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Diffstat (limited to 'llvm/lib/Transforms/Scalar/JumpThreading.cpp')
-rw-r--r--llvm/lib/Transforms/Scalar/JumpThreading.cpp63
1 files changed, 44 insertions, 19 deletions
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 96aef90c1c1a..9dc3b0351346 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -31,6 +31,7 @@
#include "llvm/Analysis/LazyValueInfo.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
@@ -370,7 +371,6 @@ PreservedAnalyses JumpThreadingPass::run(Function &F,
if (!Changed)
return PreservedAnalyses::all();
PreservedAnalyses PA;
- PA.preserve<GlobalsAA>();
PA.preserve<DominatorTreeAnalysis>();
PA.preserve<LazyValueAnalysis>();
return PA;
@@ -462,7 +462,7 @@ bool JumpThreadingPass::runImpl(Function &F, TargetLibraryInfo *TLI_,
BasicBlock *Succ = BI->getSuccessor(0);
if (
// The terminator must be the only non-phi instruction in BB.
- BB.getFirstNonPHIOrDbg()->isTerminator() &&
+ BB.getFirstNonPHIOrDbg(true)->isTerminator() &&
// Don't alter Loop headers and latches to ensure another pass can
// detect and transform nested loops later.
!LoopHeaders.count(&BB) && !LoopHeaders.count(Succ) &&
@@ -733,23 +733,26 @@ bool JumpThreadingPass::computeValueKnownInPredecessorsImpl(
// Handle some boolean conditions.
if (I->getType()->getPrimitiveSizeInBits() == 1) {
+ using namespace PatternMatch;
+
assert(Preference == WantInteger && "One-bit non-integer type?");
// X | true -> true
// X & false -> false
- if (I->getOpcode() == Instruction::Or ||
- I->getOpcode() == Instruction::And) {
+ Value *Op0, *Op1;
+ if (match(I, m_LogicalOr(m_Value(Op0), m_Value(Op1))) ||
+ match(I, m_LogicalAnd(m_Value(Op0), m_Value(Op1)))) {
PredValueInfoTy LHSVals, RHSVals;
- computeValueKnownInPredecessorsImpl(I->getOperand(0), BB, LHSVals,
- WantInteger, RecursionSet, CxtI);
- computeValueKnownInPredecessorsImpl(I->getOperand(1), BB, RHSVals,
- WantInteger, RecursionSet, CxtI);
+ computeValueKnownInPredecessorsImpl(Op0, BB, LHSVals, WantInteger,
+ RecursionSet, CxtI);
+ computeValueKnownInPredecessorsImpl(Op1, BB, RHSVals, WantInteger,
+ RecursionSet, CxtI);
if (LHSVals.empty() && RHSVals.empty())
return false;
ConstantInt *InterestingVal;
- if (I->getOpcode() == Instruction::Or)
+ if (match(I, m_LogicalOr()))
InterestingVal = ConstantInt::getTrue(I->getContext());
else
InterestingVal = ConstantInt::getFalse(I->getContext());
@@ -1105,6 +1108,7 @@ bool JumpThreadingPass::processBlock(BasicBlock *BB) {
LLVM_DEBUG(dbgs() << " In block '" << BB->getName()
<< "' folding undef terminator: " << *BBTerm << '\n');
BranchInst::Create(BBTerm->getSuccessor(BestSucc), BBTerm);
+ ++NumFolds;
BBTerm->eraseFromParent();
DTU->applyUpdatesPermissive(Updates);
if (FI)
@@ -1150,8 +1154,8 @@ bool JumpThreadingPass::processBlock(BasicBlock *BB) {
assert(CondBr->isConditional() && "Threading on unconditional terminator");
LazyValueInfo::Tristate Ret =
- LVI->getPredicateAt(CondCmp->getPredicate(), CondCmp->getOperand(0),
- CondConst, CondBr);
+ LVI->getPredicateAt(CondCmp->getPredicate(), CondCmp->getOperand(0),
+ CondConst, CondBr, /*UseBlockValue=*/false);
if (Ret != LazyValueInfo::Unknown) {
unsigned ToRemove = Ret == LazyValueInfo::True ? 1 : 0;
unsigned ToKeep = Ret == LazyValueInfo::True ? 0 : 1;
@@ -1160,6 +1164,7 @@ bool JumpThreadingPass::processBlock(BasicBlock *BB) {
BranchInst *UncondBr =
BranchInst::Create(CondBr->getSuccessor(ToKeep), CondBr);
UncondBr->setDebugLoc(CondBr->getDebugLoc());
+ ++NumFolds;
CondBr->eraseFromParent();
if (CondCmp->use_empty())
CondCmp->eraseFromParent();
@@ -1275,6 +1280,7 @@ bool JumpThreadingPass::processImpliedCondition(BasicBlock *BB) {
RemoveSucc->removePredecessor(BB);
BranchInst *UncondBI = BranchInst::Create(KeepSucc, BI);
UncondBI->setDebugLoc(BI->getDebugLoc());
+ ++NumFolds;
BI->eraseFromParent();
DTU->applyUpdatesPermissive({{DominatorTree::Delete, BB, RemoveSucc}});
if (HasProfileData)
@@ -1384,10 +1390,14 @@ bool JumpThreadingPass::simplifyPartiallyRedundantLoad(LoadInst *LoadI) {
"Attempting to CSE volatile or atomic loads");
// If this is a load on a phi pointer, phi-translate it and search
// for available load/store to the pointer in predecessors.
