benchtests/bench-skeleton.c

   1 /* Skeleton for benchmark programs.
   2    Copyright (C) 2013-2017 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 #include <string.h>
  20 #include <stdint.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <time.h>
  24 #include <inttypes.h>
  25 #include "bench-timing.h"
  26 #include "json-lib.h"
  27 #include "bench-util.h"
  28
  29 #include "bench-util.c"
  30
  31 #define TIMESPEC_AFTER(a, b) \
  32   (((a).tv_sec == (b).tv_sec) ?                                               \
  33      ((a).tv_nsec > (b).tv_nsec) :                                            \
  34         ((a).tv_sec > (b).tv_sec))
  35 int
  36 main (int argc, char **argv)
  37 {
  38   unsigned long i, k;
  39   struct timespec runtime;
  40   timing_t start, end;
  41   bool detailed = false;
  42   json_ctx_t json_ctx;
  43
  44   if (argc == 2 && !strcmp (argv[1], "-d"))
  45     detailed = true;
  46
  47   bench_start ();
  48
  49   memset (&runtime, 0, sizeof (runtime));
  50
  51   unsigned long iters, res;
  52
  53 #ifdef BENCH_INIT
  54   BENCH_INIT ();
  55 #endif
  56   TIMING_INIT (res);
  57
  58   iters = 1000 * res;
  59
  60   json_init (&json_ctx, 2, stdout);
  61
  62   /* Begin function.  */
  63   json_attr_object_begin (&json_ctx, FUNCNAME);
  64
  65   for (int v = 0; v < NUM_VARIANTS; v++)
  66     {
  67       /* Run for approximately DURATION seconds.  */
  68       clock_gettime (CLOCK_MONOTONIC_RAW, &runtime);
  69       runtime.tv_sec += DURATION;
  70
  71       double d_total_i = 0;
  72       timing_t total = 0, max = 0, min = 0x7fffffffffffffff;
  73       int64_t c = 0;
  74       while (1)
  75         {
  76           for (i = 0; i < NUM_SAMPLES (v); i++)
  77             {
  78               uint64_t cur;
  79               TIMING_NOW (start);
  80               for (k = 0; k < iters; k++)
  81                 BENCH_FUNC (v, i);
  82               TIMING_NOW (end);
  83
  84               TIMING_DIFF (cur, start, end);
  85
  86               if (cur > max)
  87                 max = cur;
  88
  89               if (cur < min)
  90                 min = cur;
  91
  92               TIMING_ACCUM (total, cur);
  93               /* Accumulate timings for the value.  In the end we will divide
  94                  by the total iterations.  */
  95               RESULT_ACCUM (cur, v, i, c * iters, (c + 1) * iters);
  96
  97               d_total_i += iters;
  98             }
  99           c++;
 100           struct timespec curtime;
 101
 102           memset (&curtime, 0, sizeof (curtime));
 103           clock_gettime (CLOCK_MONOTONIC_RAW, &curtime);
 104           if (TIMESPEC_AFTER (curtime, runtime))
 105             goto done;
 106         }
 107
 108       double d_total_s;
 109       double d_iters;
 110
 111     done:
 112       d_total_s = total;
 113       d_iters = iters;
 114
 115       /* Begin variant.  */
 116       json_attr_object_begin (&json_ctx, VARIANT (v));
 117
 118       json_attr_double (&json_ctx, "duration", d_total_s);
 119       json_attr_double (&json_ctx, "iterations", d_total_i);
 120       json_attr_double (&json_ctx, "max", max / d_iters);
 121       json_attr_double (&json_ctx, "min", min / d_iters);
 122       json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
 123
 124       if (detailed)
 125         {
 126           json_array_begin (&json_ctx, "timings");
 127
 128           for (int i = 0; i < NUM_SAMPLES (v); i++)
 129             json_element_double (&json_ctx, RESULT (v, i));
 130
 131           json_array_end (&json_ctx);
 132         }
 133
 134       /* End variant.  */
 135       json_attr_object_end (&json_ctx);
 136     }
 137
 138   /* End function.  */
 139   json_attr_object_end (&json_ctx);
 140
 141   return 0;
 142 }