summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc32/power6/memcpy.S
blob: e35ab1ee36ba8bfc60e6ad0a3d51b3baf5f33321 (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
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
/* Optimized memcpy implementation for PowerPC32 on POWER6.
   Copyright (C) 2003-2014 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
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

/* __ptr_t [r3] memcpy (__ptr_t dst [r3], __ptr_t src [r4], size_t len [r5]);
   Returns 'dst'.

   Memcpy handles short copies (< 32-bytes) using a binary move blocks
   (no loops) of lwz/stw.  The tail (remaining 1-3) bytes is handled
   with the appropriate combination of byte and halfword load/stores.
   There is minimal effort to optimize the alignment of short moves.

   Longer moves (>= 32-bytes) justify the effort to get at least the
   destination word (4-byte) aligned.  Further optimization is
   possible when both source and destination are word aligned.
   Each case has an optimized unrolled loop.   */

	.machine power6
EALIGN (memcpy, 5, 0)
	CALL_MCOUNT

    stwu   1,-32(1)
    cfi_adjust_cfa_offset(32)
    cmplwi cr1,5,31     /* check for short move.  */
    neg    0,3
    cmplwi cr1,5,31
    clrlwi 10,4,30	/* check alignment of src.  */
    andi.  11,3,3	/* check alignment of dst.  */
    clrlwi 0,0,30	/* Number of bytes until the 1st word of dst.  */
    ble-   cr1,L(word_unaligned_short)	/* If move < 32 bytes.  */
    cmplw  cr6,10,11
    stw    31,24(1)
    cfi_offset(31,(24-32))
    stw    30,20(1)
    cfi_offset(30,(20-32))
    mr     30,3
    beq    .L0
    mtcrf  0x01,0
    subf  31,0,5        /* Length after alignment.  */
    add   12,4,0        /* Compute src addr after alignment.  */
  /* Move 0-3 bytes as needed to get the destination word aligned.  */
1:  bf    31,2f
    lbz   6,0(4)
    bf    30,3f
    lhz   7,1(4)
    stb   6,0(3)
    sth   7,1(3)
    addi  3,3,3
    b     0f
3:
    stb   6,0(3)
    addi  3,3,1
    b     0f
2:  bf    30,0f
    lhz   6,0(4)
    sth   6,0(3)
    addi  3,3,2
0:
    clrlwi 10,12,30	/* check alignment of src again.  */
    srwi   9,31,2	/* Number of full words remaining.  */
    bne-   cr6,L(wdu)   /* If source is not word aligned. .L6 */
    clrlwi 11,31,30  /* calculate the number of tail bytes */
    b      L(word_aligned)
  /* Copy words from source to destination, assuming the destination is
     aligned on a word boundary.

     At this point we know there are at least 29 bytes left (32-3) to copy.
     The next step is to determine if the source is also word aligned.
     If not branch to the unaligned move code at .L6. which uses
     a load, shift, store strategy.

     Otherwise source and destination are word aligned, and we can use
     the optimized word copy loop.  */
    .align  4
.L0:
    mr     31,5
    mr     12,4
    bne-   cr6,L(wdu)   /* If source is not word aligned. .L6 */
    srwi   9,5,2	/* Number of full words remaining.  */
    clrlwi 11,5,30      /* calculate the number of tail bytes */

  /* Move words where destination and source are word aligned.
     Use an unrolled loop to copy 4 words (16-bytes) per iteration.
     If the copy is not an exact multiple of 16 bytes, 1-3
     words are copied as needed to set up the main loop.  After
     the main loop exits there may be a tail of 1-3 bytes. These bytes are
     copied a halfword/byte at a time as needed to preserve alignment.  */
L(word_aligned):
    mtcrf 0x01,9
    srwi  8,31,4    /* calculate the 16 byte loop count */
    cmplwi	cr1,9,4
    cmplwi	cr6,11,0
    mr    11,12

    bf    30,1f
    lwz   6,0(12)
    lwz   7,4(12)
    addi  11,12,8
    mtctr 8
    stw   6,0(3)
    stw   7,4(3)
    addi  10,3,8
    bf    31,4f
    lwz   0,8(12)
    stw   0,8(3)
    blt   cr1,3f
    addi  11,12,12
    addi  10,3,12
    b     4f
    .align  4
1:
    mr    10,3
    mtctr 8
    bf    31,4f
    lwz   6,0(12)
    addi  11,12,4
    stw   6,0(3)
    addi  10,3,4

