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[PATCH] Remove Prefer_SSE_for_memop on x64


Hello, 
As I asked in
http://www.sourceware.org/ml/libc-alpha/2013-02/msg00203.html
nobody objected to keep non-sse memset on x64.

This patch removes that implementation and flag Prefer_SSE_for_memop
which is always set and only choose sse memset over nonsse one.

2013-02-14   OndÅej BÃlka  <neleai@seznam.cz>

	* sysdeps/x86_64/memset.S: Always define bcopy.
	* sysdeps/x86_64/multiarch/Makefile: Update.
	* sysdeps/x86_64/multiarch/ifunc-impl-list.c: Update.
	* sysdeps/x86_64/multiarch/init-arch.c: Remove Prefer_SSE_for_memop.
	* sysdeps/x86_64/multiarch/init-arch.h: Likewise.
	* sysdeps/x86_64/multiarch/bzero.S: Remove.
	* sysdeps/x86_64/multiarch/memset-x86-64.S: Likewise.
	* sysdeps/x86_64/multiarch/memset.S: Likewise.
	* sysdeps/x86_64/multiarch/memset_chk.S: Likewise.

---
 sysdeps/x86_64/memset.S                    |    2 +-
 sysdeps/x86_64/multiarch/Makefile          |    2 +-
 sysdeps/x86_64/multiarch/bzero.S           |   28 ----------
 sysdeps/x86_64/multiarch/ifunc-impl-list.c |   11 ----
 sysdeps/x86_64/multiarch/init-arch.c       |   11 ----
 sysdeps/x86_64/multiarch/init-arch.h       |    4 --
 sysdeps/x86_64/multiarch/memset-x86-64.S   |   19 -------
 sysdeps/x86_64/multiarch/memset.S          |   79 ----------------------------
 sysdeps/x86_64/multiarch/memset_chk.S      |   44 ---------------
 9 files changed, 2 insertions(+), 198 deletions(-)
 delete mode 100644 sysdeps/x86_64/multiarch/bzero.S
 delete mode 100644 sysdeps/x86_64/multiarch/memset-x86-64.S
 delete mode 100644 sysdeps/x86_64/multiarch/memset.S
 delete mode 100644 sysdeps/x86_64/multiarch/memset_chk.S

diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
index f3a4d44..b393efe 100644
--- a/sysdeps/x86_64/memset.S
+++ b/sysdeps/x86_64/memset.S
@@ -23,7 +23,7 @@
 #define __STOS_UPPER_BOUNDARY	$65536
 
 	.text
-#if !defined NOT_IN_libc && !defined USE_MULTIARCH
+#if !defined NOT_IN_libc
 ENTRY(__bzero)
 	mov	%rsi,%rdx	/* Adjust parameter.  */
 	xorl	%esi,%esi	/* Fill with 0s.  */
diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
index dd6c27d..4f7c070 100644
--- a/sysdeps/x86_64/multiarch/Makefile
+++ b/sysdeps/x86_64/multiarch/Makefile
@@ -10,7 +10,7 @@ sysdep_routines += strncat-c stpncpy-c strncpy-c strcmp-ssse3 strncmp-ssse3 \
 		   strend-sse4 memcmp-sse4 memcpy-ssse3 mempcpy-ssse3 \
 		   memmove-ssse3 memcpy-ssse3-back mempcpy-ssse3-back \
 		   memmove-ssse3-back strcasestr-nonascii strcasecmp_l-ssse3 \
-		   strncase_l-ssse3 strlen-sse4 strlen-sse2-no-bsf memset-x86-64 \
+		   strncase_l-ssse3 strlen-sse4 strlen-sse2-no-bsf \
 		   strcpy-ssse3 strncpy-ssse3 stpcpy-ssse3 stpncpy-ssse3 \
 		   strcpy-sse2-unaligned strncpy-sse2-unaligned \
 		   stpcpy-sse2-unaligned stpncpy-sse2-unaligned \
diff --git a/sysdeps/x86_64/multiarch/bzero.S b/sysdeps/x86_64/multiarch/bzero.S
deleted file mode 100644
index 88e96ea..0000000
--- a/sysdeps/x86_64/multiarch/bzero.S
+++ /dev/null
@@ -1,28 +0,0 @@
-/* bzero.  x86-64 version.
-   Copyright (C) 2010-2013 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>
-#include <init-arch.h>
-
-	.text
-ENTRY(__bzero)
-	mov	%rsi,%rdx	/* Adjust parameter.  */
-	xorl	%esi,%esi	/* Fill with 0s.  */
-	jmp	__libc_memset	/* Branch to IFUNC memset.  */
-END(__bzero)
-weak_alias (__bzero, bzero)
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index 643cb2d..cb4aba3 100644
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -61,17 +61,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 			      __memmove_ssse3)
 	      IFUNC_IMPL_ADD (array, i, memmove, 1, __memmove_sse2))
 
