PowerPC: Optimized strcmp for PPC64/POWER7
Optimization is achieved on 8 byte aligned strings with double word comparison using cmpb instruction. On unaligned strings loop unrolling is applied for Power7 gain.
This commit is contained in:
Vidya Ranganathan
Adhemerval Zanella
parent
42b1161e8c
commit
e23d3d2690
12
ChangeLog
12
ChangeLog
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@ -1,3 +1,15 @@
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2014-06-11 Vidya Ranganathan <vidya@linux.vnet.ibm.com>
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* sysdeps/powerpc/powerpc64/power7/strcmp.S: New file: Optimization.
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* sysdeps/powerpc/powerpc64/multiarch/strcmp.c: New file:
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multiarch strcmp for PPC64.
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* sysdeps/powerpc/powerpc64/multiarch/strcmp-ppc64.S: New file.
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* sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S: New file.
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* sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strcmp
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multiarch optimizations.
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* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c:
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(__libc_ifunc_impl_list): Likewise.
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2014-06-11 Siddhesh Poyarekar <siddhesh@redhat.com>
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* benchtests/scripts/validate_benchout.py: New script.
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@ -17,7 +17,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
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strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
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strspn-power7 strspn-ppc64 strcspn-power7 strcspn-ppc64 \
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strpbrk-power7 strpbrk-ppc64 strncpy-power7 strncpy-ppc64 \
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stpncpy-power7 stpncpy-ppc64
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stpncpy-power7 stpncpy-ppc64 strcmp-power7 strcmp-ppc64
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CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops
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CFLAGS-strncase_l-power7.c += -mcpu=power7 -funroll-loops
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@ -294,5 +294,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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IFUNC_IMPL_ADD (array, i, stpncpy, 1,
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__stpncpy_ppc))
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/* Support sysdeps/powerpc/powerpc64/multiarch/strcmp.c. */
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IFUNC_IMPL (i, name, strcmp,
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IFUNC_IMPL_ADD (array, i, strcmp,
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hwcap & PPC_FEATURE_HAS_VSX,
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__strcmp_power7)
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IFUNC_IMPL_ADD (array, i, strcmp, 1,
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__strcmp_ppc))
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return i;
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}
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@ -0,0 +1,40 @@
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/* Optimized strcmp implementation for POWER7.
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Copyright (C) 2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#undef EALIGN
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#define EALIGN(name, alignt, words) \
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.section ".text"; \
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ENTRY_2(__strcmp_power7) \
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.align ALIGNARG(alignt); \
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EALIGN_W_##words; \
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BODY_LABEL(__strcmp_power7): \
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cfi_startproc; \
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LOCALENTRY(__strcmp_power7)
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#undef END
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#define END(name) \
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cfi_endproc; \
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TRACEBACK(__strcmp_power7) \
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END_2(__strcmp_power7)
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#undef libc_hidden_builtin_def
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#define libc_hidden_builtin_def(name)
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#include <sysdeps/powerpc/powerpc64/power7/strcmp.S>
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@ -0,0 +1,43 @@
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/* Default strcmp implementation for PowerPC64.
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Copyright (C) 2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#if defined SHARED && !defined NOT_IN_libc
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# undef EALIGN
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# define EALIGN(name, alignt, words) \
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.section ".text"; \
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ENTRY_2(__strcmp_ppc) \
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.align ALIGNARG(alignt); \
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EALIGN_W_##words; \
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BODY_LABEL(__strcmp_ppc): \
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cfi_startproc; \
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LOCALENTRY(__strcmp_ppc)
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# undef END
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# define END(name) \
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cfi_endproc; \
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TRACEBACK(__strcmp_ppc) \
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END_2(__strcmp_ppc)
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# undef libc_hidden_builtin_def
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# define libc_hidden_builtin_def(name) \
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.globl __GI_strcmp; __GI_strcmp = __strcmp_ppc
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#endif
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#include <sysdeps/powerpc/powerpc64/strcmp.S>
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@ -0,0 +1,31 @@
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/* Multiple versions of strcmp. PowerPC64 version.