    .align  4
4:
    lwz   6,0(11)
    lwz   7,4(11)
    lwz   8,8(11)
    lwz   0,12(11)
    stw   6,0(10)
    stw   7,4(10)
    stw   8,8(10)
    stw   0,12(10)
    addi  11,11,16
    addi  10,10,16
    bdnz  4b
3:
    clrrwi 0,31,2
    mtcrf 0x01,31
    beq   cr6,0f
.L9:
    add   3,3,0
    add   12,12,0

/*  At this point we have a tail of 0-3 bytes and we know that the
    destination is word aligned.  */
2:  bf    30,1f
    lhz   6,0(12)
    addi  12,12,2
    sth   6,0(3)
    addi  3,3,2
1:  bf    31,0f
    lbz   6,0(12)
    stb   6,0(3)
0:
  /* Return original dst pointer.  */
    mr  3,30
    lwz 30,20(1)
    lwz 31,24(1)
    addi 1,1,32
    blr

/* Copy up to 31 bytes.  This divided into two cases 0-8 bytes and 9-31
   bytes.  Each case is handled without loops, using binary (1,2,4,8)
   tests.

   In the short (0-8 byte) case no attempt is made to force alignment
   of either source or destination.  The hardware will handle the
   unaligned load/stores with small delays for crossing 32- 128-byte,
   and 4096-byte boundaries. Since these short moves are unlikely to be
   unaligned or cross these boundaries, the overhead to force
   alignment is not justified.

   The longer (9-31 byte) move is more likely to cross 32- or 128-byte
   boundaries.  Since only loads are sensitive to the 32-/128-byte
   boundaries it is more important to align the source then the
   destination.  If the source is not already word aligned, we first
   move 1-3 bytes as needed.  Since we are only word aligned we don't
   use double word load/stores to insure that all loads are aligned.
   While the destination and stores may still be unaligned, this
   is only an issue for page (4096 byte boundary) crossing, which
   should be rare for these short moves.  The hardware handles this
   case automatically with a small (~20 cycle) delay.  */
    .align  4

