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[PATCH] powerpc: strstr optimization
- From: Rajalakshmi Srinivasaraghavan <raji at linux dot vnet dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Cc: sjmunroe at us dot ibm dot com, Rajalakshmi Srinivasaraghavan <raji at linux dot vnet dot ibm dot com>
- Date: Fri, 17 Apr 2015 02:09:44 -0500
- Subject: [PATCH] powerpc: strstr optimization
- Authentication-results: sourceware.org; auth=none
This patch optimizes strstr function for power >= 7 systems. Performance
gain is obtained using doubleword aligned memory access and usage of cmpb
instruction for quicker comparison. The average improvement of this
optimization is ~40%.
2015-04-17 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
* sysdeps/powerpc/powerpc64/multiarch/Makefile: Add strstr().
* sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c: Likewise.
* sysdeps/powerpc/powerpc64/power7/strstr.S: New File.
* sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S: New File.
* sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c: New File.
* sysdeps/powerpc/powerpc64/multiarch/strstr.c: New File.
---
sysdeps/powerpc/powerpc64/multiarch/Makefile | 2 +-
.../powerpc/powerpc64/multiarch/ifunc-impl-list.c | 8 +
.../powerpc/powerpc64/multiarch/strstr-power7.S | 44 ++
sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c | 29 ++
sysdeps/powerpc/powerpc64/multiarch/strstr.c | 34 ++
sysdeps/powerpc/powerpc64/power7/strstr.S | 500 +++++++++++++++++++++
6 files changed, 616 insertions(+), 1 deletion(-)
create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S
create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c
create mode 100644 sysdeps/powerpc/powerpc64/multiarch/strstr.c
create mode 100644 sysdeps/powerpc/powerpc64/power7/strstr.S
diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 17265bd..3b0e3a0 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -19,7 +19,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
strcmp-power8 strcmp-power7 strcmp-ppc64 \
strcat-power8 strcat-power7 strcat-ppc64 \
memmove-power7 memmove-ppc64 wordcopy-ppc64 bcopy-ppc64 \
- strncpy-power8
+ strncpy-power8 strstr-power7 strstr-ppc64
CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops
CFLAGS-strncase_l-power7.c += -mcpu=power7 -funroll-loops
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index f5fdea5..9d808e0 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -322,5 +322,13 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_IMPL_ADD (array, i, strcat, 1,
__strcat_ppc))
+ /* Support sysdeps/powerpc/powerpc64/multiarch/strstr.c. */
+ IFUNC_IMPL (i, name, strstr,
+ IFUNC_IMPL_ADD (array, i, strstr,
+ hwcap & PPC_FEATURE_HAS_VSX,
+ __strstr_power7)
+ IFUNC_IMPL_ADD (array, i, strstr, 1,
+ __strstr_ppc))
+
return i;
}
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S
new file mode 100644
index 0000000..68b93b0
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strstr-power7.S
@@ -0,0 +1,44 @@
+/* Optimized strstr implementation for POWER7.
+ Copyright (C) 2015-2016 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>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words) \
+ .section ".text"; \
+ ENTRY_2(__strstr_power7) \
+ .align ALIGNARG(alignt); \
+ EALIGN_W_##words; \
+ BODY_LABEL(__strstr_power7): \
+ cfi_startproc; \
+ LOCALENTRY(__strstr_power7)
+
+#undef END
+#define END(name) \
+ cfi_endproc; \
+ TRACEBACK(__strstr_power7) \
+ END_2(__strstr_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#define STRLEN __strlen_power7
+#define STRNLEN __strnlen_power7
+#define STRCHR __strchr_power7
+
+#include <sysdeps/powerpc/powerpc64/power7/strstr.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c
new file mode 100644
index 0000000..2ca62c4
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strstr-ppc64.c
@@ -0,0 +1,29 @@
+/* Copyright (C) 2015-2016 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 <string.h>
+
+#define STRSTR __strstr_ppc
+#if IS_IN (libc) && defined(SHARED)
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name) \
+ __hidden_ver1(__strstr_ppc, __GI_strstr, __strstr_ppc);
+#endif
+
+extern __typeof (strstr) __strstr_ppc attribute_hidden;
+
+#include <string/strstr.c>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strstr.c b/sysdeps/powerpc/powerpc64/multiarch/strstr.c
new file mode 100644
index 0000000..7efc4b0
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strstr.c
@@ -0,0 +1,34 @@
+/* Multiple versions of strstr. PowerPC64 version.
