diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 26 |
1 files changed, 10 insertions, 16 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 2de83a01062..98e3fde95b3 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1097,20 +1097,11 @@ static Instruction *foldLogicCastConstant(BinaryOperator &Logic, CastInst *Cast, Type *DestTy = Logic.getType(); Type *SrcTy = Cast->getSrcTy(); - // If the first operand is bitcast, move the logic operation ahead of the - // bitcast (do the logic operation in the original type). This can eliminate - // bitcasts and allow combines that would otherwise be impeded by the bitcast. + // Move the logic operation ahead of a zext if the constant is unchanged in + // the smaller source type. Performing the logic in a smaller type may provide + // more information to later folds, and the smaller logic instruction may be + // cheaper (particularly in the case of vectors). Value *X; - if (match(Cast, m_BitCast(m_Value(X)))) { - Value *NewConstant = ConstantExpr::getBitCast(C, SrcTy); - Value *NewOp = Builder->CreateBinOp(LogicOpc, X, NewConstant); - return CastInst::CreateBitOrPointerCast(NewOp, DestTy); - } - - // Similarly, move the logic operation ahead of a zext if the constant is - // unchanged in the smaller source type. Performing the logic in a smaller - // type may provide more information to later folds, and the smaller logic - // instruction may be cheaper (particularly in the case of vectors). if (match(Cast, m_OneUse(m_ZExt(m_Value(X))))) { Constant *TruncC = ConstantExpr::getTrunc(C, SrcTy); Constant *ZextTruncC = ConstantExpr::getZExt(TruncC, DestTy); @@ -1579,11 +1570,14 @@ static Value *getSelectCondition(Value *A, Value *B, // If A and B are sign-extended, look through the sexts to find the booleans. Value *Cond; + Value *NotB; if (match(A, m_SExt(m_Value(Cond))) && Cond->getType()->getScalarType()->isIntegerTy(1) && - match(B, m_CombineOr(m_Not(m_SExt(m_Specific(Cond))), - m_SExt(m_Not(m_Specific(Cond)))))) - return Cond; + match(B, m_OneUse(m_Not(m_Value(NotB))))) { + NotB = peekThroughBitcast(NotB, true); + if (match(NotB, m_SExt(m_Specific(Cond)))) + return Cond; + } // All scalar (and most vector) possibilities should be handled now. // Try more matches that only apply to non-splat constant vectors. |
