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| author | Igor Laevsky <igmyrj@gmail.com> | 2017-12-05 12:18:15 +0000 |
|---|---|---|
| committer | Igor Laevsky <igmyrj@gmail.com> | 2017-12-05 12:18:15 +0000 |
| commit | cec8f47e77f1cb917ba9af24b2517b985a649202 (patch) | |
| tree | 7551f349f68ff1b25f2ccd11ecca551508b7f263 /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | aa91155960e18350a8dd21f646ac341c82775191 (diff) | |
| download | llvm-cec8f47e77f1cb917ba9af24b2517b985a649202.zip llvm-cec8f47e77f1cb917ba9af24b2517b985a649202.tar.gz llvm-cec8f47e77f1cb917ba9af24b2517b985a649202.tar.bz2 | |
[InstCombine] Don't crash on out of bounds shifts
Differential Revision: https://reviews.llvm.org/D40649
llvm-svn: 319761
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 106a4a7..8270f9c 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -548,7 +548,7 @@ static void computeKnownBitsFromAssume(const Value *V, KnownBits &Known, m_BitCast(m_Specific(V)))); CmpInst::Predicate Pred; - ConstantInt *C; + uint64_t C; // assume(v = a) if (match(Arg, m_c_ICmp(Pred, m_V, m_Value(A))) && Pred == ICmpInst::ICMP_EQ && isValidAssumeForContext(I, Q.CxtI, Q.DT)) { @@ -650,51 +650,55 @@ static void computeKnownBitsFromAssume(const Value *V, KnownBits &Known, } else if (match(Arg, m_c_ICmp(Pred, m_Shl(m_V, m_ConstantInt(C)), m_Value(A))) && Pred == ICmpInst::ICMP_EQ && - isValidAssumeForContext(I, Q.CxtI, Q.DT)) { + isValidAssumeForContext(I, Q.CxtI, Q.DT) && + C < BitWidth) { KnownBits RHSKnown(BitWidth); computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I)); // For those bits in RHS that are known, we can propagate them to known // bits in V shifted to the right by C. - RHSKnown.Zero.lshrInPlace(C->getZExtValue()); + RHSKnown.Zero.lshrInPlace(C); Known.Zero |= RHSKnown.Zero; - RHSKnown.One.lshrInPlace(C->getZExtValue()); + RHSKnown.One.lshrInPlace(C); Known.One |= RHSKnown.One; // assume(~(v << c) = a) } else if (match(Arg, m_c_ICmp(Pred, m_Not(m_Shl(m_V, m_ConstantInt(C))), m_Value(A))) && Pred == ICmpInst::ICMP_EQ && - isValidAssumeForContext(I, Q.CxtI, Q.DT)) { + isValidAssumeForContext(I, Q.CxtI, Q.DT) && + C < BitWidth) { KnownBits RHSKnown(BitWidth); computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I)); // For those bits in RHS that are known, we can propagate them inverted // to known bits in V shifted to the right by C. - RHSKnown.One.lshrInPlace(C->getZExtValue()); + RHSKnown.One.lshrInPlace(C); Known.Zero |= RHSKnown.One; - RHSKnown.Zero.lshrInPlace(C->getZExtValue()); + RHSKnown.Zero.lshrInPlace(C); Known.One |= RHSKnown.Zero; // assume(v >> c = a) } else if (match(Arg, m_c_ICmp(Pred, m_Shr(m_V, m_ConstantInt(C)), m_Value(A))) && Pred == ICmpInst::ICMP_EQ && - isValidAssumeForContext(I, Q.CxtI, Q.DT)) { + isValidAssumeForContext(I, Q.CxtI, Q.DT) && + C < BitWidth) { KnownBits RHSKnown(BitWidth); computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I)); // For those bits in RHS that are known, we can propagate them to known // bits in V shifted to the right by C. - Known.Zero |= RHSKnown.Zero << C->getZExtValue(); - Known.One |= RHSKnown.One << C->getZExtValue(); + Known.Zero |= RHSKnown.Zero << C; + Known.One |= RHSKnown.One << C; // assume(~(v >> c) = a) } else if (match(Arg, m_c_ICmp(Pred, m_Not(m_Shr(m_V, m_ConstantInt(C))), m_Value(A))) && Pred == ICmpInst::ICMP_EQ && - isValidAssumeForContext(I, Q.CxtI, Q.DT)) { + isValidAssumeForContext(I, Q.CxtI, Q.DT) && + C < BitWidth) { KnownBits RHSKnown(BitWidth); computeKnownBits(A, RHSKnown, Depth+1, Query(Q, I)); // For those bits in RHS that are known, we can propagate them inverted // to known bits in V shifted to the right by C. - Known.Zero |= RHSKnown.One << C->getZExtValue(); - Known.One |= RHSKnown.Zero << C->getZExtValue(); + Known.Zero |= RHSKnown.One << C; + Known.One |= RHSKnown.Zero << C; // assume(v >=_s c) where c is non-negative } else if (match(Arg, m_ICmp(Pred, m_V, m_Value(A))) && Pred == ICmpInst::ICMP_SGE && |