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tidy up code.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123564 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-01-16 04:37:29 +00:00
parent 66f708f7e5
commit 5aac83288c
1 changed files with 20 additions and 16 deletions
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36
lib/Transforms/InstCombine/InstructionCombining.cpp
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@ -520,12 +520,13 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I,
AllowAggressive = false;
PHINode *PN = cast<PHINode>(I.getOperand(0));
unsigned NumPHIValues = PN->getNumIncomingValues();
if (NumPHIValues == 0 ||
// We normally only transform phis with a single use, unless we're trying
// hard to make jump threading happen.
(!PN->hasOneUse() && !AllowAggressive))
if (NumPHIValues == 0)
return 0;
// We normally only transform phis with a single use, unless we're trying
// hard to make jump threading happen.
if (!PN->hasOneUse() && !AllowAggressive)
return 0;
// Check to see if all of the operands of the PHI are simple constants
// (constantint/constantfp/undef). If there is one non-constant value,
@ -533,18 +534,21 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I,
// bail out. We don't do arbitrary constant expressions here because moving
// their computation can be expensive without a cost model.
BasicBlock *NonConstBB = 0;
for (unsigned i = 0; i != NumPHIValues; ++i)
if (!isa<Constant>(PN->getIncomingValue(i)) ||
isa<ConstantExpr>(PN->getIncomingValue(i))) {
if (NonConstBB) return 0; // More than one non-const value.
if (isa<PHINode>(PN->getIncomingValue(i))) return 0; // Itself a phi.
NonConstBB = PN->getIncomingBlock(i);
// If the incoming non-constant value is in I's block, we have an infinite
// loop.
if (NonConstBB == I.getParent())
return 0;
}
for (unsigned i = 0; i != NumPHIValues; ++i) {
Value *InVal = PN->getIncomingValue(i);
if (isa<Constant>(InVal) && !isa<ConstantExpr>(InVal))
continue;
if (isa<PHINode>(InVal)) return 0; // Itself a phi.
if (NonConstBB) return 0; // More than one non-const value.
NonConstBB = PN->getIncomingBlock(i);
// If the incoming non-constant value is in I's block, we have an infinite
// loop.
if (NonConstBB == I.getParent())
return 0;
}
// If there is exactly one non-constant value, we can insert a copy of the
// operation in that block. However, if this is a critical edge, we would be