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
  34 /* Need to add a fflush windows console with mingw, otherwise nothing
  35  * shows up until program exit.  May want to add logging here.
  36  */
  37 void
  38 perf_printf(const char *format, ...)
  39 {
  40    va_list ap;
  41    va_start(ap, format);
  42
  43    fflush(stdout);
  44    vfprintf(stdout, format, ap);
  45    fflush(stdout);
  46
  47    va_end(ap);
  48 }
  49
  50
  51
  52 /**
  53  * Run function 'f' for enough iterations to reach a steady state.
  54  * Return the rate (iterations/second).
  55  */
  56 double
  57 PerfMeasureRate(PerfRateFunc f)
  58 {
  59    const double minDuration = 1.0;
  60    double rate = 0.0, prevRate = 0.0;
  61    unsigned subiters;
  62
  63    /* Compute initial number of iterations to try.
  64     * If the test function is pretty slow this helps to avoid
  65     * extraordarily long run times.
  66     */
  67    subiters = 2;
  68    {
  69       const double t0 = PerfGetTime();
  70       double t1;
  71       do {
  72          f(subiters); /* call the rendering function */
  73          t1 = PerfGetTime();
  74          subiters *= 2;
  75       } while (t1 - t0 < 0.1 * minDuration);
  76    }
  77    /*perf_printf("initial subIters = %u\n", subiters);*/
  78
  79    while (1) {
  80       const double t0 = PerfGetTime();
  81       unsigned iters = 0;
  82       double t1;
  83
  84       do {
  85          f(subiters); /* call the rendering function */
  86          t1 = PerfGetTime();
  87          iters += subiters;
  88       } while (t1 - t0 < minDuration);
  89
  90       rate = iters / (t1 - t0);
  91
  92       if (0)
  93          perf_printf("prevRate %f  rate  %f  ratio %f  iters %u\n",
  94                 prevRate, rate, rate/prevRate, iters);
  95
  96       /* Try and speed the search up by skipping a few steps:
  97        */
  98       if (rate > prevRate * 1.6)
  99          subiters *= 8;
 100       else if (rate > prevRate * 1.2)
 101          subiters *= 4;
 102       else if (rate > prevRate * 1.05)
 103          subiters *= 2;
 104       else
 105          break;
 106
 107       prevRate = rate;
 108    }
 109
 110    if (0)
 111       perf_printf("%s returning iters %u  rate %f\n", __FUNCTION__, subiters, rate);
 112    return rate;
 113 }
 114
 115
 116 /* Note static buffer, can only use once per printf.
 117  */
 118 const char *
 119 PerfHumanFloat( double d )
 120 {
 121    static char buf[80];
 122
 123    if (d > 1000000000.0)
 124       snprintf(buf, sizeof(buf), "%.1f billion", d / 1000000000.0);
 125    else if (d > 1000000.0)
 126       snprintf(buf, sizeof(buf), "%.1f million", d / 1000000.0);
 127    else if (d > 1000.0)
 128       snprintf(buf, sizeof(buf), "%.1f thousand", d / 1000.0);
 129    else
 130       snprintf(buf, sizeof(buf), "%.1f", d);
 131
 132    return buf;
 133 }