diff options
Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/powerpc64/strcmp.S')
| -rw-r--r-- | REORG.TODO/sysdeps/powerpc/powerpc64/strcmp.S | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/powerpc64/strcmp.S b/REORG.TODO/sysdeps/powerpc/powerpc64/strcmp.S new file mode 100644 index 0000000000..ab5f8c231c --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/powerpc64/strcmp.S @@ -0,0 +1,180 @@ +/* Optimized strcmp implementation for PowerPC64. + Copyright (C) 1997-2017 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 Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +/* See strlen.s for comments on how the end-of-string testing works. */ + +/* int [r3] strcmp (const char *s1 [r3], const char *s2 [r4]) */ + +#ifndef STRCMP +# define STRCMP strcmp +#endif + +EALIGN (STRCMP, 4, 0) + CALL_MCOUNT 2 + +#define rTMP2 r0 +#define rRTN r3 +#define rSTR1 r3 /* first string arg */ +#define rSTR2 r4 /* second string arg */ +#define rWORD1 r5 /* current word in s1 */ +#define rWORD2 r6 /* current word in s2 */ +#define rFEFE r7 /* constant 0xfefefefefefefeff (-0x0101010101010101) */ +#define r7F7F r8 /* constant 0x7f7f7f7f7f7f7f7f */ +#define rNEG r9 /* ~(word in s1 | 0x7f7f7f7f7f7f7f7f) */ +#define rBITDIF r10 /* bits that differ in s1 & s2 words */ +#define rTMP r11 + + dcbt 0,rSTR1 + or rTMP, rSTR2, rSTR1 + dcbt 0,rSTR2 + clrldi. rTMP, rTMP, 61 + lis rFEFE, -0x101 + bne L(unaligned) + + ld rWORD1, 0(rSTR1) + ld rWORD2, 0(rSTR2) + lis r7F7F, 0x7f7f + addi rFEFE, rFEFE, -0x101 + addi r7F7F, r7F7F, 0x7f7f + sldi rTMP, rFEFE, 32 + insrdi r7F7F, r7F7F, 32, 0 + add rFEFE, rFEFE, rTMP + b L(g1) + +L(g0): ldu rWORD1, 8(rSTR1) + bne cr1, L(different) + ldu rWORD2, 8(rSTR2) +L(g1): add rTMP, rFEFE, rWORD1 + nor rNEG, r7F7F, rWORD1 + and. rTMP, rTMP, rNEG + cmpd cr1, rWORD1, rWORD2 + beq+ L(g0) + +/* 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... */ +#ifdef __LITTLE_ENDIAN__ +L(endstring): + addi rTMP2, rTMP, -1 + beq cr1, L(equal) + andc rTMP2, rTMP2, rTMP + rldimi rTMP2, rTMP2, 1, 0 + and rWORD2, rWORD2, rTMP2 /* Mask off gunk. */ + and rWORD1, rWORD1, rTMP2 + cmpd cr1, rWORD1, rWORD2 + beq cr1, L(equal) + xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */ + neg rNEG, rBITDIF + and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */ + cntlzd rNEG, rNEG /* bitcount of the bit. */ + andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */ + sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */ + sld rWORD2, rWORD2, rNEG + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 /* must return an int. */ + ori rRTN, rRTN, 1 + blr +L(equal): + li rRTN, 0 + blr + +L(different): + ld rWORD1, -8(rSTR1) + xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */ + neg rNEG, rBITDIF + and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */ + cntlzd rNEG, rNEG /* bitcount of the bit. */ + andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */ + sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */ + sld rWORD2, rWORD2, rNEG + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 + ori rRTN, rRTN, 1 + blr +L(highbit): + sradi rRTN, rWORD2, 63 + ori rRTN, rRTN, 1 + blr + +#else +L(endstring): + and rTMP, r7F7F, rWORD1 + beq cr1, L(equal) + add rTMP, rTMP, r7F7F + xor. rBITDIF, rWORD1, rWORD2 + andc rNEG, rNEG, rTMP + blt- L(highbit) + cntlzd rBITDIF, rBITDIF + cntlzd rNEG, rNEG + addi rNEG, rNEG, 7 + cmpd cr1, rNEG, rBITDIF + sub rRTN, rWORD1, rWORD2 + blt- cr1, L(equal) + sradi rRTN, rRTN, 63 /* must return an int. */ + ori rRTN, rRTN, 1 + blr +L(equal): + li rRTN, 0 + blr + +L(different): + ld rWORD1, -8(rSTR1) + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 + ori rRTN, rRTN, 1 + blr +L(highbit): + sradi rRTN, rWORD2, 63 + ori rRTN, rRTN, 1 + blr +#endif + +/* Oh well. In this case, we just do a byte-by-byte comparison. */ + .align 4 +L(unaligned): + lbz rWORD1, 0(rSTR1) + lbz rWORD2, 0(rSTR2) + b L(u1) + +L(u0): lbzu rWORD1, 1(rSTR1) + bne- L(u4) + lbzu rWORD2, 1(rSTR2) +L(u1): cmpwi cr1, rWORD1, 0 + beq- cr1, L(u3) + cmpd rWORD1, rWORD2 + bne- L(u3) + lbzu rWORD1, 1(rSTR1) + lbzu rWORD2, 1(rSTR2) + cmpdi cr1, rWORD1, 0 + cmpd rWORD1, rWORD2 + bne+ cr1, L(u0) +L(u3): sub rRTN, rWORD1, rWORD2 + blr +L(u4): lbz rWORD1, -1(rSTR1) + sub rRTN, rWORD1, rWORD2 + blr +END (STRCMP) +libc_hidden_builtin_def (strcmp) |