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