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789c299ca2
Here is a patch from Paul Mackerras that improves the ppc64 copy_tofrom_user.
The loop now does 32 bytes at a time and as well as pairing loads and stores.
A quick test case that reads 8kB over and over shows the improvement:
POWER6: 53% faster
POWER7: 51% faster
#define _XOPEN_SOURCE 500
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#define BUFSIZE (8 * 1024)
#define ITERATIONS 10000000
int main()
{
char tmpfile[] = "/tmp/copy_to_user_testXXXXXX";
int fd;
char *buf[BUFSIZE];
unsigned long i;
fd = mkstemp(tmpfile);
if (fd < 0) {
perror("open");
exit(1);
}
if (write(fd, buf, BUFSIZE) != BUFSIZE) {
perror("open");
exit(1);
}
for (i = 0; i < 10000000; i++) {
if (pread(fd, buf, BUFSIZE, 0) != BUFSIZE) {
perror("pread");
exit(1);
}
}
unlink(tmpfile);
return 0;
}
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
646 lines
10 KiB
ArmAsm
646 lines
10 KiB
ArmAsm
/*
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* Copyright (C) 2002 Paul Mackerras, IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <asm/processor.h>
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#include <asm/ppc_asm.h>
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.align 7
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_GLOBAL(__copy_tofrom_user)
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/* first check for a whole page copy on a page boundary */
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cmpldi cr1,r5,16
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cmpdi cr6,r5,4096
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or r0,r3,r4
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neg r6,r3 /* LS 3 bits = # bytes to 8-byte dest bdry */
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andi. r0,r0,4095
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std r3,-24(r1)
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crand cr0*4+2,cr0*4+2,cr6*4+2
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std r4,-16(r1)
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std r5,-8(r1)
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dcbt 0,r4
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beq .Lcopy_page_4K
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andi. r6,r6,7
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PPC_MTOCRF 0x01,r5
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blt cr1,.Lshort_copy
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/* Below we want to nop out the bne if we're on a CPU that has the
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* CPU_FTR_UNALIGNED_LD_STD bit set and the CPU_FTR_CP_USE_DCBTZ bit
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* cleared.
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* At the time of writing the only CPU that has this combination of bits
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* set is Power6.
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*/
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BEGIN_FTR_SECTION
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nop
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FTR_SECTION_ELSE
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bne .Ldst_unaligned
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ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \
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CPU_FTR_UNALIGNED_LD_STD)
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.Ldst_aligned:
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addi r3,r3,-16
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BEGIN_FTR_SECTION
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andi. r0,r4,7
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bne .Lsrc_unaligned
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END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
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blt cr1,.Ldo_tail /* if < 16 bytes to copy */
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srdi r0,r5,5
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cmpdi cr1,r0,0
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20: ld r7,0(r4)
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220: ld r6,8(r4)
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addi r4,r4,16
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mtctr r0
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andi. r0,r5,0x10
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beq 22f
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addi r3,r3,16
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addi r4,r4,-16
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mr r9,r7
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mr r8,r6
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beq cr1,72f
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21: ld r7,16(r4)
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221: ld r6,24(r4)
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addi r4,r4,32
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70: std r9,0(r3)
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270: std r8,8(r3)
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22: ld r9,0(r4)
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222: ld r8,8(r4)
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71: std r7,16(r3)
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271: std r6,24(r3)
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addi r3,r3,32
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bdnz 21b
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72: std r9,0(r3)
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272: std r8,8(r3)
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andi. r5,r5,0xf
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beq+ 3f
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addi r4,r4,16
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.Ldo_tail:
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addi r3,r3,16
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bf cr7*4+0,246f
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244: ld r9,0(r4)
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addi r4,r4,8
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245: std r9,0(r3)
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addi r3,r3,8
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246: bf cr7*4+1,1f
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23: lwz r9,0(r4)
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addi r4,r4,4
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73: stw r9,0(r3)
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addi r3,r3,4
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1: bf cr7*4+2,2f
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44: lhz r9,0(r4)
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addi r4,r4,2
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74: sth r9,0(r3)
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addi r3,r3,2
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2: bf cr7*4+3,3f
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45: lbz r9,0(r4)
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75: stb r9,0(r3)
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3: li r3,0
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blr
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.Lsrc_unaligned:
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srdi r6,r5,3
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addi r5,r5,-16
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subf r4,r0,r4
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srdi r7,r5,4
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sldi r10,r0,3
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cmpldi cr6,r6,3
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andi. r5,r5,7
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mtctr r7
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subfic r11,r10,64
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add r5,r5,r0
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bt cr7*4+0,28f
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24: ld r9,0(r4) /* 3+2n loads, 2+2n stores */
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25: ld r0,8(r4)
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sld r6,r9,r10
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26: ldu r9,16(r4)
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srd r7,r0,r11
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sld r8,r0,r10
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or r7,r7,r6
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blt cr6,79f
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27: ld r0,8(r4)
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b 2f
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28: ld r0,0(r4) /* 4+2n loads, 3+2n stores */
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29: ldu r9,8(r4)
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sld r8,r0,r10
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addi r3,r3,-8
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blt cr6,5f
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30: ld r0,8(r4)
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srd r12,r9,r11
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sld r6,r9,r10
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31: ldu r9,16(r4)
