string.S
上传用户：lgb322
上传日期：2013-02-24
资源大小：30529k
文件大小：2k
- /*
- * BK Id: SCCS/s.string.S 1.8 05/18/01 06:20:29 patch
- */
- /*
- * String handling functions for PowerPC.
- *
- * Copyright (C) 1996 Paul Mackerras.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
- #define r0 0
- #define r3 3
- #define r4 4
- #define r5 5
- #define r6 6
- #define r7 7
- #define r8 8
- .globl strlen
- strlen:
- addi r4,r3,-1
- 1: lbzu r0,1(r4)
- cmpwi 0,r0,0
- bne 1b
- subf r3,r3,r4
- blr
- .globl memset
- memset:
- rlwimi r4,r4,8,16,23
- rlwimi r4,r4,16,0,15
- addi r6,r3,-4
- cmplwi 0,r5,4
- blt 7f
- stwu r4,4(r6)
- beqlr
- andi. r0,r6,3
- add r5,r0,r5
- subf r6,r0,r6
- rlwinm r0,r5,32-2,2,31
- mtctr r0
- bdz 6f
- 1: stwu r4,4(r6)
- bdnz 1b
- 6: andi. r5,r5,3
- 7: cmpwi 0,r5,0
- beqlr
- mtctr r5
- addi r6,r6,3
- 8: stbu r4,1(r6)
- bdnz 8b
- blr
- .globl memmove
- memmove:
- cmplw 0,r3,r4
- bgt backwards_memcpy
- /* fall through */
- .globl memcpy
- memcpy:
- rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
- addi r6,r3,-4
- addi r4,r4,-4
- beq 2f /* if less than 8 bytes to do */
- andi. r0,r6,3 /* get dest word aligned */
- mtctr r7
- bne 5f
- 1: lwz r7,4(r4)
- lwzu r8,8(r4)
- stw r7,4(r6)
- stwu r8,8(r6)
- bdnz 1b
- andi. r5,r5,7
- 2: cmplwi 0,r5,4
- blt 3f
- lwzu r0,4(r4)
- addi r5,r5,-4
- stwu r0,4(r6)
- 3: cmpwi 0,r5,0
- beqlr
- mtctr r5
- addi r4,r4,3
- addi r6,r6,3
- 4: lbzu r0,1(r4)
- stbu r0,1(r6)
- bdnz 4b
- blr
- 5: subfic r0,r0,4
- mtctr r0
- 6: lbz r7,4(r4)
- addi r4,r4,1
- stb r7,4(r6)
- addi r6,r6,1
- bdnz 6b
- subf r5,r0,r5
- rlwinm. r7,r5,32-3,3,31
- beq 2b
- mtctr r7
- b 1b
- .globl backwards_memcpy
- backwards_memcpy:
- rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
- add r6,r3,r5
- add r4,r4,r5
- beq 2f
- andi. r0,r6,3
- mtctr r7
- bne 5f
- 1: lwz r7,-4(r4)
- lwzu r8,-8(r4)
- stw r7,-4(r6)
- stwu r8,-8(r6)
- bdnz 1b
- andi. r5,r5,7
- 2: cmplwi 0,r5,4
- blt 3f
- lwzu r0,-4(r4)
- subi r5,r5,4
- stwu r0,-4(r6)
- 3: cmpwi 0,r5,0
- beqlr
- mtctr r5
- 4: lbzu r0,-1(r4)
- stbu r0,-1(r6)
- bdnz 4b
- blr
- 5: mtctr r0
- 6: lbzu r7,-1(r4)
- stbu r7,-1(r6)
- bdnz 6b
- subf r5,r0,r5
- rlwinm. r7,r5,32-3,3,31
- beq 2b
- mtctr r7
- b 1b
- .globl memcmp
- memcmp:
- cmpwi 0,r5,0
- blelr
- mtctr r5
- addi r6,r3,-1
- addi r4,r4,-1
- 1: lbzu r3,1(r6)
- lbzu r0,1(r4)
- subf. r3,r0,r3
- bdnzt 2,1b
- blr
English