-  /* Support sysdeps/x86_64/multiarch/memset_chk.S.  */
-  IFUNC_IMPL (i, name, __memset_chk,
-	      IFUNC_IMPL_ADD (array, i, __memset_chk, 1, __memset_chk_sse2)
-	      IFUNC_IMPL_ADD (array, i, __memset_chk, 1,
-			      __memset_chk_x86_64))
-
-  /* Support sysdeps/x86_64/multiarch/memset.S.  */
-  IFUNC_IMPL (i, name, memset,
-	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_sse2)
-	      IFUNC_IMPL_ADD (array, i, memset, 1, __memset_x86_64))
-
   /* Support sysdeps/x86_64/multiarch/rawmemchr.S.  */
   IFUNC_IMPL (i, name, rawmemchr,
 	      IFUNC_IMPL_ADD (array, i, rawmemchr, HAS_SSE4_2,
diff --git a/sysdeps/x86_64/multiarch/init-arch.c b/sysdeps/x86_64/multiarch/init-arch.c
index 992cbfb..7daaf46 100644
--- a/sysdeps/x86_64/multiarch/init-arch.c
+++ b/sysdeps/x86_64/multiarch/init-arch.c
@@ -58,11 +58,6 @@ __init_cpu_features (void)
 
       get_common_indeces (&family, &model);
 
-      /* Intel processors prefer SSE instruction for memory/string
-	 routines if they are available.  */
-      __cpu_features.feature[index_Prefer_SSE_for_memop]
-	|= bit_Prefer_SSE_for_memop;
-
       unsigned int eax = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].eax;
       unsigned int extended_family = (eax >> 20) & 0xff;
       unsigned int extended_model = (eax >> 12) & 0xf0;
@@ -125,12 +120,6 @@ __init_cpu_features (void)
 
       ecx = __cpu_features.cpuid[COMMON_CPUID_INDEX_1].ecx;
 