+ Copyright (C) 2015-2016 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/>. */
+
+/* Define multiple versions only for definition in libc. */
+#if IS_IN (libc)
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strstr) __strstr_ppc attribute_hidden;
+extern __typeof (strstr) __strstr_power7 attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+ ifunc symbol properly. */
+libc_ifunc (strstr,
+ (hwcap & PPC_FEATURE_HAS_VSX)
+ ? __strstr_power7
+ : __strstr_ppc);
+#endif
diff --git a/sysdeps/powerpc/powerpc64/power7/strstr.S b/sysdeps/powerpc/powerpc64/power7/strstr.S
new file mode 100644
index 0000000..e895d36
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power7/strstr.S
@@ -0,0 +1,500 @@
+/* Optimized strstr implementation for PowerPC64/POWER7.
+ Copyright (C) 2015-2016 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>
+
+/* char * [r3] strstr (char *s [r3], char * pat[r4]) */
+
+/*
+ * The performance gain is obtained using aligned memory access, load doubleword
+ * and usage of cmpb instruction for quicker comparison.
+ */
+
+#ifndef STRLEN
+/* For builds with no IFUNC support, local calls should be made to internal
+ GLIBC symbol (created by libc_hidden_builtin_def). */
+# ifdef SHARED
+# define STRLEN __GI_strlen
+# else
+# define STRLEN strlen
+# endif
+#endif
+
+#ifndef STRNLEN
+/* For builds with no IFUNC support, local calls should be made to internal
+ GLIBC symbol (created by libc_hidden_builtin_def). */
+# ifdef SHARED
+# define STRNLEN __GI_strnlen
+# else
+# define STRNLEN strnlen
+# endif
+#endif
+
+#ifndef STRCHR
+# ifdef SHARED
+# define STRCHR __GI_strchr
+# else
+# define STRCHR strchr
+# endif
+#endif
+
+#define FRAMESIZE (FRAME_MIN_SIZE+32)
+ .machine power7
+EALIGN (strstr, 4, 0)
+ CALL_MCOUNT 2
+ mflr r0 /* load link register LR to r0 */
+ std r20, -8(r1) /* save callers register , r20 */
+ std r19, -16(r1) /* save callers register , r19 */
+ std r18, -24(r1) /* save callers register , r18 */
+ std r0, 16(r1) /* store the link register */
+ stdu r1, -FRAMESIZE(r1) /* create the stack frame */
+
+ dcbt 0, r3
+ dcbt 0, r4
+
+ and r0, r3, r4
+ cmpdi cr7, r0, 0
+ beq cr7, L(retnull)
+
+ mr r18, r3
+ mr r19, r4
+ mr r3, r4
+ bl STRLEN
+ nop
+
+ cmpdi cr7, r3, 0 /* if search str is null */
+ beq cr7, L(ret_r3)
+ mr r20, r3
+ mr r4, r3
+ mr r3, r18
+ bl STRNLEN
+ nop
+
+ cmpd cr7, r3, r20 /* if len(r3) < len(r4) */
+ blt cr7, L(retnull)
+ mr r3, r18
+ lbz r4, 0(r19)
+ bl STRCHR
+ nop
+
+ mr r11, r3
+ /* if first char of search str is not present */
+ cmpdi cr7, r3, 0
+ ble cr7, L(end)
+
+ rldicl r8, r3, 0, 52 /* page cross check */
+ cmpldi cr7, r8, 4096-16
+ bgt cr7, L(bytebybyte)
+
+ rldicl r8, r19, 0, 52
+ cmpldi cr7, r8, 4096-16
