arch/ppc64/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 _GLOBAL(strcpy)
  16         addi    r5,r3,-1
  17         addi    r4,r4,-1
  18 1:      lbzu    r0,1(r4)
  19         cmpwi   0,r0,0
  20         stbu    r0,1(r5)
  21         bne     1b
  22         blr
  23
  24 _GLOBAL(strncpy)
  25         cmpwi   0,r5,0
  26         beqlr
  27         mtctr   r5
  28         addi    r6,r3,-1
  29         addi    r4,r4,-1
  30 1:      lbzu    r0,1(r4)
  31         cmpwi   0,r0,0
  32         stbu    r0,1(r6)
  33         bdnzf   2,1b            /* dec ctr, branch if ctr != 0 && !cr0.eq */
  34         blr
  35
  36 _GLOBAL(strcat)
  37         addi    r5,r3,-1
  38         addi    r4,r4,-1
  39 1:      lbzu    r0,1(r5)
  40         cmpwi   0,r0,0
  41         bne     1b
  42         addi    r5,r5,-1
  43 1:      lbzu    r0,1(r4)
  44         cmpwi   0,r0,0
  45         stbu    r0,1(r5)
  46         bne     1b
  47         blr
  48
  49 _GLOBAL(strcmp)
  50         addi    r5,r3,-1
  51         addi    r4,r4,-1
  52 1:      lbzu    r3,1(r5)
  53         cmpwi   1,r3,0
  54         lbzu    r0,1(r4)
  55         subf.   r3,r0,r3
  56         beqlr   1
  57         beq     1b
  58         blr
  59
  60 _GLOBAL(strlen)
  61         addi    r4,r3,-1
  62 1:      lbzu    r0,1(r4)
  63         cmpwi   0,r0,0
  64         bne     1b
  65         subf    r3,r3,r4
  66         blr
  67
  68 _GLOBAL(memset)
  69         neg     r0,r3
  70         rlwimi  r4,r4,8,16,23
  71         andi.   r0,r0,7                 /* # bytes to be 8-byte aligned */
  72         rlwimi  r4,r4,16,0,15
  73         cmplw   cr1,r5,r0               /* do we get that far? */
  74         rldimi  r4,r4,32,0
  75         mtcrf   1,r0
  76         mr      r6,r3
  77         blt     cr1,8f
  78         beq+    3f                      /* if already 8-byte aligned */
  79         subf    r5,r0,r5
  80         bf      31,1f
  81         stb     r4,0(r6)
  82         addi    r6,r6,1
  83 1:      bf      30,2f
  84         sth     r4,0(r6)
  85         addi    r6,r6,2
  86 2:      bf      29,3f
  87         stw     r4,0(r6)
  88         addi    r6,r6,4
  89 3:      srdi.   r0,r5,6
  90         clrldi  r5,r5,58
  91         mtctr   r0
  92         beq     5f
  93 4:      std     r4,0(r6)
  94         std     r4,8(r6)
  95         std     r4,16(r6)
  96         std     r4,24(r6)
  97         std     r4,32(r6)
  98         std     r4,40(r6)
  99         std     r4,48(r6)
 100         std     r4,56(r6)
 101         addi    r6,r6,64
 102         bdnz    4b
 103 5:      srwi.   r0,r5,3
 104         clrlwi  r5,r5,29
 105         mtcrf   1,r0
 106         beq     8f
 107         bf      29,6f
 108         std     r4,0(r6)
 109         std     r4,8(r6)
 110         std     r4,16(r6)
 111         std     r4,24(r6)
 112         addi    r6,r6,32
 113 6:      bf      30,7f
 114         std     r4,0(r6)
 115         std     r4,8(r6)
 116         addi    r6,r6,16
 117 7:      bf      31,8f
 118         std     r4,0(r6)
 119         addi    r6,r6,8
 120 8:      cmpwi   r5,0
 121         mtcrf   1,r5
 122         beqlr+
 123         bf      29,9f
 124         stw     r4,0(r6)
 125         addi    r6,r6,4
 126 9:      bf      30,10f
 127         sth     r4,0(r6)
 128         addi    r6,r6,2
 129 10:     bflr    31
 130         stb     r4,0(r6)
 131         blr
 132
 133 _GLOBAL(memmove)
 134         cmplw   0,r3,r4
 135         bgt     .backwards_memcpy
 136         b       .memcpy
 137
 138 _GLOBAL(backwards_memcpy)
 139         rlwinm. r7,r5,32-3,3,31         /* r0 = r5 >> 3 */
 140         add     r6,r3,r5
 141         add     r4,r4,r5
 142         beq     2f
 143         andi.   r0,r6,3
 144         mtctr   r7
 145         bne     5f
 146 1:      lwz     r7,-4(r4)
 147         lwzu    r8,-8(r4)
 148         stw     r7,-4(r6)
 149         stwu    r8,-8(r6)
 150         bdnz    1b