-      /* AMD processors prefer SSE instructions for memory/string routines
-	 if they are available, otherwise they prefer integer instructions.  */
-      if ((ecx & 0x200))
-	__cpu_features.feature[index_Prefer_SSE_for_memop]
-	  |= bit_Prefer_SSE_for_memop;
-
       unsigned int eax;
       __cpuid (0x80000000, eax, ebx, ecx, edx);
       if (eax >= 0x80000001)
diff --git a/sysdeps/x86_64/multiarch/init-arch.h b/sysdeps/x86_64/multiarch/init-arch.h
index 0aece18..28edbf7 100644
--- a/sysdeps/x86_64/multiarch/init-arch.h
+++ b/sysdeps/x86_64/multiarch/init-arch.h
@@ -18,7 +18,6 @@
 #define bit_Fast_Rep_String		(1 << 0)
 #define bit_Fast_Copy_Backward		(1 << 1)
 #define bit_Slow_BSF			(1 << 2)
-#define bit_Prefer_SSE_for_memop	(1 << 3)
 #define bit_Fast_Unaligned_Load		(1 << 4)
 #define bit_Prefer_PMINUB_for_stringop	(1 << 5)
 #define bit_AVX_Usable			(1 << 6)
@@ -58,7 +57,6 @@
 # define index_Fast_Rep_String		FEATURE_INDEX_1*FEATURE_SIZE
 # define index_Fast_Copy_Backward	FEATURE_INDEX_1*FEATURE_SIZE
 # define index_Slow_BSF			FEATURE_INDEX_1*FEATURE_SIZE
-# define index_Prefer_SSE_for_memop	FEATURE_INDEX_1*FEATURE_SIZE
 # define index_Fast_Unaligned_Load	FEATURE_INDEX_1*FEATURE_SIZE
 # define index_Prefer_PMINUB_for_stringop FEATURE_INDEX_1*FEATURE_SIZE
 # define index_AVX_Usable		FEATURE_INDEX_1*FEATURE_SIZE
@@ -157,7 +155,6 @@ extern const struct cpu_features *__get_cpu_features (void)
 # define index_Fast_Rep_String		FEATURE_INDEX_1
 # define index_Fast_Copy_Backward	FEATURE_INDEX_1
 # define index_Slow_BSF			FEATURE_INDEX_1
-# define index_Prefer_SSE_for_memop	FEATURE_INDEX_1
 # define index_Fast_Unaligned_Load	FEATURE_INDEX_1
 # define index_AVX_Usable		FEATURE_INDEX_1
 # define index_FMA_Usable		FEATURE_INDEX_1
@@ -169,7 +166,6 @@ extern const struct cpu_features *__get_cpu_features (void)
 # define HAS_FAST_REP_STRING		HAS_ARCH_FEATURE (Fast_Rep_String)
 # define HAS_FAST_COPY_BACKWARD		HAS_ARCH_FEATURE (Fast_Copy_Backward)
 # define HAS_SLOW_BSF			HAS_ARCH_FEATURE (Slow_BSF)
-# define HAS_PREFER_SSE_FOR_MEMOP	HAS_ARCH_FEATURE (Prefer_SSE_for_memop)
 # define HAS_FAST_UNALIGNED_LOAD	HAS_ARCH_FEATURE (Fast_Unaligned_Load)
 # define HAS_AVX			HAS_ARCH_FEATURE (AVX_Usable)
 # define HAS_FMA			HAS_ARCH_FEATURE (FMA_Usable)
diff --git a/sysdeps/x86_64/multiarch/memset-x86-64.S b/sysdeps/x86_64/multiarch/memset-x86-64.S
deleted file mode 100644
index 551d105..0000000
--- a/sysdeps/x86_64/multiarch/memset-x86-64.S
+++ /dev/null
@@ -1,19 +0,0 @@
-#include <sysdep.h>
-
-#ifndef NOT_IN_libc
-# undef ENTRY_CHK
-# define ENTRY_CHK(name) \
-	.type __memset_chk_x86_64, @function; \
-	.globl __memset_chk_x86_64; \
-	.p2align 4; \
-	__memset_chk_x86_64: cfi_startproc; \
-	CALL_MCOUNT
-# undef END_CHK
-# define END_CHK(name) \
-	cfi_endproc; .size __memset_chk_x86_64, .-__memset_chk_x86_64
-
-# undef libc_hidden_builtin_def
-# define libc_hidden_builtin_def(name)
-# define memset __memset_x86_64
-# include "../memset.S"
-#endif
diff --git a/sysdeps/x86_64/multiarch/memset.S b/sysdeps/x86_64/multiarch/memset.S
deleted file mode 100644
