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Value# select instructions, allowing -gcse to remove duplicates

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25969 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-02-04 09:15:29 +00:00
parent 9c4815a036
commit 03f774ad80
1 changed files with 36 additions and 1 deletions
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37
lib/Analysis/ValueNumbering.cpp
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@ -80,8 +80,9 @@ namespace {
void visitGetElementPtrInst(GetElementPtrInst &I);
void visitCastInst(CastInst &I);
void visitShiftInst(ShiftInst &I) { handleBinaryInst((Instruction&)I); }
void visitSelectInst(SelectInst &I);
void visitInstruction(Instruction &) {
// Cannot value number calls or terminator instructions...
// Cannot value number calls or terminator instructions.
}
};
}
@ -198,4 +199,38 @@ void BVNImpl::visitGetElementPtrInst(GetElementPtrInst &I) {
}
}
// isIdenticalSelectInst - Return true if the two select instructions are
// identical.
//
static inline bool isIdenticalSelectInst(const SelectInst &I1,
const SelectInst *I2) {
// Is it embedded in the same function? (This could be false if LHS
// is a constant or global!)
if (I1.getParent()->getParent() != I2->getParent()->getParent())
return false;
// They are identical if both operands are the same!
return I1.getOperand(0) == I2->getOperand(0) &&
I1.getOperand(1) == I2->getOperand(1) &&
I1.getOperand(2) == I2->getOperand(2);
return true;
return false;
}
void BVNImpl::visitSelectInst(SelectInst &I) {
Value *Cond = I.getOperand(0);
for (Value::use_iterator UI = Cond->use_begin(), UE = Cond->use_end();
UI != UE; ++UI)
if (SelectInst *Other = dyn_cast<SelectInst>(*UI))
// Check to see if this new select is not I, but has the same operands.
if (Other != &I && isIdenticalSelectInst(I, Other)) {
// These instructions are identical. Handle the situation.
RetVals.push_back(Other);
}
}
void llvm::BasicValueNumberingStub() { }