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 PointerType *arrayType) {
27 LLVMContext &Context = MainFn->getContext();
29 PointerType::getUnqual(Type::getInt8PtrTy(Context));
30 const PointerType *UIntPtr = arrayType ? arrayType :
31 Type::getInt32PtrTy(Context);
32 Module &M = *MainFn->getParent();
33 Constant *InitFn = M.getOrInsertFunction(FnName, Type::getInt32Ty(Context),
34 Type::getInt32Ty(Context),
36 Type::getInt32Ty(Context),
39 // This could force argc and argv into programs that wouldn't otherwise have
40 // them, but instead we just pass null values in.
41 std::vector<Value*> Args(4);
42 Args[0] = Constant::getNullValue(Type::getInt32Ty(Context));
43 Args[1] = Constant::getNullValue(ArgVTy);
45 // Skip over any allocas in the entry block.
46 BasicBlock *Entry = MainFn->begin();
47 BasicBlock::iterator InsertPos = Entry->begin();
48 while (isa<AllocaInst>(InsertPos)) ++InsertPos;
50 std::vector<Constant*> GEPIndices(2,
51 Constant::getNullValue(Type::getInt32Ty(Context)));
52 unsigned NumElements = 0;
54 Args[2] = ConstantExpr::getGetElementPtr(Array, &GEPIndices[0],
57 cast<ArrayType>(Array->getType()->getElementType())->getNumElements();
59 // If this profiling instrumentation doesn't have a constant array, just
61 Args[2] = ConstantPointerNull::get(UIntPtr);
63 Args[3] = ConstantInt::get(Type::getInt32Ty(Context), NumElements);
65 CallInst *InitCall = CallInst::Create(InitFn, Args.begin(), Args.end(),
66 "newargc", InsertPos);
68 // If argc or argv are not available in main, just pass null values in.
69 Function::arg_iterator AI;
70 switch (MainFn->arg_size()) {
73 AI = MainFn->arg_begin(); ++AI;
74 if (AI->getType() != ArgVTy) {
75 Instruction::CastOps opcode = CastInst::getCastOpcode(AI, false, ArgVTy,
77 InitCall->setArgOperand(1,
78 CastInst::Create(opcode, AI, ArgVTy, "argv.cast", InitCall));
80 InitCall->setArgOperand(1, AI);
85 AI = MainFn->arg_begin();
86 // If the program looked at argc, have it look at the return value of the
88 if (!AI->getType()->isIntegerTy(32)) {
89 Instruction::CastOps opcode;
90 if (!AI->use_empty()) {
91 opcode = CastInst::getCastOpcode(InitCall, true, AI->getType(), true);
92 AI->replaceAllUsesWith(
93 CastInst::Create(opcode, InitCall, AI->getType(), "", InsertPos));
95 opcode = CastInst::getCastOpcode(AI, true,
96 Type::getInt32Ty(Context), true);
97 InitCall->setArgOperand(0,
98 CastInst::Create(opcode, AI, Type::getInt32Ty(Context),
99 "argc.cast", InitCall));
101 AI->replaceAllUsesWith(InitCall);
102 InitCall->setArgOperand(0, AI);
109 void llvm::IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
110 GlobalValue *CounterArray, bool beginning) {
111 // Insert the increment after any alloca or PHI instructions...
112 BasicBlock::iterator InsertPos = beginning ? BB->getFirstNonPHI() :
114 while (isa<AllocaInst>(InsertPos))
117 LLVMContext &Context = BB->getContext();
119 // Create the getelementptr constant expression
120 std::vector<Constant*> Indices(2);
121 Indices[0] = Constant::getNullValue(Type::getInt32Ty(Context));
122 Indices[1] = ConstantInt::get(Type::getInt32Ty(Context), CounterNum);
123 Constant *ElementPtr =
124 ConstantExpr::getGetElementPtr(CounterArray, &Indices[0],
127 // Load, increment and store the value back.
128 Value *OldVal = new LoadInst(ElementPtr, "OldFuncCounter", InsertPos);
129 Value *NewVal = BinaryOperator::Create(Instruction::Add, OldVal,
130 ConstantInt::get(Type::getInt32Ty(Context), 1),
131 "NewFuncCounter", InsertPos);
132 new StoreInst(NewVal, ElementPtr, InsertPos);