void IndVarSimplify::EliminateIVComparisons() {
// Look for ICmp users.
for (IVUsers::iterator I = IU->begin(), E = IU->end(); I != E; ++I) {
IVStrideUse &UI = *I;
ICmpInst *ICmp = dyn_cast<ICmpInst>(UI.getUser());
if (!ICmp) continue;
bool Swapped = UI.getOperandValToReplace() == ICmp->getOperand(1);
ICmpInst::Predicate Pred = ICmp->getPredicate();
if (Swapped) Pred = ICmpInst::getSwappedPredicate(Pred);
// Get the SCEVs for the ICmp operands.
const SCEV *S = IU->getReplacementExpr(UI);
const SCEV *X = SE->getSCEV(ICmp->getOperand(!Swapped));
// Simplify unnecessary loops away.
const Loop *ICmpLoop = LI->getLoopFor(ICmp->getParent());
S = SE->getSCEVAtScope(S, ICmpLoop);
X = SE->getSCEVAtScope(X, ICmpLoop);
// If the condition is always true or always false, replace it with
// a constant value.
if (SE->isKnownPredicate(Pred, S, X))
ICmp->replaceAllUsesWith(ConstantInt::getTrue(ICmp->getContext()));
else if (SE->isKnownPredicate(ICmpInst::getInversePredicate(Pred), S, X))
ICmp->replaceAllUsesWith(ConstantInt::getFalse(ICmp->getContext()));
else
continue;
DEBUG(dbgs() << "INDVARS: Eliminated comparison: " << *ICmp << '\n');
DeadInsts.push_back(ICmp);
}
}
bool visitICmpInst(ICmpInst& inst) {
// errs() << "got icmp instruction! " << inst << '\n';
bool changed = false;
if (inst.getPredicate() == CmpInst::ICMP_EQ) {
assert(inst.getNumOperands() == 2);
if (inst.getOperand(1) == processing) {
inst.swapOperands();
changed = true;
any_changes = true;
}
assert(dyn_cast<Instruction>(inst.getOperand(0)) == processing);
Value* other = inst.getOperand(1);
if (isa<ConstantPointerNull>(other)) {
if (VERBOSITY("opt") >= 2) {
errs() << inst << '\n';
errs() << "replacing with false!\n";
}
Value* new_value = ConstantInt::getFalse(other->getContext());
inst.replaceAllUsesWith(new_value);
inst.eraseFromParent();
changed = true;
any_changes = true;
}
}
return changed;
}
bool AMDGPUCodeGenPrepare::promoteUniformOpToI32(ICmpInst &I) const {
assert(needsPromotionToI32(I.getOperand(0)->getType()) &&
"I does not need promotion to i32");
IRBuilder<> Builder(&I);
Builder.SetCurrentDebugLocation(I.getDebugLoc());
Type *I32Ty = getI32Ty(Builder, I.getOperand(0)->getType());
Value *ExtOp0 = nullptr;
Value *ExtOp1 = nullptr;
Value *NewICmp = nullptr;
if (I.isSigned()) {
ExtOp0 = Builder.CreateSExt(I.getOperand(0), I32Ty);
ExtOp1 = Builder.CreateSExt(I.getOperand(1), I32Ty);
} else {
ExtOp0 = Builder.CreateZExt(I.getOperand(0), I32Ty);
ExtOp1 = Builder.CreateZExt(I.getOperand(1), I32Ty);
}
NewICmp = Builder.CreateICmp(I.getPredicate(), ExtOp0, ExtOp1);
I.replaceAllUsesWith(NewICmp);
I.eraseFromParent();
return true;
}
void IndVarSimplify::EliminateIVComparisons() {
SmallVector<WeakVH, 16> DeadInsts;
// Look for ICmp users.
for (IVUsers::iterator I = IU->begin(), E = IU->end(); I != E; ++I) {
IVStrideUse &UI = *I;
ICmpInst *ICmp = dyn_cast<ICmpInst>(UI.getUser());
if (!ICmp) continue;
bool Swapped = UI.getOperandValToReplace() == ICmp->getOperand(1);
ICmpInst::Predicate Pred = ICmp->getPredicate();
if (Swapped) Pred = ICmpInst::getSwappedPredicate(Pred);
// Get the SCEVs for the ICmp operands.
const SCEV *S = IU->getReplacementExpr(UI);
const SCEV *X = SE->getSCEV(ICmp->getOperand(!Swapped));
// Simplify unnecessary loops away.
