sysdeps/generic/hp-timing-common.h

   1 /* High precision, low overhead timing functions.  Generic version.
   2    Copyright (C) 1998-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 /* In case a platform supports timers in the hardware the following macros
  21    and types must be defined:
  22
  23    - HP_TIMING_AVAIL: test for availability.
  24
  25    - HP_TIMING_INLINE: this macro is non-zero if the functionality is not
  26      implemented using function calls but instead uses some inlined code
  27      which might simply consist of a few assembler instructions.  We have to
  28      know this since we might want to use the macros here in places where we
  29      cannot make function calls.
  30
  31    - hp_timing_t: This is the type for variables used to store the time
  32      values.  This type must be integral.
  33
  34    - HP_TIMING_NOW: place timestamp for current time in variable given as
  35      parameter.
  36 */
  37
  38 /* The target supports hp-timing.  Share the common infrastructure.  */
  39
  40 #include <string.h>
  41 #include <sys/param.h>
  42 #include <_itoa.h>
  43
  44 /* Compute the difference between START and END, storing into DIFF.  */
  45 #define HP_TIMING_DIFF(Diff, Start, End)        ((Diff) = (End) - (Start))
  46
  47 /* Accumulate ADD into SUM.  No attempt is made to be thread-safe.  */
  48 #define HP_TIMING_ACCUM_NT(Sum, Diff)           ((Sum) += (Diff))
  49
  50 /* Write a decimal representation of the timing value into the given string.  */
  51 #define HP_TIMING_PRINT(Dest, Len, Val)                                 \
  52   do {                                                                  \
  53     char __buf[20];                                                     \
  54     char *__dest = (Dest);                                              \
  55     size_t __len = (Len);                                               \
  56     char *__cp = _itoa ((Val), __buf + sizeof (__buf), 10, 0);          \
  57     size_t __cp_len = MIN (__buf + sizeof (__buf) - __cp, __len);       \
  58     memcpy (__dest, __cp, __cp_len);                                    \
  59     memcpy (__dest + __cp_len, " cycles",                               \
  60             MIN (__len - __cp_len, sizeof (" cycles")));                \
  61     __dest[__len - 1] = '\0';                                           \
  62   } while (0)