openmp/runtime/src/kmp_stats_timing.cpp

   1 /** @file kmp_stats_timing.cpp
   2  * Timing functions
   3  */
   4
   5 //===----------------------------------------------------------------------===//
   6 //
   7 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   8 // See https://llvm.org/LICENSE.txt for license information.
   9 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15
  16 #include <iomanip>
  17 #include <iostream>
  18 #include <sstream>
  19
  20 #include "kmp.h"
  21 #include "kmp_stats_timing.h"
  22
  23 using namespace std;
  24
  25 #if KMP_HAVE_TICK_TIME
  26 #if KMP_MIC
  27 double tsc_tick_count::tick_time() {
  28   // pretty bad assumption of 1GHz clock for MIC
  29   return 1 / ((double)1000 * 1.e6);
  30 }
  31 #elif KMP_ARCH_X86 || KMP_ARCH_X86_64
  32 #include <string.h>
  33 // Extract the value from the CPUID information
  34 double tsc_tick_count::tick_time() {
  35   static double result = 0.0;
  36
  37   if (result == 0.0) {
  38     kmp_cpuid_t cpuinfo;
  39     char brand[256];
  40
  41     __kmp_x86_cpuid(0x80000000, 0, &cpuinfo);
  42     memset(brand, 0, sizeof(brand));
  43     int ids = cpuinfo.eax;
  44
  45     for (unsigned int i = 2; i < (ids ^ 0x80000000) + 2; i++)
  46       __kmp_x86_cpuid(i | 0x80000000, 0,
  47                       (kmp_cpuid_t *)(brand + (i - 2) * sizeof(kmp_cpuid_t)));
  48
  49     char *start = &brand[0];
  50     for (; *start == ' '; start++)
  51       ;
  52
  53     char *end = brand + KMP_STRLEN(brand) - 3;
  54     uint64_t multiplier;
  55
  56     if (*end == 'M')
  57       multiplier = 1000LL * 1000LL;
  58     else if (*end == 'G')
  59       multiplier = 1000LL * 1000LL * 1000LL;
  60     else if (*end == 'T')
  61       multiplier = 1000LL * 1000LL * 1000LL * 1000LL;
  62     else {
  63       cout << "Error determining multiplier '" << *end << "'\n";
  64       exit(-1);
  65     }
  66     *end = 0;
  67     while (*end != ' ')
  68       end--;
  69     end++;
  70
  71     double freq = strtod(end, &start);
  72     if (freq == 0.0) {
  73       cout << "Error calculating frequency " << end << "\n";
  74       exit(-1);
  75     }
  76
  77     result = ((double)1.0) / (freq * multiplier);
  78   }
  79   return result;
  80 }
  81 #endif
  82 #endif
  83
  84 static bool useSI = true;
  85
  86 // Return a formatted string after normalising the value into
  87 // engineering style and using a suitable unit prefix (e.g. ms, us, ns).
  88 std::string formatSI(double interval, int width, char unit) {
  89   std::stringstream os;
  90
  91   if (useSI) {
  92     // Preserve accuracy for small numbers, since we only multiply and the
  93     // positive powers of ten are precisely representable.
  94     static struct {
  95       double scale;
  96       char prefix;
  97     } ranges[] = {{1.e21, 'y'},  {1.e18, 'z'},  {1.e15, 'a'},  {1.e12, 'f'},
  98                   {1.e9, 'p'},   {1.e6, 'n'},   {1.e3, 'u'},   {1.0, 'm'},
  99                   {1.e-3, ' '},  {1.e-6, 'k'},  {1.e-9, 'M'},  {1.e-12, 'G'},
 100                   {1.e-15, 'T'}, {1.e-18, 'P'}, {1.e-21, 'E'}, {1.e-24, 'Z'},
 101                   {1.e-27, 'Y'}};
 102
 103     if (interval == 0.0) {
 104       os << std::setw(width - 3) << std::right << "0.00" << std::setw(3)
 105          << unit;
 106       return os.str();
 107     }
 108
 109     bool negative = false;
 110     if (interval < 0.0) {
 111       negative = true;
 112       interval = -interval;
 113     }
 114
 115     for (int i = 0; i < (int)(sizeof(ranges) / sizeof(ranges[0])); i++) {
 116       if (interval * ranges[i].scale < 1.e0) {
 117         interval = interval * 1000.e0 * ranges[i].scale;
 118         os << std::fixed << std::setprecision(2) << std::setw(width - 3)
 119            << std::right << (negative ? -interval : interval) << std::setw(2)
 120            << ranges[i].prefix << std::setw(1) << unit;
 121
 122         return os.str();
 123       }
 124     }
 125   }
 126   os << std::setprecision(2) << std::fixed << std::right << std::setw(width - 3)
 127      << interval << std::setw(3) << unit;
 128
 129   return os.str();
 130 }