index 7f673fa..0000000
--- a/sysdeps/x86_64/multiarch/memset.S
+++ /dev/null
@@ -1,79 +0,0 @@
-/* Multiple versions of memset
-   All versions must be listed in ifunc-impl-list.c.
-   Copyright (C) 2010-2013 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>
-#include <init-arch.h>
-
-/* Define multiple versions only for the definition in lib.  */
-#ifndef NOT_IN_libc
-ENTRY(memset)
-	.type	memset, @gnu_indirect_function
-	cmpl	$0, __cpu_features+KIND_OFFSET(%rip)
-	jne	1f
-	call	__init_cpu_features
-1:	leaq	__memset_x86_64(%rip), %rax
-	testl	$bit_Prefer_SSE_for_memop, __cpu_features+FEATURE_OFFSET+index_Prefer_SSE_for_memop(%rip)
-	jz	2f
-	leaq	__memset_sse2(%rip), %rax
-2:	ret
-END(memset)
-
-/* Define internal IFUNC memset for bzero.  */
-	.globl __libc_memset
-	.hidden __libc_memset
-	__libc_memset = memset
-
-# define USE_SSE2 1
-
-# undef ENTRY
-# define ENTRY(name) \
-	.type __memset_sse2, @function; \
-	.globl __memset_sse2; \
-	.p2align 4; \
-	__memset_sse2: cfi_startproc; \
-	CALL_MCOUNT
-# undef END
-# define END(name) \
-	cfi_endproc; .size __memset_sse2, .-__memset_sse2
-
-# undef ENTRY_CHK
-# define ENTRY_CHK(name) \
-	.type __memset_chk_sse2, @function; \
-	.globl __memset_chk_sse2; \
-	.p2align 4; \
-	__memset_chk_sse2: cfi_startproc; \
-	CALL_MCOUNT
-# undef END_CHK
-# define END_CHK(name) \
-	cfi_endproc; .size __memset_chk_sse2, .-__memset_chk_sse2
-
-# ifdef SHARED
-#  undef libc_hidden_builtin_def
-/* It doesn't make sense to send libc-internal memset calls through a PLT.
-   The speedup we get from using GPR instruction is likely eaten away
-   by the indirect call in the PLT.  */
-#  define libc_hidden_builtin_def(name) \
-	.globl __GI_memset; __GI_memset = __memset_sse2
-# endif
-
-# undef strong_alias
-# define strong_alias(original, alias)
-#endif
-
-#include "../memset.S"
diff --git a/sysdeps/x86_64/multiarch/memset_chk.S b/sysdeps/x86_64/multiarch/memset_chk.S
deleted file mode 100644
index 55e2635..0000000
--- a/sysdeps/x86_64/multiarch/memset_chk.S
+++ /dev/null
@@ -1,44 +0,0 @@
-/* Multiple versions of __memset_chk
-   All versions must be listed in ifunc-impl-list.c.
-   Copyright (C) 2010-2013 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>
-#include <init-arch.h>
-
-/* Define multiple versions only for the definition in lib.  */
-#ifndef NOT_IN_libc
-# ifdef SHARED
-ENTRY(__memset_chk)
-	.type	__memset_chk, @gnu_indirect_function
-	cmpl	$0, __cpu_features+KIND_OFFSET(%rip)
-	jne	1f
-	call	__init_cpu_features
-1:	leaq	__memset_chk_x86_64(%rip), %rax
-	testl	$bit_Prefer_SSE_for_memop, __cpu_features+FEATURE_OFFSET+index_Prefer_SSE_for_memop(%rip)
-	jz	2f
-	leaq	__memset_chk_sse2(%rip), %rax
-2:	ret
-END(__memset_chk)
-
-strong_alias (__memset_chk, __memset_zero_constant_len_parameter)
-	.section .gnu.warning.__memset_zero_constant_len_parameter
-	.string "memset used with constant zero length parameter; this could be due to transposed parameters"
-# else
-#  include "../memset_chk.S"
-# endif
-#endif
-- 
1.7.4.4


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