diff options
| author | Chen Zheng <shchenz@cn.ibm.com> | 2018-07-21 12:27:54 +0000 |
|---|---|---|
| committer | Chen Zheng <shchenz@cn.ibm.com> | 2018-07-21 12:27:54 +0000 |
| commit | 69bb064539612120250539afb1ee961c698b182b (patch) | |
| tree | 8adf075c3bad159a730f374e891c562fc6af8a97 /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | 23c2d1c15a9c89f313304c22180fb5cae97211bc (diff) | |
| download | llvm-69bb064539612120250539afb1ee961c698b182b.zip llvm-69bb064539612120250539afb1ee961c698b182b.tar.gz llvm-69bb064539612120250539afb1ee961c698b182b.tar.bz2 | |
[InstrSimplify] fold sdiv if two operands are negated and non-overflow
Differential Revision: https://reviews.llvm.org/D49382
llvm-svn: 337642
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 054f981..54828e3 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -4511,21 +4511,25 @@ static SelectPatternResult matchMinMax(CmpInst::Predicate Pred, return {SPF_UNKNOWN, SPNB_NA, false}; } -bool llvm::isKnownNegation(const Value *X, const Value *Y) { +bool llvm::isKnownNegation(const Value *X, const Value *Y, bool NeedNSW) { assert(X && Y && "Invalid operand"); - // X = sub (0, Y) - if (match(X, m_Neg(m_Specific(Y)))) + // X = sub (0, Y) || X = sub nsw (0, Y) + if ((!NeedNSW && match(X, m_Sub(m_ZeroInt(), m_Specific(Y)))) || + (NeedNSW && match(X, m_NSWSub(m_ZeroInt(), m_Specific(Y))))) return true; - // Y = sub (0, X) - if (match(Y, m_Neg(m_Specific(X)))) + // Y = sub (0, X) || Y = sub nsw (0, X) + if ((!NeedNSW && match(Y, m_Sub(m_ZeroInt(), m_Specific(X)))) || + (NeedNSW && match(Y, m_NSWSub(m_ZeroInt(), m_Specific(X))))) return true; - // X = sub (A, B), Y = sub (B, A) + // X = sub (A, B), Y = sub (B, A) || X = sub nsw (A, B), Y = sub nsw (B, A) Value *A, *B; - return match(X, m_Sub(m_Value(A), m_Value(B))) && - match(Y, m_Sub(m_Specific(B), m_Specific(A))); + return (!NeedNSW && (match(X, m_Sub(m_Value(A), m_Value(B))) && + match(Y, m_Sub(m_Specific(B), m_Specific(A))))) || + (NeedNSW && (match(X, m_NSWSub(m_Value(A), m_Value(B))) && + match(Y, m_NSWSub(m_Specific(B), m_Specific(A))))); } static SelectPatternResult matchSelectPattern(CmpInst::Predicate Pred, |