[v2] x86_64: Remove bzero optimization
Checks
Context |
Check |
Description |
dj/TryBot-apply_patch |
success
|
Patch applied to master at the time it was sent
|
dj/TryBot-32bit |
success
|
Build for i686
|
Commit Message
Both symbols are marked as legacy in POSIX.1-2001 and removed on
POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE
or _DEFAULT_SOURCE.
GCC also replaces bcopy with a memmove and bzero with memset on default
configuration (to actually get a bzero libc call the code requires
to omit string.h inclusion and built with --fno-builtin), so it is
highly unlikely programs are actually calling libc bzero symbol.
On a recent Linux distro (Ubuntu 22.04), there is no bzero calls
by the installed binaries.
$ cat count_bstring.sh
#!/bin/bash
files=`IFS=':';for i in $PATH; do test -d "$i" && find "$i" -maxdepth 1 -executable -type f; done`
total=0
for file in $files; do
symbols=`objdump -R $file 2>&1`
if [ $? -eq 0 ]; then
ncalls=`echo $symbols | grep -w $1 | wc -l`
((total=total+ncalls))
if [ $ncalls -gt 0 ]; then
echo "$file: $ncalls"
fi
fi
done
echo "TOTAL=$total"
$ ./count_bstring.sh bzero
TOTAL=0
Checked on x86_64-linux-gnu.
---
v2: Remove L(less_vec_no_vdup) label.
---
sysdeps/x86_64/bzero.S | 1 -
sysdeps/x86_64/memset.S | 10 +-
sysdeps/x86_64/multiarch/Makefile | 1 -
sysdeps/x86_64/multiarch/bzero.c | 106 ------------------
sysdeps/x86_64/multiarch/ifunc-impl-list.c | 42 -------
.../memset-avx2-unaligned-erms-rtm.S | 1 -
.../multiarch/memset-avx2-unaligned-erms.S | 6 -
.../multiarch/memset-avx512-unaligned-erms.S | 3 -
.../multiarch/memset-evex-unaligned-erms.S | 3 -
.../multiarch/memset-sse2-unaligned-erms.S | 1 -
.../multiarch/memset-vec-unaligned-erms.S | 63 +----------
11 files changed, 2 insertions(+), 235 deletions(-)
delete mode 100644 sysdeps/x86_64/bzero.S
delete mode 100644 sysdeps/x86_64/multiarch/bzero.c
Comments
On Fri, May 13, 2022 at 1:33 PM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
> Both symbols are marked as legacy in POSIX.1-2001 and removed on
> POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE
> or _DEFAULT_SOURCE.
>
> GCC also replaces bcopy with a memmove and bzero with memset on default
> configuration (to actually get a bzero libc call the code requires
> to omit string.h inclusion and built with --fno-builtin), so it is
> highly unlikely programs are actually calling libc bzero symbol.
>
> On a recent Linux distro (Ubuntu 22.04), there is no bzero calls
> by the installed binaries.
>
> $ cat count_bstring.sh
> #!/bin/bash
>
> files=`IFS=':';for i in $PATH; do test -d "$i" && find "$i" -maxdepth 1 -executable -type f; done`
> total=0
> for file in $files; do
> symbols=`objdump -R $file 2>&1`
> if [ $? -eq 0 ]; then
> ncalls=`echo $symbols | grep -w $1 | wc -l`
> ((total=total+ncalls))
> if [ $ncalls -gt 0 ]; then
> echo "$file: $ncalls"
> fi
> fi
> done
> echo "TOTAL=$total"
> $ ./count_bstring.sh bzero
> TOTAL=0
>
> Checked on x86_64-linux-gnu.
> ---
> v2: Remove L(less_vec_no_vdup) label.
> ---
> sysdeps/x86_64/bzero.S | 1 -
> sysdeps/x86_64/memset.S | 10 +-
> sysdeps/x86_64/multiarch/Makefile | 1 -
> sysdeps/x86_64/multiarch/bzero.c | 106 ------------------
> sysdeps/x86_64/multiarch/ifunc-impl-list.c | 42 -------
> .../memset-avx2-unaligned-erms-rtm.S | 1 -
> .../multiarch/memset-avx2-unaligned-erms.S | 6 -
> .../multiarch/memset-avx512-unaligned-erms.S | 3 -
> .../multiarch/memset-evex-unaligned-erms.S | 3 -
> .../multiarch/memset-sse2-unaligned-erms.S | 1 -
> .../multiarch/memset-vec-unaligned-erms.S | 63 +----------
> 11 files changed, 2 insertions(+), 235 deletions(-)
> delete mode 100644 sysdeps/x86_64/bzero.S
> delete mode 100644 sysdeps/x86_64/multiarch/bzero.c
>
> diff --git a/sysdeps/x86_64/bzero.S b/sysdeps/x86_64/bzero.S
> deleted file mode 100644
> index f96d567fd8..0000000000
> --- a/sysdeps/x86_64/bzero.S
> +++ /dev/null
> @@ -1 +0,0 @@
> -/* Implemented in memset.S. */
> diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
> index af26e9cedc..a6eea61a4d 100644
> --- a/sysdeps/x86_64/memset.S
> +++ b/sysdeps/x86_64/memset.S
> @@ -1,4 +1,4 @@
> -/* memset/bzero -- set memory area to CH/0
> +/* memset -- set memory area to CH/0
> Optimized version for x86-64.
> Copyright (C) 2002-2022 Free Software Foundation, Inc.
> This file is part of the GNU C Library.
