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[ValueTracking] Early exit known non zero for phis 

After D88276 we no longer expect computeKnownBits() to prove
non-zeroness for cases where isKnownNonZero() can't, so don't
fall through to it.
This commit is contained in:
Nikita Popov 2020-09-29 20:48:32 +02:00
parent 15fbae8ac3
commit ac8a51c701
1 changed files with 1 additions and 3 deletions
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4
llvm/lib/Analysis/ValueTracking.cpp
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@ -2564,14 +2564,12 @@ bool isKnownNonZero(const Value *V, const APInt &DemandedElts, unsigned Depth,
// Check if all incoming values are non-zero using recursion. // Check if all incoming values are non-zero using recursion.
Query RecQ = Q; Query RecQ = Q;
unsigned NewDepth = std::max(Depth, MaxAnalysisRecursionDepth - 1); unsigned NewDepth = std::max(Depth, MaxAnalysisRecursionDepth - 1);
bool AllNonZero = llvm::all_of(PN->operands(), [&](const Use &U) { return llvm::all_of(PN->operands(), [&](const Use &U) {
if (U.get() == PN) if (U.get() == PN)
return true; return true;
RecQ.CxtI = PN->getIncomingBlock(U)->getTerminator(); RecQ.CxtI = PN->getIncomingBlock(U)->getTerminator();
return isKnownNonZero(U.get(), DemandedElts, NewDepth, RecQ); return isKnownNonZero(U.get(), DemandedElts, NewDepth, RecQ);
}); });
if (AllNonZero)
return true;
} }
// ExtractElement // ExtractElement
else if (const auto *EEI = dyn_cast<ExtractElementInst>(V)) { else if (const auto *EEI = dyn_cast<ExtractElementInst>(V)) {