const Loop *ICmpLoop = LI->getLoopFor(ICmp->getParent());
S = SE->getSCEVAtScope(S, ICmpLoop);
X = SE->getSCEVAtScope(X, ICmpLoop);
// If the condition is always true or always false, replace it with
// a constant value.
if (SE->isKnownPredicate(Pred, S, X))
ICmp->replaceAllUsesWith(ConstantInt::getTrue(ICmp->getContext()));
else if (SE->isKnownPredicate(ICmpInst::getInversePredicate(Pred), S, X))
ICmp->replaceAllUsesWith(ConstantInt::getFalse(ICmp->getContext()));
else
continue;
DEBUG(dbgs() << "INDVARS: Eliminated comparison: " << *ICmp << '\n');
DeadInsts.push_back(ICmp);
}
// Now that we're done iterating through lists, clean up any instructions
// which are now dead.
while (!DeadInsts.empty())
if (Instruction *Inst =
dyn_cast_or_null<Instruction>(&*DeadInsts.pop_back_val()))
RecursivelyDeleteTriviallyDeadInstructions(Inst);
}
bool GambasPass::runOnFunction(Function &F){
IRBuilder<> Builder(F.getContext());
bool changed = false;
for(Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
for(BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ){
ICmpInst* ICI = dyn_cast<ICmpInst>(I);
CallInst* CI = dyn_cast<CallInst>(I++);
if (ICI && ICI->hasMetadata() && ICI->getMetadata("unref_slt") && dyn_cast<LoadInst>(ICI->getOperand(0))){
ICI->replaceAllUsesWith(ConstantInt::get(ICI->getType(), false));
ICI->eraseFromParent();
changed = true;
continue;
}
if (!CI)
continue;
Function* callee = CI->getCalledFunction();
if (callee == NULL || !callee->isDeclaration())
continue;
StringRef name = callee->getName();
if (name == "JR_release_variant" || name == "JR_borrow_variant"){
ConstantInt* vtype_int = dyn_cast<ConstantInt>(CI->getArgOperand(0));
if (!vtype_int)
continue;
uint64_t vtype = vtype_int->getZExtValue();
if (TYPE_is_string(vtype) || TYPE_is_object(vtype))
continue;
CI->eraseFromParent();
changed = true;
} else if (name == FUNCTION_NAME(__finite)){
ConstantFP* op = dyn_cast<ConstantFP>(CI->getArgOperand(0));
if (!op)
continue;
int val = __finite(op->getValueAPF().convertToDouble());
Constant* res = ConstantInt::get(CI->getType(), val);
CI->replaceAllUsesWith(res);
CI->eraseFromParent();
changed = true;
} else if (name == FUNCTION_NAME(__isnan)){
ConstantFP* op = dyn_cast<ConstantFP>(CI->getArgOperand(0));
if (!op)
continue;
int val = __isnan(op->getValueAPF().convertToDouble());
Constant* res = ConstantInt::get(CI->getType(), val);
CI->replaceAllUsesWith(res);
CI->eraseFromParent();
changed = true;
} else if (name == FUNCTION_NAME(__isinf)){
ConstantFP* op = dyn_cast<ConstantFP>(CI->getArgOperand(0));
if (!op)
continue;
int val = __isinf(op->getValueAPF().convertToDouble());
Constant* res = ConstantInt::get(CI->getType(), val);
CI->replaceAllUsesWith(res);
CI->eraseFromParent();
changed = true;
}
}
}
return changed;
}
bool AtomicExpandLoadLinked::expandAtomicCmpXchg(AtomicCmpXchgInst *CI) {
AtomicOrdering SuccessOrder = CI->getSuccessOrdering();
AtomicOrdering FailureOrder = CI->getFailureOrdering();
Value *Addr = CI->getPointerOperand();
BasicBlock *BB = CI->getParent();
Function *F = BB->getParent();
LLVMContext &Ctx = F->getContext();
// Given: cmpxchg some_op iN* %addr, iN %desired, iN %new success_ord fail_ord
//
// The full expansion we produce is:
// [...]
// fence?
// cmpxchg.start:
// %loaded = @load.linked(%addr)
// %should_store = icmp eq %loaded, %desired
// br i1 %should_store, label %cmpxchg.trystore,
// label %cmpxchg.end/%cmpxchg.barrier
// cmpxchg.trystore:
// %stored = @store_conditional(%new, %addr)
// %try_again = icmp i32 ne %stored, 0
// br i1 %try_again, label %loop, label %cmpxchg.end
// cmpxchg.barrier:
// fence?