> @@ -35,9 +35,6 @@
> punpcklwd %xmm0, %xmm0; \
> pshufd $0, %xmm0, %xmm0
>
> -# define BZERO_ZERO_VEC0() \
> - pxor %xmm0, %xmm0
> -
> # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> movd d, %xmm0; \
> pshufd $0, %xmm0, %xmm0; \
> @@ -56,10 +53,6 @@
> # define MEMSET_SYMBOL(p,s) memset
> #endif
>
> -#ifndef BZERO_SYMBOL
> -# define BZERO_SYMBOL(p,s) __bzero
> -#endif
> -
> #ifndef WMEMSET_SYMBOL
> # define WMEMSET_CHK_SYMBOL(p,s) p
> # define WMEMSET_SYMBOL(p,s) __wmemset
> @@ -70,7 +63,6 @@
> libc_hidden_builtin_def (memset)
>
> #if IS_IN (libc)
> -weak_alias (__bzero, bzero)
> libc_hidden_def (__wmemset)
> weak_alias (__wmemset, wmemset)
> libc_hidden_weak (wmemset)
> diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
> index 0400ea332b..f3ab5e0928 100644
> --- a/sysdeps/x86_64/multiarch/Makefile
> +++ b/sysdeps/x86_64/multiarch/Makefile
> @@ -1,7 +1,6 @@
> ifeq ($(subdir),string)
>
> sysdep_routines += \
> - bzero \
> memchr-avx2 \
> memchr-avx2-rtm \
> memchr-evex \
> diff --git a/sysdeps/x86_64/multiarch/bzero.c b/sysdeps/x86_64/multiarch/bzero.c
> deleted file mode 100644
> index 58a14b2c33..0000000000
> --- a/sysdeps/x86_64/multiarch/bzero.c
> +++ /dev/null
> @@ -1,106 +0,0 @@
> -/* Multiple versions of bzero.
> - All versions must be listed in ifunc-impl-list.c.
> - Copyright (C) 2022 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
> - <https://www.gnu.org/licenses/>. */
> -
> -/* Define multiple versions only for the definition in libc. */
> -#if IS_IN (libc)
> -# define __bzero __redirect___bzero
> -# include <string.h>
> -# undef __bzero
> -
> -# define SYMBOL_NAME __bzero
> -# include <init-arch.h>
> -
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned_erms)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned) attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_rtm)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms_rtm)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned_erms)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned)
> - attribute_hidden;
> -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned_erms)
> - attribute_hidden;
> -
> -static inline void *
> -IFUNC_SELECTOR (void)
> -{
> - const struct cpu_features* cpu_features = __get_cpu_features ();
> -
> - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> - && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
> - {
> - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> - && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> - && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
> - {
> - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> - return OPTIMIZE1 (avx512_unaligned_erms);
> -
> - return OPTIMIZE1 (avx512_unaligned);
> - }
> - }
> -
> - if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))
> - {
> - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> - && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> - && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
> - {
> - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> - return OPTIMIZE1 (evex_unaligned_erms);
> -
> - return OPTIMIZE1 (evex_unaligned);
> - }
> -
> - if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
> - {
> - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> - return OPTIMIZE1 (avx2_unaligned_erms_rtm);
> -
> - return OPTIMIZE1 (avx2_unaligned_rtm);
> - }
> -
> - if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
> - {
> - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> - return OPTIMIZE1 (avx2_unaligned_erms);
> -
> - return OPTIMIZE1 (avx2_unaligned);
> - }
> - }
> -
> - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> - return OPTIMIZE1 (sse2_unaligned_erms);
> -
> - return OPTIMIZE1 (sse2_unaligned);
> -}
> -
> -libc_ifunc_redirected (__redirect___bzero, __bzero, IFUNC_SELECTOR ());
> -
> -weak_alias (__bzero, bzero)
> -#endif
> diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> index a8afcf81bb..7218095430 100644
> --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> @@ -291,48 +291,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> __memset_avx512_no_vzeroupper)
> )
>
> - /* Support sysdeps/x86_64/multiarch/bzero.c. */
> - IFUNC_IMPL (i, name, bzero,
> - IFUNC_IMPL_ADD (array, i, bzero, 1,
> - __bzero_sse2_unaligned)
> - IFUNC_IMPL_ADD (array, i, bzero, 1,
> - __bzero_sse2_unaligned_erms)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - CPU_FEATURE_USABLE (AVX2),
> - __bzero_avx2_unaligned)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - CPU_FEATURE_USABLE (AVX2),
> - __bzero_avx2_unaligned_erms)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - (CPU_FEATURE_USABLE (AVX2)
> - && CPU_FEATURE_USABLE (RTM)),
> - __bzero_avx2_unaligned_rtm)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - (CPU_FEATURE_USABLE (AVX2)
> - && CPU_FEATURE_USABLE (RTM)),
> - __bzero_avx2_unaligned_erms_rtm)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - (CPU_FEATURE_USABLE (AVX512VL)
> - && CPU_FEATURE_USABLE (AVX512BW)
> - && CPU_FEATURE_USABLE (BMI2)),
> - __bzero_evex_unaligned)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - (CPU_FEATURE_USABLE (AVX512VL)
> - && CPU_FEATURE_USABLE (AVX512BW)
> - && CPU_FEATURE_USABLE (BMI2)),
> - __bzero_evex_unaligned_erms)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - (CPU_FEATURE_USABLE (AVX512VL)
> - && CPU_FEATURE_USABLE (AVX512BW)
> - && CPU_FEATURE_USABLE (BMI2)),
> - __bzero_avx512_unaligned_erms)
> - IFUNC_IMPL_ADD (array, i, bzero,
> - (CPU_FEATURE_USABLE (AVX512VL)
> - && CPU_FEATURE_USABLE (AVX512BW)
> - && CPU_FEATURE_USABLE (BMI2)),
> - __bzero_avx512_unaligned)
> - )
> -
> /* Support sysdeps/x86_64/multiarch/rawmemchr.c. */
> IFUNC_IMPL (i, name, rawmemchr,
> IFUNC_IMPL_ADD (array, i, rawmemchr,
> diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S
> index 5a5ee6f672..8ac3e479bb 100644
> --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S
> +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S
> @@ -5,7 +5,6 @@
>
> #define SECTION(p) p##.avx.rtm
> #define MEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm
> -#define BZERO_SYMBOL(p,s) p##_avx2_##s##_rtm
> #define WMEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm
>
> #include "memset-avx2-unaligned-erms.S"
> diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> index a093a2831f..c0bf2875d0 100644
> --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> @@ -14,9 +14,6 @@
> vmovd d, %xmm0; \
> movq r, %rax;
>
> -# define BZERO_ZERO_VEC0() \
> - vpxor %xmm0, %xmm0, %xmm0
> -
> # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> MEMSET_SET_VEC0_AND_SET_RETURN(d, r)
>
> @@ -32,9 +29,6 @@
> # ifndef MEMSET_SYMBOL
> # define MEMSET_SYMBOL(p,s) p##_avx2_##s
> # endif
> -# ifndef BZERO_SYMBOL
> -# define BZERO_SYMBOL(p,s) p##_avx2_##s
> -# endif
> # ifndef WMEMSET_SYMBOL
> # define WMEMSET_SYMBOL(p,s) p##_avx2_##s
> # endif
> diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> index 727c92133a..5241216a77 100644
> --- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> @@ -19,9 +19,6 @@
> vpbroadcastb d, %VEC0; \
> movq r, %rax
>
> -# define BZERO_ZERO_VEC0() \
> - vpxorq %XMM0, %XMM0, %XMM0
> -
> # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> vpbroadcastd d, %VEC0; \
> movq r, %rax
> diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> index 5d8fa78f05..6370021506 100644
> --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> @@ -19,9 +19,6 @@
> vpbroadcastb d, %VEC0; \
> movq r, %rax
>
> -# define BZERO_ZERO_VEC0() \
> - vpxorq %XMM0, %XMM0, %XMM0
> -
> # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> vpbroadcastd d, %VEC0; \
> movq r, %rax
> diff --git a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> index d52d170804..3d92f6993a 100644
> --- a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> @@ -22,7 +22,6 @@
>
> #if IS_IN (libc)
> # define MEMSET_SYMBOL(p,s) p##_sse2_##s
> -# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s)
> # define WMEMSET_SYMBOL(p,s) p##_sse2_##s
>
> # ifdef SHARED
> diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> index 785fee1d57..abc12d9cda 100644
> --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> @@ -1,4 +1,4 @@
> -/* memset/bzero with unaligned store and rep stosb
> +/* memset with unaligned store and rep stosb
> Copyright (C) 2016-2022 Free Software Foundation, Inc.
> This file is part of the GNU C Library.
>
> @@ -26,10 +26,6 @@
>
> #include <sysdep.h>
>
> -#ifndef BZERO_SYMBOL
> -# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s)
> -#endif
> -
> #ifndef MEMSET_CHK_SYMBOL
> # define MEMSET_CHK_SYMBOL(p,s) MEMSET_SYMBOL(p, s)
> #endif
> @@ -134,31 +130,6 @@ ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
> END (WMEMSET_SYMBOL (__wmemset, unaligned))
> #endif
>
> -ENTRY (BZERO_SYMBOL(__bzero, unaligned))
> -#if VEC_SIZE > 16
> - BZERO_ZERO_VEC0 ()
> -#endif
> - mov %RDI_LP, %RAX_LP
> - mov %RSI_LP, %RDX_LP
> -#ifndef USE_LESS_VEC_MASK_STORE
> - xorl %esi, %esi
> -#endif
> - cmp $VEC_SIZE, %RDX_LP
> - jb L(less_vec_no_vdup)
> -#ifdef USE_LESS_VEC_MASK_STORE
> - xorl %esi, %esi
> -#endif
> -#if VEC_SIZE <= 16
> - BZERO_ZERO_VEC0 ()
> -#endif
> - cmp $(VEC_SIZE * 2), %RDX_LP
> - ja L(more_2x_vec)
> - /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
> - VMOVU %VEC(0), (%rdi)
> - VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
> - VZEROUPPER_RETURN
> -END (BZERO_SYMBOL(__bzero, unaligned))
> -
> #if defined SHARED && IS_IN (libc)
> ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
> cmp %RDX_LP, %RCX_LP
> @@ -216,31 +187,6 @@ END (__memset_erms)
> END (MEMSET_SYMBOL (__memset, erms))
> # endif
>
> -ENTRY_P2ALIGN (BZERO_SYMBOL(__bzero, unaligned_erms), 6)
> -# if VEC_SIZE > 16
> - BZERO_ZERO_VEC0 ()
> -# endif
> - mov %RDI_LP, %RAX_LP
> - mov %RSI_LP, %RDX_LP
> -# ifndef USE_LESS_VEC_MASK_STORE
> - xorl %esi, %esi
> -# endif
> - cmp $VEC_SIZE, %RDX_LP
> - jb L(less_vec_no_vdup)
> -# ifdef USE_LESS_VEC_MASK_STORE
> - xorl %esi, %esi
> -# endif
> -# if VEC_SIZE <= 16
> - BZERO_ZERO_VEC0 ()
> -# endif
> - cmp $(VEC_SIZE * 2), %RDX_LP
> - ja L(stosb_more_2x_vec)
> - /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
> - VMOVU %VEC(0), (%rdi)
> - VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
> - VZEROUPPER_RETURN
> -END (BZERO_SYMBOL(__bzero, unaligned_erms))
> -
> # if defined SHARED && IS_IN (libc)
> ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
> cmp %RDX_LP, %RCX_LP
> @@ -282,7 +228,6 @@ L(last_2x_vec):
> #ifdef USE_LESS_VEC_MASK_STORE
> .p2align 4,, 10
> L(less_vec):
> -L(less_vec_no_vdup):
> L(less_vec_from_wmemset):
> /* Less than 1 VEC. */
> # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
> @@ -430,9 +375,6 @@ L(less_vec):
> xmm). This is only does anything for AVX2. */
> MEMSET_VDUP_TO_VEC0_LOW ()
> L(less_vec_from_wmemset):
> -#if VEC_SIZE > 16
> -L(less_vec_no_vdup):
> -#endif
> #endif
> L(cross_page):
> #if VEC_SIZE > 32
> @@ -445,9 +387,6 @@ L(cross_page):
> #endif
> #ifndef USE_XMM_LESS_VEC
> MOVQ %XMM0, %SET_REG64
> -#endif
> -#if VEC_SIZE <= 16
> -L(less_vec_no_vdup):
> #endif
> cmpl $8, %edx
> jge L(between_8_15)
> --
> 2.34.1
>
LGTM.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Thanks.
