LXR linux/arch/ppc/boot/common/string.S

   1/*
   2 * String handling functions for PowerPC.
   3 *
   4 * Copyright (C) 1996 Paul Mackerras.
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11#define r0      0
  12#define r3      3
  13#define r4      4
  14#define r5      5
  15#define r6      6
  16#define r7      7
  17#define r8      8
  18
  19        .globl  strlen
  20strlen:
  21        addi    r4,r3,-1
  221:      lbzu    r0,1(r4)
  23        cmpwi   0,r0,0
  24        bne     1b
  25        subf    r3,r3,r4
  26        blr
  27
  28        .globl  memset
  29memset:
  30        rlwimi  r4,r4,8,16,23
  31        rlwimi  r4,r4,16,0,15
  32        addi    r6,r3,-4
  33        cmplwi  0,r5,4
  34        blt     7f
  35        stwu    r4,4(r6)
  36        beqlr
  37        andi.   r0,r6,3
  38        add     r5,r0,r5
  39        subf    r6,r0,r6
  40        rlwinm  r0,r5,32-2,2,31
  41        mtctr   r0
  42        bdz     6f
  431:      stwu    r4,4(r6)
  44        bdnz    1b
  456:      andi.   r5,r5,3
  467:      cmpwi   0,r5,0
  47        beqlr
  48        mtctr   r5
  49        addi    r6,r6,3
  508:      stbu    r4,1(r6)
  51        bdnz    8b
  52        blr
  53
  54        .globl  memmove
  55memmove:
  56        cmplw   0,r3,r4
  57        bgt     backwards_memcpy
  58        /* fall through */
  59
  60        .globl  memcpy
  61memcpy:
  62        rlwinm. r7,r5,32-3,3,31         /* r0 = r5 >> 3 */
  63        addi    r6,r3,-4
  64        addi    r4,r4,-4
  65        beq     2f                      /* if less than 8 bytes to do */
  66        andi.   r0,r6,3                 /* get dest word aligned */
  67        mtctr   r7
  68        bne     5f
  691:      lwz     r7,4(r4)
  70        lwzu    r8,8(r4)
  71        stw     r7,4(r6)
  72        stwu    r8,8(r6)
  73        bdnz    1b
  74        andi.   r5,r5,7
  752:      cmplwi  0,r5,4
  76        blt     3f
  77        lwzu    r0,4(r4)
  78        addi    r5,r5,-4
  79        stwu    r0,4(r6)
  803:      cmpwi   0,r5,0
  81        beqlr
  82        mtctr   r5
  83        addi    r4,r4,3
  84        addi    r6,r6,3
  854:      lbzu    r0,1(r4)
  86        stbu    r0,1(r6)
  87        bdnz    4b
  88        blr
  895:      subfic  r0,r0,4
  90        mtctr   r0
  916:      lbz     r7,4(r4)
  92        addi    r4,r4,1
  93        stb     r7,4(r6)
  94        addi    r6,r6,1
  95        bdnz    6b
  96        subf    r5,r0,r5
  97        rlwinm. r7,r5,32-3,3,31
  98        beq     2b
  99        mtctr   r7
 100        b       1b
 101
 102        .globl  backwards_memcpy
 103backwards_memcpy:
 104        rlwinm. r7,r5,32-3,3,31         /* r0 = r5 >> 3 */
 105        add     r6,r3,r5
 106        add     r4,r4,r5
 107        beq     2f
 108        andi.   r0,r6,3
 109        mtctr   r7
 110        bne     5f
 1111:      lwz     r7,-4(r4)
 112        lwzu    r8,-8(r4)
 113        stw     r7,-4(r6)
 114        stwu    r8,-8(r6)
 115        bdnz    1b
 116        andi.   r5,r5,7
 1172:      cmplwi  0,r5,4
 118        blt     3f
 119        lwzu    r0,-4(r4)
 120        subi    r5,r5,4
 121        stwu    r0,-4(r6)
 1223:      cmpwi   0,r5,0
 123        beqlr
 124        mtctr   r5
 1254:      lbzu    r0,-1(r4)
 126        stbu    r0,-1(r6)
 127        bdnz    4b
 128        blr
 1295:      mtctr   r0
 1306:      lbzu    r7,-1(r4)
 131        stbu    r7,-1(r6)
 132        bdnz    6b
 133        subf    r5,r0,r5
 134        rlwinm. r7,r5,32-3,3,31
 135        beq     2b
 136        mtctr   r7
 137        b       1b
 138
 139        .globl  memcmp
 140memcmp:
 141        cmpwi   0,r5,0
 142        blelr
 143        mtctr   r5
 144        addi    r6,r3,-1
 145        addi    r4,r4,-1
 1461:      lbzu    r3,1(r6)
 147        lbzu    r0,1(r4)
 148        subf.   r3,r0,r3
 149        bdnzt   2,1b
 150        blr
 151