Re-enable "[ValueTracking] Teach isKnownNonNullFromDominatingCondition about AND"
The patch was reverted because of bug detected by sanitizer. The bug is fixed,
respective tests added.
Differential Revision: https://reviews.llvm.org/D50172
llvm-svn: 339005
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index edd46c5..afaa800 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -1860,19 +1860,42 @@
(Pred != ICmpInst::ICMP_EQ && Pred != ICmpInst::ICMP_NE))
continue;
+ SmallVector<const User *, 4> WorkList;
+ SmallPtrSet<const User *, 4> Visited;
for (auto *CmpU : U->users()) {
- if (const BranchInst *BI = dyn_cast<BranchInst>(CmpU)) {
- assert(BI->isConditional() && "uses a comparison!");
+ assert(WorkList.empty() && "Should be!");
+ if (Visited.insert(CmpU).second)
+ WorkList.push_back(CmpU);
- BasicBlock *NonNullSuccessor =
- BI->getSuccessor(Pred == ICmpInst::ICMP_EQ ? 1 : 0);
- BasicBlockEdge Edge(BI->getParent(), NonNullSuccessor);
- if (Edge.isSingleEdge() && DT->dominates(Edge, CtxI->getParent()))
+ while (!WorkList.empty()) {
+ auto *Curr = WorkList.pop_back_val();
+
+ // If a user is an AND, add all its users to the work list. We only
+ // propagate "pred != null" condition through AND because it is only
+ // correct to assume that all conditions of AND are met in true branch.
+ // TODO: Support similar logic of OR and EQ predicate?
+ if (Pred == ICmpInst::ICMP_NE)
+ if (auto *BO = dyn_cast<BinaryOperator>(Curr))
+ if (BO->getOpcode() == Instruction::And) {
+ for (auto *BOU : BO->users())
+ if (Visited.insert(BOU).second)
+ WorkList.push_back(BOU);
+ continue;
+ }
+
+ if (const BranchInst *BI = dyn_cast<BranchInst>(Curr)) {
+ assert(BI->isConditional() && "uses a comparison!");
+
+ BasicBlock *NonNullSuccessor =
+ BI->getSuccessor(Pred == ICmpInst::ICMP_EQ ? 1 : 0);
+ BasicBlockEdge Edge(BI->getParent(), NonNullSuccessor);
+ if (Edge.isSingleEdge() && DT->dominates(Edge, CtxI->getParent()))
+ return true;
+ } else if (Pred == ICmpInst::ICMP_NE &&
+ match(Curr, m_Intrinsic<Intrinsic::experimental_guard>()) &&
+ DT->dominates(cast<Instruction>(Curr), CtxI)) {
return true;
- } else if (Pred == ICmpInst::ICMP_NE &&
- match(CmpU, m_Intrinsic<Intrinsic::experimental_guard>()) &&
- DT->dominates(cast<Instruction>(CmpU), CtxI)) {
- return true;
+ }
}
}
}