1 //===- ProfilingUtils.cpp - Helper functions shared by profilers ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a few helper functions which are used by profile
11 // instrumentation code to instrument the code. This allows the profiler pass
12 // to worry about *what* to insert, and these functions take care of *how* to do
15 //===----------------------------------------------------------------------===//
17 #include "ProfilingUtils.h"
18 #include "llvm/Constants.h"
19 #include "llvm/DerivedTypes.h"
20 #include "llvm/Instructions.h"
21 #include "llvm/LLVMContext.h"
22 #include "llvm/Module.h"
24 void llvm::InsertProfilingInitCall(Function *MainFn, const char *FnName,
26 LLVMContext &Context = MainFn->getContext();
28 PointerType::getUnqual(Type::getInt8PtrTy(Context));
29 const PointerType *UIntPtr =
30 Type::getInt32PtrTy(Context);
31 Module &M = *MainFn->getParent();
32 Constant *InitFn = M.getOrInsertFunction(FnName, Type::getInt32Ty(Context),
33 Type::getInt32Ty(Context),
35 Type::getInt32Ty(Context),
38 // This could force argc and argv into programs that wouldn't otherwise have
39 // them, but instead we just pass null values in.
40 std::vector<Value*> Args(4);
41 Args[0] = Constant::getNullValue(Type::getInt32Ty(Context));
42 Args[1] = Constant::getNullValue(ArgVTy);
44 // Skip over any allocas in the entry block.
45 BasicBlock *Entry = MainFn->begin();
46 BasicBlock::iterator InsertPos = Entry->begin();
47 while (isa<AllocaInst>(InsertPos)) ++InsertPos;
49 std::vector<Constant*> GEPIndices(2,
50 Constant::getNullValue(Type::getInt32Ty(Context)));
51 unsigned NumElements = 0;
53 Args[2] = ConstantExpr::getGetElementPtr(Array, &GEPIndices[0],
56 cast<ArrayType>(Array->getType()->getElementType())->getNumElements();
58 // If this profiling instrumentation doesn't have a constant array, just
60 Args[2] = ConstantPointerNull::get(UIntPtr);
62 Args[3] = ConstantInt::get(Type::getInt32Ty(Context), NumElements);
64 Instruction *InitCall = CallInst::Create(InitFn, Args.begin(), Args.end(),
65 "newargc", InsertPos);
67 // If argc or argv are not available in main, just pass null values in.
68 Function::arg_iterator AI;
69 switch (MainFn->arg_size()) {
72 AI = MainFn->arg_begin(); ++AI;
73 if (AI->getType() != ArgVTy) {
74 Instruction::CastOps opcode = CastInst::getCastOpcode(AI, false, ArgVTy,
76 InitCall->setOperand(2,
77 CastInst::Create(opcode, AI, ArgVTy, "argv.cast", InitCall));
79 InitCall->setOperand(2, AI);
84 AI = MainFn->arg_begin();
85 // If the program looked at argc, have it look at the return value of the
87 if (!AI->getType()->isIntegerTy(32)) {
88 Instruction::CastOps opcode;
89 if (!AI->use_empty()) {
90 opcode = CastInst::getCastOpcode(InitCall, true, AI->getType(), true);
91 AI->replaceAllUsesWith(
92 CastInst::Create(opcode, InitCall, AI->getType(), "", InsertPos));
94 opcode = CastInst::getCastOpcode(AI, true,
95 Type::getInt32Ty(Context), true);
96 InitCall->setOperand(1,
97 CastInst::Create(opcode, AI, Type::getInt32Ty(Context),
98 "argc.cast", InitCall));
100 AI->replaceAllUsesWith(InitCall);
101 InitCall->setOperand(1, AI);
108 void llvm::IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
109 GlobalValue *CounterArray) {
110 // Insert the increment after any alloca or PHI instructions...
111 BasicBlock::iterator InsertPos = BB->getFirstNonPHI();
112 while (isa<AllocaInst>(InsertPos))
115 LLVMContext &Context = BB->getContext();
117 // Create the getelementptr constant expression
118 std::vector<Constant*> Indices(2);
119 Indices[0] = Constant::getNullValue(Type::getInt32Ty(Context));
120 Indices[1] = ConstantInt::get(Type::getInt32Ty(Context), CounterNum);
121 Constant *ElementPtr =
122 ConstantExpr::getGetElementPtr(CounterArray, &Indices[0],
125 // Load, increment and store the value back.
126 Value *OldVal = new LoadInst(ElementPtr, "OldFuncCounter", InsertPos);
127 Value *NewVal = BinaryOperator::Create(Instruction::Add, OldVal,
128 ConstantInt::get(Type::getInt32Ty(Context), 1),
129 "NewFuncCounter", InsertPos);
130 new StoreInst(NewVal, ElementPtr, InsertPos);