r8, r11
#else
	subfic	r11, r11, 64
	sld	r7, r8, r11
	srdi	r7, r7, 32
#endif
	stw	r7, 1(r3)
	addi	r3, r3, 4
	addi	r5, r5, -4

L(proceed1):
	mr	r7, r8
	/* calculate the Left over bytes to be written  */
	subfic	r11, r10, 64
	subfic	r12, r12, 64
	subf	r12, r12, r11	/* remaining bytes on second dw  */
	subfic	r10, r12, 64	/* remaining bytes on first dw  */
	subfic	r9, r9, 8
	subf	r6, r9, r6	/* recalculate padding  */
L(srcunaligndstalign):
	addi	r3, r3, 1
	subfic	r12, r10, 64	/* remaining bytes on second dw  */
	addi	r4, r4, 8
	li	r0,0
	b       L(storedouble)

	.align 4
L(dst_align_small):
	mtctr	r6
	/* Write until src is aligned  */
L(storebyte2):
#ifdef __LITTLE_ENDIAN__
	addi	r11, r11, 8	/* Adjust byte pointer on dw  */
#else
	addi	r11, r11, -8
#endif
	srd	r7, r8, r11
	stbu	r7, 1(r3)
	addi	r5, r5, -1
	bdnz    L(storebyte2)

	addi	r4, r4, 8	/* Increment src pointer  */
	addi	r3, r3, 1	/* Increment dst pointer  */
	mr	r9, r3
	li	r8, 0
	cmpd    cr7, r12, r10
	beq     cr7, L(aligned)
	rldicl	r6, r3, 0, 61	/* Recalculate padding */
	mr	r7, r6

	/* src is algined */
L(srcaligndstunalign):
	mr	r9, r3
	mr	r6, r7
	ld	r8, 0(r4)
	subfic	r10, r7, 8
	mr	r7, r8
	li	r0, 0	/* Check null */
	cmpb	r0, r8, r0
	cmpdi	r0, 0
	bne     L(byte_by_byte)	/* Do byte by byte if there is NULL  */
	rlwinm	r12, r3, 3,26,28	/* Calculate padding  */
	addi	r3, r3, -1
	/* write byte by byte until aligned  */
#ifdef __LITTLE_ENDIAN__
	li	r11, -8
#else
	li	r11, 64
#endif
	mtctr	r10
	cmpdi	r0, r10, 4
	blt     L(storebyte)
	beq     L(equal)
	addi	r0, r10, -4
	mtctr	r0
L(storebyte):
#ifdef __LITTLE_ENDIAN__
	addi	r11, r11, 8	/* Adjust byte pointer on  dw  */
#else
	addi	r11, r11, -8
#endif
	srd	r7, r8, r11
	stbu	r7, 1(r3)
	addi	r5, r5, -1
	bdnz    L(storebyte)

	cmpdi	r0, r10, 4
	blt     L(align)

	.align 4
L(equal):
#ifdef __LITTLE_ENDIAN__
	addi	r11, r11, 8
	srd	r7, r8, r11
#else
	subfic	r11, r11, 64
	sld	r7, r8, r11
	srdi	r7, r7, 32
#endif
	stw	r7, 1(r3)
	addi	r5, r5, -4
	addi	r3, r3, 4
L(align):
	addi	r3, r3, 1
	addi	r4, r4, 8	/* Increment src pointer  */
	subfic	r10, r12, 64
	li	r0, 0
	/* dst addr aligned to 8 */
L(storedouble):
	cmpdi	r5, 8
	ble	L(null1)
	ld	r7, 0(r4)	/* load next dw  */
	cmpb	r0, r7, r0
	cmpdi	r0, 0	/* check for null on each new dw  */
	bne     L(null)
#ifdef __LITTLE_ENDIAN__
	srd	r9, r8, r10	/* bytes from first dw  */
	sld	r11, r7, r12	/* bytes from second dw  */
#else
	sld	r9, r8, r10
	srd	r11, r7, r12
#endif
	or	r11, r9, r11	/* make as a single dw  */
	std	r11, 0(r3)	/* store as std on aligned addr  */
	mr	r8, r7		/* still few bytes left to be written  */
	addi	r3, r3, 8	/* increment dst addr  */
	addi	r4, r4, 8	/* increment src addr  */
	addi	r5, r5, -8
	b       L(storedouble)	/* Loop until NULL  */

	.align 4

/* We've hit the end of the string.  Do the rest byte-by-byte.  */
L(null):
	addi	r3, r3, -1
	mr	r10, r12
	mtctr	r6
#ifdef __LITTLE_ENDIAN__
	subfic	r10, r10, 64
	addi	r10, r10, -8
#endif
	cmpdi	r0, r5, 4
	blt	L(loop)
	cmpdi	r0, r6, 4
	blt     L(loop)

	/* we can still use stw if leftover >= 4  */
#ifdef __LITTLE_ENDIAN__
	addi	r10, r10, 8
	srd	r11, r8, r10
#else
	subfic	r10, r10, 64
	sld	r11, r8, r10
	srdi	r11, r11, 32
#endif
	stw	r11, 1(r3)
	addi	r5, r5, -4
	addi	r3, r3, 4
	cmpdi	r0, r5, 0
	beq	L(g1)
	cmpdi	r0, r6, 4
	beq     L(bytebybyte1)
	addi	r10, r10, 32
#ifdef __LITTLE_ENDIAN__
	addi	r10, r10, -8
#else
	subfic	r10, r10, 64
#endif
	addi	r0, r6, -4
	mtctr	r0
	/* remaining byte by byte part of first dw  */
L(loop):
#ifdef __LITTLE_ENDIAN__
	addi	r10, r10, 8
#else
	addi	r10, r10, -8
#endif
	srd	r0, r8, r10
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	cmpdi	r0, r5, 0
	beq	L(g1)
	bdnz    L(loop)
L(bytebybyte1):
	addi	r3, r3, 1
	/* remaining byte by byte part of second dw   */
L(bytebybyte):
	addi	r3, r3, -8
	addi	r4, r4, -1

#ifdef __LITTLE_ENDIAN__
	extrdi. r0, r7, 8, 56
	stbu	r7, 8(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 48
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 40
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 32
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 24
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 16
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 8
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi	r0, r7, 8, 0
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	b	L(g2)
#else
	extrdi. r0, r7, 8, 0
	stbu	r0, 8(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 8
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 16
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 24
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 32
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 40
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	extrdi. r0, r7, 8, 48
	stbu	r0, 1(r3)
	addi	r5, r5, -1
	beq	L(g2)
	cmpdi	r5, 0
	beq	L(g1)
	stbu	r7, 1(r3)
	addi	r5, r5, -1
	b	L(g2)
#endif
L(g1):
#ifdef USE_AS_STPNCPY
	addi	r3, r3, 1
#endif
L(g2):
	addi	r3, r3, 1
	mr	r19, r3
	mr	r8, r5
	b	L(zeroFill)
L(null1):
	mr	r9, r3
	subf	r4, r6, r4
	b	L(byte_by_byte)
END(FUNC_NAME)
#ifndef USE_AS_STPNCPY
libc_hidden_builtin_def (strncpy)
#endif