On Fri, May 13, 2022 at 3:05 PM H.J. Lu via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> On Fri, May 13, 2022 at 1:33 PM Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
> >
> > Both symbols are marked as legacy in POSIX.1-2001 and removed on
> > POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE
> > or _DEFAULT_SOURCE.
> >
> > GCC also replaces bcopy with a memmove and bzero with memset on default
> > configuration (to actually get a bzero libc call the code requires
> > to omit string.h inclusion and built with --fno-builtin), so it is
> > highly unlikely programs are actually calling libc bzero symbol.
> >
> > On a recent Linux distro (Ubuntu 22.04), there is no bzero calls
> > by the installed binaries.
> >
> > $ cat count_bstring.sh
> > #!/bin/bash
> >
> > files=`IFS=':';for i in $PATH; do test -d "$i" && find "$i" -maxdepth 1 -executable -type f; done`
> > total=0
> > for file in $files; do
> > symbols=`objdump -R $file 2>&1`
> > if [ $? -eq 0 ]; then
> > ncalls=`echo $symbols | grep -w $1 | wc -l`
> > ((total=total+ncalls))
> > if [ $ncalls -gt 0 ]; then
> > echo "$file: $ncalls"
> > fi
> > fi
> > done
> > echo "TOTAL=$total"
> > $ ./count_bstring.sh bzero
> > TOTAL=0
> >
> > Checked on x86_64-linux-gnu.
> > ---
> > v2: Remove L(less_vec_no_vdup) label.
> > ---
> > sysdeps/x86_64/bzero.S | 1 -
> > sysdeps/x86_64/memset.S | 10 +-
> > sysdeps/x86_64/multiarch/Makefile | 1 -
> > sysdeps/x86_64/multiarch/bzero.c | 106 ------------------
> > sysdeps/x86_64/multiarch/ifunc-impl-list.c | 42 -------
> > .../memset-avx2-unaligned-erms-rtm.S | 1 -
> > .../multiarch/memset-avx2-unaligned-erms.S | 6 -
> > .../multiarch/memset-avx512-unaligned-erms.S | 3 -
> > .../multiarch/memset-evex-unaligned-erms.S | 3 -
> > .../multiarch/memset-sse2-unaligned-erms.S | 1 -
> > .../multiarch/memset-vec-unaligned-erms.S | 63 +----------
> > 11 files changed, 2 insertions(+), 235 deletions(-)
> > delete mode 100644 sysdeps/x86_64/bzero.S
> > delete mode 100644 sysdeps/x86_64/multiarch/bzero.c
> >
> > diff --git a/sysdeps/x86_64/bzero.S b/sysdeps/x86_64/bzero.S
> > deleted file mode 100644
> > index f96d567fd8..0000000000
> > --- a/sysdeps/x86_64/bzero.S
> > +++ /dev/null
> > @@ -1 +0,0 @@
> > -/* Implemented in memset.S. */
> > diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S
> > index af26e9cedc..a6eea61a4d 100644
> > --- a/sysdeps/x86_64/memset.S
> > +++ b/sysdeps/x86_64/memset.S
> > @@ -1,4 +1,4 @@
> > -/* memset/bzero -- set memory area to CH/0
> > +/* memset -- set memory area to CH/0
> > Optimized version for x86-64.
> > Copyright (C) 2002-2022 Free Software Foundation, Inc.
> > This file is part of the GNU C Library.
> > @@ -35,9 +35,6 @@
> > punpcklwd %xmm0, %xmm0; \
> > pshufd $0, %xmm0, %xmm0
> >
> > -# define BZERO_ZERO_VEC0() \
> > - pxor %xmm0, %xmm0
> > -
> > # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> > movd d, %xmm0; \
> > pshufd $0, %xmm0, %xmm0; \
> > @@ -56,10 +53,6 @@
> > # define MEMSET_SYMBOL(p,s) memset
> > #endif
> >
> > -#ifndef BZERO_SYMBOL
> > -# define BZERO_SYMBOL(p,s) __bzero
> > -#endif
> > -
> > #ifndef WMEMSET_SYMBOL
> > # define WMEMSET_CHK_SYMBOL(p,s) p
> > # define WMEMSET_SYMBOL(p,s) __wmemset
> > @@ -70,7 +63,6 @@
> > libc_hidden_builtin_def (memset)
> >
> > #if IS_IN (libc)
> > -weak_alias (__bzero, bzero)
> > libc_hidden_def (__wmemset)
> > weak_alias (__wmemset, wmemset)
> > libc_hidden_weak (wmemset)
> > diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile
> > index 0400ea332b..f3ab5e0928 100644
> > --- a/sysdeps/x86_64/multiarch/Makefile
> > +++ b/sysdeps/x86_64/multiarch/Makefile
> > @@ -1,7 +1,6 @@
> > ifeq ($(subdir),string)
> >
> > sysdep_routines += \
> > - bzero \
> > memchr-avx2 \
> > memchr-avx2-rtm \
> > memchr-evex \
> > diff --git a/sysdeps/x86_64/multiarch/bzero.c b/sysdeps/x86_64/multiarch/bzero.c
> > deleted file mode 100644
> > index 58a14b2c33..0000000000
> > --- a/sysdeps/x86_64/multiarch/bzero.c
> > +++ /dev/null
> > @@ -1,106 +0,0 @@
> > -/* Multiple versions of bzero.