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or r12,r8,r12
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srd r7,r0,r11
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sld r8,r0,r10
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addi r3,r3,16
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beq cr6,78f
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1: or r7,r7,r6
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32: ld r0,8(r4)
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76: std r12,8(r3)
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2: srd r12,r9,r11
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sld r6,r9,r10
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33: ldu r9,16(r4)
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or r12,r8,r12
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77: stdu r7,16(r3)
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srd r7,r0,r11
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sld r8,r0,r10
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bdnz 1b
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78: std r12,8(r3)
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or r7,r7,r6
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79: std r7,16(r3)
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5: srd r12,r9,r11
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or r12,r8,r12
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80: std r12,24(r3)
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bne 6f
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li r3,0
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blr
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6: cmpwi cr1,r5,8
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addi r3,r3,32
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sld r9,r9,r10
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ble cr1,7f
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34: ld r0,8(r4)
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srd r7,r0,r11
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or r9,r7,r9
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7:
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bf cr7*4+1,1f
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rotldi r9,r9,32
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94: stw r9,0(r3)
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addi r3,r3,4
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1: bf cr7*4+2,2f
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rotldi r9,r9,16
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95: sth r9,0(r3)
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addi r3,r3,2
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2: bf cr7*4+3,3f
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rotldi r9,r9,8
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96: stb r9,0(r3)
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3: li r3,0
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blr
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.Ldst_unaligned:
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PPC_MTOCRF 0x01,r6 /* put #bytes to 8B bdry into cr7 */
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subf r5,r6,r5
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li r7,0
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cmpldi cr1,r5,16
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bf cr7*4+3,1f
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35: lbz r0,0(r4)
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81: stb r0,0(r3)
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addi r7,r7,1
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1: bf cr7*4+2,2f
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36: lhzx r0,r7,r4
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82: sthx r0,r7,r3
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addi r7,r7,2
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2: bf cr7*4+1,3f
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37: lwzx r0,r7,r4
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83: stwx r0,r7,r3
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3: PPC_MTOCRF 0x01,r5
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add r4,r6,r4
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add r3,r6,r3
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b .Ldst_aligned
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.Lshort_copy:
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bf cr7*4+0,1f
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38: lwz r0,0(r4)
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39: lwz r9,4(r4)
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addi r4,r4,8
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84: stw r0,0(r3)
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85: stw r9,4(r3)
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addi r3,r3,8
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1: bf cr7*4+1,2f
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40: lwz r0,0(r4)
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addi r4,r4,4
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86: stw r0,0(r3)
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addi r3,r3,4
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2: bf cr7*4+2,3f
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41: lhz r0,0(r4)
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addi r4,r4,2
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87: sth r0,0(r3)
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addi r3,r3,2
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3: bf cr7*4+3,4f
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42: lbz r0,0(r4)
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88: stb r0,0(r3)
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4: li r3,0
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blr
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/*
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* exception handlers follow
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* we have to return the number of bytes not copied
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* for an exception on a load, we set the rest of the destination to 0
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*/
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136:
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137:
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add r3,r3,r7
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b 1f
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130:
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131:
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addi r3,r3,8
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120:
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320:
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122:
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322:
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124:
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125:
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126:
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127:
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128:
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129:
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133:
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addi r3,r3,8
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132:
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addi r3,r3,8
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121:
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321:
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344:
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134:
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135:
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138:
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139:
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140:
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141:
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142:
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123:
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144:
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145:
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/*
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* here we have had a fault on a load and r3 points to the first
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* unmodified byte of the destination
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*/
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1: ld r6,-24(r1)
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ld r4,-16(r1)
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ld r5,-8(r1)
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subf r6,r6,r3
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add r4,r4,r6
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subf r5,r6,r5 /* #bytes left to go */
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/*
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* first see if we can copy any more bytes before hitting another exception
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*/
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mtctr r5
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43: lbz r0,0(r4)
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addi r4,r4,1