    cfi_same_value (31)
    cfi_same_value (30)
L(word_unaligned_short):
    mtcrf 0x01,5
    cmplwi cr6,5,8
    neg   8,4
    clrrwi	9,4,2
    andi. 0,8,3
    beq   cr6,L(wus_8)	/* Handle moves of 8 bytes.  */
/* At least 9 bytes left.  Get the source word aligned.  */
    cmplwi	cr1,5,16
    mr    12,4
    ble   cr6,L(wus_4)  /* Handle moves of 0-8 bytes.  */
    mr    11,3
    mr    10,5
    cmplwi	cr6,0,2
    beq   L(wus_tail)	/* If the source is already word aligned skip this.  */
/* Copy 1-3 bytes to get source address word aligned.  */
    lwz   6,0(9)
    subf  10,0,5
    add   12,4,0
    blt   cr6,5f
    srwi  7,6,16
    bgt	  cr6,3f
#ifdef __LITTLE_ENDIAN__
    sth   7,0(3)
#else
    sth   6,0(3)
#endif
    b     7f
    .align  4
3:
#ifdef __LITTLE_ENDIAN__
    rotlwi 6,6,24
    stb   6,0(3)
    sth   7,1(3)
#else
    stb   7,0(3)
    sth   6,1(3)
#endif
    b     7f
    .align  4
5:
#ifdef __LITTLE_ENDIAN__
    rotlwi 6,6,8
#endif
    stb   6,0(3)
7:
    cmplwi	cr1,10,16
    add   11,3,0
    mtcrf 0x01,10
    .align  4
L(wus_tail):
/* At least 6 bytes left and the source is word aligned.  This allows
   some speculative loads up front.  */
/* We need to special case the fall-through because the biggest delays
   are due to address computation not being ready in time for the
   AGEN.  */
    lwz   6,0(12)
    lwz   7,4(12)
    blt   cr1,L(wus_tail8)
    cmplwi	cr0,10,24
L(wus_tail16): /* Move 16 bytes.  */
    stw   6,0(11)
    stw   7,4(11)
    lwz   6,8(12)
    lwz   7,12(12)
    stw   6,8(11)
    stw   7,12(11)
/* Move 8 bytes more.  */
    bf    28,L(wus_tail16p8)
    cmplwi	cr1,10,28
    lwz   6,16(12)
    lwz   7,20(12)
    stw   6,16(11)
    stw   7,20(11)
/* Move 4 bytes more.  */
    bf    29,L(wus_tail16p4)
    lwz   6,24(12)
    stw   6,24(11)
    addi  12,12,28
    addi  11,11,28
    bgt   cr1,L(wus_tail2)
 /* exactly 28 bytes.  Return original dst pointer and exit.  */
    addi  1,1,32
    blr
    .align  4
L(wus_tail16p8):  /* less than 8 bytes left.  */
    beq   cr1,L(wus_tailX) /* exactly 16 bytes, early exit.  */
    cmplwi	cr1,10,20
    bf    29,L(wus_tail16p2)
/* Move 4 bytes more.  */
    lwz   6,16(12)
    stw   6,16(11)
    addi  12,12,20
    addi  11,11,20
    bgt   cr1,L(wus_tail2)
 /* exactly 20 bytes.  Return original dst pointer and exit.  */
    addi  1,1,32
    blr
    .align  4
L(wus_tail16p4):  /* less than 4 bytes left.  */
    addi  12,12,24
    addi  11,11,24
    bgt   cr0,L(wus_tail2)
 /* exactly 24 bytes.  Return original dst pointer and exit.  */
    addi  1,1,32
    blr
    .align  4
L(wus_tail16p2):  /* 16 bytes moved, less than 4 bytes left.  */
    addi  12,12,16
    addi  11,11,16
    b     L(wus_tail2)

    .align  4
L(wus_tail8):  /* Move 8 bytes.  */
/*  r6, r7 already loaded speculatively.  */
    cmplwi	cr1,10,8
    cmplwi	cr0,10,12
    bf    28,L(wus_tail4)
    stw   6,0(11)
    stw   7,4(11)
/* Move 4 bytes more.  */
    bf    29,L(wus_tail8p4)
    lwz   6,8(12)
    stw   6,8(11)
    addi  12,12,12
    addi  11,11,12
    bgt   cr0,L(wus_tail2)
 /* exactly 12 bytes.  Return original dst pointer and exit.  */
    addi  1,1,32
    blr
    .align  4
L(wus_tail8p4):  /* less than 4 bytes left.  */
    addi  12,12,8
    addi  11,11,8
    bgt   cr1,L(wus_tail2)
 /* exactly 8 bytes.  Return original dst pointer and exit.  */
    addi  1,1,32
    blr

    .align  4
L(wus_tail4):  /* Move 4 bytes.  */
/*  r6 already loaded speculatively.  If we are here we know there is
    more than 4 bytes left.  So there is no need to test.  */
    addi  12,12,4
    stw   6,0(11)
    addi  11,11,4
L(wus_tail2):  /* Move 2-3 bytes.  */
    bf    30,L(wus_tail1)
    lhz   6,0(12)
    sth   6,0(11)
    bf    31,L(wus_tailX)
    lbz   7,2(12)
    stb   7,2(11)
    addi  1,1,32
    blr
L(wus_tail1):  /* Move 1 byte.  */
    bf    31,L(wus_tailX)
    lbz   6,0(12)
    stb   6,0(11)
L(wus_tailX):
  /* Return original dst pointer.  */
    addi  1,1,32
    blr

