Revert r137781; I agree with Duncan's comment that the situation in question is clearly impossible given the current structure of the code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137853 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Friedman 2011-08-17 19:31:49 +00:00
parent 511961a44c
commit f23d4adbfa

View File

@ -1348,11 +1348,6 @@ static Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
std::swap(Op0, Op1);
}
// A ^ A = 0
// Do this first so that we catch the undef ^ undef "idiom".
if (Op0 == Op1)
return Constant::getNullValue(Op0->getType());
// A ^ undef -> undef
if (match(Op1, m_Undef()))
return Op1;
@ -1361,6 +1356,10 @@ static Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD,
if (match(Op1, m_Zero()))
return Op0;
// A ^ A = 0
if (Op0 == Op1)
return Constant::getNullValue(Op0->getType());
// A ^ ~A = ~A ^ A = -1
if (match(Op0, m_Not(m_Specific(Op1))) ||
match(Op1, m_Not(m_Specific(Op0))))