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simplify code.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59390 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-11-16 04:26:55 +00:00
parent a74cefa6d3
commit a6a474dca9
1 changed files with 12 additions and 17 deletions
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29
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -4210,30 +4210,25 @@ Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) {
/// we can simplify this expression to "cond ? C : D or B".
static Instruction *MatchSelectFromAndOr(Value *A, Value *B,
Value *C, Value *D) {
// If A is not a select of constants, this can't match.
// If A is not a select of -1/0, this cannot match.
Value *Cond = 0, *Cond2 = 0;
ConstantInt *C1, *C2;
if (!match(A, m_Select(m_Value(Cond), m_ConstantInt(C1), m_ConstantInt(C2))))
if (!match(A, m_Select(m_Value(Cond), m_ConstantInt(-1), m_ConstantInt(0))))
return 0;
#define SELECT_MATCH(Val, I1, I2) \
m_Select(m_Value(Val), m_ConstantInt(I1), m_ConstantInt(I2))
// Handle "cond ? -1 : 0".
if (C1->isAllOnesValue() && C2->isZero()) {
// ((cond?-1:0)&C) | (B&(cond?0:-1)) -> cond ? C : B.
if (match(D, SELECT_MATCH(Cond2, 0, -1)) && Cond2 == Cond)
return SelectInst::Create(Cond, C, B);
if (match(D, m_Not(SELECT_MATCH(Cond2, -1, 0))) && Cond2 == Cond)
return SelectInst::Create(Cond, C, B);
// ((cond?-1:0)&C) | ((cond?0:-1)&D) -> cond ? C : D.
if (match(B, SELECT_MATCH(Cond2, 0, -1)) && Cond2 == Cond)
return SelectInst::Create(Cond, C, D);
if (match(B, m_Not(SELECT_MATCH(Cond2, -1, 0))) && Cond2 == Cond)
return SelectInst::Create(Cond, C, D);
}
// ((cond?-1:0)&C) | (B&(cond?0:-1)) -> cond ? C : B.
if (match(D, SELECT_MATCH(Cond2, 0, -1)) && Cond2 == Cond)
return SelectInst::Create(Cond, C, B);
if (match(D, m_Not(SELECT_MATCH(Cond2, -1, 0))) && Cond2 == Cond)
return SelectInst::Create(Cond, C, B);
// ((cond?-1:0)&C) | ((cond?0:-1)&D) -> cond ? C : D.
if (match(B, SELECT_MATCH(Cond2, 0, -1)) && Cond2 == Cond)
return SelectInst::Create(Cond, C, D);
if (match(B, m_Not(SELECT_MATCH(Cond2, -1, 0))) && Cond2 == Cond)
return SelectInst::Create(Cond, C, D);
#undef SELECT_MATCH
return 0;
}