1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 04:02:41 +01:00
llvm-mirror/lib/Transforms/Instrumentation/ProfilingUtils.cpp
Jeff Cohen a38c737e85 When a function takes a variable number of pointer arguments, with a zero
pointer marking the end of the list, the zero *must* be cast to the pointer
type.  An un-cast zero is a 32-bit int, and at least on x86_64, gcc will
not extend the zero to 64 bits, thus allowing the upper 32 bits to be
random junk.

The new END_WITH_NULL macro may be used to annotate a such a function
so that GCC (version 4 or newer) will detect the use of un-casted zero
at compile time.

llvm-svn: 23888
2005-10-23 04:37:20 +00:00

109 lines
4.2 KiB
C++

//===- 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 PointerType *UIntPtr = PointerType::get(Type::UIntTy);
Module &M = *MainFn->getParent();
Function *InitFn = M.getOrInsertFunction(FnName, Type::IntTy, Type::IntTy,
ArgVTy, UIntPtr, Type::UIntTy,
(Type *)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;
std::vector<Constant*> GEPIndices(2, Constant::getNullValue(Type::IntTy));
unsigned NumElements = 0;
if (Array) {
Args[2] = ConstantExpr::getGetElementPtr(Array, GEPIndices);
NumElements =
cast<ArrayType>(Array->getType()->getElementType())->getNumElements();
} else {
// If this profiling instrumentation doesn't have a constant array, just
// pass null.
Args[2] = ConstantPointerNull::get(UIntPtr);
}
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::arg_iterator AI;
switch (MainFn->arg_size()) {
default:
case 2:
AI = MainFn->arg_begin(); ++AI;
if (AI->getType() != ArgVTy) {
InitCall->setOperand(2, new CastInst(AI, ArgVTy, "argv.cast", InitCall));
} else {
InitCall->setOperand(2, AI);
}
case 1:
AI = MainFn->arg_begin();
// 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,
GlobalValue *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::IntTy);
Indices[1] = ConstantSInt::get(Type::IntTy, 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);
}