Factor this code out of llvm-prof

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11314 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 180 insertions, 0 deletions

diff --git a/lib/Analysis/ProfileInfoLoader.cpp b/lib/Analysis/ProfileInfoLoader.cpp
new file mode 100644
index 0000000000..4ea4ca3b18
--- /dev/null
+++ b/lib/Analysis/ProfileInfoLoader.cpp
@@ -0,0 +1,180 @@
+//===- ProfileInfoLoad.cpp - Load profile information from disk -----------===//
+// 
+//                      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.
+// 
+//===----------------------------------------------------------------------===//
+//
+// The ProfileInfoLoader class is used to load and represent profiling
+// information read in from the dump file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/ProfileInfoLoader.h"
+#include "llvm/Module.h"
+#include <cstdio>
+using namespace llvm;
+
+enum ProfilingType {
+  ArgumentInfo = 1,   // The command line argument block
+  FunctionInfo = 2,   // Function profiling information
+  BlockInfo    = 3,   // Block profiling information
+};
+
+// ByteSwap - Byteswap 'Var' if 'Really' is true.
+//
+static inline unsigned ByteSwap(unsigned Var, bool Really) {
+  if (!Really) return Var;
+  return ((Var & (255<< 0)) << 24) | 
+         ((Var & (255<< 8)) <<  8) | 
+         ((Var & (255<<16)) >>  8) | 
+         ((Var & (255<<24)) >> 24);
+}
+
+static void ReadProfilingBlock(const char *ToolName, FILE *F,
+                               bool ShouldByteSwap,
+                               std::vector<unsigned> &Data) {
+  // Read the number of entries...
+  unsigned NumEntries;
+  if (fread(&NumEntries, sizeof(unsigned), 1, F) != 1) {
+    std::cerr << ToolName << ": data packet truncated!\n";
+    perror(0);
+    exit(1);
+  }
+  NumEntries = ByteSwap(NumEntries, ShouldByteSwap);
+
+  // Read the counts...
+  std::vector<unsigned> TempSpace(NumEntries);
+
+  // Read in the block of data...
+  if (fread(&TempSpace[0], sizeof(unsigned)*NumEntries, 1, F) != 1) {
+    std::cerr << ToolName << ": data packet truncated!\n";
+    perror(0);
+    exit(1);
+  }
+
+  // Make sure we have enough space...
+  if (Data.size() < NumEntries)
+    Data.resize(NumEntries);
+  
+  // Accumulate the data we just read into the data.
+  if (!ShouldByteSwap) {
+    for (unsigned i = 0; i != NumEntries; ++i)
+      Data[i] += TempSpace[i];
+  } else {
+    for (unsigned i = 0; i != NumEntries; ++i)
+      Data[i] += ByteSwap(TempSpace[i], true);
+  }
+}
+
+// ProfileInfoLoader ctor - Read the specified profiling data file, exiting the
+// program if the file is invalid or broken.
+//
+ProfileInfoLoader::ProfileInfoLoader(const char *ToolName,
+                                     const std::string &Filename,
+                                     Module &TheModule) : M(TheModule) {
+  FILE *F = fopen(Filename.c_str(), "r");
+  if (F == 0) {
+    std::cerr << ToolName << ": Error opening '" << Filename << ": ";
+    perror(0);
+    exit(1);
+  }
+
+  // Keep reading packets until we run out of them.
+  unsigned PacketType;
+  while (fread(&PacketType, sizeof(unsigned), 1, F) == 1) {
+    // If the low eight bits of the packet are zero, we must be dealing with an
+    // endianness mismatch.  Byteswap all words read from the profiling
+    // information.
+    bool ShouldByteSwap = (char)PacketType == 0;
+    PacketType = ByteSwap(PacketType, ShouldByteSwap);
+
+    switch (PacketType) {
+    case ArgumentInfo: {
+      unsigned ArgLength;
+      if (fread(&ArgLength, sizeof(unsigned), 1, F) != 1) {
+        std::cerr << ToolName << ": arguments packet truncated!\n";
+        perror(0);
+        exit(1);
+      }
+      ArgLength = ByteSwap(ArgLength, ShouldByteSwap);
+
+      // Read in the arguments...
+      std::vector<char> Chars(ArgLength+4);
+
+      if (ArgLength)
+        if (fread(&Chars[0], (ArgLength+3) & ~3, 1, F) != 1) {
+          std::cerr << ToolName << ": arguments packet truncated!\n";
+          perror(0);
+          exit(1);
+        }
+      CommandLines.push_back(std::string(&Chars[0], &Chars[ArgLength]));
+      break;
+    }
+      
+    case FunctionInfo:
+      ReadProfilingBlock(ToolName, F, ShouldByteSwap, FunctionCounts);
+      break;
+      
+    case BlockInfo:
+      ReadProfilingBlock(ToolName, F, ShouldByteSwap, BlockCounts);
+      break;
+
+    default:
+      std::cerr << ToolName << ": Unknown packet type #" << PacketType << "!\n";
+      exit(1);
+    }
+  }
+  
+  fclose(F);
+}
+
+
+// getFunctionCounts - This method is used by consumers of function counting
+// information.  If we do not directly have function count information, we
+// compute it from other, more refined, types of profile information.
+//
+void ProfileInfoLoader::getFunctionCounts(std::vector<std::pair<Function*,
+                                                      unsigned> > &Counts) {
+  if (FunctionCounts.empty()) {
+    // Synthesize function frequency information from the number of times their
+    // entry blocks were executed.
+    std::vector<std::pair<BasicBlock*, unsigned> > BlockCounts;
+    getBlockCounts(BlockCounts);
+
+    for (unsigned i = 0, e = BlockCounts.size(); i != e; ++i)
+      if (&BlockCounts[i].first->getParent()->front() == BlockCounts[i].first)
+        Counts.push_back(std::make_pair(BlockCounts[i].first->getParent(),
+                                        BlockCounts[i].second));
+    return;
+  }
+  
+  unsigned Counter = 0;
+  for (Module::iterator I = M.begin(), E = M.end();
+       I != E && Counter != FunctionCounts.size(); ++I)
+    if (!I->isExternal())
+      Counts.push_back(std::make_pair(I, FunctionCounts[Counter++]));
+}
+
+// getBlockCounts - This method is used by consumers of block counting
+// information.  If we do not directly have block count information, we
+// compute it from other, more refined, types of profile information.
+//
+void ProfileInfoLoader::getBlockCounts(std::vector<std::pair<BasicBlock*,
+                                                         unsigned> > &Counts) {
+  if (BlockCounts.empty()) {
+    std::cerr << "Block counts not available, and no synthesis "
+              << "is implemented yet!\n";
+    return;
+  }
+
+  unsigned Counter = 0;
+  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F)
+    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+      Counts.push_back(std::make_pair(BB, BlockCounts[Counter++]));
+      if (Counter == BlockCounts.size())
+        return;
+    }
+}