1  /* High precision, low overhead timing functions.  powerpc64 version.
       2     Copyright (C) 2005-2023 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     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _HP_TIMING_H
      20  #define _HP_TIMING_H	1
      21  
      22  /* We indeed have inlined functions.  */
      23  #define HP_TIMING_INLINE	(1)
      24  
      25  /* We use 64bit values for the times.  */
      26  typedef unsigned long long int hp_timing_t;
      27  
      28  /* That's quite simple.  Use the `mftb' instruction.  Note that the value
      29     might not be 100% accurate since there might be some more instructions
      30     running in this moment.  This could be changed by using a barrier like
      31     'lwsync' right before the `mftb' instruction.  But we are not interested
      32     in accurate clock cycles here so we don't do this.  */
      33  #ifdef _ARCH_PWR4
      34  #define HP_TIMING_NOW(Var)	__asm__ __volatile__ ("mfspr %0,268" : "=r" (Var))
      35  #else
      36  #define HP_TIMING_NOW(Var)	__asm__ __volatile__ ("mftb %0" : "=r" (Var))
      37  #endif
      38  
      39  #include <hp-timing-common.h>
      40  
      41  #endif	/* hp-timing.h */