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89: stb r0,0(r3)
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addi r3,r3,1
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bdnz 43b
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li r3,0 /* huh? all copied successfully this time? */
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blr
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/*
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* here we have trapped again, need to clear ctr bytes starting at r3
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*/
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143: mfctr r5
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li r0,0
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mr r4,r3
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mr r3,r5 /* return the number of bytes not copied */
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1: andi. r9,r4,7
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beq 3f
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90: stb r0,0(r4)
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addic. r5,r5,-1
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addi r4,r4,1
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bne 1b
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blr
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3: cmpldi cr1,r5,8
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srdi r9,r5,3
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andi. r5,r5,7
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blt cr1,93f
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mtctr r9
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91: std r0,0(r4)
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addi r4,r4,8
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bdnz 91b
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93: beqlr
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mtctr r5
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92: stb r0,0(r4)
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addi r4,r4,1
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bdnz 92b
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blr
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/*
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* exception handlers for stores: we just need to work
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* out how many bytes weren't copied
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*/
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182:
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183:
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add r3,r3,r7
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b 1f
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371:
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180:
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addi r3,r3,8
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171:
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177:
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addi r3,r3,8
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370:
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372:
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176:
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178:
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addi r3,r3,4
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185:
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addi r3,r3,4
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170:
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172:
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345:
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173:
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174:
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175:
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179:
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181:
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184:
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186:
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187:
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188:
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189:
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194:
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195:
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196:
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1:
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ld r6,-24(r1)
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ld r5,-8(r1)
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add r6,r6,r5
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subf r3,r3,r6 /* #bytes not copied */
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190:
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191:
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192:
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blr /* #bytes not copied in r3 */
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.section __ex_table,"a"
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.align 3
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.llong 20b,120b
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.llong 220b,320b
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.llong 21b,121b
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.llong 221b,321b
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.llong 70b,170b
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.llong 270b,370b
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.llong 22b,122b
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.llong 222b,322b
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.llong 71b,171b
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.llong 271b,371b
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.llong 72b,172b
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.llong 272b,372b
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.llong 244b,344b
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.llong 245b,345b
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.llong 23b,123b
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.llong 73b,173b
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.llong 44b,144b
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.llong 74b,174b
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.llong 45b,145b
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.llong 75b,175b
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.llong 24b,124b
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.llong 25b,125b
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.llong 26b,126b
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.llong 27b,127b
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.llong 28b,128b
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.llong 29b,129b
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.llong 30b,130b
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.llong 31b,131b
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.llong 32b,132b
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.llong 76b,176b
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.llong 33b,133b
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.llong 77b,177b
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.llong 78b,178b
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.llong 79b,179b
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.llong 80b,180b
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.llong 34b,134b
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.llong 94b,194b
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.llong 95b,195b
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.llong 96b,196b
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.llong 35b,135b
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.llong 81b,181b
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.llong 36b,136b
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.llong 82b,182b
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.llong 37b,137b
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.llong 83b,183b
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.llong 38b,138b
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.llong 39b,139b
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.llong 84b,184b
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.llong 85b,185b
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.llong 40b,140b
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.llong 86b,186b
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.llong 41b,141b
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.llong 87b,187b
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.llong 42b,142b
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.llong 88b,188b
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.llong 43b,143b
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.llong 89b,189b
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.llong 90b,190b
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.llong 91b,191b
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.llong 92b,192b
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.text
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/*
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* Routine to copy a whole page of data, optimized for POWER4.
