[llvm-commits] CVS: llvm/utils/fpcmp/Makefile fpcmp.cpp

[Chris Lattner]

Changes in directory llvm/utils/fpcmp:

Makefile added (r1.1)
fpcmp.cpp added (r1.1)

---
Log message:

Okay, spiff is completely incapable of handling files of nontrivial size.
Here is a simple minimal program that does what we want.  Instead of taking
minutes to compare mesa's output, and crashing on binary files (like spiff 
does), this take < .02s in the common case and doesn't crash.


---
Diffs of the changes:  (+171 -0)

Index: llvm/utils/fpcmp/Makefile
diff -c /dev/null llvm/utils/fpcmp/Makefile:1.1
*** /dev/null	Tue Apr 13 15:55:59 2004
--- llvm/utils/fpcmp/Makefile	Tue Apr 13 15:55:49 2004
***************
*** 0 ****
--- 1,15 ----
+ ##===- utils/fpcmp/Makefile --------------------------------*- Makefile -*-===##
+ # 
+ #                     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.
+ # 
+ ##===----------------------------------------------------------------------===##
+ 
+ LEVEL = ../..
+ TOOLNAME = fpcmp
+ USEDLIBS = support.a
+ 
+ include $(LEVEL)/Makefile.common
+ 


Index: llvm/utils/fpcmp/fpcmp.cpp
diff -c /dev/null llvm/utils/fpcmp/fpcmp.cpp:1.1
*** /dev/null	Tue Apr 13 15:55:59 2004
--- llvm/utils/fpcmp/fpcmp.cpp	Tue Apr 13 15:55:49 2004
***************
*** 0 ****
--- 1,156 ----
+ //===- 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 <iostream>
+ #include <cmath>
+ 
+ using namespace llvm;
+ 
+ namespace {
+   cl::opt<std::string>
+   File1(cl::Positional, cl::desc("<input file #1>"), cl::Required);
+   cl::opt<std::string>
+   File2(cl::Positional, cl::desc("<input file #2>"), cl::Required);
+ 
+   cl::opt<double>
+   RelTolerance("r", cl::desc("Relative error tolerated"), cl::init(0));
+   cl::opt<double>
+   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;
+ }
+