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Copyright (C) 2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#if defined SHARED && !defined NOT_IN_libc
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# include <string.h>
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# include <shlib-compat.h>
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# include "init-arch.h"
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extern __typeof (strcmp) __strcmp_ppc attribute_hidden;
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extern __typeof (strcmp) __strcmp_power7 attribute_hidden;
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libc_ifunc (strcmp,
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(hwcap & PPC_FEATURE_HAS_VSX)
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? __strcmp_power7
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: __strcmp_ppc);
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#endif
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@ -0,0 +1,195 @@
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/* Optimized strcmp implementation for Power7 using 'cmpb' instruction
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Copyright (C) 2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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/* The optimization is achieved here through cmpb instruction.
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8byte aligned strings are processed with double word comparision
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and unaligned strings are handled effectively with loop unrolling
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technique */
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#include <sysdep.h>
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/* int [r3] strcmp (const char *s1 [r3], const char *s2 [r4]) */
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EALIGN (strcmp, 4, 0)
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CALL_MCOUNT 2
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or r9, r3, r4
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rldicl. r10, r9, 0, 61 /* are s1 and s2 8 byte aligned..? */
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bne cr0, L(process_unaligned_bytes)
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/* process input parameters on double word aligned boundary */
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ld r9, 0(r4) /* load s2 at offset=0 */
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li r10, 0 /* load mask=0 */
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cmpb r10, r9, r10 /* compare bytes at s2 with mask */
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cmpdi cr7, r10, 0 /* is NULL found ..? is end of string HIT */
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bne cr7, L(process_unaligned_bytes) /* process byte by byte */
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ld r10, 0(r3) /* load s1 at offset=0 */
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li r8, 0 /* load mask=0 */
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cmpb r8, r10, r8 /* compare bytes at s1 with mask */
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cmpdi cr7, r8, 0 /* is NULL found ..? is end of string HIT */
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bne cr7, L(process_unaligned_bytes) /* process byte by byte */
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/*s1 and s2 does not contain NULL now , so compare all 8 bytes in a GO */
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cmpb r9, r10, r9 /* compare s1 and s2 */
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cmpdi cr7, r9, -1 /* compare result with 0xFFFFFFFFFFFFFFFF */
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bne cr7, L(process_unaligned_bytes) /* s1,s2 mismatch found */
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addi r5, r3, 8 /* save next offset of s2 */
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addi r11, r4, 8 /* save next offset of s1 */
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ld r8, 8(r4) /* load s2 at offset=8 */
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li r9, 0 /* load mask=0 */
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cmpb r9, r8, r9 /* compare bytes at s2 with mask */
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cmpdi cr7, r9, 0 /* NULL found ..? */
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bne cr7, L(processBytes)/* update input and process bytes one by one */
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mr r9, r4 /* save s2 */
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li r10, 0 /* load mask=0 */
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ld r7, 8(r3) /* load s1 at offset=8 */
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cmpb r6, r7, r10 /* compare bytes at s1 with mask */
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cmpdi cr7, r6, 0 /* is NULL found */
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bne cr7, L(processBytes)/* mismatch, so process one by one */
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L(unrollDword):
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cmpb r8, r7, r8 /* compare s1 and s2 */
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cmpdi cr7, r8, -1 /* compare result with 0xFFFFFFFFFFFFFFFF */
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bne cr7, L(processBytes)/* mismatch with s1 and s2 */
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addi r5, r3, 16 /* save offset=16 of s1 */
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addi r4, r9, 16 /* save offset=16 of s2 */
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ld r8, 16(r9) /* load s2 at offset=16 */
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cmpb r7, r8, r10 /* compare bytes at s2 with mask */
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cmpdi cr7, r7, 0 /* NULL found ..? */
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bne cr7, L(update2processBytes)
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ld r7, 16(r3) /* load s1 at offset=16 */
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cmpb r6, r7, r10 /* check s1 for end of string */
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cmpdi cr7, r6, 0 /* end of s1 ?,then handle byte by byte */
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bne 7,L(update2processBytes)
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cmpb r8, r7, r8 /* compare s1 and s2 double words */
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cmpdi cr7, r8, -1 /* compare results with 0xFFFFFFFFFFFFFFFF */
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bne cr7,L(update2processBytes)
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addi r5, r3, 24 /* update s1 to offset=24 */
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addi r4, r9, 24 /* update s2 to offset=24 */
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ld r8, 24(r9) /* load s2 */
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cmpb r7, r8, r10 /* compare s2 for NULL */