 151         andi.   r5,r5,7
 152 2:      cmplwi  0,r5,4
 153         blt     3f
 154         lwzu    r0,-4(r4)
 155         subi    r5,r5,4
 156         stwu    r0,-4(r6)
 157 3:      cmpwi   0,r5,0
 158         beqlr
 159         mtctr   r5
 160 4:      lbzu    r0,-1(r4)
 161         stbu    r0,-1(r6)
 162         bdnz    4b
 163         blr
 164 5:      mtctr   r0
 165 6:      lbzu    r7,-1(r4)
 166         stbu    r7,-1(r6)
 167         bdnz    6b
 168         subf    r5,r0,r5
 169         rlwinm. r7,r5,32-3,3,31
 170         beq     2b
 171         mtctr   r7
 172         b       1b
 173
 174 _GLOBAL(memcmp)
 175         cmpwi   0,r5,0
 176         ble-    2f
 177         mtctr   r5
 178         addi    r6,r3,-1
 179         addi    r4,r4,-1
 180 1:      lbzu    r3,1(r6)
 181         lbzu    r0,1(r4)
 182         subf.   r3,r0,r3
 183         bdnzt   2,1b
 184         blr
 185 2:      li      r3,0
 186         blr
 187
 188 _GLOBAL(memchr)
 189         cmpwi   0,r5,0
 190         ble-    2f
 191         mtctr   r5
 192         addi    r3,r3,-1
 193 1:      lbzu    r0,1(r3)
 194         cmpw    0,r0,r4
 195         bdnzf   2,1b
 196         beqlr
 197 2:      li      r3,0
 198         blr
 199
 200 _GLOBAL(__clear_user)
 201         addi    r6,r3,-4
 202         li      r3,0
 203         li      r5,0
 204         cmplwi  0,r4,4
 205         blt     7f
 206         /* clear a single word */
 207 11:     stwu    r5,4(r6)
 208         beqlr
 209         /* clear word sized chunks */
 210         andi.   r0,r6,3
 211         add     r4,r0,r4
 212         subf    r6,r0,r6
 213         srwi    r0,r4,2
 214         andi.   r4,r4,3
 215         mtctr   r0
 216         bdz     7f
 217 1:      stwu    r5,4(r6)
 218         bdnz    1b
 219         /* clear byte sized chunks */
 220 7:      cmpwi   0,r4,0
 221         beqlr
 222         mtctr   r4
 223         addi    r6,r6,3
 224 8:      stbu    r5,1(r6)
 225         bdnz    8b
 226         blr
 227 90:     mr      r3,r4
 228         blr
 229 91:     mfctr   r3
 230         slwi    r3,r3,2
 231         add     r3,r3,r4
 232         blr
 233 92:     mfctr   r3
 234         blr
 235
 236         .section __ex_table,"a"
 237         .align  3
 238         .llong  11b,90b
 239         .llong  1b,91b
 240         .llong  8b,92b
 241         .text
 242
 243 /* r3 = dst, r4 = src, r5 = count */
 244 _GLOBAL(__strncpy_from_user)
 245         addi    r6,r3,-1
 246         addi    r4,r4,-1
 247         cmpwi   0,r5,0
 248         beq     2f
 249         mtctr   r5
 250 1:      lbzu    r0,1(r4)
 251         cmpwi   0,r0,0
 252         stbu    r0,1(r6)
 253         bdnzf   2,1b            /* dec ctr, branch if ctr != 0 && !cr0.eq */
 254         beq     3f
 255 2:      addi    r6,r6,1
 256 3:      subf    r3,r3,r6
 257         blr
 258 99:     li      r3,-EFAULT
 259         blr
 260
 261         .section __ex_table,"a"
 262         .align  3
 263         .llong  1b,99b
 264         .text
 265
 266 /* r3 = str, r4 = len (> 0) */
 267 _GLOBAL(__strnlen_user)
 268         addi    r7,r3,-1
 269         mtctr   r4              /* ctr = len */
 270 1:      lbzu    r0,1(r7)        /* get next byte */
 271         cmpwi   0,r0,0
 272         bdnzf   2,1b            /* loop if --ctr != 0 && byte != 0 */
 273         addi    r7,r7,1
 274         subf    r3,r3,r7        /* number of bytes we have looked at */
 275         beqlr                   /* return if we found a 0 byte */
 276         cmpw    0,r3,r4         /* did we look at all len bytes? */
 277         blt     99f             /* if not, must have hit top */
 278         addi    r3,r4,1         /* return len + 1 to indicate no null found */
 279         blr
 280 99:     li      r3,0            /* bad address, return 0 */
 281         blr
 282
 283         .section __ex_table,"a"
 284         .align  3
 285         .llong  1b,99b