LLVM OpenMP* Runtime Library
kmp_stats_timing.cpp
1 
5 //===----------------------------------------------------------------------===//
6 //
7 // The LLVM Compiler Infrastructure
8 //
9 // This file is dual licensed under the MIT and the University of Illinois Open
10 // Source Licenses. See LICENSE.txt for details.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include <stdlib.h>
15 #include <unistd.h>
16 
17 #include <iomanip>
18 #include <iostream>
19 #include <sstream>
20 
21 #include "kmp.h"
22 #include "kmp_stats_timing.h"
23 
24 using namespace std;
25 
26 #if KMP_HAVE_TICK_TIME
27 #if KMP_MIC
28 double tsc_tick_count::tick_time() {
29  // pretty bad assumption of 1GHz clock for MIC
30  return 1 / ((double)1000 * 1.e6);
31 }
32 #elif KMP_ARCH_X86 || KMP_ARCH_X86_64
33 #include <string.h>
34 // Extract the value from the CPUID information
35 double tsc_tick_count::tick_time() {
36  static double result = 0.0;
37 
38  if (result == 0.0) {
39  kmp_cpuid_t cpuinfo;
40  char brand[256];
41 
42  __kmp_x86_cpuid(0x80000000, 0, &cpuinfo);
43  memset(brand, 0, sizeof(brand));
44  int ids = cpuinfo.eax;
45 
46  for (unsigned int i = 2; i < (ids ^ 0x80000000) + 2; i++)
47  __kmp_x86_cpuid(i | 0x80000000, 0,
48  (kmp_cpuid_t *)(brand + (i - 2) * sizeof(kmp_cpuid_t)));
49 
50  char *start = &brand[0];
51  for (; *start == ' '; start++)
52  ;
53 
54  char *end = brand + KMP_STRLEN(brand) - 3;
55  uint64_t multiplier;
56 
57  if (*end == 'M')
58  multiplier = 1000LL * 1000LL;
59  else if (*end == 'G')
60  multiplier = 1000LL * 1000LL * 1000LL;
61  else if (*end == 'T')
62  multiplier = 1000LL * 1000LL * 1000LL * 1000LL;
63  else {
64  cout << "Error determining multiplier '" << *end << "'\n";
65  exit(-1);
66  }
67  *end = 0;
68  while (*end != ' ')
69  end--;
70  end++;
71 
72  double freq = strtod(end, &start);
73  if (freq == 0.0) {
74  cout << "Error calculating frequency " << end << "\n";
75  exit(-1);
76  }
77 
78  result = ((double)1.0) / (freq * multiplier);
79  }
80  return result;
81 }
82 #endif
83 #endif
84 
85 static bool useSI = true;
86 
87 // Return a formatted string after normalising the value into
88 // engineering style and using a suitable unit prefix (e.g. ms, us, ns).
89 std::string formatSI(double interval, int width, char unit) {
90  std::stringstream os;
91 
92  if (useSI) {
93  // Preserve accuracy for small numbers, since we only multiply and the
94  // positive powers of ten are precisely representable.
95  static struct {
96  double scale;
97  char prefix;
98  } ranges[] = {{1.e21, 'y'}, {1.e18, 'z'}, {1.e15, 'a'}, {1.e12, 'f'},
99  {1.e9, 'p'}, {1.e6, 'n'}, {1.e3, 'u'}, {1.0, 'm'},
100  {1.e-3, ' '}, {1.e-6, 'k'}, {1.e-9, 'M'}, {1.e-12, 'G'},
101  {1.e-15, 'T'}, {1.e-18, 'P'}, {1.e-21, 'E'}, {1.e-24, 'Z'},
102  {1.e-27, 'Y'}};
103 
104  if (interval == 0.0) {
105  os << std::setw(width - 3) << std::right << "0.00" << std::setw(3)
106  << unit;
107  return os.str();
108  }
109 
110  bool negative = false;
111  if (interval < 0.0) {
112  negative = true;
113  interval = -interval;
114  }
115 
116  for (int i = 0; i < (int)(sizeof(ranges) / sizeof(ranges[0])); i++) {
117  if (interval * ranges[i].scale < 1.e0) {
118  interval = interval * 1000.e0 * ranges[i].scale;
119  os << std::fixed << std::setprecision(2) << std::setw(width - 3)
120  << std::right << (negative ? -interval : interval) << std::setw(2)
121  << ranges[i].prefix << std::setw(1) << unit;
122 
123  return os.str();
124  }
125  }
126  }
127  os << std::setprecision(2) << std::fixed << std::right << std::setw(width - 3)
128  << interval << std::setw(3) << unit;
129 
130  return os.str();
131 }