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x86: Use _rdtsc intrinsic for HP_TIMING_NOW

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Since _rdtsc intrinsic is supported in GCC 4.9, we can use it for
HP_TIMING_NOW.  This patch

1. Create x86 hp-timing.h to replace i686 and x86_64 hp-timing.h.
2. Move MINIMUM_ISA from init-arch.h to isa.h so that x86 hp-timing.h
can check minimum x86 ISA to decide if _rdtsc can be used.

NB: Checking if __i686__ isn't sufficient since __i686__ may not be
defined when building for i686 class processors.

	* sysdeps/i386/init-arch.h: Removed.
	* sysdeps/i386/i586/init-arch.h: Likewise.
	* sysdeps/i386/i686/init-arch.h: Likewise.
	* sysdeps/i386/i686/hp-timing.h: Likewise.
	* sysdeps/x86_64/hp-timing.h: Likewise.
	* sysdeps/i386/isa.h: New file.
	* sysdeps/i386/i586/isa.h: Likewise.
	* sysdeps/i386/i686/isa.h: Likewise.
	* sysdeps/x86_64/isa.h: Likewise.
	* sysdeps/x86/hp-timing.h: New file.
	* sysdeps/x86/init-arch.h: Include <isa.h>.
This commit is contained in:
H.J. Lu 2018-10-17 15:16:38 -07:00
parent c2b7ccad93
commit 72771e5375
8 changed files with 79 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
ChangeLog
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@ -1,3 +1,17 @@
2018-10-17 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/i386/init-arch.h: Removed.
* sysdeps/i386/i586/init-arch.h: Likewise.
* sysdeps/i386/i686/init-arch.h: Likewise.
* sysdeps/i386/i686/hp-timing.h: Likewise.
* sysdeps/x86_64/hp-timing.h: Likewise.
* sysdeps/i386/isa.h: New file.
* sysdeps/i386/i586/isa.h: Likewise.
* sysdeps/i386/i686/isa.h: Likewise.
* sysdeps/x86_64/isa.h: Likewise.
* sysdeps/x86/hp-timing.h: New file.
* sysdeps/x86/init-arch.h: Include <isa.h>.
2018-10-17 Joseph Myers <joseph@codesourcery.com> 2018-10-17 Joseph Myers <joseph@codesourcery.com>
* math/libm-test-pow.inc (pow_test_data): Do not allow * math/libm-test-pow.inc (pow_test_data): Do not allow

9
sysdeps/i386/i586/init-arch.h → sysdeps/i386/i586/isa.h
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@ -1,4 +1,5 @@
/* Copyright (C) 2015-2018 Free Software Foundation, Inc. /* x86 ISA info. i586 version.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
@ -15,5 +16,9 @@
License along with the GNU C Library; if not, see License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */ <http://www.gnu.org/licenses/>. */
#ifndef _ISA_H
#define _ISA_H
#define MINIMUM_ISA 586 #define MINIMUM_ISA 586
#include <sysdeps/x86/init-arch.h>
#endif

9
sysdeps/i386/i686/init-arch.h → sysdeps/i386/i686/isa.h
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@ -1,4 +1,5 @@
/* Copyright (C) 2015-2018 Free Software Foundation, Inc. /* x86 ISA info. i686 version.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
@ -15,5 +16,9 @@
License along with the GNU C Library; if not, see License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */ <http://www.gnu.org/licenses/>. */
#ifndef _ISA_H
#define _ISA_H
#define MINIMUM_ISA 686 #define MINIMUM_ISA 686
#include <sysdeps/x86/init-arch.h>
#endif

9
sysdeps/i386/init-arch.h → sysdeps/i386/isa.h
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@ -1,4 +1,5 @@
/* Copyright (C) 2015-2018 Free Software Foundation, Inc. /* x86 ISA info. i486 version.
Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
@ -15,5 +16,9 @@
License along with the GNU C Library; if not, see License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */ <http://www.gnu.org/licenses/>. */
#ifndef _ISA_H
#define _ISA_H
#define MINIMUM_ISA 486 #define MINIMUM_ISA 486
#include <sysdeps/x86/init-arch.h>
#endif

