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Diffstat (limited to 'sysdeps/powerpc/strcmp.s')
| -rw-r--r-- | sysdeps/powerpc/strcmp.s | 273 |
1 files changed, 0 insertions, 273 deletions
diff --git a/sysdeps/powerpc/strcmp.s b/sysdeps/powerpc/strcmp.s deleted file mode 100644 index f901b82..0000000 --- a/sysdeps/powerpc/strcmp.s +++ /dev/null @@ -1,273 +0,0 @@ - # Optimized strcmp 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. - - # See strlen.s for comments on how the end-of-string testing works. - - .section ".text" - .align 3 - .globl strcmp - .type strcmp,@function -strcmp: - # int [r3] strcmp (const char *p1 [r3], const char *p2 [r4]) - - # General register assignments: - # r0: temporary - # r3: pointer to previous word in s1 - # r4: pointer to previous word in s2 - # r5: current first word in s1 - # r6: current first word in s2 (after re-alignment) - # r7: 0xfefefeff - # r8: 0x7f7f7f7f - # r9: ~(word in s1 | 0x7f7f7f7f) - - # Register assignments in the prologue: - # r10: low 2 bits of p2-p1 - # r11: mask to orc with r5/r6 - - subf. %r10,%r4,%r3 - beq- equal - andi. %r10,%r10,3 - cmpi %cr1,%r10,2 - beq- %cr1,align2 - lis %r7,0xfeff - lis %r8,0x7f7f - addi %r8,%r8,0x7f7f - addi %r7,%r7,0xfffffeff - bgt- %cr1,align3 -strcmp3: - rlwinm %r0,%r3,3,27,28 - li %r11,-1 - srw %r11,%r11,%r0 - clrrwi %r3,%r3,2 - clrrwi %r4,%r4,2 - lwz %r5,0(%r3) - lwz %r6,0(%r4) - bne- align1 - - # The loop, case when both strings are aligned the same. - # on entry, cr1.eq must be 1. - # r10: second word in s1 - # r11: second word in s2 OR mask to orc with first two words. -align0: - andi. %r0,%r3,4 - orc %r5,%r5,%r11 - orc %r6,%r6,%r11 - beq+ a0start - add %r0,%r7,%r5 - nor %r9,%r8,%r5 - and. %r0,%r0,%r9 - cmplw %cr1,%r5,%r6 - subi %r3,%r3,4 - bne- endstringeq - subi %r4,%r4,4 - bne- %cr1,difference - -loopalign0: - lwzu %r5,8(%r3) - bne- %cr1,difference2 - lwzu %r6,8(%r4) -a0start: - add %r0,%r7,%r5 - nor %r9,%r8,%r5 - and. %r0,%r0,%r9 - cmplw %cr1,%r5,%r6 - lwz %r10,4(%r3) - bne- endstringeq - add %r0,%r7,%r10 - bne- %cr1,difference - nor %r9,%r8,%r10 - lwz %r11,4(%r4) - and. %r0,%r0,%r9 - cmplw %cr1,%r10,%r11 - beq+ loopalign0 - - mr %r5,%r10 - mr %r6,%r11 - - # fall through to... - -endstringeq: - # (like 'endstring', but an equality code is in cr1) - beq %cr1,equal -endstring: - # OK. We've hit the end of the string. We need to be careful that - # we don't compare two strings as different because of gunk beyond - # the end of the strings. We do it like this... - and %r0,%r8,%r5 - add %r0,%r0,%r8 - xor. %r10,%r5,%r6 - andc %r9,%r9,%r0 - cntlzw %r10,%r10 - cntlzw %r9,%r9 - addi %r9,%r9,7 - cmpw %cr1,%r9,%r10 - blt %cr1,equal - sub %r3,%r5,%r6 - bgelr+ - mr %r3,%r6 - blr -equal: li %r3,0 - blr - - # The loop, case when s2 is aligned 1 char behind s1. - # r10: current word in s2 (before re-alignment) - -align1: - cmpwi %cr1,%r0,0 - orc %r5,%r5,%r11 - bne %cr1,align1_123 - # When s1 is aligned to a word boundary, the startup processing is special. - slwi. %r6,%r6,24 - bne+ a1entry_0 - nor %r9,%r8,%r5 - b endstring - -align1_123: - # Otherwise (s1 not aligned to a word boundary): - mr %r10,%r6 - add %r0,%r7,%r5 - nor %r9,%r8,%r5 - and. %r0,%r0,%r9 - srwi %r6,%r6,8 - orc %r6,%r6,%r11 - cmplw %cr1,%r5,%r6 - bne- endstringeq - bne- %cr1,difference - -loopalign1: - slwi. %r6,%r10,24 - bne- %cr1,a1difference - lwzu %r5,4(%r3) - beq- endstring1 -a1entry_0: - lwzu %r10,4(%r4) -a1entry_123: - add %r0,%r7,%r5 - nor %r9,%r8,%r5 - and. %r0,%r0,%r9 - rlwimi %r6,%r10,24,8,31 - cmplw %cr1,%r5,%r6 - beq+ loopalign1 - b endstringeq - -endstring1: - srwi %r3,%r5,24 - blr - -a1difference: - lbz %r6,-1(%r4) - slwi %r6,%r6,24 - rlwimi %r6,%r10,24,8,31 - - # fall through to... - -difference: - # The idea here is that we could just return '%r5 - %r6', except - # that the result might overflow. Overflow can only happen when %r5 - # and %r6 have different signs (thus the xor), in which case we want to - # return negative iff %r6 has its high bit set so %r5 < %r6. - # A branch-free implementation of this is - # xor %r0,%r5,%r6 - # rlwinm %r0,%r0,1,31,31 - # rlwnm %r5,%r5,%r0,1,31 - # rlwnm %r6,%r6,%r0,1,31 - # sub %r3,%r5,%r6 - # blr - # but this is usually more expensive. - xor. %r0,%r5,%r6 - sub %r3,%r5,%r6 - bgelr+ - mr %r3,%r6 - blr - -difference2: - # As for 'difference', but use registers r10 and r11 instead of r5 and r6. - xor. %r0,%r10,%r11 - sub %r3,%r10,%r11 - bgelr+ - mr %r3,%r11 - blr - - # For the case when s2 is aligned 3 chars behind s1, we switch - # s1 and s2... - # r10: used by 'align2' (see below) - # r11: used by 'align2' (see below) - # r12: saved link register - # cr0.eq: must be left as 1. - -align3: mflr %r12 - mr %r0,%r3 - mr %r3,%r4 - mr %r4,%r0 - bl strcmp3 - mtlr %r12 - neg %r3,%r3 - blr - - # The loop, case when s2 and s1's alignments differ by 2 - # This is the ugly case... - # FIXME: on a 601, the loop takes 7 cycles instead of the 6 you'd expect, - # because there are too many branches. This loop should probably be - # coded like the align1 case. - -a2even: lhz %r5,0(%r3) - lhz %r6,0(%r4) - b a2entry - -align2: - andi. %r0,%r3,1 - beq+ a2even - subi %r3,%r3,1 - subi %r4,%r4,1 - lbz %r5,1(%r3) - lbz %r6,1(%r4) - cmpwi %cr0,%r5,0 - cmpw %cr1,%r5,%r6 - beq- align2end2 - lhzu %r5,2(%r3) - beq+ %cr1,a2entry1 - lbz %r5,-1(%r3) - sub %r3,%r5,%r6 - blr - -loopalign2: - cmpw %cr1,%r5,%r6 - beq- align2end2 - lhzu %r5,2(%r3) - bne- %cr1,align2different -a2entry1: - lhzu %r6,2(%r4) -a2entry: - cmpwi %cr5,%r5,0x00ff - andi. %r0,%r5,0x00ff - bgt+ %cr5,loopalign2 - -align2end: - andi. %r3,%r6,0xff00 - neg %r3,%r3 - blr - -align2different: - lhzu %r5,-2(%r3) -align2end2: - sub %r3,%r5,%r6 - blr - -0: - .size strcmp,0b-strcmp |