sysdeps/x86_64/hp-timing.h

   1 /* High precision, low overhead timing functions.  x86-64 version.
   2    Copyright (C) 2002-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _HP_TIMING_H
  20 #define _HP_TIMING_H    1
  21
  22 /* We always assume having the timestamp register.  */
  23 #define HP_TIMING_AVAIL         (1)
  24 #define HP_SMALL_TIMING_AVAIL   (1)
  25
  26 /* We indeed have inlined functions.  */
  27 #define HP_TIMING_INLINE        (1)
  28
  29 /* We use 64bit values for the times.  */
  30 typedef unsigned long long int hp_timing_t;
  31
  32 /* The "=A" constraint used in 32-bit mode does not work in 64-bit mode.  */
  33 #define HP_TIMING_NOW(Var) \
  34   ({ unsigned int _hi, _lo; \
  35      asm volatile ("rdtsc" : "=a" (_lo), "=d" (_hi)); \
  36      (Var) = ((unsigned long long int) _hi << 32) | _lo; })
  37
  38 #include <hp-timing-common.h>
  39
  40 #endif /* hp-timing.h */