Split utility functions out of BlockProfiling.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12224 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 102 insertions, 0 deletions

diff --git a/lib/Transforms/Instrumentation/ProfilingUtils.cpp b/lib/Transforms/Instrumentation/ProfilingUtils.cpp
new file mode 100644
index 0000000000..5baefe9b36
--- /dev/null
+++ b/lib/Transforms/Instrumentation/ProfilingUtils.cpp
@@ -0,0 +1,102 @@
+//===- ProfilingUtils.cpp - Helper functions shared by profilers ----------===//
+// 
+//                     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.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This files implements a few helper functions which are used by profile
+// instrumentation code to instrument the code.  This allows the profiler pass
+// to worry about *what* to insert, and these functions take care of *how* to do
+// it.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ProfilingUtils.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Instructions.h"
+#include "llvm/Module.h"
+
+void llvm::InsertProfilingInitCall(Function *MainFn, const char *FnName,
+                                   GlobalValue *Array) {
+  const Type *ArgVTy = PointerType::get(PointerType::get(Type::SByteTy));
+  const Type *UIntPtr = PointerType::get(Type::UIntTy);
+  Module &M = *MainFn->getParent();
+  Function *InitFn = M.getOrInsertFunction(FnName, Type::IntTy, Type::IntTy,
+                                           ArgVTy, UIntPtr, Type::UIntTy, 0);
+
+  // This could force argc and argv into programs that wouldn't otherwise have
+  // them, but instead we just pass null values in.
+  std::vector<Value*> Args(4);
+  Args[0] = Constant::getNullValue(Type::IntTy);
+  Args[1] = Constant::getNullValue(ArgVTy);
+
+  // Skip over any allocas in the entry block.
+  BasicBlock *Entry = MainFn->begin();
+  BasicBlock::iterator InsertPos = Entry->begin();
+  while (isa<AllocaInst>(InsertPos)) ++InsertPos;
+
+  ConstantPointerRef *ArrayCPR = ConstantPointerRef::get(Array);
+  std::vector<Constant*> GEPIndices(2, Constant::getNullValue(Type::LongTy));
+  Args[2] = ConstantExpr::getGetElementPtr(ArrayCPR, GEPIndices);
+  
+  unsigned NumElements =
+    cast<ArrayType>(Array->getType()->getElementType())->getNumElements();
+  Args[3] = ConstantUInt::get(Type::UIntTy, NumElements);
+  
+  Instruction *InitCall = new CallInst(InitFn, Args, "newargc", InsertPos);
+
+  // If argc or argv are not available in main, just pass null values in.
+  Function::aiterator AI;
+  switch (MainFn->asize()) {
+  default:
+  case 2:
+    AI = MainFn->abegin(); ++AI;
+    if (AI->getType() != ArgVTy) {
+      InitCall->setOperand(2, new CastInst(AI, ArgVTy, "argv.cast", InitCall));
+    } else {
+      InitCall->setOperand(2, AI);
+    }
+
+  case 1:
+    AI = MainFn->abegin();
+    // If the program looked at argc, have it look at the return value of the
+    // init call instead.
+    if (AI->getType() != Type::IntTy) {
+      if (!AI->use_empty())
+        AI->replaceAllUsesWith(new CastInst(InitCall, AI->getType(), "",
+                                            InsertPos));
+      InitCall->setOperand(1, new CastInst(AI, Type::IntTy, "argc.cast",
+                                           InitCall));
+    } else {
+      AI->replaceAllUsesWith(InitCall);
+      InitCall->setOperand(1, AI);
+    }
+    
+  case 0: break;
+  }
+}
+
+void llvm::IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
+                                   ConstantPointerRef *CounterArray) {
+  // Insert the increment after any alloca or PHI instructions...
+  BasicBlock::iterator InsertPos = BB->begin();
+  while (isa<AllocaInst>(InsertPos) || isa<PHINode>(InsertPos))
+    ++InsertPos;
+
+  // Create the getelementptr constant expression
+  std::vector<Constant*> Indices(2);
+  Indices[0] = Constant::getNullValue(Type::LongTy);
+  Indices[1] = ConstantSInt::get(Type::LongTy, CounterNum);
+  Constant *ElementPtr = ConstantExpr::getGetElementPtr(CounterArray, Indices);
+
+  // Load, increment and store the value back.
+  Value *OldVal = new LoadInst(ElementPtr, "OldFuncCounter", InsertPos);
+  Value *NewVal = BinaryOperator::create(Instruction::Add, OldVal,
+                                         ConstantInt::get(Type::UIntTy, 1),
+                                         "NewFuncCounter", InsertPos);
+  new StoreInst(NewVal, ElementPtr, InsertPos);
+}