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Code Issues Projects Releases Wiki Activity

Clean up a few things based on Chris' feedback.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39747 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2007-07-11 19:03:09 +00:00
parent 08d14d2469
commit bfbfb3c464
1 changed files with 10 additions and 6 deletions
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16
lib/Transforms/Scalar/FastDSE.cpp
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@ -2,7 +2,7 @@
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// This file was developed by Owen Anderson and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
@ -64,7 +64,9 @@ FunctionPass *llvm::createFastDeadStoreEliminationPass() { return new FDSE(); }
bool FDSE::runOnBasicBlock(BasicBlock &BB) {
MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
// Record the last-seen store to this pointer
DenseMap<Value*, StoreInst*> lastStore;
// Record instructions possibly made dead by deleting a store
SetVector<Instruction*> possiblyDead;
bool MadeChange = false;
@ -73,10 +75,10 @@ bool FDSE::runOnBasicBlock(BasicBlock &BB) {
for (BasicBlock::iterator BBI = BB.begin(), BBE = BB.end(); BBI != BBE; ++BBI) {
// If we find a store...
if (StoreInst* S = dyn_cast<StoreInst>(BBI)) {
StoreInst*& last = lastStore[S->getPointerOperand()];
// ... to a pointer that has been stored to before...
if (lastStore.count(S->getPointerOperand())) {
StoreInst* last = lastStore[S->getPointerOperand()];
if (last) {
// ... and no other memory dependencies are between them....
if (MD.getDependency(S) == last) {
@ -94,7 +96,7 @@ bool FDSE::runOnBasicBlock(BasicBlock &BB) {
}
// Update our most-recent-store map
lastStore.insert(std::make_pair(S->getPointerOperand(), S));
last = S;
}
}
@ -120,8 +122,10 @@ void FDSE::DeleteDeadInstructionChains(Instruction *I,
// instruction uses the same operand twice. We don't want to delete a
// value then reference it.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
if (Instruction *Op = dyn_cast<Instruction>(I->getOperand(i)))
DeadInsts.insert(Op); // Attempt to nuke it later.
if (I->getOperand(i)->hasOneUse())
if (Instruction* Op = dyn_cast<Instruction>(I->getOperand(i)))
DeadInsts.insert(Op); // Attempt to nuke it later.
I->setOperand(i, 0); // Drop from the operand list.
}