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 "llvm/Support/CommandLine.h"
16 #include "llvm/System/MappedFile.h"
24 File1(cl::Positional, cl::desc("<input file #1>"), cl::Required);
26 File2(cl::Positional, cl::desc("<input file #2>"), cl::Required);
29 RelTolerance("r", cl::desc("Relative error tolerated"), cl::init(0));
31 AbsTolerance("a", cl::desc("Absolute error tolerated"), cl::init(0));
34 static bool isNumberChar(char C) {
36 case '0': case '1': case '2': case '3': case '4':
37 case '5': case '6': case '7': case '8': case '9':
38 case '.': case '+': case '-':
40 case 'E': return true;
41 default: return false;
45 static char *BackupNumber(char *Pos, char *FirstChar) {
46 // If we didn't stop in the middle of a number, don't backup.
47 if (!isNumberChar(*Pos)) return Pos;
49 // Otherwise, return to the start of the number.
50 while (Pos > FirstChar && isNumberChar(Pos[-1]))
55 static void CompareNumbers(char *&F1P, char *&F2P, char *F1End, char *F2End) {
56 char *F1NumEnd, *F2NumEnd;
57 double V1 = 0.0, V2 = 0.0;
58 // If we stop on numbers, compare their difference.
59 if (isNumberChar(*F1P) && isNumberChar(*F2P)) {
60 V1 = strtod(F1P, &F1NumEnd);
61 V2 = strtod(F2P, &F2NumEnd);
63 // Otherwise, the diff failed.
68 if (F1NumEnd == F1P || F2NumEnd == F2P) {
69 std::cerr << "Comparison failed, not a numeric difference.\n";
73 // Check to see if these are inside the absolute tolerance
74 if (AbsTolerance < std::abs(V1-V2)) {
75 // Nope, check the relative tolerance...
78 Diff = std::abs(V1/V2 - 1.0);
80 Diff = std::abs(V2/V1 - 1.0);
82 Diff = 0; // Both zero.
83 if (Diff > RelTolerance) {
84 std::cerr << "Compared: " << V1 << " and " << V2 << ": diff = "
86 std::cerr << "Out of tolerance: rel/abs: " << RelTolerance
87 << "/" << AbsTolerance << "\n";
92 // Otherwise, advance our read pointers to the end of the numbers.
93 F1P = F1NumEnd; F2P = F2NumEnd;
96 // PadFileIfNeeded - If the files are not identical, we will have to be doing
97 // numeric comparisons in here. There are bad cases involved where we (i.e.,
98 // strtod) might run off the beginning or end of the file if it starts or ends
99 // with a number. Because of this, if needed, we pad the file so that it starts
100 // and ends with a null character.
101 static void PadFileIfNeeded(char *&FileStart, char *&FileEnd, char *&FP) {
102 if (isNumberChar(FileStart[0]) || isNumberChar(FileEnd[-1])) {
103 unsigned FileLen = FileEnd-FileStart;
104 char *NewFile = new char[FileLen+2];
105 NewFile[0] = 0; // Add null padding
106 NewFile[FileLen+1] = 0; // Add null padding
107 memcpy(NewFile+1, FileStart, FileLen);
108 FP = NewFile+(FP-FileStart)+1;
109 FileStart = NewFile+1;
110 FileEnd = FileStart+FileLen;
114 int main(int argc, char **argv) {
115 cl::ParseCommandLineOptions(argc, argv);
118 // map in the files into memory
119 sys::Path F1Path(File1);
120 sys::Path F2Path(File2);
121 sys::MappedFile F1 ( F1Path );
122 sys::MappedFile F2 ( F2Path );
126 // Okay, now that we opened the files, scan them for the first difference.
127 char *File1Start = F1.charBase();
128 char *File2Start = F2.charBase();
129 char *File1End = File1Start+F1.size();
130 char *File2End = File2Start+F2.size();
131 char *F1P = File1Start;
132 char *F2P = File2Start;
134 // Scan for the end of file or first difference.
135 while (F1P < File1End && F2P < File2End && *F1P == *F2P)
138 // Common case: identifical files.
139 if (F1P == File1End && F2P == File2End) return 0;
141 // If the files need padding, do so now.
142 PadFileIfNeeded(File1Start, File1End, F1P);
143 PadFileIfNeeded(File2Start, File2End, F2P);
146 // Scan for the end of file or next difference.
147 while (F1P < File1End && F2P < File2End && *F1P == *F2P)
150 if (F1P >= File1End || F2P >= File2End) break;
152 // Okay, we must have found a difference. Backup to the start of the
153 // current number each stream is at so that we can compare from the
155 F1P = BackupNumber(F1P, File1Start);
156 F2P = BackupNumber(F2P, File2Start);
158 // Now that we are at the start of the numbers, compare them, exiting if
160 CompareNumbers(F1P, F2P, File1End, File2End);
163 // Okay, we reached the end of file. If both files are at the end, we
165 bool F1AtEnd = F1P >= File1End;
166 bool F2AtEnd = F2P >= File2End;
167 if (F1AtEnd & F2AtEnd) return 0;
169 // Else, we might have run off the end due to a number: backup and retry.
170 if (F1AtEnd && isNumberChar(F1P[-1])) --F1P;
171 if (F2AtEnd && isNumberChar(F2P[-1])) --F2P;
172 F1P = BackupNumber(F1P, File1Start);
173 F2P = BackupNumber(F2P, File2Start);
175 // Now that we are at the start of the numbers, compare them, exiting if
177 CompareNumbers(F1P, F2P, File1End, File2End);
179 // If we found the end, we succeeded.
180 if (F1P >= File1End && F2P >= File2End) return 0;
182 } catch (const std::string& msg) {
183 std::cerr << argv[0] << ": error: " << msg << "\n";