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Now that we codegen the portable "sizeof" efficiently, we can use it for

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malloc lowering.  This means that lowerallocations doesn't need targetdata
anymore.  yaay.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14835 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-07-15 01:08:08 +00:00
parent d2995df5b7
commit 8bfc2f11a4
1 changed files with 22 additions and 18 deletions
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40
lib/Transforms/Utils/LowerAllocations.cpp
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@ -19,7 +19,6 @@
#include "llvm/iOther.h"
#include "llvm/Constants.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetData.h"
#include "Support/Statistic.h"
using namespace llvm;
@ -35,10 +34,6 @@ namespace {
public:
LowerAllocations() : MallocFunc(0), FreeFunc(0) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetData>();
}
/// doPassInitialization - For the lower allocations pass, this ensures that
/// a module contains a declaration for a malloc and a free function.
///
@ -78,6 +73,14 @@ bool LowerAllocations::doInitialization(Module &M) {
return true;
}
static Constant *getSizeof(const Type *Ty) {
Constant *Ret = ConstantPointerNull::get(PointerType::get(Ty));
std::vector<Constant*> Idx;
Idx.push_back(ConstantUInt::get(Type::UIntTy, 1));
Ret = ConstantExpr::getGetElementPtr(Ret, Idx);
return ConstantExpr::getCast(Ret, Type::UIntTy);
}
// runOnBasicBlock - This method does the actual work of converting
// instructions over, assuming that the pass has already been initialized.
//
@ -86,25 +89,26 @@ bool LowerAllocations::runOnBasicBlock(BasicBlock &BB) {
assert(MallocFunc && FreeFunc && "Pass not initialized!");
BasicBlock::InstListType &BBIL = BB.getInstList();
TargetData &DataLayout = getAnalysis<TargetData>();
// Loop over all of the instructions, looking for malloc or free instructions
for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) {
if (MallocInst *MI = dyn_cast<MallocInst>(I)) {
const Type *AllocTy = MI->getType()->getElementType();
// Get the number of bytes to be allocated for one element of the
// requested type...
unsigned Size = DataLayout.getTypeSize(AllocTy);
// malloc(type) becomes sbyte *malloc(constint)
Value *MallocArg = ConstantUInt::get(Type::UIntTy, Size);
if (MI->getNumOperands() && Size == 1) {
MallocArg = MI->getOperand(0); // Operand * 1 = Operand
} else if (MI->isArrayAllocation()) {
// Multiply it by the array size if necessary...
MallocArg = BinaryOperator::create(Instruction::Mul, MI->getOperand(0),
MallocArg, "", I);
// malloc(type) becomes sbyte *malloc(size)
Value *MallocArg = getSizeof(AllocTy);
if (MI->isArrayAllocation()) {
if (isa<ConstantUInt>(MallocArg) &&
cast<ConstantUInt>(MallocArg)->getValue() == 1) {
MallocArg = MI->getOperand(0); // Operand * 1 = Operand
} else if (Constant *CO = dyn_cast<Constant>(MI->getOperand(0))) {
MallocArg = ConstantExpr::getMul(CO, cast<Constant>(MallocArg));
} else {
// Multiply it by the array size if necessary...
MallocArg = BinaryOperator::create(Instruction::Mul,
MI->getOperand(0),
MallocArg, "", I);
}
}
const FunctionType *MallocFTy = MallocFunc->getFunctionType();