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       bool is_bench = strncmp (VARIANT (v), "workload-", 9) == 0;
  72       double d_total_i = 0;
  73       timing_t total = 0, max = 0, min = 0x7fffffffffffffff;
  74       int64_t c = 0;
  75       uint64_t cur;
  76       while (1)
  77         {
  78           if (is_bench)
  79             {
  80               /* Benchmark a real trace of calls - all samples are iterated
  81                  over once before repeating.  This models actual use more
  82                  accurately than repeating the same sample many times.  */
  83               TIMING_NOW (start);
  84               for (k = 0; k < iters; k++)
  85                 for (i = 0; i < NUM_SAMPLES (v); i++)
  86                   BENCH_FUNC (v, i);
  87               TIMING_NOW (end);
  88               TIMING_DIFF (cur, start, end);
  89               TIMING_ACCUM (total, cur);
  90               d_total_i += iters * NUM_SAMPLES (v);
  91             }
  92           else
  93             for (i = 0; i < NUM_SAMPLES (v); i++)
  94               {
  95                 TIMING_NOW (start);
  96                 for (k = 0; k < iters; k++)
  97                   BENCH_FUNC (v, i);
  98                 TIMING_NOW (end);
  99
 100                 TIMING_DIFF (cur, start, end);
 101
 102                 if (cur > max)
 103                   max = cur;
 104
 105                 if (cur < min)
 106                   min = cur;
 107
 108                 TIMING_ACCUM (total, cur);
 109                 /* Accumulate timings for the value.  In the end we will divide
 110                    by the total iterations.  */
 111                 RESULT_ACCUM (cur, v, i, c * iters, (c + 1) * iters);
 112
 113                 d_total_i += iters;
 114               }
 115           c++;
 116           struct timespec curtime;
 117
 118           memset (&curtime, 0, sizeof (curtime));
 119           clock_gettime (CLOCK_MONOTONIC_RAW, &curtime);
 120           if (TIMESPEC_AFTER (curtime, runtime))
 121             goto done;
 122         }
 123
 124       double d_total_s;
 125       double d_iters;
 126
 127     done:
 128       d_total_s = total;
 129       d_iters = iters;
 130
 131       /* Begin variant.  */
 132       json_attr_object_begin (&json_ctx, VARIANT (v));
 133
 134       json_attr_double (&json_ctx, "duration", d_total_s);
 135       json_attr_double (&json_ctx, "iterations", d_total_i);
 136       if (is_bench)
 137         json_attr_double (&json_ctx, "throughput", d_total_s / d_total_i);
 138       else
 139         {
 140           json_attr_double (&json_ctx, "max", max / d_iters);
 141           json_attr_double (&json_ctx, "min", min / d_iters);
 142           json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
 143         }
 144
 145       if (detailed && !is_bench)
 146         {
 147           json_array_begin (&json_ctx, "timings");
 148
 149           for (int i = 0; i < NUM_SAMPLES (v); i++)
 150             json_element_double (&json_ctx, RESULT (v, i));
 151
 152           json_array_end (&json_ctx);
 153         }
 154
 155       /* End variant.  */
 156       json_attr_object_end (&json_ctx);
 157     }
 158
 159   /* End function.  */
 160   json_attr_object_end (&json_ctx);
 161
 162   return 0;
 163 }