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/IR/InstrTypes.h"
18#include "llvm/IR/Module.h"
19#include "llvm/Support/raw_ostream.h"
20#include <cstdio>
21#include <cstdlib>
22using namespace llvm;
23
24// ByteSwap - Byteswap 'Var' if 'Really' is true.
25//
26static 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
34static 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
41static 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
80const 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//
85ProfileInfoLoader::ProfileInfoLoader(const char *ToolName,
86                                     const std::string &Filename)
87  : Filename(Filename) {
88  FILE *F = fopen(Filename.c_str(), "rb");
89  if (F == 0) {
90    errs() << ToolName << ": Error opening '" << Filename << "': ";
91    perror(0);
92    exit(1);
93  }
94
95  // Keep reading packets until we run out of them.
96  unsigned PacketType;
97  while (fread(&PacketType, sizeof(unsigned), 1, F) == 1) {
98    // If the low eight bits of the packet are zero, we must be dealing with an
99    // endianness mismatch.  Byteswap all words read from the profiling
100    // information.
101    bool ShouldByteSwap = (char)PacketType == 0;
102    PacketType = ByteSwap(PacketType, ShouldByteSwap);
103
104    switch (PacketType) {
105    case ArgumentInfo: {
106      unsigned ArgLength;
107      if (fread(&ArgLength, sizeof(unsigned), 1, F) != 1) {
108        errs() << ToolName << ": arguments packet truncated!\n";
109        perror(0);
110        exit(1);
111      }
112      ArgLength = ByteSwap(ArgLength, ShouldByteSwap);
113
114      // Read in the arguments...
115      std::vector<char> Chars(ArgLength+4);
116
117      if (ArgLength)
118        if (fread(&Chars[0], (ArgLength+3) & ~3, 1, F) != 1) {
119          errs() << ToolName << ": arguments packet truncated!\n";
120          perror(0);
121          exit(1);
122        }
123      CommandLines.push_back(std::string(&Chars[0], &Chars[ArgLength]));
124      break;
125    }
126
127    case FunctionInfo:
128      ReadProfilingBlock(ToolName, F, ShouldByteSwap, FunctionCounts);
129      break;
130
131    case BlockInfo:
132      ReadProfilingBlock(ToolName, F, ShouldByteSwap, BlockCounts);
133      break;
134
135    case EdgeInfo:
136      ReadProfilingBlock(ToolName, F, ShouldByteSwap, EdgeCounts);
137      break;
138
139    case OptEdgeInfo:
140      ReadProfilingBlock(ToolName, F, ShouldByteSwap, OptimalEdgeCounts);
141      break;
142
143    case BBTraceInfo:
144      ReadProfilingBlock(ToolName, F, ShouldByteSwap, BBTrace);
145      break;
146
147    default:
148      errs() << ToolName << ": Unknown packet type #" << PacketType << "!\n";
149      exit(1);
150    }
151  }
152
153  fclose(F);
154}
155
156