1  /* High precision, low overhead timing functions.  Generic version.
       2     Copyright (C) 1998-2023 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  /* In case a platform supports timers in the hardware the following macros
      20     and types must be defined:
      21  
      22     - HP_TIMING_INLINE: this macro is non-zero if the functionality is not
      23       implemented using function calls but instead uses some inlined code
      24       which might simply consist of a few assembler instructions.  We have to
      25       know this since we might want to use the macros here in places where we
      26       cannot make function calls.
      27  
      28     - hp_timing_t: This is the type for variables used to store the time
      29       values.  This type must be integral.
      30  
      31     - HP_TIMING_NOW: place timestamp for current time in variable given as
      32       parameter.
      33  */
      34  
      35  /* The target supports hp-timing.  Share the common infrastructure.  */
      36  
      37  #include <string.h>
      38  #include <sys/param.h>
      39  #include <_itoa.h>
      40  
      41  /* Compute the difference between START and END, storing into DIFF.  */
      42  #define HP_TIMING_DIFF(Diff, Start, End)	((Diff) = (End) - (Start))
      43  
      44  /* Accumulate ADD into SUM.  No attempt is made to be thread-safe.  */
      45  #define HP_TIMING_ACCUM_NT(Sum, Diff)		((Sum) += (Diff))
      46  
      47  #define HP_TIMING_PRINT_SIZE (3 * sizeof (hp_timing_t) + 1)
      48  
      49  /* Write a decimal representation of the timing value into the given string.  */
      50  #define HP_TIMING_PRINT(Dest, Len, Val) 				\
      51    do {									\
      52      char __buf[HP_TIMING_PRINT_SIZE];					\
      53      char *__dest = (Dest);						\
      54      size_t __len = (Len);						\
      55      char *__cp = _itoa ((Val), __buf + sizeof (__buf), 10, 0);		\
      56      size_t __cp_len = MIN (__buf + sizeof (__buf) - __cp, __len);	\
      57      memcpy (__dest, __cp, __cp_len);					\
      58      __dest[__cp_len - 1] = '\0';					\
      59    } while (0)