Add a m_Undef pattern for convenience. This is so that code that uses

pattern matching can also pattern match undef, creating a more uniform
style.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124657 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan Sands 2011-02-01 09:06:20 +00:00
parent 93c780288d
commit f9e4a986c0
2 changed files with 26 additions and 16 deletions

View File

@ -75,6 +75,16 @@ inline constantint_ty<Val> m_ConstantInt() {
return constantint_ty<Val>();
}
struct undef_ty {
template<typename ITy>
bool match(ITy *V) {
return isa<UndefValue>(V);
}
};
/// m_Undef() - Match an arbitrary undef constant.
inline undef_ty m_Undef() { return undef_ty(); }
struct zero_ty {
template<typename ITy>
bool match(ITy *V) {

View File

@ -510,7 +510,7 @@ static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
}
// X + undef -> undef
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Op1;
// X + 0 -> X
@ -576,7 +576,7 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
// X - undef -> undef
// undef - X -> undef
if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1))
if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
return UndefValue::get(Op0->getType());
// X - 0 -> X
@ -699,7 +699,7 @@ static Value *SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD,
}
// X * undef -> 0
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Constant::getNullValue(Op0->getType());
// X * 0 -> 0
@ -771,11 +771,11 @@ static Value *SimplifyDiv(unsigned Opcode, Value *Op0, Value *Op1,
bool isSigned = Opcode == Instruction::SDiv;
// X / undef -> undef
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Op1;
// undef / X -> 0
if (isa<UndefValue>(Op0))
if (match(Op0, m_Undef()))
return Constant::getNullValue(Op0->getType());
// 0 / X -> 0, we don't need to preserve faults!
@ -859,14 +859,14 @@ Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD,
return ::SimplifyUDivInst(Op0, Op1, TD, DT, RecursionLimit);
}
static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD,
const DominatorTree *DT, unsigned MaxRecurse) {
static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *,
const DominatorTree *, unsigned) {
// undef / X -> undef (the undef could be a snan).
if (isa<UndefValue>(Op0))
if (match(Op0, m_Undef()))
return Op0;
// X / undef -> undef
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Op1;
return 0;
@ -898,7 +898,7 @@ static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
return Op0;
// X shift by undef -> undef because it may shift by the bitwidth.
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Op1;
// Shifting by the bitwidth or more is undefined.
@ -930,7 +930,7 @@ static Value *SimplifyShlInst(Value *Op0, Value *Op1, const TargetData *TD,
return V;
// undef << X -> 0
if (isa<UndefValue>(Op0))
if (match(Op0, m_Undef()))
return Constant::getNullValue(Op0->getType());
return 0;
@ -949,7 +949,7 @@ static Value *SimplifyLShrInst(Value *Op0, Value *Op1, const TargetData *TD,
return V;
// undef >>l X -> 0
if (isa<UndefValue>(Op0))
if (match(Op0, m_Undef()))
return Constant::getNullValue(Op0->getType());
return 0;
@ -972,7 +972,7 @@ static Value *SimplifyAShrInst(Value *Op0, Value *Op1, const TargetData *TD,
return Op0;
// undef >>a X -> all ones
if (isa<UndefValue>(Op0))
if (match(Op0, m_Undef()))
return Constant::getAllOnesValue(Op0->getType());
return 0;
@ -999,7 +999,7 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD,
}
// X & undef -> 0
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Constant::getNullValue(Op0->getType());
// X & X = X
@ -1088,7 +1088,7 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD,
}
// X | undef -> -1
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Constant::getAllOnesValue(Op0->getType());
// X | X = X
@ -1172,7 +1172,7 @@ static Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
}
// A ^ undef -> undef
if (isa<UndefValue>(Op1))
if (match(Op1, m_Undef()))
return Op1;
// A ^ 0 = A