instcombine: alloca: Remove nesting in simplifyAllocaArraySize(), NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232199 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith 2015-03-13 19:26:33 +00:00
parent cd67bbf07f
commit 7c93bfa994

View File

@ -174,11 +174,13 @@ static Instruction *simplifyAllocaArraySize(InstCombiner &IC, AllocaInst &AI) {
return &AI; return &AI;
} }
// Check C != 1
if (!AI.isArrayAllocation())
return nullptr;
// Convert: alloca Ty, C - where C is a constant != 1 into: alloca [C x Ty], 1 // Convert: alloca Ty, C - where C is a constant != 1 into: alloca [C x Ty], 1
if (AI.isArrayAllocation()) { // Check C != 1
if (const ConstantInt *C = dyn_cast<ConstantInt>(AI.getArraySize())) { if (const ConstantInt *C = dyn_cast<ConstantInt>(AI.getArraySize())) {
Type *NewTy = Type *NewTy = ArrayType::get(AI.getAllocatedType(), C->getZExtValue());
ArrayType::get(AI.getAllocatedType(), C->getZExtValue());
AllocaInst *New = IC.Builder->CreateAlloca(NewTy, nullptr, AI.getName()); AllocaInst *New = IC.Builder->CreateAlloca(NewTy, nullptr, AI.getName());
New->setAlignment(AI.getAlignment()); New->setAlignment(AI.getAlignment());
@ -186,7 +188,8 @@ static Instruction *simplifyAllocaArraySize(InstCombiner &IC, AllocaInst &AI) {
// allocas if possible...also skip interleaved debug info // allocas if possible...also skip interleaved debug info
// //
BasicBlock::iterator It = New; BasicBlock::iterator It = New;
while (isa<AllocaInst>(*It) || isa<DbgInfoIntrinsic>(*It)) ++It; while (isa<AllocaInst>(*It) || isa<DbgInfoIntrinsic>(*It))
++It;
// Now that I is pointing to the first non-allocation-inst in the block, // Now that I is pointing to the first non-allocation-inst in the block,
// insert our getelementptr instruction... // insert our getelementptr instruction...
@ -201,10 +204,10 @@ static Instruction *simplifyAllocaArraySize(InstCombiner &IC, AllocaInst &AI) {
// Now make everything use the getelementptr instead of the original // Now make everything use the getelementptr instead of the original
// allocation. // allocation.
return IC.ReplaceInstUsesWith(AI, GEP); return IC.ReplaceInstUsesWith(AI, GEP);
} else if (isa<UndefValue>(AI.getArraySize())) { }
if (isa<UndefValue>(AI.getArraySize()))
return IC.ReplaceInstUsesWith(AI, Constant::getNullValue(AI.getType())); return IC.ReplaceInstUsesWith(AI, Constant::getNullValue(AI.getType()));
}
}
return nullptr; return nullptr;
} }