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factor a bunch of copy/paste code out into a helper function.

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Eliminate the cases checking for cond?0:-1, since that is already
handled by commutative checking.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59388 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-11-16 04:24:12 +00:00
parent f5b55475b3
commit faaf951fab
1 changed files with 35 additions and 61 deletions
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96
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -4205,6 +4205,33 @@ Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) {
return CallInst::Create(F, V);
}
/// MatchSelectFromAndOr - We have an expression of the form (A&C)|(B&D). Check
/// If A is (cond?-1:0) and either B or D is ~(cond?-1,0) or (cond?0,-1), then
/// 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.
Value *Cond = 0, *Cond2 = 0;
ConstantInt *C1, *C2;
if (!match(A, m_Select(m_Value(Cond), m_ConstantInt(C1), m_ConstantInt(C2))))
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, 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, m_Not(SELECT_MATCH(Cond2, -1, 0))) && Cond2 == Cond)
return SelectInst::Create(Cond, C, D);
}
#undef SELECT_MATCH
return 0;
}
Instruction *InstCombiner::visitOr(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
@ -4354,68 +4381,15 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
}
}
#define SELECT_MATCH(Val, I1, I2) \
m_Select(m_Value(Val), m_ConstantInt(I1), m_ConstantInt(I2))
// (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B, and commuted variants
Value *C0 = 0;
if (match(A, SELECT_MATCH(C0, -1, 0))) {
Value *C1 = 0;
if (match(D, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, C, B);
if (match(B, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, C, D);
}
if (match(A, SELECT_MATCH(C0, 0, -1))) {
Value *C1 = 0;
if (match(D, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, B, C);
if (match(B, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, D, C);
}
if (match(B, SELECT_MATCH(C0, -1, 0))) {
Value *C1 = 0;
if (match(C, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, A, D);
if (match(A, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, C, D);
}
if (match(B, SELECT_MATCH(C0, 0, -1))) {
Value *C1 = 0;
if (match(C, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, D, A);
if (match(A, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, D, C);
}
if (match(C, SELECT_MATCH(C0, -1, 0))) {
Value *C1 = 0;
if (match(D, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, A, B);
if (match(B, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, A, D);
}
if (match(C, SELECT_MATCH(C0, 0, -1))) {
Value *C1 = 0;
if (match(D, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, B, A);
if (match(B, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, D, A);
}
if (match(D, SELECT_MATCH(C0, -1, 0))) {
Value *C1 = 0;
if (match(C, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, A, B);
if (match(A, m_Not(SELECT_MATCH(C1, -1, 0))) && C1 == C0)
return SelectInst::Create(C1, C, B);
}
if (match(D, SELECT_MATCH(C0, 0, -1))) {
Value *C1 = 0;
if (match(C, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, B, A);
if (match(A, m_Not(SELECT_MATCH(C1, 0, -1))) && C1 == C0)
return SelectInst::Create(C1, B, C);
}
#undef SELECT_MATCH
if (Instruction *Match = MatchSelectFromAndOr(A, B, C, D))
return Match;
if (Instruction *Match = MatchSelectFromAndOr(B, A, D, C))
return Match;
if (Instruction *Match = MatchSelectFromAndOr(C, B, A, D))
return Match;
if (Instruction *Match = MatchSelectFromAndOr(D, A, B, C))
return Match;
}
// (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts.