arm: Implement memcpy ifunc selection in C

This patch refactor ARM memcpy ifunc selector to a C implementation.
No functional change is expected, including ifunc resolution rules.

It also adds some cleanup:

  - Internal memcpy hidden definition (__GI_memcpy) is now a hidden
    symbol.

  - No need to create hidden definition for the ifunc variants.

Checked on armv7-linux-gnueabihf and with a build for arm-linux-gnueabi,
arm-linux-gnueabihf with and without multiarch support and with both
GCC 7.1 and GCC mainline.  I also checked with the some possible
multiarch different configurations that trigger different memcpy
buids (__ARM_NEON__ && !__SOFT_FP__, !__ARM_NEON__ && !__SOFT_FP__, and
!__ARM_NEON__ && __SOFT_FP__).

	* sysdeps/arm/arm-ifunc.h: New file.
	* sysdeps/arm/armv7/multiarch/ifunc-memcpy.h: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy.c: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_arm.S: Likewise.
	* sysdeps/arm/armv7/multiarch/rtld-memcpy.S: Likewise.
	* sysdeps/arm/armv7/multiarch/memcpy_neon.S [!__ARM_NEON__]
	(__memcpy_neon): Avoid create hidden alias.
	* sysdeps/arm/armv7/multiarch/memcpy_vfp.S [!__ARM_NEON_]
	(__memcpy_vfp): Likewise.
	* sysdeps/arm/armv7/multiarch/Makefile [$(subdir) = string]
	(sysdep_routines): Add memcpy_arm.
	* sysdeps/arm/armv7/multiarch/memcpy.S: Remove file.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This commit is contained in:
Adhemerval Zanella 2017-10-04 17:44:08 -03:00
parent abcb584d0e
commit 802c1f1645
10 changed files with 139 additions and 82 deletions

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@ -1,3 +1,18 @@
2017-11-06 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* sysdeps/arm/arm-ifunc.h: New file.
* sysdeps/arm/armv7/multiarch/ifunc-memcpy.h: Likewise.
* sysdeps/arm/armv7/multiarch/memcpy.c: Likewise.
* sysdeps/arm/armv7/multiarch/memcpy_arm.S: Likewise.
* sysdeps/arm/armv7/multiarch/rtld-memcpy.S: Likewise.
* sysdeps/arm/armv7/multiarch/memcpy_neon.S [!__ARM_NEON__]
(__memcpy_neon): Avoid create hidden alias.
* sysdeps/arm/armv7/multiarch/memcpy_vfp.S [!__ARM_NEON_]
(__memcpy_vfp): Likewise.
* sysdeps/arm/armv7/multiarch/Makefile [$(subdir) = string]
(sysdep_routines): Add memcpy_arm.
* sysdeps/arm/armv7/multiarch/memcpy.S: Remove file.
2017-11-06 H.J. Lu <hongjiu.lu@intel.com>
[BZ #22362]

33
sysdeps/arm/arm-ifunc.h Normal file
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/* Common definition for ifunc resolvers. Linux/ARM version.
This file is part of the GNU C Library.
Copyright (C) 2017 Free Software Foundation, Inc.
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 <ifunc-init.h>
#define INIT_ARCH()
#define arm_libc_ifunc_redirected(redirected_name, name, expr) \
__ifunc (redirected_name, name, expr(hwcap), int hwcap, INIT_ARCH)
#if defined SHARED
# define arm_libc_ifunc_hidden_def(redirect_name, name) \
__hidden_ver1 (name, __GI_##name, redirect_name) \
__attribute__ ((visibility ("hidden")))
#else
# define arm_libc_ifunc_hidden_def(redirect_name, name)
#endif

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@ -1,3 +1,3 @@
ifeq ($(subdir),string)
sysdep_routines += memcpy_neon memcpy_vfp memchr_neon
sysdep_routines += memcpy_neon memcpy_vfp memchr_neon memcpy_arm
endif

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/* Common definition for memcpy resolver.
Copyright (C) 2017 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/>. */
#ifdef __SOFTFP__
__typeof (REDIRECT_NAME) OPTIMIZE (arm) attribute_hidden;
#endif
__typeof (REDIRECT_NAME) OPTIMIZE (vfp) attribute_hidden;
__typeof (REDIRECT_NAME) OPTIMIZE (neon) attribute_hidden;
static inline void *
IFUNC_SELECTOR (int hwcap)
{
if (hwcap & HWCAP_ARM_NEON)
return OPTIMIZE (neon);
#ifdef __SOFTFP__
if (hwcap & HWCAP_ARM_VFP)
return OPTIMIZE (vfp);
return OPTIMIZE (arm);
#else
return OPTIMIZE (vfp);
#endif
}

