[llvm-commits] [llvm] r140670 - /llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp

[Andrew Trick]

r140671
-Andy

On Sep 27, 2011, at 6:51 PM, Cameron Zwarich wrote:

> Test case?
> 
> Cameron
> 
> On Sep 27, 2011, at 6:35 PM, Andrew Trick <atrick at apple.com> wrote:
> 
>> Author: atrick
>> Date: Tue Sep 27 20:35:36 2011
>> New Revision: 140670
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=140670&view=rev
>> Log:
>> indvars should hoist [sz]ext because licm is not rerun.
>> 
>> Modified:
>>   llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
>> 
>> Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=140670&r1=140669&r2=140670&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
>> +++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Tue Sep 27 20:35:36 2011
>> @@ -834,6 +834,9 @@
>>  PHINode *CreateWideIV(SCEVExpander &Rewriter);
>> 
>> protected:
>> +  Value *getExtend(Value *NarrowOper, Type *WideType, bool IsSigned,
>> +                   Instruction *Use);
>> +
>>  Instruction *CloneIVUser(NarrowIVDefUse DU);
>> 
>>  const SCEVAddRecExpr *GetWideRecurrence(Instruction *NarrowUse);
>> @@ -846,8 +849,27 @@
>> };
>> } // anonymous namespace
>> 
>> -static Value *getExtend( Value *NarrowOper, Type *WideType,
>> -                               bool IsSigned, IRBuilder<> &Builder) {
>> +/// isLoopInvariant - Perform a quick domtree based check for loop invariance
>> +/// assuming that V is used within the loop. LoopInfo::isLoopInvariant() seems
>> +/// gratuitous for this purpose.
>> +static bool isLoopInvariant(Value *V, const Loop *L, const DominatorTree *DT) {
>> +  Instruction *Inst = dyn_cast<Instruction>(V);
>> +  if (!Inst)
>> +    return true;
>> +
>> +  return DT->properlyDominates(Inst->getParent(), L->getHeader());
>> +}
>> +
>> +Value *WidenIV::getExtend(Value *NarrowOper, Type *WideType, bool IsSigned,
>> +                          Instruction *Use) {
>> +  // Set the debug location and conservative insertion point.
>> +  IRBuilder<> Builder(Use);
>> +  // Hoist the insertion point into loop preheaders as far as possible.
>> +  for (const Loop *L = LI->getLoopFor(Use->getParent());
>> +       L && L->getLoopPreheader() && isLoopInvariant(NarrowOper, L, DT);
>> +       L = L->getParentLoop())
>> +    Builder.SetInsertPoint(L->getLoopPreheader()->getTerminator());
>> +
>>  return IsSigned ? Builder.CreateSExt(NarrowOper, WideType) :
>>                    Builder.CreateZExt(NarrowOper, WideType);
>> }
>> @@ -872,22 +894,21 @@
>>  case Instruction::AShr:
>>    DEBUG(dbgs() << "Cloning IVUser: " << *DU.NarrowUse << "\n");
>> 
>> -    IRBuilder<> Builder(DU.NarrowUse);
>> -
>>    // Replace NarrowDef operands with WideDef. Otherwise, we don't know
>>    // anything about the narrow operand yet so must insert a [sz]ext. It is
>>    // probably loop invariant and will be folded or hoisted. If it actually
>>    // comes from a widened IV, it should be removed during a future call to
>>    // WidenIVUse.
>>    Value *LHS = (DU.NarrowUse->getOperand(0) == DU.NarrowDef) ? DU.WideDef :
>> -      getExtend(DU.NarrowUse->getOperand(0), WideType, IsSigned, Builder);
>> +      getExtend(DU.NarrowUse->getOperand(0), WideType, IsSigned, DU.NarrowUse);
>>    Value *RHS = (DU.NarrowUse->getOperand(1) == DU.NarrowDef) ? DU.WideDef :
>> -      getExtend(DU.NarrowUse->getOperand(1), WideType, IsSigned, Builder);
>> +      getExtend(DU.NarrowUse->getOperand(1), WideType, IsSigned, DU.NarrowUse);
>> 
>>    BinaryOperator *NarrowBO = cast<BinaryOperator>(DU.NarrowUse);
>>    BinaryOperator *WideBO = BinaryOperator::Create(NarrowBO->getOpcode(),
>>                                                    LHS, RHS,
>>                                                    NarrowBO->getName());
>> +    IRBuilder<> Builder(DU.NarrowUse);
>>    Builder.Insert(WideBO);
>>    if (const OverflowingBinaryOperator *OBO =
>>        dyn_cast<OverflowingBinaryOperator>(NarrowBO)) {
>> @@ -1391,17 +1412,6 @@
>>  return Ty;
>> }
>> 
>> -/// isLoopInvariant - Perform a quick domtree based check for loop invariance
>> -/// assuming that V is used within the loop. LoopInfo::isLoopInvariant() seems
>> -/// gratuitous for this purpose.
>> -static bool isLoopInvariant(Value *V, Loop *L, DominatorTree *DT) {
>> -  Instruction *Inst = dyn_cast<Instruction>(V);
>> -  if (!Inst)
>> -    return true;
>> -
>> -  return DT->properlyDominates(Inst->getParent(), L->getHeader());
>> -}
>> -
>> /// getLoopPhiForCounter - Return the loop header phi IFF IncV adds a loop
>> /// invariant value to the phi.
>> static PHINode *getLoopPhiForCounter(Value *IncV, Loop *L, DominatorTree *DT) {
>> 
>> 
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