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cmpdi cr7, r7, 0 /* verify if s2 is ending now */
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bne cr7,L(update2processBytes)
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ld r7, 24(r3) /* load s1 at offset=24 */
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cmpb r6, r7, r10 /* verify for NULL */
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cmpdi cr7, r6, 0 /* is NULL found */
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bne cr7, L(update2processBytes)
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cmpb r8, r7, r8 /* compare s1 and s2 */
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cmpdi cr7, r8, -1 /* are s1 and s2 same ..? */
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bne cr7, L(update2processBytes)
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addi r7, r9, 32 /* update s2 to next double word */
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addi r3, r3, 32 /* update s1 to next double word */
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ld r8, 32(r9) /* load s2 */
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mr r4, r7 /* save s2 */
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cmpb r6, r8, r10 /* compare s2 with NULL */
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cmpdi cr7, r6, 0 /* end of s2 ..? */
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bne cr7, L(process_unaligned_bytes)
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ld r6, 0(r3) /* load and compare s1 for NULL */
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cmpb r5, r6, r10
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cmpdi cr7, r5, 0
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bne cr7, L(process_unaligned_bytes)
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cmpb r8, r6, r8 /* compare s1 and s2 */
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cmpdi cr7, r8, -1
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bne cr7, L(process_unaligned_bytes)
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addi r5, r3, 8 /* increment s1 and d2 here */
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addi r11, r9, 40
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ld r8, 40(r9) /* process s2 now */
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cmpb r9, r8, r10
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cmpdi cr7, r9, 0
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bne cr7, L(processBytes)
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mr r9, r7
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ld r7, 8(r3) /* process s1 now */
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cmpb r6, r7, r10
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cmpdi cr7, r6, 0
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beq cr7, L(unrollDword) /* unroll to compare s1 and s2 */
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L(processBytes):
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mr r4, r11 /* update input params */
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mr r3, r5
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.p2align 4
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L(process_unaligned_bytes):
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lbz r9, 0(r3) /* load byte from s1 */
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lbz r10, 0(r4) /* load byte from s2 */
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cmpdi cr7, r9, 0 /* compare *s1 with NULL */
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beq cr7, L(diffOfNULL) /* if *s1 is NULL , return *s1 - *s2 */
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cmplw cr7, r9, r10 /* compare *s1 and *s2 */
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bne cr7, L(ComputeDiff) /* branch to compute difference and return */
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lbz r9, 1(r3) /* load next byte from s1 */
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lbz r10, 1(r4) /* load next byte from s2 */
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cmpdi cr7, r9, 0 /* compare *s1 with NULL */
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beq cr7, L(diffOfNULL) /* if *s1 is NULL , return *s1 - *s2 */
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cmplw cr7, r9, r10 /* compare *s1 and *s2 */
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bne cr7, L(ComputeDiff) /* branch to compute difference and return */
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lbz r9, 2(r3) /* unroll 3rd byte here */
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lbz r10, 2(r4)
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cmpdi cr7, r9, 0
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beq cr7, L(diffOfNULL)
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cmplw cr7, r9, r10
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bne 7, L(ComputeDiff)
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lbz r9, 3(r3) /* unroll 4th byte now */
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lbz r10, 3(r4)
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addi r3, r3, 4 /* increment s1 by unroll factor */
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cmpdi cr7, r9, 0
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cmplw cr6, 9, r10
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beq cr7, L(diffOfNULL)
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addi r4, r4, 4 /* increment s2 by unroll factor */
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beq cr6, L(process_unaligned_bytes) /* unroll byte processing */
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.p2align 4
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L(ComputeDiff):
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extsw r9, r9
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subf r10, r10, r9 /* compute s1 - s2 */
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extsw r3, r10
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blr /* return */
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.p2align 4
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L(diffOfNULL):
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li r9, 0
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subf r10, r10, r9 /* compute s1 - s2 */
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extsw r3, r10 /* sign extend result */
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blr /* return */
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.p2align 4
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L(update2processBytes):
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mr r3, r5 /* update and proceed */
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b L(process_unaligned_bytes)
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END (strcmp)
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libc_hidden_builtin_def (strcmp)
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