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
tick_time()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
tick_time()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).
formatSI(double interval,int width,char unit)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