diff options
Diffstat (limited to 'sysdeps/powerpc/strcpy.S')
-rw-r--r-- | sysdeps/powerpc/strcpy.S | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/sysdeps/powerpc/strcpy.S b/sysdeps/powerpc/strcpy.S new file mode 100644 index 0000000000..3c0cce7844 --- /dev/null +++ b/sysdeps/powerpc/strcpy.S @@ -0,0 +1,100 @@ +/* Optimized strcpy implementation for PowerPC. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <sysdep.h> + +/* See strlen.s for comments on how the end-of-string testing works. */ + +EALIGN(strcpy,4,0) +/* char * [r3] strcpy (char *dest [r3], const char *src [r4]) */ + +/* General register assignments: + r0: temporary + r3: saved `dest' + r4: pointer to previous word in src + r5: pointer to previous word in dest + r6: current word from src + r7: 0xfefefeff + r8: 0x7f7f7f7f + r9: ~(word in src | 0x7f7f7f7f) + r10: alternate word from src. */ + + or %r0,%r4,%r3 + clrlwi. %r0,%r0,30 + addi %r5,%r3,-4 + bne L(unaligned) + + lis %r7,0xfeff + lis %r8,0x7f7f + lwz %r6,0(%r4) + addi %r7,%r7,-0x101 + addi %r8,%r8,0x7f7f + b 2f + +0: lwzu %r10,4(%r4) + stwu %r6,4(%r5) + add %r0,%r7,%r10 + nor %r9,%r8,%r10 + and. %r0,%r0,%r9 + bne- 1f + lwzu %r6,4(%r4) + stwu %r10,4(%r5) +2: add %r0,%r7,%r6 + nor %r9,%r8,%r6 + and. %r0,%r0,%r9 + beq+ 0b + + mr %r10,%r6 +/* We've hit the end of the string. Do the rest byte-by-byte. */ +1: rlwinm. %r0,%r10,8,24,31 + stb %r0,4(%r5) + beqlr- + rlwinm. %r0,%r10,16,24,31 + stb %r0,5(%r5) + beqlr- + rlwinm. %r0,%r10,24,24,31 + stb %r0,6(%r5) + beqlr- + stb %r10,7(%r5) + blr + +/* Oh well. In this case, we just do a byte-by-byte copy. */ + .align 4 + nop +L(unaligned): + lbz %r6,0(%r4) + addi %r5,%r3,-1 + cmpwi %r6,0 + beq- 2f + +0: lbzu %r10,1(%r4) + stbu %r6,1(%r5) + cmpwi %r10,0 + beq- 1f + nop /* Let 601 load start of loop. */ + lbzu %r6,1(%r4) + stbu %r10,1(%r5) + cmpwi %r6,0 + bne+ 0b +2: stb %r6,1(%r5) + blr +1: stb %r10,1(%r5) + blr + +END(strcpy) |