lib/Analysis/ProfileInfoLoader.cpp

   1 //===- ProfileInfoLoad.cpp - Load profile information from disk -----------===//
   2 //
   3 //                      The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // The ProfileInfoLoader class is used to load and represent profiling
  11 // information read in from the dump file.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Analysis/ProfileInfoLoader.h"
  16 #include "llvm/Analysis/ProfileInfoTypes.h"
  17 #include "llvm/Module.h"
  18 #include "llvm/InstrTypes.h"
  19 #include "llvm/Support/raw_ostream.h"
  20 #include <cstdio>
  21 #include <cstdlib>
  22 using namespace llvm;
  23
  24 // ByteSwap - Byteswap 'Var' if 'Really' is true.
  25 //
  26 static inline unsigned ByteSwap(unsigned Var, bool Really) {
  27   if (!Really) return Var;
  28   return ((Var & (255U<< 0U)) << 24U) |
  29          ((Var & (255U<< 8U)) <<  8U) |
  30          ((Var & (255U<<16U)) >>  8U) |
  31          ((Var & (255U<<24U)) >> 24U);
  32 }
  33
  34 static unsigned AddCounts(unsigned A, unsigned B) {
  35   // If either value is undefined, use the other.
  36   if (A == ProfileInfoLoader::Uncounted) return B;
  37   if (B == ProfileInfoLoader::Uncounted) return A;
  38   return A + B;
  39 }
  40
  41 static void ReadProfilingBlock(const char *ToolName, FILE *F,
  42                                bool ShouldByteSwap,
  43                                std::vector<unsigned> &Data) {
  44   // Read the number of entries...
  45   unsigned NumEntries;
  46   if (fread(&NumEntries, sizeof(unsigned), 1, F) != 1) {
  47     errs() << ToolName << ": data packet truncated!\n";
  48     perror(0);
  49     exit(1);
  50   }
  51   NumEntries = ByteSwap(NumEntries, ShouldByteSwap);
  52
  53   // Read the counts...
  54   std::vector<unsigned> TempSpace(NumEntries);
  55
  56   // Read in the block of data...
  57   if (fread(&TempSpace[0], sizeof(unsigned)*NumEntries, 1, F) != 1) {
  58     errs() << ToolName << ": data packet truncated!\n";
  59     perror(0);
  60     exit(1);
  61   }
  62
  63   // Make sure we have enough space... The space is initialised to -1 to
  64   // facitiltate the loading of missing values for OptimalEdgeProfiling.
  65   if (Data.size() < NumEntries)
  66     Data.resize(NumEntries, ProfileInfoLoader::Uncounted);
  67
  68   // Accumulate the data we just read into the data.
  69   if (!ShouldByteSwap) {
  70     for (unsigned i = 0; i != NumEntries; ++i) {
  71       Data[i] = AddCounts(TempSpace[i], Data[i]);
  72     }
  73   } else {
  74     for (unsigned i = 0; i != NumEntries; ++i) {
  75       Data[i] = AddCounts(ByteSwap(TempSpace[i], true), Data[i]);
  76     }
  77   }
  78 }
  79
  80 const unsigned ProfileInfoLoader::Uncounted = ~0U;
  81
  82 // ProfileInfoLoader ctor - Read the specified profiling data file, exiting the
  83 // program if the file is invalid or broken.
  84 //
  85 ProfileInfoLoader::ProfileInfoLoader(const char *ToolName,
  86                                      const std::string &Filename,
  87                                      Module &TheModule) :
  88                                      Filename(Filename),
  89                                      M(TheModule), Warned(false) {
  90   FILE *F = fopen(Filename.c_str(), "rb");
  91   if (F == 0) {
  92     errs() << ToolName << ": Error opening '" << Filename << "': ";
  93     perror(0);
  94     exit(1);
  95   }
  96
  97   // Keep reading packets until we run out of them.
  98   unsigned PacketType;
  99   while (fread(&PacketType, sizeof(unsigned), 1, F) == 1) {
 100     // If the low eight bits of the packet are zero, we must be dealing with an
 101     // endianness mismatch.  Byteswap all words read from the profiling
 102     // information.
 103     bool ShouldByteSwap = (char)PacketType == 0;
 104     PacketType = ByteSwap(PacketType, ShouldByteSwap);
 105
 106     switch (PacketType) {
 107     case ArgumentInfo: {
 108       unsigned ArgLength;
 109       if (fread(&ArgLength, sizeof(unsigned), 1, F) != 1) {
 110         errs() << ToolName << ": arguments packet truncated!\n";
 111         perror(0);
 112         exit(1);
 113       }
 114       ArgLength = ByteSwap(ArgLength, ShouldByteSwap);
 115
 116       // Read in the arguments...
 117       std::vector<char> Chars(ArgLength+4);
 118
 119       if (ArgLength)
 120         if (fread(&Chars[0], (ArgLength+3) & ~3, 1, F) != 1) {
 121           errs() << ToolName << ": arguments packet truncated!\n";
 122           perror(0);
 123           exit(1);
 124         }
 125       CommandLines.push_back(std::string(&Chars[0], &Chars[ArgLength]));
 126       break;
 127     }
 128
 129     case FunctionInfo:
 130       ReadProfilingBlock(ToolName, F, ShouldByteSwap, FunctionCounts);
 131       break;
 132
 133     case BlockInfo:
 134       ReadProfilingBlock(ToolName, F, ShouldByteSwap, BlockCounts);
 135       break;
 136
 137     case EdgeInfo:
 138       ReadProfilingBlock(ToolName, F, ShouldByteSwap, EdgeCounts);
 139       break;
 140
 141     case OptEdgeInfo:
 142       ReadProfilingBlock(ToolName, F, ShouldByteSwap, OptimalEdgeCounts);
 143       break;
 144
 145     case BBTraceInfo:
 146       ReadProfilingBlock(ToolName, F, ShouldByteSwap, BBTrace);
 147       break;
 148
 149     default:
 150       errs() << ToolName << ": Unknown packet type #" << PacketType << "!\n";
 151       exit(1);
 152     }
 153   }
 154
 155   fclose(F);
 156 }
 157