/* Special case to copy 0-8 bytes.  */
    .align  4
L(wus_8):
    lwz   6,0(4)
    lwz   7,4(4)
    stw   6,0(3)
    stw   7,4(3)
  /* Return original dst pointer.  */
    addi  1,1,32
    blr
    .align  4
L(wus_4):
    bf    29,L(wus_2)
    lwz   6,0(4)
    stw   6,0(3)
    bf    30,L(wus_5)
    lhz   7,4(4)
    sth   7,4(3)
    bf    31,L(wus_0)
    lbz   8,6(4)
    stb   8,6(3)
    addi  1,1,32
    blr
    .align  4
L(wus_5):
    bf    31,L(wus_0)
    lbz   6,4(4)
    stb   6,4(3)
  /* Return original dst pointer.  */
    addi 1,1,32
    blr
    .align  4
L(wus_2):  /* Move 2-3 bytes.  */
    bf    30,L(wus_1)
    lhz   6,0(4)
    sth   6,0(3)
    bf    31,L(wus_0)
    lbz   7,2(4)
    stb   7,2(3)
    addi  1,1,32
    blr
    .align  4
L(wus_1):  /* Move 1 byte.  */
    bf    31,L(wus_0)
    lbz   6,0(4)
    stb   6,0(3)
    .align  3
L(wus_0):
  /* Return original dst pointer.  */
    addi  1,1,32
    blr

    .align  4
    cfi_offset(31,(24-32))
    cfi_offset(30,(20-32))
L(wdu):

  /* Copy words where the destination is aligned but the source is
     not.  For power4, power5 and power6 machines there is penalty for
     unaligned loads (src) that cross 32-byte, cacheline, or page
     boundaries. So we want to use simple (unaligned) loads where
     possible but avoid them where we know the load would span a 32-byte
     boundary.

     At this point we know we have at least 29 (32-3) bytes to copy
     the src is unaligned. and we may cross at least one 32-byte
     boundary. Also we have the following register values:
     r3 == adjusted dst, word aligned
     r4 == unadjusted src
     r5 == unadjusted len
     r9 == adjusted Word length
     r10 == src alignment (1-3)
     r12 == adjusted src, not aligned
     r31 == adjusted len

     First we need to copy word up to but not crossing the next 32-byte
     boundary. Then perform aligned loads just before and just after
     the boundary and use shifts and or to generate the next aligned
     word for dst. If more than 32 bytes remain we copy (unaligned src)
     the next 7 words and repeat the loop until less than 32-bytes
     remain.

     Then if more than 4 bytes remain we again use aligned loads,
     shifts and or to generate the next dst word. We then process the
     remaining words using unaligned loads as needed. Finally we check
     if there are more than 0 bytes (1-3) bytes remaining and use
     halfword and or byte load/stores to complete the copy.
*/
    mr      4,12      /* restore unaligned adjusted src ptr */
    clrlwi  0,12,27   /* Find dist from previous 32-byte boundary.  */
    slwi    10,10,3   /* calculate number of bits to shift 1st word left */
    cmplwi  cr5,0,16
    subfic  8,0,32   /* Number of bytes to next 32-byte boundary.  */