- Value *Ptr = LoadedPtr->DoPHITranslation(LoadBB, PredBB);
- PredAvailable = FindAvailablePtrLoadStore(
- Ptr, LoadI->getType(), LoadI->isAtomic(), PredBB, BBIt,
- DefMaxInstsToScan, AA, &IsLoadCSE, &NumScanedInst);
+ Type *AccessTy = LoadI->getType();
+ const auto &DL = LoadI->getModule()->getDataLayout();
+ MemoryLocation Loc(LoadedPtr->DoPHITranslation(LoadBB, PredBB),
+ LocationSize::precise(DL.getTypeStoreSize(AccessTy)),
+ AATags);
+ PredAvailable = findAvailablePtrLoadStore(Loc, AccessTy, LoadI->isAtomic(),
+ PredBB, BBIt, DefMaxInstsToScan,
+ AA, &IsLoadCSE, &NumScanedInst);
// If PredBB has a single predecessor, continue scanning through the
// single predecessor.
@@ -1397,8 +1407,8 @@ bool JumpThreadingPass::simplifyPartiallyRedundantLoad(LoadInst *LoadI) {
SinglePredBB = SinglePredBB->getSinglePredecessor();
if (SinglePredBB) {
BBIt = SinglePredBB->end();
- PredAvailable = FindAvailablePtrLoadStore(
- Ptr, LoadI->getType(), LoadI->isAtomic(), SinglePredBB, BBIt,
+ PredAvailable = findAvailablePtrLoadStore(
+ Loc, AccessTy, LoadI->isAtomic(), SinglePredBB, BBIt,
(DefMaxInstsToScan - NumScanedInst), AA, &IsLoadCSE,
&NumScanedInst);
}
@@ -1720,6 +1730,7 @@ bool JumpThreadingPass::processThreadableEdges(Value *Cond, BasicBlock *BB,
// Finally update the terminator.
Instruction *Term = BB->getTerminator();
BranchInst::Create(OnlyDest, Term);
+ ++NumFolds;
Term->eraseFromParent();
DTU->applyUpdatesPermissive(Updates);
if (HasProfileData)
@@ -2076,6 +2087,15 @@ JumpThreadingPass::cloneInstructions(BasicBlock::iterator BI,
ValueMapping[PN] = NewPN;
}
+ // Clone noalias scope declarations in the threaded block. When threading a
+ // loop exit, we would otherwise end up with two idential scope declarations
+ // visible at the same time.
+ SmallVector<MDNode *> NoAliasScopes;
+ DenseMap<MDNode *, MDNode *> ClonedScopes;
+ LLVMContext &Context = PredBB->getContext();
+ identifyNoAliasScopesToClone(BI, BE, NoAliasScopes);
+ cloneNoAliasScopes(NoAliasScopes, ClonedScopes, "thread", Context);
+
// Clone the non-phi instructions of the source basic block into NewBB,
// keeping track of the mapping and using it to remap operands in the cloned
// instructions.
@@ -2084,6 +2104,7 @@ JumpThreadingPass::cloneInstructions(BasicBlock::iterator BI,
New->setName(BI->getName());
NewBB->getInstList().push_back(New);
ValueMapping[&*BI] = New;
+ adaptNoAliasScopes(New, ClonedScopes, Context);
// Remap operands to patch up intra-block references.
for (unsigned i = 0, e = New->getNumOperands(); i != e; ++i)
@@ -2727,7 +2748,8 @@ void JumpThreadingPass::unfoldSelectInstr(BasicBlock *Pred, BasicBlock *BB,
PredTerm->removeFromParent();
NewBB->getInstList().insert(NewBB->end(), PredTerm);
// Create a conditional branch and update PHI nodes.
- BranchInst::Create(NewBB, BB, SI->getCondition(), Pred);
+ auto *BI = BranchInst::Create(NewBB, BB, SI->getCondition(), Pred);
+ BI->applyMergedLocation(PredTerm->getDebugLoc(), SI->getDebugLoc());
SIUse->setIncomingValue(Idx, SI->getFalseValue());
SIUse->addIncoming(SI->getTrueValue(), NewBB);
@@ -2861,11 +2883,14 @@ bool JumpThreadingPass::tryToUnfoldSelectInCurrBB(BasicBlock *BB) {
continue;
auto isUnfoldCandidate = [BB](SelectInst *SI, Value *V) {
+ using namespace PatternMatch;
+
// Check if SI is in BB and use V as condition.
if (SI->getParent() != BB)
return false;
Value *Cond = SI->getCondition();
- return (Cond && Cond == V && Cond->getType()->isIntegerTy(1));
+ bool IsAndOr = match(SI, m_CombineOr(m_LogicalAnd(), m_LogicalOr()));
+ return Cond && Cond == V && Cond->getType()->isIntegerTy(1) && !IsAndOr;
};
SelectInst *SI = nullptr;
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-06 17:16:34 +0000