//===- fpcmp.cpp - A fuzzy "cmp" that permits floating point noise --------===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // fpcmp is a tool that basically works like the 'cmp' tool, except that it can // tolerate errors due to floating point noise, with the -r option. // //===----------------------------------------------------------------------===// #include "Support/CommandLine.h" #include "Support/FileUtilities.h" #include "Config/fcntl.h" #include "Config/sys/mman.h" #include #include using namespace llvm; namespace { cl::opt File1(cl::Positional, cl::desc(""), cl::Required); cl::opt File2(cl::Positional, cl::desc(""), cl::Required); cl::opt RelTolerance("r", cl::desc("Relative error tolerated"), cl::init(0)); cl::opt AbsTolerance("a", cl::desc("Absolute error tolerated"), cl::init(0)); } /// OpenFile - mmap the specified file into the address space for reading, and /// return the length and address of the buffer. static void OpenFile(const std::string &Filename, unsigned &Len, char* &BufPtr){ int FD = open(Filename.c_str(), O_RDONLY); if (FD == -1 || (Len = getFileSize(Filename)) == ~0U) { std::cerr << "Error: cannot open file '" << Filename << "'\n"; exit(2); } // mmap in the file all at once... BufPtr = (char*)mmap(0, Len, PROT_READ, MAP_PRIVATE, FD, 0); if (BufPtr == (char*)MAP_FAILED) { std::cerr << "Error: cannot open file '" << Filename << "'\n"; exit(2); } } static bool isNumberChar(char C) { switch (C) { case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case '.': case 'e': case 'E': return true; default: return false; } } static char *BackupNumber(char *Pos, char *FirstChar) { while (Pos < FirstChar && isNumberChar(Pos[-1])) --Pos; return Pos; } static void CompareNumbers(char *&F1P, char *&F2P, char *F1End, char *F2End) { char *F1NumEnd, *F2NumEnd; double V1 = strtod(F1P, &F1NumEnd); double V2 = strtod(F2P, &F2NumEnd); if (F1NumEnd == F1P || F2NumEnd == F2P) { std::cerr << "Comparison failed, not a numeric difference.\n"; exit(1); } // Check to see if these are inside the absolute tolerance if (AbsTolerance < std::abs(V1-V2)) { // Nope, check the relative tolerance... double Diff; if (V2) Diff = std::abs(V1/V2 - 1.0); else if (V1) Diff = std::abs(V2/V1 - 1.0); else Diff = 0; // Both zero. if (Diff > RelTolerance) { std::cerr << "Compared: " << V1 << " and " << V2 << ": diff = " << Diff << "\n"; std::cerr << "Out of tolerence: rel/abs: " << RelTolerance << "/" << AbsTolerance << "\n"; exit(1); } } // Otherwise, advance our read pointers to the end of the numbers. F1P = F1NumEnd; F2P = F2NumEnd; } int main(int argc, char **argv) { cl::ParseCommandLineOptions(argc, argv); // mmap in the files. unsigned File1Len, File2Len; char *File1Start, *File2Start; OpenFile(File1, File1Len, File1Start); OpenFile(File2, File2Len, File2Start); // Okay, now that we opened the files, scan them for the first difference. char *File1End = File1Start+File1Len; char *File2End = File2Start+File2Len; char *F1P = File1Start; char *F2P = File2Start; while (1) { // Scan for the end of file or first difference. while (F1P < File1End && F2P < File2End && *F1P == *F2P) ++F1P, ++F2P; if (F1P >= File1End || F2P >= File2End) break; // Okay, we must have found a difference. Backup to the start of the // current number each stream is at so that we can compare from the // beginning. F1P = BackupNumber(F1P, File1Start); F2P = BackupNumber(F2P, File2Start); // Now that we are at the start of the numbers, compare them, exiting if // they don't match. CompareNumbers(F1P, F2P, File1End, File2End); } // Okay, we reached the end of file. If both files are at the end, we // succeeded. if (F1P >= File1End && F2P >= File2End) return 0; // Otherwise, we might have run off the end due to a number, backup and retry. F1P = BackupNumber(F1P, File1Start); F2P = BackupNumber(F2P, File2Start); // Now that we are at the start of the numbers, compare them, exiting if // they don't match. CompareNumbers(F1P, F2P, File1End, File2End); // If we found the end, we succeeded. if (F1P >= File1End && F2P >= File2End) return 0; return 1; }