+ bgt cr7, L(bytebybyte)
+
+ /* if len(r4) < 8 handle in a different way */
+ /* Shift position based on null and use cmpb */
+ cmpdi cr7, r20, 8
+ blt cr7, L(lessthan8)
+
+ /* len(r4) >= 8 reaches here */
+ mr r8, r3 /* save r3 for future use */
+L(begin):
+ mr r3, r8
+ mr r4, r19 /* restore r4 */
+ li r0, 0
+
+L(begin2):
+ rlwinm r10, r19, 3, 26, 28 /* calculate padding in bits */
+ clrrdi r4, r4, 3 /* Make r4 aligned to 8 */
+ ld r6, 0(r4)
+ addi r4, r4, 8
+ cmpdi cr7, r10, 0 /* check if its already aligned? */
+ beq cr7, L(begin1)
+#ifdef __LITTLE_ENDIAN__
+ srd r6, r6, r10 /* Discard unwanted bits */
+#else
+ sld r6, r6, r10
+#endif
+ ld r9, 0(r4)
+ subfic r10, r10, 64
+#ifdef __LITTLE_ENDIAN__
+ sld r9, r9, r10 /* Discard unwanted bits */
+#else
+ srd r9, r9, r10
+#endif
+ or r6, r6, r9 /* Form complete search str */
+L(begin1):
+ rlwinm r10, r3, 3, 26, 28
+ clrrdi r3, r3, 3
+ ld r5, 0(r3)
+ cmpb r9, r0, r6 /* check if input has null */
+ cmpdi cr7, r9, 0
+ bne cr7, L(return3)
+ cmpb r9, r0, r5 /* check if input has null */
+#ifdef __LITTLE_ENDIAN__
+ srd r9, r9, r10
+#else
+ sld r9, r9, r10
+#endif
+ cmpdi cr7, r9, 0
+ bne cr7, L(return2)
+
+ cmpdi cr7, r10, 0
+ beq cr7, L(loop2)
+ ldu r7, 8(r3)
+ mr r12, r10
+ addi r12, r12, -8
+ subfic r11, r12, 64
+ srdi r9, r11, 3
+ addi r9, r9, -1
+ mtctr r9
+ b L(nextbyte1)
+
+L(loop2):
+ li r9, 8
+ li r12, -8 /* shift values */
+ li r11, 72 /* shift values */
+ ldu r7, 8(r3) /* load next dw */
+ mtctr r9
+L(nextbyte1):
+ addi r12, r12, 8 /* shift one byte and compare */
+ addi r11, r11, -8
+#ifdef __LITTLE_ENDIAN__
+ srd r9, r5, r12 /* rotate based on mask */
+ sld r10, r7, r11
+#else
+ sld r9, r5, r12
+ srd r10, r7, r11
+#endif
+ /* Form single dw from few bytes on first load and second load */
+ or r10, r9, r10
+ /* Check for null in the formed dw */
+ cmpb r9, r0, r10
+ cmpdi cr7, r9, 0
+ bne cr7, L(retnull)
+ /* cmpb search str and input str */
+ cmpb r9, r10, r6
+ cmpdi cr7, r9, -1
+ beq cr7, L(match)
+ bdnz L(nextbyte1)
+ /* Check if input has null before next load */
+ cmpb r9, r0, r7
+ cmpdi cr7, r9, 0
+ bne cr7, L(retnull)
+ mr r5, r7
+ /* Proceed to next load */
+ b L(loop2)
+
+ .align 4
+L(match):
+ /* There is a match of 8 bytes, check next bytes */
+ cmpdi cr7, r20, 8
+ beq cr7, L(return)
+ /* Update next starting point r8 */
+ srdi r9, r11, 3
+ subf r9, r9, r3
+ mr r8, r9
+
+L(secondmatch):
+ mr r5, r7
+ rlwinm r10, r19, 3, 26, 28 /* calculate padding in bits */
+ ld r6, 0(r4)
+ addi r4, r4, 8
+ cmpdi cr7, r10, 0 /* check if its already aligned? */
+ beq cr7, L(proceed3)
+#ifdef __LITTLE_ENDIAN__
+ srd r6, r6, r10 /* Discard unwanted bits */
+ cmpb r9, r0, r6
+ sld r9, r9, r10
+#else
+ sld r6, r6, r10
