[llvm-commits] [llvm] r39747 - /llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp
Owen Anderson
resistor at mac.com
Wed Jul 11 12:03:09 PDT 2007
Author: resistor
Date: Wed Jul 11 14:03:09 2007
New Revision: 39747
URL: http://llvm.org/viewvc/llvm-project?rev=39747&view=rev
Log:
Clean up a few things based on Chris' feedback.
Modified:
llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp?rev=39747&r1=39746&r2=39747&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp Wed Jul 11 14:03:09 2007
@@ -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 @@
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 @@
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 @@
}
// Update our most-recent-store map
- lastStore.insert(std::make_pair(S->getPointerOperand(), S));
+ last = S;
}
}
@@ -120,8 +122,10 @@
// 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.
}
More information about the llvm-commits
mailing list