arch/powerpc/lib/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 #include <asm/processor.h>
  12 #include <asm/errno.h>
  13 #include <asm/ppc_asm.h>
  14
  15         .section __ex_table,"a"
  16         PPC_LONG_ALIGN
  17         .text
  18
  19 _GLOBAL(strcpy)
  20         addi    r5,r3,-1
  21         addi    r4,r4,-1
  22 1:      lbzu    r0,1(r4)
  23         cmpwi   0,r0,0
  24         stbu    r0,1(r5)
  25         bne     1b
  26         blr
  27
  28 /* This clears out any unused part of the destination buffer,
  29    just as the libc version does.  -- paulus */
  30 _GLOBAL(strncpy)
  31         PPC_LCMPI 0,r5,0
  32         beqlr
  33         mtctr   r5
  34         addi    r6,r3,-1
  35         addi    r4,r4,-1
  36 1:      lbzu    r0,1(r4)
  37         cmpwi   0,r0,0
  38         stbu    r0,1(r6)
  39         bdnzf   2,1b            /* dec ctr, branch if ctr != 0 && !cr0.eq */
  40         bnelr                   /* if we didn't hit a null char, we're done */
  41         mfctr   r5
  42         PPC_LCMPI 0,r5,0        /* any space left in destination buffer? */
  43         beqlr                   /* we know r0 == 0 here */
  44 2:      stbu    r0,1(r6)        /* clear it out if so */
  45         bdnz    2b
  46         blr
  47
  48 _GLOBAL(strcat)
  49         addi    r5,r3,-1
  50         addi    r4,r4,-1
  51 1:      lbzu    r0,1(r5)
  52         cmpwi   0,r0,0
  53         bne     1b
  54         addi    r5,r5,-1
  55 1:      lbzu    r0,1(r4)
  56         cmpwi   0,r0,0
  57         stbu    r0,1(r5)
  58         bne     1b
  59         blr
  60
  61 _GLOBAL(strcmp)
  62         addi    r5,r3,-1
  63         addi    r4,r4,-1
  64 1:      lbzu    r3,1(r5)
  65         cmpwi   1,r3,0
  66         lbzu    r0,1(r4)
  67         subf.   r3,r0,r3
  68         beqlr   1
  69         beq     1b
  70         blr
  71
  72 _GLOBAL(strncmp)
  73         PPC_LCMPI 0,r5,0
  74         beq-    2f
  75         mtctr   r5
  76         addi    r5,r3,-1
  77         addi    r4,r4,-1
  78 1:      lbzu    r3,1(r5)
  79         cmpwi   1,r3,0
  80         lbzu    r0,1(r4)
  81         subf.   r3,r0,r3
  82         beqlr   1
  83         bdnzt   eq,1b
  84         blr
  85 2:      li      r3,0
  86         blr
  87
  88 _GLOBAL(strlen)
  89         addi    r4,r3,-1
  90 1:      lbzu    r0,1(r4)
  91         cmpwi   0,r0,0
  92         bne     1b
  93         subf    r3,r3,r4
  94         blr
  95
  96 #ifdef CONFIG_PPC32
  97 _GLOBAL(memcmp)
  98         PPC_LCMPI 0,r5,0
  99         beq-    2f
 100         mtctr   r5
 101         addi    r6,r3,-1
 102         addi    r4,r4,-1
 103 1:      lbzu    r3,1(r6)
 104         lbzu    r0,1(r4)
 105         subf.   r3,r0,r3
 106         bdnzt   2,1b
 107         blr
 108 2:      li      r3,0
 109         blr
 110 #endif
 111
 112 _GLOBAL(memchr)
 113         PPC_LCMPI 0,r5,0
 114         beq-    2f
 115         mtctr   r5
 116         addi    r3,r3,-1
 117 1:      lbzu    r0,1(r3)
 118         cmpw    0,r0,r4
 119         bdnzf   2,1b
 120         beqlr
 121 2:      li      r3,0
 122         blr
 123
 124 #ifdef CONFIG_PPC32
 125 _GLOBAL(__clear_user)
 126         addi    r6,r3,-4
 127         li      r3,0
 128         li      r5,0
 129         cmplwi  0,r4,4
 130         blt     7f
 131         /* clear a single word */
 132 11:     stwu    r5,4(r6)
 133         beqlr
 134         /* clear word sized chunks */
 135         andi.   r0,r6,3
 136         add     r4,r0,r4
 137         subf    r6,r0,r6
 138         srwi    r0,r4,2
 139         andi.   r4,r4,3
 140         mtctr   r0
 141         bdz     7f
 142 1:      stwu    r5,4(r6)
 143         bdnz    1b
 144         /* clear byte sized chunks */
 145 7:      cmpwi   0,r4,0
 146         beqlr
 147         mtctr   r4
 148         addi    r6,r6,3
 149 8:      stbu    r5,1(r6)
 150         bdnz    8b
 151         blr
 152 90:     mr      r3,r4
 153         blr
 154 91:     mfctr   r3
 155         slwi    r3,r3,2
 156         add     r3,r3,r4
 157         blr
 158 92:     mfctr   r3
 159         blr
 160
 161         .section __ex_table,"a"
 162         PPC_LONG        11b,90b
 163         PPC_LONG        1b,91b
 164         PPC_LONG        8b,92b
 165         .text
 166 #endif