> > - All versions must be listed in ifunc-impl-list.c.
> > - Copyright (C) 2022 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
> > - <https://www.gnu.org/licenses/>. */
> > -
> > -/* Define multiple versions only for the definition in libc. */
> > -#if IS_IN (libc)
> > -# define __bzero __redirect___bzero
> > -# include <string.h>
> > -# undef __bzero
> > -
> > -# define SYMBOL_NAME __bzero
> > -# include <init-arch.h>
> > -
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned_erms)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned) attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_rtm)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms_rtm)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned_erms)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned)
> > - attribute_hidden;
> > -extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned_erms)
> > - attribute_hidden;
> > -
> > -static inline void *
> > -IFUNC_SELECTOR (void)
> > -{
> > - const struct cpu_features* cpu_features = __get_cpu_features ();
> > -
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > - && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
> > - {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> > - && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> > - && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
> > - {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> > - return OPTIMIZE1 (avx512_unaligned_erms);
> > -
> > - return OPTIMIZE1 (avx512_unaligned);
> > - }
> > - }
> > -
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))
> > - {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
> > - && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> > - && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
> > - {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> > - return OPTIMIZE1 (evex_unaligned_erms);
> > -
> > - return OPTIMIZE1 (evex_unaligned);
> > - }
> > -
> > - if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
> > - {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> > - return OPTIMIZE1 (avx2_unaligned_erms_rtm);
> > -
> > - return OPTIMIZE1 (avx2_unaligned_rtm);
> > - }
> > -
> > - if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
> > - {
> > - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> > - return OPTIMIZE1 (avx2_unaligned_erms);
> > -
> > - return OPTIMIZE1 (avx2_unaligned);
> > - }
> > - }
> > -
> > - if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
> > - return OPTIMIZE1 (sse2_unaligned_erms);
> > -
> > - return OPTIMIZE1 (sse2_unaligned);
> > -}
> > -
> > -libc_ifunc_redirected (__redirect___bzero, __bzero, IFUNC_SELECTOR ());
> > -
> > -weak_alias (__bzero, bzero)
> > -#endif
> > diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > index a8afcf81bb..7218095430 100644
> > --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
> > @@ -291,48 +291,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
> > __memset_avx512_no_vzeroupper)
> > )
> >
> > - /* Support sysdeps/x86_64/multiarch/bzero.c. */
> > - IFUNC_IMPL (i, name, bzero,
> > - IFUNC_IMPL_ADD (array, i, bzero, 1,
> > - __bzero_sse2_unaligned)
> > - IFUNC_IMPL_ADD (array, i, bzero, 1,
> > - __bzero_sse2_unaligned_erms)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - CPU_FEATURE_USABLE (AVX2),
> > - __bzero_avx2_unaligned)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - CPU_FEATURE_USABLE (AVX2),
> > - __bzero_avx2_unaligned_erms)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - (CPU_FEATURE_USABLE (AVX2)
> > - && CPU_FEATURE_USABLE (RTM)),
> > - __bzero_avx2_unaligned_rtm)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - (CPU_FEATURE_USABLE (AVX2)
> > - && CPU_FEATURE_USABLE (RTM)),
> > - __bzero_avx2_unaligned_erms_rtm)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)),
> > - __bzero_evex_unaligned)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)),
> > - __bzero_evex_unaligned_erms)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)),
> > - __bzero_avx512_unaligned_erms)
> > - IFUNC_IMPL_ADD (array, i, bzero,
> > - (CPU_FEATURE_USABLE (AVX512VL)
> > - && CPU_FEATURE_USABLE (AVX512BW)
> > - && CPU_FEATURE_USABLE (BMI2)),
> > - __bzero_avx512_unaligned)
> > - )
> > -
> > /* Support sysdeps/x86_64/multiarch/rawmemchr.c. */
> > IFUNC_IMPL (i, name, rawmemchr,
> > IFUNC_IMPL_ADD (array, i, rawmemchr,
> > diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S
> > index 5a5ee6f672..8ac3e479bb 100644
> > --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S
> > +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S
> > @@ -5,7 +5,6 @@
> >
> > #define SECTION(p) p##.avx.rtm
> > #define MEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm
> > -#define BZERO_SYMBOL(p,s) p##_avx2_##s##_rtm
> > #define WMEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm
> >
> > #include "memset-avx2-unaligned-erms.S"
> > diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> > index a093a2831f..c0bf2875d0 100644
> > --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> > +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S
> > @@ -14,9 +14,6 @@
> > vmovd d, %xmm0; \
> > movq r, %rax;
> >
> > -# define BZERO_ZERO_VEC0() \
> > - vpxor %xmm0, %xmm0, %xmm0
> > -
> > # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> > MEMSET_SET_VEC0_AND_SET_RETURN(d, r)
> >
> > @@ -32,9 +29,6 @@
> > # ifndef MEMSET_SYMBOL
> > # define MEMSET_SYMBOL(p,s) p##_avx2_##s
> > # endif
> > -# ifndef BZERO_SYMBOL
> > -# define BZERO_SYMBOL(p,s) p##_avx2_##s
> > -# endif
> > # ifndef WMEMSET_SYMBOL
> > # define WMEMSET_SYMBOL(p,s) p##_avx2_##s
> > # endif
> > diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> > index 727c92133a..5241216a77 100644
> > --- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> > +++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S
> > @@ -19,9 +19,6 @@
> > vpbroadcastb d, %VEC0; \
> > movq r, %rax
> >
> > -# define BZERO_ZERO_VEC0() \
> > - vpxorq %XMM0, %XMM0, %XMM0
> > -
> > # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> > vpbroadcastd d, %VEC0; \
> > movq r, %rax
> > diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> > index 5d8fa78f05..6370021506 100644
> > --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> > +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> > @@ -19,9 +19,6 @@
> > vpbroadcastb d, %VEC0; \
> > movq r, %rax
> >
> > -# define BZERO_ZERO_VEC0() \
> > - vpxorq %XMM0, %XMM0, %XMM0
> > -
> > # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
> > vpbroadcastd d, %VEC0; \
> > movq r, %rax
> > diff --git a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> > index d52d170804..3d92f6993a 100644
> > --- a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> > +++ b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S
> > @@ -22,7 +22,6 @@
> >
> > #if IS_IN (libc)
> > # define MEMSET_SYMBOL(p,s) p##_sse2_##s
> > -# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s)
> > # define WMEMSET_SYMBOL(p,s) p##_sse2_##s
> >
> > # ifdef SHARED
> > diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> > index 785fee1d57..abc12d9cda 100644
> > --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> > +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
> > @@ -1,4 +1,4 @@
> > -/* memset/bzero with unaligned store and rep stosb
> > +/* memset with unaligned store and rep stosb
> > Copyright (C) 2016-2022 Free Software Foundation, Inc.
