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Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S')
| -rw-r--r-- | REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S b/REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S new file mode 100644 index 0000000000..14e14f457e --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S @@ -0,0 +1,168 @@ +/* Optimized strcmp implementation for Power7 using 'cmpb' instruction + Copyright (C) 2014-2017 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/>. */ + +/* The optimization is achieved here through cmpb instruction. + 8byte aligned strings are processed with double word comparision + and unaligned strings are handled effectively with loop unrolling + technique */ + +#include <sysdep.h> + +#ifndef STRCMP +# define STRCMP strcmp +#endif + +/* int [r3] strcmp (const char *s1 [r3], const char *s2 [r4]) */ + + .machine power7 +EALIGN (STRCMP, 4, 0) + CALL_MCOUNT 2 + + or r9, r3, r4 + rldicl. r10, r9, 0, 61 /* are s1 and s2 8 byte aligned..? */ + bne cr0, L(process_unaligned_bytes) + li r5, 0 + + .align 4 +/* process input parameters on double word aligned boundary */ +L(unrollDword): + ld r8,0(r3) + ld r10,0(r4) + cmpb r7,r8,r5 + cmpdi cr7,r7,0 + mr r9,r7 + bne cr7,L(null_found) + cmpld cr7,r8,r10 + bne cr7,L(different) + + ld r8,8(r3) + ld r10,8(r4) + cmpb r7,r8,r5 + cmpdi cr7,r7,0 + mr r9,r7 + bne cr7,L(null_found) + cmpld cr7,r8,r10 + bne cr7,L(different) + + ld r8,16(r3) + ld r10,16(r4) + cmpb r7,r8,r5 + cmpdi cr7,r7,0 + mr r9,r7 + bne cr7,L(null_found) + cmpld cr7,r8,r10 + bne cr7,L(different) + + ld r8,24(r3) + ld r10,24(r4) + cmpb r7,r8,r5 + cmpdi cr7,r7,0 + mr r9,r7 + bne cr7,L(null_found) + cmpld cr7,r8,r10 + bne cr7,L(different) + + addi r3, r3, 32 + addi r4, r4, 32 + beq cr7, L(unrollDword) + + .align 4 +L(null_found): +#ifdef __LITTLE_ENDIAN__ + neg r7,r9 + and r9,r9,r7 + li r7,-1 + cntlzd r9,r9 + subfic r9,r9,71 + sld r9,r7,r9 +#else + cntlzd r9,r9 + li r7,-1 + addi r9,r9,8 + srd r9,r7,r9 +#endif + or r8,r8,r9 + or r10,r10,r9 + +L(different): + cmpb r9,r8,r10 +#ifdef __LITTLE_ENDIAN__ + addi r7,r9,1 + andc r9,r7,r9 + cntlzd r9,r9 + subfic r9,r9,63 +#else + not r9,r9 + cntlzd r9,r9 + subfic r9,r9,56 +#endif + srd r3,r8,r9 + srd r10,r10,r9 + rldicl r10,r10,0,56 + rldicl r3,r3,0,56 + subf r3,r10,r3 + blr + + .align 4 +L(process_unaligned_bytes): + lbz r9, 0(r3) /* load byte from s1 */ + lbz r10, 0(r4) /* load byte from s2 */ + cmpdi cr7, r9, 0 /* compare *s1 with NULL */ + beq cr7, L(diffOfNULL) /* if *s1 is NULL , return *s1 - *s2 */ + cmplw cr7, r9, r10 /* compare *s1 and *s2 */ + bne cr7, L(ComputeDiff) /* branch to compute difference and return */ + + lbz r9, 1(r3) /* load next byte from s1 */ + lbz r10, 1(r4) /* load next byte from s2 */ + cmpdi cr7, r9, 0 /* compare *s1 with NULL */ + beq cr7, L(diffOfNULL) /* if *s1 is NULL , return *s1 - *s2 */ + cmplw cr7, r9, r10 /* compare *s1 and *s2 */ + bne cr7, L(ComputeDiff) /* branch to compute difference and return */ + + lbz r9, 2(r3) /* unroll 3rd byte here */ + lbz r10, 2(r4) + cmpdi cr7, r9, 0 + beq cr7, L(diffOfNULL) + cmplw cr7, r9, r10 + bne 7, L(ComputeDiff) + + lbz r9, 3(r3) /* unroll 4th byte now */ + lbz r10, 3(r4) + addi r3, r3, 4 /* increment s1 by unroll factor */ + cmpdi cr7, r9, 0 + cmplw cr6, 9, r10 + beq cr7, L(diffOfNULL) + addi r4, r4, 4 /* increment s2 by unroll factor */ + beq cr6, L(process_unaligned_bytes) /* unroll byte processing */ + + .align 4 +L(ComputeDiff): + extsw r9, r9 + subf r10, r10, r9 /* compute s1 - s2 */ + extsw r3, r10 + blr /* return */ + + .align 4 +L(diffOfNULL): + li r9, 0 + subf r10, r10, r9 /* compute s1 - s2 */ + extsw r3, r10 /* sign extend result */ + blr /* return */ + +END (STRCMP) +libc_hidden_builtin_def (strcmp) |