    mtcrf   0x01,8
    cmplwi  cr1,10,16
    subfic  9,10,32  /* number of bits to shift 2nd word right */
/*  This test is reversed because the timing to compare the bytes to
    32-byte boundary could not be meet.  So we compare the bytes from
    previous 32-byte boundary and invert the test.  */
    bge     cr5,L(wdu_h32_8)
    .align  4
    lwz   6,0(4)
    lwz   7,4(4)
    addi  12,4,16    /* generate alternate pointers to avoid agen */
    addi  11,3,16    /* timing issues downstream.  */
    stw   6,0(3)
    stw   7,4(3)
    subi  31,31,16
    lwz   6,8(4)
    lwz   7,12(4)
    addi  4,4,16
    stw   6,8(3)
    stw   7,12(3)
    addi  3,3,16
    bf    28,L(wdu_h32_4)
    lwz   6,0(12)
    lwz   7,4(12)
    subi  31,31,8
    addi  4,4,8
    stw   6,0(11)
    stw   7,4(11)
    addi  3,3,8
    bf    29,L(wdu_h32_0)
    lwz   6,8(12)
    addi  4,4,4
    subi  31,31,4
    stw   6,8(11)
    addi  3,3,4
    b     L(wdu_h32_0)
    .align  4
L(wdu_h32_8):
    bf    28,L(wdu_h32_4)
    lwz   6,0(4)
    lwz   7,4(4)
    subi  31,31,8
    bf    29,L(wdu_h32_8x)
    stw   6,0(3)
    stw   7,4(3)
    lwz   6,8(4)
    addi  4,4,12
    subi  31,31,4
    stw   6,8(3)
    addi  3,3,12
    b     L(wdu_h32_0)
    .align  4
L(wdu_h32_8x):
    addi  4,4,8
    stw   6,0(3)
    stw   7,4(3)
    addi  3,3,8
    b     L(wdu_h32_0)
    .align  4
L(wdu_h32_4):
    bf    29,L(wdu_h32_0)
    lwz   6,0(4)
    subi  31,31,4
    addi  4,4,4
    stw   6,0(3)
    addi  3,3,4
    .align  4
L(wdu_h32_0):
/*  set up for 32-byte boundary crossing word move and possibly 32-byte
    move loop.  */
    clrrwi  12,4,2
    cmplwi  cr5,31,32
    bge     cr1,L(wdu2_32)
#if 0
    b       L(wdu1_32)
/*
    cmplwi  cr1,10,8
    beq     cr1,L(wdu1_32)
    cmplwi  cr1,10,16
    beq     cr1,L(wdu2_32)
    cmplwi  cr1,10,24
    beq     cr1,L(wdu3_32)
*/
L(wdu_32):
    lwz     6,0(12)
    cmplwi  cr6,31,4
    srwi    8,31,5    /* calculate the 32 byte loop count */
    slw     0,6,10
    clrlwi  31,31,27   /* The remaining bytes, < 32.  */
    blt     cr5,L(wdu_32tail)
    mtctr   8
    cmplwi  cr6,31,4
    .align  4
L(wdu_loop32):
    /* copy 32 bytes at a time */
    lwz   8,4(12)
    addi  12,12,32
    lwz   7,4(4)
    srw   8,8,9
    or    0,0,8
    stw   0,0(3)
    stw   7,4(3)
    lwz   6,8(4)
    lwz   7,12(4)
    stw   6,8(3)
    stw   7,12(3)
    lwz   6,16(4)
    lwz   7,20(4)
    stw   6,16(3)
    stw   7,20(3)
    lwz   6,24(4)
    lwz   7,28(4)
    lwz   8,0(12)
    addi  4,4,32
    stw   6,24(3)
    stw   7,28(3)
    addi  3,3,32
    slw   0,8,10
    bdnz+ L(wdu_loop32)

L(wdu_32tail):
    mtcrf   0x01,31
    cmplwi  cr5,31,16
    blt     cr6,L(wdu_4tail)
    /* calculate and store the final word */
    lwz   8,4(12)
    srw   8,8,9
    or    6,0,8
    b     L(wdu_32tailx)
#endif
    .align  4
L(wdu1_32):
    lwz     6,-1(4)
    cmplwi  cr6,31,4
    srwi    8,31,5    /* calculate the 32 byte loop count */
#ifdef __LITTLE_ENDIAN__
    srwi    6,6,8
#else
    slwi    6,6,8
#endif
    clrlwi  31,31,27   /* The remaining bytes, < 32.  */
    blt     cr5,L(wdu1_32tail)
    mtctr   8
    cmplwi  cr6,31,4

