1 files changed, 126 insertions, 0 deletions
diff --git a/lib/Transforms/Instrumentation/BlockProfiling.cpp b/lib/Transforms/Instrumentation/BlockProfiling.cpp
new file mode 100644
index 0000000..2bd9809
--- /dev/null
+++ b/lib/Transforms/Instrumentation/BlockProfiling.cpp
@@ -0,0 +1,126 @@
+//===- BlockProfiling.cpp - Insert counters for block profiling -----------===//
+//
+//                      The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass instruments the specified program with counters for basic block or
+// function profiling.  This is the most basic form of profiling, which can tell
+// which blocks are hot, but cannot reliably detect hot paths through the CFG.
+// Block profiling counts the number of times each basic block executes, and
+// function profiling counts the number of times each function is called.
+//
+// Note that this implementation is very naive.  Control equivalent regions of
+// the CFG should not require duplicate counters, but we do put duplicate
+// counters in.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Streams.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "RSProfiling.h"
+#include "ProfilingUtils.h"
+using namespace llvm;
+
+namespace {
+  class VISIBILITY_HIDDEN FunctionProfiler : public RSProfilers_std {
+  public:
+    static char ID;
+    bool runOnModule(Module &M);
+  };
+}
+
+char FunctionProfiler::ID = 0;
+
+static RegisterPass<FunctionProfiler>
+X("insert-function-profiling",
+  "Insert instrumentation for function profiling");
+static RegisterAnalysisGroup<RSProfilers> XG(X);
+
+ModulePass *llvm::createFunctionProfilerPass() {
+  return new FunctionProfiler();
+}
+
+bool FunctionProfiler::runOnModule(Module &M) {
+  Function *Main = M.getFunction("main");
+  if (Main == 0) {
+    cerr << "WARNING: cannot insert function profiling into a module"
+         << " with no main function!\n";
+    return false;  // No main, no instrumentation!
+  }
+
+  unsigned NumFunctions = 0;
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (!I->isDeclaration())
+      ++NumFunctions;
+
+  const Type *ATy = ArrayType::get(Type::Int32Ty, NumFunctions);
+  GlobalVariable *Counters =
+    new GlobalVariable(ATy, false, GlobalValue::InternalLinkage,
+                       Constant::getNullValue(ATy), "FuncProfCounters", &M);
+
+  // Instrument all of the functions...
+  unsigned i = 0;
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (!I->isDeclaration())
+      // Insert counter at the start of the function
+      IncrementCounterInBlock(&I->getEntryBlock(), i++, Counters);
+
+  // Add the initialization call to main.
+  InsertProfilingInitCall(Main, "llvm_start_func_profiling", Counters);
+  return true;
+}
+
+
+namespace {
+  class BlockProfiler : public RSProfilers_std {
+    bool runOnModule(Module &M);
+  public:
+    static char ID;
+  };
+}
+
+char BlockProfiler::ID = 0;
+static RegisterPass<BlockProfiler>
+Y("insert-block-profiling", "Insert instrumentation for block profiling");
+static RegisterAnalysisGroup<RSProfilers> YG(Y);
+
+ModulePass *llvm::createBlockProfilerPass() { return new BlockProfiler(); }
+
+bool BlockProfiler::runOnModule(Module &M) {
+  Function *Main = M.getFunction("main");
+  if (Main == 0) {
+    cerr << "WARNING: cannot insert block profiling into a module"
+         << " with no main function!\n";
+    return false;  // No main, no instrumentation!
+  }
+
+  unsigned NumBlocks = 0;
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    NumBlocks += I->size();
+
+  const Type *ATy = ArrayType::get(Type::Int32Ty, NumBlocks);
+  GlobalVariable *Counters =
+    new GlobalVariable(ATy, false, GlobalValue::InternalLinkage,
+                       Constant::getNullValue(ATy), "BlockProfCounters", &M);
+
+  // Instrument all of the blocks...
+  unsigned i = 0;
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    for (Function::iterator BB = I->begin(), E = I->end(); BB != E; ++BB)
+      // Insert counter at the start of the block
+      IncrementCounterInBlock(BB, i++, Counters);
+
+  // Add the initialization call to main.
+  InsertProfilingInitCall(Main, "llvm_start_block_profiling", Counters);
+  return true;
+}
+