> > This file is part of the GNU C Library.
> >
> > @@ -26,10 +26,6 @@
> >
> > #include <sysdep.h>
> >
> > -#ifndef BZERO_SYMBOL
> > -# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s)
> > -#endif
> > -
> > #ifndef MEMSET_CHK_SYMBOL
> > # define MEMSET_CHK_SYMBOL(p,s) MEMSET_SYMBOL(p, s)
> > #endif
> > @@ -134,31 +130,6 @@ ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
> > END (WMEMSET_SYMBOL (__wmemset, unaligned))
> > #endif
> >
> > -ENTRY (BZERO_SYMBOL(__bzero, unaligned))
> > -#if VEC_SIZE > 16
> > - BZERO_ZERO_VEC0 ()
> > -#endif
> > - mov %RDI_LP, %RAX_LP
> > - mov %RSI_LP, %RDX_LP
> > -#ifndef USE_LESS_VEC_MASK_STORE
> > - xorl %esi, %esi
> > -#endif
> > - cmp $VEC_SIZE, %RDX_LP
> > - jb L(less_vec_no_vdup)
> > -#ifdef USE_LESS_VEC_MASK_STORE
> > - xorl %esi, %esi
> > -#endif
> > -#if VEC_SIZE <= 16
> > - BZERO_ZERO_VEC0 ()
> > -#endif
> > - cmp $(VEC_SIZE * 2), %RDX_LP
> > - ja L(more_2x_vec)
> > - /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
> > - VMOVU %VEC(0), (%rdi)
> > - VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
> > - VZEROUPPER_RETURN
> > -END (BZERO_SYMBOL(__bzero, unaligned))
> > -
> > #if defined SHARED && IS_IN (libc)
> > ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
> > cmp %RDX_LP, %RCX_LP
> > @@ -216,31 +187,6 @@ END (__memset_erms)
> > END (MEMSET_SYMBOL (__memset, erms))
> > # endif
> >
> > -ENTRY_P2ALIGN (BZERO_SYMBOL(__bzero, unaligned_erms), 6)
> > -# if VEC_SIZE > 16
> > - BZERO_ZERO_VEC0 ()
> > -# endif
> > - mov %RDI_LP, %RAX_LP
> > - mov %RSI_LP, %RDX_LP
> > -# ifndef USE_LESS_VEC_MASK_STORE
> > - xorl %esi, %esi
> > -# endif
> > - cmp $VEC_SIZE, %RDX_LP
> > - jb L(less_vec_no_vdup)
> > -# ifdef USE_LESS_VEC_MASK_STORE
> > - xorl %esi, %esi
> > -# endif
> > -# if VEC_SIZE <= 16
> > - BZERO_ZERO_VEC0 ()
> > -# endif
> > - cmp $(VEC_SIZE * 2), %RDX_LP
> > - ja L(stosb_more_2x_vec)
> > - /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
> > - VMOVU %VEC(0), (%rdi)
> > - VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
> > - VZEROUPPER_RETURN
> > -END (BZERO_SYMBOL(__bzero, unaligned_erms))
> > -
> > # if defined SHARED && IS_IN (libc)
> > ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
> > cmp %RDX_LP, %RCX_LP
> > @@ -282,7 +228,6 @@ L(last_2x_vec):
> > #ifdef USE_LESS_VEC_MASK_STORE
> > .p2align 4,, 10
> > L(less_vec):
> > -L(less_vec_no_vdup):
> > L(less_vec_from_wmemset):
> > /* Less than 1 VEC. */
> > # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
> > @@ -430,9 +375,6 @@ L(less_vec):
> > xmm). This is only does anything for AVX2. */
> > MEMSET_VDUP_TO_VEC0_LOW ()
> > L(less_vec_from_wmemset):
> > -#if VEC_SIZE > 16
> > -L(less_vec_no_vdup):
> > -#endif
> > #endif
> > L(cross_page):
> > #if VEC_SIZE > 32
> > @@ -445,9 +387,6 @@ L(cross_page):
> > #endif
> > #ifndef USE_XMM_LESS_VEC
> > MOVQ %XMM0, %SET_REG64
> > -#endif
> > -#if VEC_SIZE <= 16
> > -L(less_vec_no_vdup):
> > #endif
> > cmpl $8, %edx
> > jge L(between_8_15)
> > --
> > 2.34.1
> >
>
> LGTM.
>
> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
>
> Thanks.
>
> --
> H.J.