+ cmpb r9, r0, r6
+ srd r9, r9, r10
+#endif
+ cmpdi cr7, r9, 0
+ bne cr7, L(proceed3)
+ ld r9, 0(r4)
+ subfic r10, r10, 64
+#ifdef __LITTLE_ENDIAN__
+ sld r9, r9, r10 /* Discard unwanted bits */
+#else
+ srd r9, r9, r10
+#endif
+ or r6, r6, r9 /* Form complete search str */
+
+L(proceed3):
+ li r7, 0
+ addi r3, r3, 8
+ cmpb r9, r0, r5
+ cmpdi cr7, r9, 0
+ bne cr7, L(proceed4)
+ ld r7, 0(r3)
+L(proceed4):
+#ifdef __LITTLE_ENDIAN__
+ srd r9, r5, r12
+ sld r10, r7, r11
+#else
+ sld r9, r5, r12
+ srd r10, r7, r11
+#endif
+ /* Form single dw with few bytes from first and second load */
+ or r10, r9, r10
+ cmpb r9, r0, r6
+ cmpdi cr7, r9, 0
+ bne cr7, L(return4)
+ /* Check for null in the formed dw */
+ cmpb r9, r0, r10
+ cmpdi cr7, r9, 0
+ bne cr7, L(retnull)
+ /* If the next 8 bytes dont match, start search again */
+ cmpb r9, r10, r6
+ cmpdi cr7, r9, -1
+ bne cr7, L(reset)
+ /* If the next 8 bytes match, load and compare next 8 */
+ b L(secondmatch)
+
+ .align 4
+L(reset):
+ /* start the search again */
+ addi r8, r8, 1
+ b L(begin)
+
+ .align 4
+L(loadnext):
+ /* Update r3 and proceed */
+ addi r3, r3, 8
+ b L(begin2)
+
+ .align 4
+L(return2):
+ mr r3, r8
+ b L(end)
+
+ .align 4
+L(return3):
+ /* Count leading zeros and compare partial dw*/
+#ifdef __LITTLE_ENDIAN__
+ addi r7, r9, -1
+ andc r7, r7, r9
+ popcntd r7, r7
+ subfic r7, r7, 64
+ sld r10, r5, r7
+ sld r6, r6, r7
+#else
+ cntlzd r7, r9
+ subfic r7, r7, 64
+ srd r10, r5, r7
+ srd r6, r6, r7
+#endif
+ cmpb r9, r10, r6
+ cmpdi cr7, r9, -1
+ addi r8, r8, 1
+ /* start search again if there is no match */
+ bne cr7, L(begin)
+ /* if the words match, update return values */
+ subfic r7, r7, 64
+ srdi r7, r7, 3
+ add r3, r3, r7
+ subf r3, r20, r3
+ b L(end)
+
+ .align 4
+L(return4):
+ /* Count leading zeros and compare partial dw*/
+#ifdef __LITTLE_ENDIAN__
+ addi r7, r9, -1
+ andc r7, r7, r9
+ popcntd r7, r7
+ subfic r7, r7, 64
+ sld r10, r10, r7
+ sld r6, r6, r7
+#else
+ cntlzd r7, r9
+ subfic r7, r7, 64
+ srd r10, r10, r7
+ srd r6, r6, r7
+#endif
+ cmpb r9, r10, r6
+ cmpdi cr7, r9, -1
+ addi r8, r8, 1
+ bne cr7, L(begin)
+ subfic r7, r7, 64
+ srdi r11, r11, 3
+ subf r3, r11, r3
+ srdi r7, r7, 3
+ add r3, r3, r7
+ subf r3, r20, r3
+ b L(end)
+
+ /* handle less than 8 search string */
+ .align 4
+L(lessthan8):
+ mr r4, r19
+ li r0, 0
+
+ rlwinm r10, r4, 3, 26, 28 /* calculate padding in bits */
+ srdi r8, r10, 3 /* padding in bytes */
+ clrrdi r4, r4, 3 /* Make r4 aligned to 8 */
+ ld r6, 0(r4)
+ cmpdi cr7, r10, 0 /* check if its already aligned? */
+ beq cr7, L(proceed2)
+#ifdef __LITTLE_ENDIAN__
+ srd r6, r6, r10 /* Discard unwanted bits */
+#else
+ sld r6, r6, r10
+#endif
+ subfic r8, r8, 8
+ cmpd cr7, r8, r20 /* Next load needed? */