// br label %cmpxchg.end
// cmpxchg.end:
// [...]
BasicBlock *ExitBB = BB->splitBasicBlock(CI, "cmpxchg.end");
auto BarrierBB = BasicBlock::Create(Ctx, "cmpxchg.barrier", F, ExitBB);
auto TryStoreBB = BasicBlock::Create(Ctx, "cmpxchg.trystore", F, BarrierBB);
auto LoopBB = BasicBlock::Create(Ctx, "cmpxchg.start", F, TryStoreBB);
// This grabs the DebugLoc from CI
IRBuilder<> Builder(CI);
// The split call above "helpfully" added a branch at the end of BB (to the
// wrong place), but we might want a fence too. It's easiest to just remove
// the branch entirely.
std::prev(BB->end())->eraseFromParent();
Builder.SetInsertPoint(BB);
AtomicOrdering MemOpOrder = insertLeadingFence(Builder, SuccessOrder);
Builder.CreateBr(LoopBB);
// Start the main loop block now that we've taken care of the preliminaries.
Builder.SetInsertPoint(LoopBB);
Value *Loaded = TLI->emitLoadLinked(Builder, Addr, MemOpOrder);
Value *ShouldStore =
Builder.CreateICmpEQ(Loaded, CI->getCompareOperand(), "should_store");
// If the the cmpxchg doesn't actually need any ordering when it fails, we can
// jump straight past that fence instruction (if it exists).
BasicBlock *FailureBB = FailureOrder == Monotonic ? ExitBB : BarrierBB;
Builder.CreateCondBr(ShouldStore, TryStoreBB, FailureBB);
Builder.SetInsertPoint(TryStoreBB);
Value *StoreSuccess = TLI->emitStoreConditional(
Builder, CI->getNewValOperand(), Addr, MemOpOrder);
Value *TryAgain = Builder.CreateICmpNE(
StoreSuccess, ConstantInt::get(Type::getInt32Ty(Ctx), 0), "success");
Builder.CreateCondBr(TryAgain, LoopBB, BarrierBB);
// Make sure later instructions don't get reordered with a fence if necessary.
Builder.SetInsertPoint(BarrierBB);
insertTrailingFence(Builder, SuccessOrder);
Builder.CreateBr(ExitBB);
// Finally, we have control-flow based knowledge of whether the cmpxchg
// succeeded or not. We expose this to later passes by converting any
// subsequent "icmp eq/ne %loaded, %oldval" into a use of an appropriate PHI.
// Setup the builder so we can create any PHIs we need.
Builder.SetInsertPoint(FailureBB, FailureBB->begin());
BasicBlock *SuccessBB = FailureOrder == Monotonic ? BarrierBB : TryStoreBB;
PHINode *Success = 0, *Failure = 0;
// Look for any users of the cmpxchg that are just comparing the loaded value
// against the desired one, and replace them with the CFG-derived version.
for (auto User : CI->users()) {
ICmpInst *ICmp = dyn_cast<ICmpInst>(User);
if (!ICmp)
continue;
// Because we know ICmp uses CI, we only need one operand to be the old
// value.
if (ICmp->getOperand(0) != CI->getCompareOperand() &&
ICmp->getOperand(1) != CI->getCompareOperand())
continue;
if (ICmp->getPredicate() == CmpInst::ICMP_EQ) {
if (!Success) {
Success = Builder.CreatePHI(Type::getInt1Ty(Ctx), 2);
Success->addIncoming(ConstantInt::getTrue(Ctx), SuccessBB);
Success->addIncoming(ConstantInt::getFalse(Ctx), LoopBB);
}
ICmp->replaceAllUsesWith(Success);
} else if (ICmp->getPredicate() == CmpInst::ICMP_NE) {
if (!Failure) {
Failure = Builder.CreatePHI(Type::getInt1Ty(Ctx), 2);
Failure->addIncoming(ConstantInt::getFalse(Ctx), SuccessBB);
Failure->addIncoming(ConstantInt::getTrue(Ctx), LoopBB);
}
ICmp->replaceAllUsesWith(Failure);
}
}
CI->replaceAllUsesWith(Loaded);
CI->eraseFromParent();
return true;
}
