diff options
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 8c29c24..8e7f0c6 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -388,10 +388,9 @@ static void computeKnownBitsMul(const Value *Op0, const Value *Op1, bool NSW, } bool SelfMultiply = Op0 == Op1; - // TODO: SelfMultiply can be poison, but not undef. if (SelfMultiply) SelfMultiply &= - isGuaranteedNotToBeUndefOrPoison(Op0, Q.AC, Q.CxtI, Q.DT, Depth + 1); + isGuaranteedNotToBeUndef(Op0, Q.AC, Q.CxtI, Q.DT, Depth + 1); Known = KnownBits::mul(Known, Known2, SelfMultiply); // Only make use of no-wrap flags if we failed to compute the sign bit @@ -6488,7 +6487,7 @@ OverflowResult llvm::computeOverflowForUnsignedSub(const Value *LHS, // See simplifyICmpWithBinOpOnLHS() for candidates. if (match(RHS, m_URem(m_Specific(LHS), m_Value())) || match(RHS, m_NUWSub(m_Specific(LHS), m_Value()))) - if (isGuaranteedNotToBeUndefOrPoison(LHS, SQ.AC, SQ.CxtI, SQ.DT)) + if (isGuaranteedNotToBeUndef(LHS, SQ.AC, SQ.CxtI, SQ.DT)) return OverflowResult::NeverOverflows; // Checking for conditions implied by dominating conditions may be expensive. @@ -6521,7 +6520,7 @@ OverflowResult llvm::computeOverflowForSignedSub(const Value *LHS, // then determining no-overflow may allow other transforms. if (match(RHS, m_SRem(m_Specific(LHS), m_Value())) || match(RHS, m_NSWSub(m_Specific(LHS), m_Value()))) - if (isGuaranteedNotToBeUndefOrPoison(LHS, SQ.AC, SQ.CxtI, SQ.DT)) + if (isGuaranteedNotToBeUndef(LHS, SQ.AC, SQ.CxtI, SQ.DT)) return OverflowResult::NeverOverflows; // If LHS and RHS each have at least two sign bits, the subtraction @@ -6982,6 +6981,13 @@ bool llvm::isGuaranteedNotToBePoison(const Value *V, AssumptionCache *AC, return ::isGuaranteedNotToBeUndefOrPoison(V, AC, CtxI, DT, Depth, true); } +bool llvm::isGuaranteedNotToBeUndef(const Value *V, AssumptionCache *AC, + const Instruction *CtxI, + const DominatorTree *DT, unsigned Depth) { + // TODO: This is currently equivalent to isGuaranteedNotToBeUndefOrPoison(). + return ::isGuaranteedNotToBeUndefOrPoison(V, AC, CtxI, DT, Depth, false); +} + /// Return true if undefined behavior would provably be executed on the path to /// OnPathTo if Root produced a posion result. Note that this doesn't say /// anything about whether OnPathTo is actually executed or whether Root is |