+ bge cr7, L(proceed2)
+ ld r7, 8(r4)
+ subfic r10, r10, 64
+#ifdef __LITTLE_ENDIAN__
+ sld r7, r7, r10 /* Discard unwanted bits */
+#else
+ srd r7, r7, r10
+#endif
+ or r6, r6, r7 /* Form complete search str */
+L(proceed2):
+ rlwinm r10, r3, 3, 26, 28
+ clrrdi r3, r3, 3 /* Make r3 aligned */
+ ld r5, 0(r3)
+ sldi r8, r20, 3
+ subfic r8, r8, 64
+#ifdef __LITTLE_ENDIAN__
+ sld r6, r6, r8
+ cmpb r9, r0, r5
+ srd r9, r9, r10
+#else
+ srd r6, r6, r8
+ cmpb r9, r0, r5
+ sld r9, r9, r10
+#endif
+ cmpdi cr7, r9, 0
+ bne cr7, L(noload)
+ cmpdi cr7, r10, 0
+ beq cr7, L(continue)
+ ldu r7, 8(r3)
+ mr r12, r10
+ addi r12, r12, -8
+ subfic r11, r12, 64
+ srdi r9, r11, 3
+ addi r9, r9, -1
+ mtctr r9
+ b L(nextbyte)
+L(continue):
+ ldu r7, 8(r3)
+L(continue1):
+ li r9, 8
+ li r12, -8 /* shift values */
+ li r11, 72 /* shift values */
+ mtctr r9
+L(nextbyte):
+ addi r12, r12, 8 /* mask for rotation */
+ addi r11, r11, -8
+#ifdef __LITTLE_ENDIAN__
+ srd r9, r5, r12
+ sld r10, r7, r11
+ or r10, r9, r10
+ sld r10, r10, r8
+ cmpb r9, r0, r10
+ srd r9, r9, r8
+#else
+ sld r9, r5, r12
+ srd r10, r7, r11
+ or r10, r9, r10
+ srd r10, r10, r8
+ cmpb r9, r0, r10
+ sld r9, r9, r8
+#endif
+ cmpdi cr7, r9, 0
+ bne cr7, L(retnull)
+ cmpb r9, r10, r6
+ cmpdi cr7, r9, -1
+ beq cr7, L(return)
+ bdnz L(nextbyte)
+ mr r5, r7
+ /* Check null in loaded dw */
+ cmpb r9, r0, r7
+ cmpdi cr7, r9, 0
+ bne cr7, L(noload)
+ b L(continue)
+
+ .align 4
+L(noload):
+ /* Reached null in r3, so skip next load */
+ addi r3, r3, 8
+ li r7, 0
+ b L(continue1)
+
+ .align 4
+L(return):
+ /* Update return values */
+ srdi r9, r11, 3
+ subf r3, r9, r3
+ b L(end)
+
+ /* handling byte by byte */
+ .align 4
+L(bytebybyte):
+ mr r8, r3
+ addi r8, r8, -1
+L(loop1):
+ addi r8, r8, 1
+ mr r3, r8
+ mr r4, r19
+ lbz r6, 0(r4)
+ cmpdi cr7, r6, 0
+ beq cr7, L(updater3)
+L(loop):
+ lbz r5, 0(r3)
+ cmpdi cr7, r5, 0
+ beq cr7, L(retnull)
+ cmpld cr7, r6, r5
+ bne cr7, L(loop1)
+ addi r3, r3, 1
+ addi r4, r4, 1
+ lbz r6, 0(r4)
+ cmpdi cr7, r6, 0
+ beq cr7, L(updater3)
+ b L(loop)
+
+ /* handling return values */
+ .align 4
+L(updater3):
+ subf r3, r20, r3 /* reduce len of r4 from r3 */
+ b L(end)
+
+ .align 4
+L(ret_r3):
+ mr r3, r18 /* return r3 */
+ b L(end)
+
+ .align 4
+L(retnull):
+ li r3, 0 /* return NULL */
+
+ .align 4
+L(end):
+ addi r1, r1, FRAMESIZE /* restore stack pointer */
+ ld r0, 16(r1) /* read the saved link register */
+ ld r18, -24(r1) /* restore callers save register, r18 */
+ ld r19, -16(r1) /* restore callers save register, r19 */
+ ld r20, -8(r1) /* restore callers save register, r20 */
+ mtlr r0 /* branch to link register */
+ blr
+END (strstr)
+libc_hidden_builtin_def (strstr)
--
1.8.3.1