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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 //
ByteSwap(unsigned Var,bool Really)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 
AddCounts(unsigned A,unsigned B)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 
ReadProfilingBlock(const char * ToolName,FILE * F,bool ShouldByteSwap,std::vector<unsigned> & Data)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 //
ProfileInfoLoader(const char * ToolName,const std::string & Filename,Module & TheModule)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 
158