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
23using namespace std;
24
25#if KMP_HAVE_TICK_TIME
26#if KMP_MIC
27double 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
34double 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
84static 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).
88std::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}
131