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https://github.com/c64scene-ar/llvm-6502.git
synced 2024-09-01 19:29:22 +00:00
rename doesClobberMemory -> hasMemoryWrite to be more specific, and
remove an actively-wrong comment. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120378 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -91,9 +91,9 @@ INITIALIZE_PASS_END(DSE, "dse", "Dead Store Elimination", false, false)
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FunctionPass *llvm::createDeadStoreEliminationPass() { return new DSE(); }
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/// doesClobberMemory - Does this instruction clobber (write without reading)
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/// some memory?
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static bool doesClobberMemory(Instruction *I) {
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/// hasMemoryWrite - Does this instruction write some memory? This only returns
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/// true for things that we can analyze with other helpers below.
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static bool hasMemoryWrite(Instruction *I) {
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if (isa<StoreInst>(I))
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return true;
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if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
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@ -114,7 +114,7 @@ static bool doesClobberMemory(Instruction *I) {
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/// isElidable - If the value of this instruction and the memory it writes to is
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/// unused, may we delete this instrtction?
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static bool isElidable(Instruction *I) {
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assert(doesClobberMemory(I));
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assert(hasMemoryWrite(I));
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if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
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return II->getIntrinsicID() != Intrinsic::lifetime_end;
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if (StoreInst *SI = dyn_cast<StoreInst>(I))
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@ -124,7 +124,7 @@ static bool isElidable(Instruction *I) {
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/// getPointerOperand - Return the pointer that is being written to.
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static Value *getPointerOperand(Instruction *I) {
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assert(doesClobberMemory(I));
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assert(hasMemoryWrite(I));
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if (StoreInst *SI = dyn_cast<StoreInst>(I))
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return SI->getPointerOperand();
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if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I))
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@ -143,7 +143,7 @@ static Value *getPointerOperand(Instruction *I) {
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/// getStoreSize - Return the length in bytes of the write by the clobbering
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/// instruction. If variable or unknown, returns AliasAnalysis::UnknownSize.
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static uint64_t getStoreSize(Instruction *I, const TargetData *TD) {
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assert(doesClobberMemory(I));
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assert(hasMemoryWrite(I));
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if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
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if (!TD) return AliasAnalysis::UnknownSize;
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return TD->getTypeStoreSize(SI->getOperand(0)->getType());
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@ -206,8 +206,8 @@ bool DSE::runOnBasicBlock(BasicBlock &BB) {
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continue;
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}
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// If we find a store, get its memory dependence.
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if (!doesClobberMemory(Inst))
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// If we find something that writes memory, get its memory dependence.
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if (!hasMemoryWrite(Inst))
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continue;
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MemDepResult InstDep = MD.getDependency(Inst);
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@ -264,7 +264,7 @@ bool DSE::runOnBasicBlock(BasicBlock &BB) {
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// If this is a store-store dependence, then the previous store is dead so
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// long as this store is at least as big as it.
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if (InstDep.isDef() && doesClobberMemory(InstDep.getInst())) {
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if (InstDep.isDef() && hasMemoryWrite(InstDep.getInst())) {
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Instruction *DepStore = InstDep.getInst();
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if (isStoreAtLeastAsWideAs(Inst, DepStore, TD) && isElidable(DepStore)) {
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// Delete the store and now-dead instructions that feed it.
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@ -301,7 +301,7 @@ bool DSE::HandleFree(CallInst *F) {
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if (Dep.isNonLocal()) return false;
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Instruction *Dependency = Dep.getInst();
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if (!doesClobberMemory(Dependency) || !isElidable(Dependency))
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if (!hasMemoryWrite(Dependency) || !isElidable(Dependency))
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return false;
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Value *DepPointer = getPointerOperand(Dependency)->getUnderlyingObject();
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@ -358,7 +358,7 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
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--BBI;
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// If we find a store whose pointer is dead.
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if (doesClobberMemory(BBI)) {
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if (hasMemoryWrite(BBI)) {
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if (isElidable(BBI)) {
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// See through pointer-to-pointer bitcasts
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Value *pointerOperand = getPointerOperand(BBI)->getUnderlyingObject();
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