FunctionPass *llvm::createDeadStoreEliminationPass() { return new DSE(); }
+/// isValueAtLeastAsBigAs - Return true if V1 is greater than or equal to the
+/// stored size of V2. This returns false if we don't know.
+///
+static bool isValueAtLeastAsBigAs(Value *V1, Value *V2, const TargetData *TD) {
+ const Type *V1Ty = V1->getType(), *V2Ty = V2->getType();
+
+ // Exactly the same type, must have exactly the same size.
+ if (V1Ty == V2Ty) return true;
+
+ // If we don't have target data, we don't know.
+ if (TD == 0) return false;
+
+ return TD->getTypeStoreSize(V1Ty) >= TD->getTypeStoreSize(V2Ty);
+}
+
bool DSE::runOnBasicBlock(BasicBlock &BB) {
MemoryDependenceAnalysis& MD = getAnalysis<MemoryDependenceAnalysis>();
TD = getAnalysisIfAvailable<TargetData>();
// If this is a store-store dependence, then the previous store is dead so
// long as this store is at least as big as it.
if (StoreInst *DepStore = dyn_cast<StoreInst>(InstDep.getInst()))
- if (TD &&
- TD->getTypeStoreSize(DepStore->getOperand(0)->getType()) <=
- TD->getTypeStoreSize(SI->getOperand(0)->getType())) {
+ if (isValueAtLeastAsBigAs(SI->getOperand(0), DepStore->getOperand(0),TD)){
// Delete the store and now-dead instructions that feed it.
DeleteDeadInstruction(DepStore);
NumFastStores++;
static char ID; // Pass identification
JumpThreading() : FunctionPass(&ID) {}
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- }
-
bool runOnFunction(Function &F);
void FindLoopHeaders(Function &F);
--- /dev/null
+; RUN: opt %s -dse -S | FileCheck %s
+
+declare void @test1f()
+
+define void @test1(i32* noalias %p) {
+ store i32 1, i32* %p;
+ call void @test1f()
+ store i32 2, i32 *%p
+ ret void
+; CHECK: define void @test1
+; CHECK-NOT: store
+; CHECK-NEXT: call void
+; CHECK-NEXT: store i32 2
+; CHECK-NEXT: ret void
+}
\ No newline at end of file