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* On POWER4 it is more than 50% faster than the simple loop
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* above (following the .Ldst_aligned label) but it runs slightly
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* slower on POWER3.
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*/
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.Lcopy_page_4K:
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std r31,-32(1)
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std r30,-40(1)
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std r29,-48(1)
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std r28,-56(1)
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std r27,-64(1)
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std r26,-72(1)
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std r25,-80(1)
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std r24,-88(1)
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std r23,-96(1)
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std r22,-104(1)
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std r21,-112(1)
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std r20,-120(1)
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li r5,4096/32 - 1
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addi r3,r3,-8
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li r0,5
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0: addi r5,r5,-24
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mtctr r0
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20: ld r22,640(4)
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21: ld r21,512(4)
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22: ld r20,384(4)
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23: ld r11,256(4)
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24: ld r9,128(4)
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25: ld r7,0(4)
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26: ld r25,648(4)
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27: ld r24,520(4)
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28: ld r23,392(4)
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29: ld r10,264(4)
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30: ld r8,136(4)
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31: ldu r6,8(4)
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cmpwi r5,24
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1:
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32: std r22,648(3)
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33: std r21,520(3)
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34: std r20,392(3)
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35: std r11,264(3)
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36: std r9,136(3)
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37: std r7,8(3)
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38: ld r28,648(4)
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39: ld r27,520(4)
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40: ld r26,392(4)
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41: ld r31,264(4)
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42: ld r30,136(4)
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43: ld r29,8(4)
