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Re: [PATCH] Remove Prefer_SSE_for_memop on x64
On Thu, Mar 07, 2013 at 08:18:19PM +0100, Andreas Jaeger wrote:
> On 03/07/2013 05:20 PM, OndÅej BÃlka wrote:
> >On Thu, Mar 07, 2013 at 10:12:27AM +0100, Andreas Jaeger wrote:
> >>On 02/14/2013 10:30 PM, OndÅej BÃlka wrote:
> >>>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.
> >>
> >>I suggest:
> >>Remove USE_MULTIARCH conditional for definining bcopy.
> >
> >I will remove that.
>
> You did not change the entry at all.
>
> >>
> >>> * sysdeps/x86_64/multiarch/Makefile: Update.
> >>
> >>Which variable are you changing - and how?
>
> Seems you did not understand what I asked for.
>
> We mention the name of the variable changed and comment on it, e.g.
>
> * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Remove memset-x86-64.
>
> >>
> >>> * sysdeps/x86_64/multiarch/ifunc-impl-list.c: Update.
> >>> * sysdeps/x86_64/multiarch/init-arch.c: Remove Prefer_SSE_for_memop.
> >>
> >>The two entries above miss the function changed. Replace Update with
> >>a proper description.
> >>
> >>> * sysdeps/x86_64/multiarch/init-arch.h: Likewise.
> >>
> >>Mention every single define your remove.
> >>
> >>> * 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.
> >>>
> >>
> >>The patch itself is fine, please send an updated changelog for review,
> >>
> >>thanks,
> >>Andreas
> >Here is updated changelog
> >
> > * sysdeps/x86_64/memset.S: Always define bcopy.
> >
> > * sysdeps/x86_64/multiarch/init-arch.c: Remove
> > Prefer_SSE_for_memop.
>
> This is done in function __init_cpu_features, so add it:
> * sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
> Remove Prefer_SSE_for_memop.
>
> > * sysdeps/x86_64/multiarch/init-arch.h: Remove
> > bit_Prefer_SSE_for_memop, index_Prefer_SSE_for_memop,
> > HAS_PREFER_SSE_FOR_MEMOP.
>
>
> >
> > * sysdeps/x86_64/multiarch/bzero.S: Remove.
>
> Let's just say Remove file so that it's clear.
>
> > * 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/multiarch/Makefile: Do not compile memset-x86-64.
>
> See above for my suggestion.
> > * sysdeps/x86_64/multiarch/ifunc-impl-list.c (bzero, memset):
> > Remove ifunc
> >
>
> This is function __libc_ifunc_impl_list, so the entry should be
> something like:
> * sysdeps/x86_64/multiarch/ifunc-impl-list.c
> (__libc_ifunc_impl_list): Remove bzero, memset ifunc support.
>
> Please update the changes entry and repost it with the complete patch,
>
> Andreas
Here is repost.
* sysdeps/x86_64/memset.S: Remove USE_MULTIARCH conditional for
definining bcopy.
* sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
Remove Prefer_SSE_for_memop.
* sysdeps/x86_64/multiarch/init-arch.h: Remove
bit_Prefer_SSE_for_memop, index_Prefer_SSE_for_memop,
HAS_PREFER_SSE_FOR_MEMOP.
* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Remove
memset-x86-64.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list):
Remove zero, memset ifunc support.
* sysdeps/x86_64/multiarch/bzero.S: Remove file.
* 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