28
sysdeps/i386/i686/hp-timing.h → sysdeps/x86/hp-timing.h
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@ -1,7 +1,6 @@
/* High precision, low overhead timing functions. i686 version. /* High precision, low overhead timing functions. x86 version.
Copyright (C) 1998-2018 Free Software Foundation, Inc. Copyright (C) 2018 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public modify it under the terms of the GNU Lesser General Public
@ -20,12 +19,17 @@
#ifndef _HP_TIMING_H #ifndef _HP_TIMING_H
#define _HP_TIMING_H 1 #define _HP_TIMING_H 1
#include <isa.h>
#if MINIMUM_ISA == 686 || MINIMUM_ISA == 8664
# include <x86intrin.h>
/* We always assume having the timestamp register. */ /* We always assume having the timestamp register. */
#define HP_TIMING_AVAIL (1) # define HP_TIMING_AVAIL (1)
#define HP_SMALL_TIMING_AVAIL (1) # define HP_SMALL_TIMING_AVAIL (1)
/* We indeed have inlined functions. */ /* We indeed have inlined functions. */
#define HP_TIMING_INLINE (1) # define HP_TIMING_INLINE (1)
/* We use 64bit values for the times. */ /* We use 64bit values for the times. */
typedef unsigned long long int hp_timing_t; typedef unsigned long long int hp_timing_t;
@ -35,8 +39,14 @@ typedef unsigned long long int hp_timing_t;
running in this moment. This could be changed by using a barrier like running in this moment. This could be changed by using a barrier like
'cpuid' right before the `rdtsc' instruciton. But we are not interested 'cpuid' right before the `rdtsc' instruciton. But we are not interested
in accurate clock cycles here so we don't do this. */ in accurate clock cycles here so we don't do this. */
#define HP_TIMING_NOW(Var) __asm__ __volatile__ ("rdtsc" : "=A" (Var)) # define HP_TIMING_NOW(Var) ((Var) = _rdtsc ())
#include <hp-timing-common.h> # include <hp-timing-common.h>
#else
/* NB: Undefine _HP_TIMING_H so that <sysdeps/generic/hp-timing.h> will
be included. */
# undef _HP_TIMING_H
# include <sysdeps/generic/hp-timing.h>
#endif
#endif /* hp-timing.h */ #endif /* hp-timing.h */

1
sysdeps/x86/init-arch.h
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@ -21,6 +21,7 @@
# include <ldsodefs.h> # include <ldsodefs.h>
#endif #endif
#include <ifunc-init.h> #include <ifunc-init.h>
#include <isa.h>
#ifndef __x86_64__ #ifndef __x86_64__
/* Due to the reordering and the other nifty extensions in i686, it is /* Due to the reordering and the other nifty extensions in i686, it is

40
sysdeps/x86_64/hp-timing.h
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@ -1,40 +0,0 @@
/* High precision, low overhead timing functions. x86-64 version.
Copyright (C) 2002-2018 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/>. */
#ifndef _HP_TIMING_H
#define _HP_TIMING_H 1
/* We always assume having the timestamp register. */
#define HP_TIMING_AVAIL (1)
#define HP_SMALL_TIMING_AVAIL (1)
/* We indeed have inlined functions. */
#define HP_TIMING_INLINE (1)
/* We use 64bit values for the times. */
typedef unsigned long long int hp_timing_t;
/* The "=A" constraint used in 32-bit mode does not work in 64-bit mode. */
#define HP_TIMING_NOW(Var) \
({ unsigned int _hi, _lo; \
asm volatile ("rdtsc" : "=a" (_lo), "=d" (_hi)); \
(Var) = ((unsigned long long int) _hi << 32) | _lo; })
#include <hp-timing-common.h>
#endif /* hp-timing.h */

24
sysdeps/x86_64/isa.h Normal file
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@ -0,0 +1,24 @@
/* x86 ISA info. x86-64 version.
Copyright (C) 2018 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/>. */
#ifndef _ISA_H
#define _ISA_H
#define MINIMUM_ISA 8664
#endif