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44: std r25,656(3)
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45: std r24,528(3)
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46: std r23,400(3)
|
|
47: std r10,272(3)
|
|
48: std r8,144(3)
|
|
49: std r6,16(3)
|
|
50: ld r22,656(4)
|
|
51: ld r21,528(4)
|
|
52: ld r20,400(4)
|
|
53: ld r11,272(4)
|
|
54: ld r9,144(4)
|
|
55: ld r7,16(4)
|
|
56: std r28,664(3)
|
|
57: std r27,536(3)
|
|
58: std r26,408(3)
|
|
59: std r31,280(3)
|
|
60: std r30,152(3)
|
|
61: stdu r29,24(3)
|
|
62: ld r25,664(4)
|
|
63: ld r24,536(4)
|
|
64: ld r23,408(4)
|
|
65: ld r10,280(4)
|
|
66: ld r8,152(4)
|
|
67: ldu r6,24(4)
|
|
bdnz 1b
|
|
68: std r22,648(3)
|
|
69: std r21,520(3)
|
|
70: std r20,392(3)
|
|
71: std r11,264(3)
|
|
72: std r9,136(3)
|
|
73: std r7,8(3)
|
|
74: addi r4,r4,640
|
|
75: addi r3,r3,648
|
|
bge 0b
|
|
mtctr r5
|
|
76: ld r7,0(4)
|
|
77: ld r8,8(4)
|
|
78: ldu r9,16(4)
|
|
3:
|
|
79: ld r10,8(4)
|
|
80: std r7,8(3)
|
|
81: ld r7,16(4)
|
|
82: std r8,16(3)
|
|
83: ld r8,24(4)
|
|
84: std r9,24(3)
|
|
85: ldu r9,32(4)
|
|
86: stdu r10,32(3)
|
|
bdnz 3b
|
|
4:
|
|
87: ld r10,8(4)
|
|
88: std r7,8(3)
|
|
89: std r8,16(3)
|
|
90: std r9,24(3)
|
|
91: std r10,32(3)
|
|
9: ld r20,-120(1)
|
|
ld r21,-112(1)
|
|
ld r22,-104(1)
|
|
ld r23,-96(1)
|
|
ld r24,-88(1)
|
|
ld r25,-80(1)
|
|
ld r26,-72(1)
|
|
ld r27,-64(1)
|
|
ld r28,-56(1)
|
|
ld r29,-48(1)
|
|
ld r30,-40(1)
|
|
ld r31,-32(1)
|
|
li r3,0
|
|
blr
|
|
|
|
/*
|
|
* on an exception, reset to the beginning and jump back into the
|
|
* standard __copy_tofrom_user
|
|
*/
|
|
100: ld r20,-120(1)
|
|
ld r21,-112(1)
|
|
ld r22,-104(1)
|
|
ld r23,-96(1)
|
|
ld r24,-88(1)
|
|
ld r25,-80(1)
|
|
ld r26,-72(1)
|
|
ld r27,-64(1)
|
|
ld r28,-56(1)
|
|
ld r29,-48(1)
|
|
ld r30,-40(1)
|
|
ld r31,-32(1)
|
|
ld r3,-24(r1)
|
|
ld r4,-16(r1)
|
|
li r5,4096
|
|
b .Ldst_aligned
|
|
|
|
.section __ex_table,"a"
|
|
.align 3
|
|
.llong 20b,100b
|
|
.llong 21b,100b
|
|
.llong 22b,100b
|
|
.llong 23b,100b
|
|
.llong 24b,100b
|
|
.llong 25b,100b
|
|
.llong 26b,100b
|
|
.llong 27b,100b
|
|
.llong 28b,100b
|
|
.llong 29b,100b
|
|
.llong 30b,100b
|
|
.llong 31b,100b
|
|
.llong 32b,100b
|
|
.llong 33b,100b
|
|
.llong 34b,100b
|
|
.llong 35b,100b
|
|
.llong 36b,100b
|
|
.llong 37b,100b
|
|
.llong 38b,100b
|
|
.llong 39b,100b
|
|
.llong 40b,100b
|
|
.llong 41b,100b
|
|
.llong 42b,100b
|
|
.llong 43b,100b
|
|
.llong 44b,100b
|
|
.llong 45b,100b
|
|
.llong 46b,100b
|
|
.llong 47b,100b
|
|
.llong 48b,100b
|
|
.llong 49b,100b
|
|
.llong 50b,100b
|
|
.llong 51b,100b
|
|
.llong 52b,100b
|
|
.llong 53b,100b
|
|
.llong 54b,100b
|
|
.llong 55b,100b
|
|
.llong 56b,100b
|
|
.llong 57b,100b
|
|
.llong 58b,100b
|
|
.llong 59b,100b
|
|
.llong 60b,100b
|
|
.llong 61b,100b
|
|
.llong 62b,100b
|
|
.llong 63b,100b
|
|
.llong 64b,100b
|
|
.llong 65b,100b
|
|
.llong 66b,100b
|
|
.llong 67b,100b
|
|
.llong 68b,100b
|
|
.llong 69b,100b
|
|
.llong 70b,100b
|
|
.llong 71b,100b
|
|
.llong 72b,100b
|
|
.llong 73b,100b
|
|
.llong 74b,100b
|
|
.llong 75b,100b
|
|
.llong 76b,100b
|
|
.llong 77b,100b
|
|
.llong 78b,100b
|
|
.llong 79b,100b
|
|
.llong 80b,100b
|
|
.llong 81b,100b
|
|
.llong 82b,100b
|
|
.llong 83b,100b
|
|
.llong 84b,100b
|
|
.llong 85b,100b
|
|
.llong 86b,100b
|
|
.llong 87b,100b
|
|
.llong 88b,100b
|
|
.llong 89b,100b
|
|
.llong 90b,100b
|
|
.llong 91b,100b
|