xref: /freebsd/contrib/llvm-project/openmp/runtime/src/kmp_stats_timing.cpp (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 }
131