    lwz   8,3(4)
    lwz   7,4(4)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,24,32
#else
/*  Equivalent to: srwi   8,8,32-8;  or    6,6,8 */
    rlwimi 6,8,8,(32-8),31
#endif
    b      L(wdu1_loop32x)
    .align  4
L(wdu1_loop32):
    /* copy 32 bytes at a time */
    lwz   8,3(4)
    lwz   7,4(4)
    stw   10,-8(3)
    stw   11,-4(3)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,24,32
#else
/*  Equivalent to  srwi   8,8,32-8; or    6,6,8 */
    rlwimi 6,8,8,(32-8),31
#endif
L(wdu1_loop32x):
    lwz   10,8(4)
    lwz   11,12(4)
    stw   6,0(3)
    stw   7,4(3)
    lwz   6,16(4)
    lwz   7,20(4)
    stw   10,8(3)
    stw   11,12(3)
    lwz   10,24(4)
    lwz   11,28(4)
    lwz   8,32-1(4)
    addi  4,4,32
    stw   6,16(3)
    stw   7,20(3)
    addi  3,3,32
#ifdef __LITTLE_ENDIAN__
    srwi  6,8,8
#else
    slwi  6,8,8
#endif
    bdnz+ L(wdu1_loop32)
    stw   10,-8(3)
    stw   11,-4(3)

L(wdu1_32tail):
    mtcrf   0x01,31
    cmplwi  cr5,31,16
    blt     cr6,L(wdu_4tail)
    /* calculate and store the final word */
    lwz   8,3(4)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,24,32
#else
/*  Equivalent to: srwi   8,8,32-8;  or    6,6,8  */
    rlwimi 6,8,8,(32-8),31
#endif
    b     L(wdu_32tailx)

L(wdu2_32):
    bgt     cr1,L(wdu3_32)
    lwz     6,-2(4)
    cmplwi  cr6,31,4
    srwi    8,31,5    /* calculate the 32 byte loop count */
#ifdef __LITTLE_ENDIAN__
    srwi    6,6,16
#else
    slwi    6,6,16
#endif
    clrlwi  31,31,27   /* The remaining bytes, < 32.  */
    blt     cr5,L(wdu2_32tail)
    mtctr   8
    cmplwi  cr6,31,4

    lwz   8,2(4)
    lwz   7,4(4)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,16,32
#else
    rlwimi 6,8,16,(32-16),31
#endif
    b      L(wdu2_loop32x)
    .align  4
L(wdu2_loop32):
    /* copy 32 bytes at a time */
    lwz   8,2(4)
    lwz   7,4(4)
    stw   10,-8(3)
    stw   11,-4(3)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,16,32
#else
    rlwimi 6,8,16,(32-16),31
#endif
L(wdu2_loop32x):
    lwz   10,8(4)
    lwz   11,12(4)
    stw   6,0(3)
    stw   7,4(3)
    lwz   6,16(4)
    lwz   7,20(4)
    stw   10,8(3)
    stw   11,12(3)
    lwz   10,24(4)
    lwz   11,28(4)
/*    lwz   8,0(12) */
    lwz   8,32-2(4)
    addi  4,4,32
    stw   6,16(3)
    stw   7,20(3)
    addi  3,3,32
#ifdef __LITTLE_ENDIAN__
    srwi  6,8,16
#else
    slwi  6,8,16
#endif
    bdnz+ L(wdu2_loop32)
    stw   10,-8(3)
    stw   11,-4(3)

L(wdu2_32tail):
    mtcrf   0x01,31
    cmplwi  cr5,31,16
    blt     cr6,L(wdu_4tail)
    /* calculate and store the final word */
    lwz   8,2(4)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,16,32
#else
    rlwimi 6,8,16,(32-16),31
#endif
    b     L(wdu_32tailx)

L(wdu3_32):
/*    lwz     6,0(12) */
    lwz     6,-3(4)
    cmplwi  cr6,31,4
    srwi    8,31,5    /* calculate the 32 byte loop count */
#ifdef __LITTLE_ENDIAN__
    srwi    6,6,24
#else
    slwi    6,6,24
#endif
    clrlwi  31,31,27   /* The remaining bytes, < 32.  */
    blt     cr5,L(wdu3_32tail)
    mtctr   8
    cmplwi  cr6,31,4

