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glibc  2.9
hp-timing.h
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00001 /* High precision, low overhead timing functions.  x86-64 version.
00002    Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #ifndef _HP_TIMING_H
00021 
00022 /* We can use some of the i686 implementation without changes.  */
00023 # include <sysdeps/i386/i686/hp-timing.h>
00024 
00025 /* The "=A" constraint used in 32-bit mode does not work in 64-bit mode.  */
00026 # undef HP_TIMING_NOW
00027 # define HP_TIMING_NOW(Var) \
00028   ({ unsigned int _hi, _lo; \
00029      asm volatile ("rdtsc" : "=a" (_lo), "=d" (_hi)); \
00030      (Var) = ((unsigned long long int) _hi << 32) | _lo; })
00031 
00032 /* The funny business for 32-bit mode is not required here.  */
00033 # undef HP_TIMING_ACCUM
00034 # define HP_TIMING_ACCUM(Sum, Diff)                                         \
00035   do {                                                               \
00036     hp_timing_t __diff = (Diff) - GLRO(dl_hp_timing_overhead);              \
00037     __asm__ __volatile__ ("lock; addq %1, %0"                               \
00038                        : "=m" (Sum) : "r" (__diff), "m" (Sum));             \
00039   } while (0)
00040 
00041 #endif /* hp-timing.h */