I would like to backport this patch to release branches.
Any comments or objections?
--Sunil
deleted file mode 100644
@@ -1 +0,0 @@
-/* Implemented in memset.S. */
@@ -1,4 +1,4 @@
-/* memset/bzero -- set memory area to CH/0
+/* memset -- set memory area to CH/0
Optimized version for x86-64.
Copyright (C) 2002-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -35,9 +35,6 @@
punpcklwd %xmm0, %xmm0; \
pshufd $0, %xmm0, %xmm0
-# define BZERO_ZERO_VEC0() \
- pxor %xmm0, %xmm0
-
# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
movd d, %xmm0; \
pshufd $0, %xmm0, %xmm0; \
@@ -56,10 +53,6 @@
# define MEMSET_SYMBOL(p,s) memset
#endif
-#ifndef BZERO_SYMBOL
-# define BZERO_SYMBOL(p,s) __bzero
-#endif
-
#ifndef WMEMSET_SYMBOL
# define WMEMSET_CHK_SYMBOL(p,s) p
# define WMEMSET_SYMBOL(p,s) __wmemset
@@ -70,7 +63,6 @@
libc_hidden_builtin_def (memset)
#if IS_IN (libc)
-weak_alias (__bzero, bzero)
libc_hidden_def (__wmemset)
weak_alias (__wmemset, wmemset)
libc_hidden_weak (wmemset)
@@ -1,7 +1,6 @@
ifeq ($(subdir),string)
sysdep_routines += \
- bzero \
memchr-avx2 \
memchr-avx2-rtm \
memchr-evex \
deleted file mode 100644
@@ -1,106 +0,0 @@
-/* Multiple versions of bzero.
- All versions must be listed in ifunc-impl-list.c.
- Copyright (C) 2022 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
- <https://www.gnu.org/licenses/>. */
-
-/* Define multiple versions only for the definition in libc. */
-#if IS_IN (libc)
-# define __bzero __redirect___bzero
-# include <string.h>
-# undef __bzero
-
-# define SYMBOL_NAME __bzero
-# include <init-arch.h>
-
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned_erms)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned) attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_rtm)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms_rtm)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned_erms)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned)
- attribute_hidden;
-extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned_erms)
- attribute_hidden;
-
-static inline void *
-IFUNC_SELECTOR (void)
-{
- const struct cpu_features* cpu_features = __get_cpu_features ();
-
- if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
- && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512))
- {
- if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
- && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
- && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
- {
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE1 (avx512_unaligned_erms);
-
- return OPTIMIZE1 (avx512_unaligned);
- }
- }
-
- if (CPU_FEATURE_USABLE_P (cpu_features, AVX2))
- {
- if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)
- && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
- && CPU_FEATURE_USABLE_P (cpu_features, BMI2))
- {
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE1 (evex_unaligned_erms);
-
- return OPTIMIZE1 (evex_unaligned);
- }
-
- if (CPU_FEATURE_USABLE_P (cpu_features, RTM))
- {
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE1 (avx2_unaligned_erms_rtm);
-
- return OPTIMIZE1 (avx2_unaligned_rtm);
- }
-
- if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER))
- {
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE1 (avx2_unaligned_erms);
-
- return OPTIMIZE1 (avx2_unaligned);
- }
- }
-
- if (CPU_FEATURE_USABLE_P (cpu_features, ERMS))
- return OPTIMIZE1 (sse2_unaligned_erms);
-
- return OPTIMIZE1 (sse2_unaligned);
-}
-
-libc_ifunc_redirected (__redirect___bzero, __bzero, IFUNC_SELECTOR ());
-
-weak_alias (__bzero, bzero)
-#endif
@@ -291,48 +291,6 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
__memset_avx512_no_vzeroupper)
)
- /* Support sysdeps/x86_64/multiarch/bzero.c. */
- IFUNC_IMPL (i, name, bzero,
- IFUNC_IMPL_ADD (array, i, bzero, 1,
- __bzero_sse2_unaligned)
- IFUNC_IMPL_ADD (array, i, bzero, 1,
- __bzero_sse2_unaligned_erms)
- IFUNC_IMPL_ADD (array, i, bzero,
- CPU_FEATURE_USABLE (AVX2),
- __bzero_avx2_unaligned)
- IFUNC_IMPL_ADD (array, i, bzero,
- CPU_FEATURE_USABLE (AVX2),
- __bzero_avx2_unaligned_erms)
- IFUNC_IMPL_ADD (array, i, bzero,
- (CPU_FEATURE_USABLE (AVX2)
- && CPU_FEATURE_USABLE (RTM)),
- __bzero_avx2_unaligned_rtm)
- IFUNC_IMPL_ADD (array, i, bzero,
- (CPU_FEATURE_USABLE (AVX2)
- && CPU_FEATURE_USABLE (RTM)),
- __bzero_avx2_unaligned_erms_rtm)
- IFUNC_IMPL_ADD (array, i, bzero,
- (CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)
- && CPU_FEATURE_USABLE (BMI2)),
- __bzero_evex_unaligned)
- IFUNC_IMPL_ADD (array, i, bzero,
- (CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)