    lwz   8,1(4)
    lwz   7,4(4)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,8,32
#else
    rlwimi 6,8,24,(32-24),31
#endif
    b      L(wdu3_loop32x)
    .align  4
L(wdu3_loop32):
    /* copy 32 bytes at a time */
    lwz   8,1(4)
    lwz   7,4(4)
    stw   10,-8(3)
    stw   11,-4(3)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,8,32
#else
    rlwimi 6,8,24,(32-24),31
#endif
L(wdu3_loop32x):
    lwz   10,8(4)
    lwz   11,12(4)
    stw   6,0(3)
    stw   7,4(3)
    lwz   6,16(4)
    lwz   7,20(4)
    stw   10,8(3)
    stw   11,12(3)
    lwz   10,24(4)
    lwz   11,28(4)
    lwz   8,32-3(4)
    addi  4,4,32
    stw   6,16(3)
    stw   7,20(3)
    addi  3,3,32
#ifdef __LITTLE_ENDIAN__
    srwi  6,8,24
#else
    slwi  6,8,24
#endif
    bdnz+ L(wdu3_loop32)
    stw   10,-8(3)
    stw   11,-4(3)

L(wdu3_32tail):
    mtcrf   0x01,31
    cmplwi  cr5,31,16
    blt     cr6,L(wdu_4tail)
    /* calculate and store the final word */
    lwz   8,1(4)
#ifdef __LITTLE_ENDIAN__
    rldimi 6,8,8,32
#else
    rlwimi 6,8,24,(32-24),31
#endif
    b     L(wdu_32tailx)
    .align  4
L(wdu_32tailx):
    blt     cr5,L(wdu_t32_8)
    lwz   7,4(4)
    addi  12,4,16    /* generate alternate pointers to avoid agen */
    addi  11,3,16    /* timing issues downstream.  */
    stw   6,0(3)
    stw   7,4(3)
    subi  31,31,16
    lwz   6,8(4)
    lwz   7,12(4)
    addi  4,4,16
    stw   6,8(3)
    stw   7,12(3)
    addi  3,3,16
    bf    28,L(wdu_t32_4x)
    lwz   6,0(12)
    lwz   7,4(12)
    addi  4,4,8
    subi  31,31,8
    stw   6,0(11)
    stw   7,4(11)
    addi  3,3,8
    bf    29,L(wdu_t32_0)
    lwz   6,8(12)
    addi  4,4,4
    subi  31,31,4
    stw   6,8(11)
    addi  3,3,4
    b     L(wdu_t32_0)
    .align  4
L(wdu_t32_4x):
    bf    29,L(wdu_t32_0)
    lwz   6,0(4)
    addi  4,4,4
    subi  31,31,4
    stw   6,0(3)
    addi  3,3,4
    b     L(wdu_t32_0)
    .align  4
L(wdu_t32_8):
    bf    28,L(wdu_t32_4)
    lwz   7,4(4)
    subi  31,31,8
    bf    29,L(wdu_t32_8x)
    stw   6,0(3)
    stw   7,4(3)
    lwz   6,8(4)
    subi  31,31,4
    addi  4,4,12
    stw   6,8(3)
    addi  3,3,12
    b     L(wdu_t32_0)
    .align  4
L(wdu_t32_8x):
    addi  4,4,8
    stw   6,0(3)
    stw   7,4(3)
    addi  3,3,8
    b     L(wdu_t32_0)
    .align  4
L(wdu_t32_4):
    subi  31,31,4
    stw   6,0(3)
    addi  4,4,4
    addi  3,3,4
    .align  4
L(wdu_t32_0):
L(wdu_4tail):
    cmplwi  cr6,31,0
    beq   cr6,L(wdus_0)	/* If the tail is 0 bytes we are done!  */
    bf    30,L(wdus_3)
    lhz   7,0(4)
    sth   7,0(3)
    bf    31,L(wdus_0)
    lbz   8,2(4)
    stb   8,2(3)
    mr    3,30
    lwz   30,20(1)
    lwz   31,24(1)
    addi  1,1,32
    blr
    .align  4
L(wdus_3):
    bf    31,L(wus_0)
    lbz   6,0(4)
    stb   6,0(3)
    .align  4
L(wdus_0):
  /* Return original dst pointer.  */
    mr   3,30
    lwz  30,20(1)
    lwz  31,24(1)
    addi 1,1,32
    blr
END (memcpy)

libc_hidden_builtin_def (memcpy)