1 /** @file kmp_stats_timing.cpp
2  * Timing functions
3  */
4 
5 
6 //===----------------------------------------------------------------------===//
7 //
8 //                     The LLVM Compiler Infrastructure
9 //
10 // This file is dual licensed under the MIT and the University of Illinois Open
11 // Source Licenses. See LICENSE.txt for details.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 
16 #include <stdlib.h>
17 #include <unistd.h>
18 
19 #include <iostream>
20 #include <iomanip>
21 #include <sstream>
22 
23 #include "kmp.h"
24 #include "kmp_stats_timing.h"
25 
26 using namespace std;
27 
28 #if KMP_HAVE_TICK_TIME
29 # if KMP_MIC
30 double tsc_tick_count::tick_time()
31 {
32     // pretty bad assumption of 1GHz clock for MIC
33     return 1/((double)1000*1.e6);
34 }
35 # elif KMP_ARCH_X86 || KMP_ARCH_X86_64
36 #  include <string.h>
37 // Extract the value from the CPUID information
38 double tsc_tick_count::tick_time()
39 {
40     static double result = 0.0;
41 
42     if (result == 0.0)
43     {
44         kmp_cpuid_t cpuinfo;
45         char brand[256];
46 
47         __kmp_x86_cpuid(0x80000000, 0, &cpuinfo);
48         memset(brand, 0, sizeof(brand));
49         int ids = cpuinfo.eax;
50 
51         for (unsigned int i=2; i<(ids^0x80000000)+2; i++)
52             __kmp_x86_cpuid(i | 0x80000000, 0, (kmp_cpuid_t*)(brand+(i-2)*sizeof(kmp_cpuid_t)));
53 
54         char * start = &brand[0];
55         for (;*start == ' '; start++)
56             ;
57 
58         char * end = brand + KMP_STRLEN(brand) - 3;
59         uint64_t multiplier;
60 
61         if (*end == 'M') multiplier = 1000LL*1000LL;
62         else if (*end == 'G') multiplier = 1000LL*1000LL*1000LL;
63         else if (*end == 'T') multiplier = 1000LL*1000LL*1000LL*1000LL;
64         else
65         {
66             cout << "Error determining multiplier '" << *end << "'\n";
67             exit (-1);
68         }
69         *end = 0;
70         while (*end != ' ') end--;
71         end++;
72 
73         double freq = strtod(end, &start);
74         if (freq == 0.0)
75         {
76             cout << "Error calculating frequency " <<  end << "\n";
77             exit (-1);
78         }
79 
80         result = ((double)1.0)/(freq * multiplier);
81     }
82     return result;
83 }
84 # endif
85 #endif
86 
87 static bool useSI = true;
88 
89 // Return a formatted string after normalising the value into
90 // engineering style and using a suitable unit prefix (e.g. ms, us, ns).
91 std::string formatSI(double interval, int width, char unit)
92 {
93     std::stringstream os;
94 
95     if (useSI)
96     {
97         // Preserve accuracy for small numbers, since we only multiply and the positive powers
98         // of ten are precisely representable.
99         static struct { double scale; char prefix; } ranges[] = {
100             {1.e12,'f'},
101             {1.e9, 'p'},
102             {1.e6, 'n'},
103             {1.e3, 'u'},
104             {1.0,  'm'},
105             {1.e-3,' '},
106             {1.e-6,'k'},
107             {1.e-9,'M'},
108             {1.e-12,'G'},
109             {1.e-15,'T'},
110             {1.e-18,'P'},
111             {1.e-21,'E'},
112             {1.e-24,'Z'},
113             {1.e-27,'Y'}
114         };
115 
116         if (interval == 0.0)
117         {
118             os << std::setw(width-3) << std::right << "0.00" << std::setw(3) << unit;
119             return os.str();
120         }
121 
122         bool negative = false;
123         if (interval < 0.0)
124         {
125             negative = true;
126             interval = -interval;
127         }
128 
129         for (int i=0; i<(int)(sizeof(ranges)/sizeof(ranges[0])); i++)
130         {
131             if (interval*ranges[i].scale < 1.e0)
132             {
133                 interval = interval * 1000.e0 * ranges[i].scale;
134                 os << std::fixed << std::setprecision(2) << std::setw(width-3) << std::right <<
135                     (negative ? -interval : interval) << std::setw(2) << ranges[i].prefix << std::setw(1) << unit;
136 
137                 return os.str();
138             }
139         }
140     }
141     os << std::setprecision(2) << std::fixed << std::right << std::setw(width-3) << interval << std::setw(3) << unit;
142 
143     return os.str();
144 }
145