- && CPU_FEATURE_USABLE (BMI2)),
- __bzero_evex_unaligned_erms)
- IFUNC_IMPL_ADD (array, i, bzero,
- (CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)
- && CPU_FEATURE_USABLE (BMI2)),
- __bzero_avx512_unaligned_erms)
- IFUNC_IMPL_ADD (array, i, bzero,
- (CPU_FEATURE_USABLE (AVX512VL)
- && CPU_FEATURE_USABLE (AVX512BW)
- && CPU_FEATURE_USABLE (BMI2)),
- __bzero_avx512_unaligned)
- )
-
/* Support sysdeps/x86_64/multiarch/rawmemchr.c. */
IFUNC_IMPL (i, name, rawmemchr,
IFUNC_IMPL_ADD (array, i, rawmemchr,
@@ -5,7 +5,6 @@
#define SECTION(p) p##.avx.rtm
#define MEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm
-#define BZERO_SYMBOL(p,s) p##_avx2_##s##_rtm
#define WMEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm
#include "memset-avx2-unaligned-erms.S"
@@ -14,9 +14,6 @@
vmovd d, %xmm0; \
movq r, %rax;
-# define BZERO_ZERO_VEC0() \
- vpxor %xmm0, %xmm0, %xmm0
-
# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
MEMSET_SET_VEC0_AND_SET_RETURN(d, r)
@@ -32,9 +29,6 @@
# ifndef MEMSET_SYMBOL
# define MEMSET_SYMBOL(p,s) p##_avx2_##s
# endif
-# ifndef BZERO_SYMBOL
-# define BZERO_SYMBOL(p,s) p##_avx2_##s
-# endif
# ifndef WMEMSET_SYMBOL
# define WMEMSET_SYMBOL(p,s) p##_avx2_##s
# endif
@@ -19,9 +19,6 @@
vpbroadcastb d, %VEC0; \
movq r, %rax
-# define BZERO_ZERO_VEC0() \
- vpxorq %XMM0, %XMM0, %XMM0
-
# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
vpbroadcastd d, %VEC0; \
movq r, %rax
@@ -19,9 +19,6 @@
vpbroadcastb d, %VEC0; \
movq r, %rax
-# define BZERO_ZERO_VEC0() \
- vpxorq %XMM0, %XMM0, %XMM0
-
# define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \
vpbroadcastd d, %VEC0; \
movq r, %rax
@@ -22,7 +22,6 @@
#if IS_IN (libc)
# define MEMSET_SYMBOL(p,s) p##_sse2_##s
-# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s)
# define WMEMSET_SYMBOL(p,s) p##_sse2_##s
# ifdef SHARED
@@ -1,4 +1,4 @@
-/* memset/bzero with unaligned store and rep stosb
+/* memset with unaligned store and rep stosb
Copyright (C) 2016-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -26,10 +26,6 @@
#include <sysdep.h>
-#ifndef BZERO_SYMBOL
-# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s)
-#endif
-
#ifndef MEMSET_CHK_SYMBOL
# define MEMSET_CHK_SYMBOL(p,s) MEMSET_SYMBOL(p, s)
#endif
@@ -134,31 +130,6 @@ ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned))
END (WMEMSET_SYMBOL (__wmemset, unaligned))
#endif
-ENTRY (BZERO_SYMBOL(__bzero, unaligned))
-#if VEC_SIZE > 16
- BZERO_ZERO_VEC0 ()
-#endif
- mov %RDI_LP, %RAX_LP
- mov %RSI_LP, %RDX_LP
-#ifndef USE_LESS_VEC_MASK_STORE
- xorl %esi, %esi
-#endif
- cmp $VEC_SIZE, %RDX_LP
- jb L(less_vec_no_vdup)
-#ifdef USE_LESS_VEC_MASK_STORE
- xorl %esi, %esi
-#endif
-#if VEC_SIZE <= 16
- BZERO_ZERO_VEC0 ()
-#endif
- cmp $(VEC_SIZE * 2), %RDX_LP
- ja L(more_2x_vec)
- /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
- VMOVU %VEC(0), (%rdi)
- VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
- VZEROUPPER_RETURN
-END (BZERO_SYMBOL(__bzero, unaligned))
-
#if defined SHARED && IS_IN (libc)
ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned))
cmp %RDX_LP, %RCX_LP
@@ -216,31 +187,6 @@ END (__memset_erms)
END (MEMSET_SYMBOL (__memset, erms))
# endif
-ENTRY_P2ALIGN (BZERO_SYMBOL(__bzero, unaligned_erms), 6)
-# if VEC_SIZE > 16
- BZERO_ZERO_VEC0 ()
-# endif
- mov %RDI_LP, %RAX_LP
- mov %RSI_LP, %RDX_LP
-# ifndef USE_LESS_VEC_MASK_STORE
- xorl %esi, %esi
-# endif
- cmp $VEC_SIZE, %RDX_LP
- jb L(less_vec_no_vdup)
-# ifdef USE_LESS_VEC_MASK_STORE
- xorl %esi, %esi
-# endif
-# if VEC_SIZE <= 16
- BZERO_ZERO_VEC0 ()
-# endif
- cmp $(VEC_SIZE * 2), %RDX_LP
- ja L(stosb_more_2x_vec)
- /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */
- VMOVU %VEC(0), (%rdi)
- VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx)
- VZEROUPPER_RETURN
-END (BZERO_SYMBOL(__bzero, unaligned_erms))
-
# if defined SHARED && IS_IN (libc)
ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms))
cmp %RDX_LP, %RCX_LP
@@ -282,7 +228,6 @@ L(last_2x_vec):
#ifdef USE_LESS_VEC_MASK_STORE
.p2align 4,, 10
L(less_vec):
-L(less_vec_no_vdup):
L(less_vec_from_wmemset):
/* Less than 1 VEC. */
# if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64
@@ -430,9 +375,6 @@ L(less_vec):
xmm). This is only does anything for AVX2. */
MEMSET_VDUP_TO_VEC0_LOW ()
L(less_vec_from_wmemset):
-#if VEC_SIZE > 16
-L(less_vec_no_vdup):
-#endif
#endif
L(cross_page):
#if VEC_SIZE > 32
@@ -445,9 +387,6 @@ L(cross_page):
#endif
#ifndef USE_XMM_LESS_VEC
MOVQ %XMM0, %SET_REG64
-#endif
-#if VEC_SIZE <= 16
-L(less_vec_no_vdup):
#endif
cmpl $8, %edx
jge L(between_8_15)