progs/perf/common.c

   1 /*
   2  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  15  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * VMWARE BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  18  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  19  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  */
  21
  22 /**
  23  * Common perf code.  This should be re-usable with other APIs.
  24  */
  25
  26 #include "common.h"
  27 #include "glmain.h"
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <stdarg.h>
  32
  33 #if defined(_MSC_VER)
  34 #define snprintf _snprintf
  35 #endif
  36
  37
  38 /* Need to add a fflush windows console with mingw, otherwise nothing
  39  * shows up until program exit.  May want to add logging here.
  40  */
  41 void
  42 perf_printf(const char *format, ...)
  43 {
  44    va_list ap;
  45    va_start(ap, format);
  46
  47    fflush(stdout);
  48    vfprintf(stdout, format, ap);
  49    fflush(stdout);
  50
  51    va_end(ap);
  52 }
  53
  54
  55
  56 /**
  57  * Run function 'f' for enough iterations to reach a steady state.
  58  * Return the rate (iterations/second).
  59  */
  60 double
  61 PerfMeasureRate(PerfRateFunc f)
  62 {
  63    const double minDuration = 1.0;
  64    double rate = 0.0, prevRate = 0.0;
  65    unsigned subiters;
  66
  67    /* Compute initial number of iterations to try.
  68     * If the test function is pretty slow this helps to avoid
  69     * extraordarily long run times.
  70     */
  71    subiters = 2;
  72    {
  73       const double t0 = PerfGetTime();
  74       double t1;
  75       do {
  76          f(subiters); /* call the rendering function */
  77          t1 = PerfGetTime();
  78          subiters *= 2;
  79       } while (t1 - t0 < 0.1 * minDuration);
  80    }
  81    /*perf_printf("initial subIters = %u\n", subiters);*/
  82
  83    while (1) {
  84       const double t0 = PerfGetTime();
  85       unsigned iters = 0;
  86       double t1;
  87
  88       do {
  89          f(subiters); /* call the rendering function */
  90          t1 = PerfGetTime();
  91          iters += subiters;
  92       } while (t1 - t0 < minDuration);
  93
  94       rate = iters / (t1 - t0);
  95
  96       if (0)
  97          perf_printf("prevRate %f  rate  %f  ratio %f  iters %u\n",
  98                 prevRate, rate, rate/prevRate, iters);
  99
 100       /* Try and speed the search up by skipping a few steps:
 101        */
 102       if (rate > prevRate * 1.6)
 103          subiters *= 8;
 104       else if (rate > prevRate * 1.2)
 105          subiters *= 4;
 106       else if (rate > prevRate * 1.05)
 107          subiters *= 2;
 108       else
 109          break;
 110
 111       prevRate = rate;
 112    }
 113
 114    if (0)
 115       perf_printf("%s returning iters %u  rate %f\n", __FUNCTION__, subiters, rate);
 116    return rate;
 117 }
 118
 119
 120 /* Note static buffer, can only use once per printf.
 121  */
 122 const char *
 123 PerfHumanFloat( double d )
 124 {
 125    static char buf[80];
 126
 127    if (d > 1000000000.0)
 128       snprintf(buf, sizeof(buf), "%.1f billion", d / 1000000000.0);
 129    else if (d > 1000000.0)
 130       snprintf(buf, sizeof(buf), "%.1f million", d / 1000000.0);
 131    else if (d > 1000.0)
 132       snprintf(buf, sizeof(buf), "%.1f thousand", d / 1000.0);
 133    else
 134       snprintf(buf, sizeof(buf), "%.1f", d);
 135
 136    return buf;
 137 }