1 //===- fpcmp.cpp - A fuzzy "cmp" that permits floating point noise --------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // fpcmp is a tool that basically works like the 'cmp' tool, except that it can
11 // tolerate errors due to floating point noise, with the -r option.
13 //===----------------------------------------------------------------------===//
15 #include "Support/CommandLine.h"
16 #include "Support/FileUtilities.h"
17 #include "Config/fcntl.h"
18 #include "Config/sys/mman.h"
26 File1(cl::Positional, cl::desc("<input file #1>"), cl::Required);
28 File2(cl::Positional, cl::desc("<input file #2>"), cl::Required);
31 RelTolerance("r", cl::desc("Relative error tolerated"), cl::init(0));
33 AbsTolerance("a", cl::desc("Absolute error tolerated"), cl::init(0));
37 /// OpenFile - mmap the specified file into the address space for reading, and
38 /// return the length and address of the buffer.
39 static void OpenFile(const std::string &Filename, unsigned &Len, char* &BufPtr){
40 BufPtr = (char*)ReadFileIntoAddressSpace(Filename, Len);
42 std::cerr << "Error: cannot open file '" << Filename << "'\n";
47 static bool isNumberChar(char C) {
49 case '0': case '1': case '2': case '3': case '4':
50 case '5': case '6': case '7': case '8': case '9':
51 case '.': case '+': case '-':
53 case 'E': return true;
54 default: return false;
58 static char *BackupNumber(char *Pos, char *FirstChar) {
59 while (Pos > FirstChar && isNumberChar(Pos[-1]))
64 static void CompareNumbers(char *&F1P, char *&F2P, char *F1End, char *F2End) {
65 char *F1NumEnd, *F2NumEnd;
66 double V1 = strtod(F1P, &F1NumEnd);
67 double V2 = strtod(F2P, &F2NumEnd);
69 if (F1NumEnd == F1P || F2NumEnd == F2P) {
70 std::cerr << "Comparison failed, not a numeric difference.\n";
74 // Check to see if these are inside the absolute tolerance
75 if (AbsTolerance < std::abs(V1-V2)) {
76 // Nope, check the relative tolerance...
79 Diff = std::abs(V1/V2 - 1.0);
81 Diff = std::abs(V2/V1 - 1.0);
83 Diff = 0; // Both zero.
84 if (Diff > RelTolerance) {
85 std::cerr << "Compared: " << V1 << " and " << V2 << ": diff = "
87 std::cerr << "Out of tolerance: rel/abs: " << RelTolerance
88 << "/" << AbsTolerance << "\n";
93 // Otherwise, advance our read pointers to the end of the numbers.
94 F1P = F1NumEnd; F2P = F2NumEnd;
98 int main(int argc, char **argv) {
99 cl::ParseCommandLineOptions(argc, argv);
101 // mmap in the files.
102 unsigned File1Len, File2Len;
103 char *File1Start, *File2Start;
104 OpenFile(File1, File1Len, File1Start);
105 OpenFile(File2, File2Len, File2Start);
107 // Okay, now that we opened the files, scan them for the first difference.
108 char *File1End = File1Start+File1Len;
109 char *File2End = File2Start+File2Len;
110 char *F1P = File1Start;
111 char *F2P = File2Start;
114 // Scan for the end of file or first difference.
115 while (F1P < File1End && F2P < File2End && *F1P == *F2P)
118 if (F1P >= File1End || F2P >= File2End) break;
120 // Okay, we must have found a difference. Backup to the start of the
121 // current number each stream is at so that we can compare from the
123 F1P = BackupNumber(F1P, File1Start);
124 F2P = BackupNumber(F2P, File2Start);
126 // Now that we are at the start of the numbers, compare them, exiting if
128 CompareNumbers(F1P, F2P, File1End, File2End);
131 // Okay, we reached the end of file. If both files are at the end, we
133 if (F1P >= File1End && F2P >= File2End) return 0;
135 // Otherwise, we might have run off the end due to a number, backup and retry.
136 F1P = BackupNumber(F1P, File1Start);
137 F2P = BackupNumber(F2P, File2Start);
139 // Now that we are at the start of the numbers, compare them, exiting if
141 CompareNumbers(F1P, F2P, File1End, File2End);
143 // If we found the end, we succeeded.
144 if (F1P >= File1End && F2P >= File2End) return 0;