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-rw-r--r--llvm/lib/Transforms/Scalar/JumpThreading.cpp37
1 files changed, 37 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 87a1d5e487e..8759563267b 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -425,6 +425,7 @@ bool JumpThreadingPass::runImpl(Function &F, TargetLibraryInfo *TLI_,
LoopHeaders.clear();
DDT->flush();
+ LVI->enableDT();
return EverChanged;
}
@@ -617,6 +618,10 @@ bool JumpThreadingPass::ComputeValueKnownInPredecessors(
// "X < 4" and "X < 3" is known true but "X < 4" itself is not available.
// Perhaps getConstantOnEdge should be smart enough to do this?
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
for (BasicBlock *P : predecessors(BB)) {
// If the value is known by LazyValueInfo to be a constant in a
// predecessor, use that information to try to thread this block.
@@ -630,6 +635,10 @@ bool JumpThreadingPass::ComputeValueKnownInPredecessors(
/// If I is a PHI node, then we know the incoming values for any constants.
if (PHINode *PN = dyn_cast<PHINode>(I)) {
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *InVal = PN->getIncomingValue(i);
if (Constant *KC = getKnownConstant(InVal, Preference)) {
@@ -759,6 +768,10 @@ bool JumpThreadingPass::ComputeValueKnownInPredecessors(
const DataLayout &DL = PN->getModule()->getDataLayout();
// We can do this simplification if any comparisons fold to true or false.
// See if any do.
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
BasicBlock *PredBB = PN->getIncomingBlock(i);
Value *LHS = PN->getIncomingValue(i);
@@ -792,6 +805,10 @@ bool JumpThreadingPass::ComputeValueKnownInPredecessors(
if (!isa<Instruction>(CmpLHS) ||
cast<Instruction>(CmpLHS)->getParent() != BB) {
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
for (BasicBlock *P : predecessors(BB)) {
// If the value is known by LazyValueInfo to be a constant in a
// predecessor, use that information to try to thread this block.
@@ -820,6 +837,10 @@ bool JumpThreadingPass::ComputeValueKnownInPredecessors(
match(CmpLHS, m_Add(m_Value(AddLHS), m_ConstantInt(AddConst)))) {
if (!isa<Instruction>(AddLHS) ||
cast<Instruction>(AddLHS)->getParent() != BB) {
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
for (BasicBlock *P : predecessors(BB)) {
// If the value is known by LazyValueInfo to be a ConstantRange in
// a predecessor, use that information to try to thread this
@@ -901,6 +922,10 @@ bool JumpThreadingPass::ComputeValueKnownInPredecessors(
}
// If all else fails, see if LVI can figure out a constant value for us.
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
Constant *CI = LVI->getConstant(V, BB, CxtI);
if (Constant *KC = getKnownConstant(CI, Preference)) {
for (BasicBlock *Pred : predecessors(BB))
@@ -1102,6 +1127,10 @@ bool JumpThreadingPass::ProcessBlock(BasicBlock *BB) {
// threading is concerned.
assert(CondBr->isConditional() && "Threading on unconditional terminator");
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
LazyValueInfo::Tristate Ret =
LVI->getPredicateAt(CondCmp->getPredicate(), CondCmp->getOperand(0),
CondConst, CondBr);
@@ -1902,6 +1931,10 @@ bool JumpThreadingPass::ThreadEdge(BasicBlock *BB,
<< ", across block:\n "
<< *BB << "\n");
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
LVI->threadEdge(PredBB, BB, SuccBB);
// We are going to have to map operands from the original BB block to the new
@@ -2371,6 +2404,10 @@ bool JumpThreadingPass::TryToUnfoldSelect(CmpInst *CondCmp, BasicBlock *BB) {
// Now check if one of the select values would allow us to constant fold the
// terminator in BB. We don't do the transform if both sides fold, those
// cases will be threaded in any case.
+ if (DDT->pending())
+ LVI->disableDT();
+ else
+ LVI->enableDT();
LazyValueInfo::Tristate LHSFolds =
LVI->getPredicateOnEdge(CondCmp->getPredicate(), SI->getOperand(1),
CondRHS, Pred, BB, CondCmp);
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