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/* Multiple versions of memcpy
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2013-2017 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/>. */
/* Thumb requires excess IT instructions here. */
#define NO_THUMB
#include <sysdep.h>
#include <rtld-global-offsets.h>
#if IS_IN (libc)
/* Under __ARM_NEON__, memcpy_neon.S defines the name memcpy. */
# ifndef __ARM_NEON__
.text
ENTRY(memcpy)
.type memcpy, %gnu_indirect_function
# ifdef __SOFTFP__
ldr r1, .Lmemcpy_arm
tst r0, #HWCAP_ARM_VFP
ldrne r1, .Lmemcpy_vfp
# else
ldr r1, .Lmemcpy_vfp
# endif
tst r0, #HWCAP_ARM_NEON
ldrne r1, .Lmemcpy_neon
1:
add r0, r1, pc
DO_RET(lr)
# ifdef __SOFTFP__
.Lmemcpy_arm:
.long C_SYMBOL_NAME(__memcpy_arm) - 1b - PC_OFS
# endif
.Lmemcpy_neon:
.long C_SYMBOL_NAME(__memcpy_neon) - 1b - PC_OFS
.Lmemcpy_vfp:
.long C_SYMBOL_NAME(__memcpy_vfp) - 1b - PC_OFS
END(memcpy)
libc_hidden_builtin_def (memcpy)
#endif /* Not __ARM_NEON__. */
/* These versions of memcpy are defined not to clobber any VFP or NEON
registers so they must always call the ARM variant of the memcpy code. */
strong_alias (__memcpy_arm, __aeabi_memcpy)
strong_alias (__memcpy_arm, __aeabi_memcpy4)
strong_alias (__memcpy_arm, __aeabi_memcpy8)
libc_hidden_def (__memcpy_arm)
#undef libc_hidden_builtin_def
#define libc_hidden_builtin_def(name)
#undef weak_alias
#define weak_alias(x, y)
#undef libc_hidden_def
#define libc_hidden_def(name)
#define memcpy __memcpy_arm
#endif
#include "memcpy_impl.S"

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/* Multiple versions of memcpy.
All versions must be listed in ifunc-impl-list.c.
Copyright (C) 2017 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/>. */
/* For __ARM_NEON__ memchr_neon.S defines memchr directly and ifunc
is not used. */
#if IS_IN (libc) && !defined (__ARM_NEON__)
# define memcpy __redirect_memcpy
# include <string.h>
# undef memcpy
# include <arm-ifunc.h>
# define SYMBOL_NAME memcpy
# include "ifunc-memcpy.h"
arm_libc_ifunc_redirected (__redirect_memcpy, memcpy, IFUNC_SELECTOR);
arm_libc_ifunc_hidden_def (__redirect_memcpy, memcpy);
#endif

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#define memcpy __memcpy_arm
#undef libc_hidden_builtin_def
#define libc_hidden_builtin_def(a)
#include "memcpy_impl.S"
/* These versions of memcpy are defined not to clobber any VFP or NEON
registers so they must always call the ARM variant of the memcpy code. */
strong_alias (__memcpy_arm, __aeabi_memcpy)
strong_alias (__memcpy_arm, __aeabi_memcpy4)
strong_alias (__memcpy_arm, __aeabi_memcpy8)

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@ -1,8 +1,8 @@
#ifdef __ARM_NEON__
/* Under __ARM_NEON__, this file defines memcpy directly. */
libc_hidden_builtin_def (memcpy)
#else
/* For __ARM_NEON__ this file defines memcpy. */
#ifndef __ARM_NEON__
# define memcpy __memcpy_neon
# undef libc_hidden_builtin_def
# define libc_hidden_builtin_def(a)
#endif
#define MEMCPY_NEON

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/* Under __ARM_NEON__, memcpy_neon.S defines memcpy directly
/* Under __ARM_NEON__ memcpy_neon.S defines memcpy directly
and the __memcpy_vfp code will never be used. */
#ifndef __ARM_NEON__
# define MEMCPY_VFP
# define memcpy __memcpy_vfp
# undef libc_hidden_builtin_def
# define libc_hidden_builtin_def(a)
# include "memcpy_impl.S"
#endif

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#include <sysdeps/arm/armv7/multiarch/memcpy_impl.S>