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indvars: cleanup the IV visitor. It does more than gather sext/zext info.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198353 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Trick 2014-01-02 21:12:11 +00:00
parent daf7c149e4
commit 5f8e79e6d2
1 changed files with 33 additions and 25 deletions
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58
lib/Transforms/Scalar/IndVarSimplify.cpp
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@ -637,30 +637,13 @@ namespace {
WideIVInfo() : NarrowIV(0), WidestNativeType(0), IsSigned(false) {}
};
class WideIVVisitor : public IVVisitor {
ScalarEvolution *SE;
const DataLayout *TD;
public:
WideIVInfo WI;
WideIVVisitor(PHINode *NarrowIV, ScalarEvolution *SCEV,
const DataLayout *TData, const DominatorTree *DTree):
SE(SCEV), TD(TData) {
DT = DTree;
WI.NarrowIV = NarrowIV;
}
// Implement the interface used by simplifyUsersOfIV.
virtual void visitCast(CastInst *Cast);
};
}
/// visitCast - Update information about the induction variable that is
/// extended by this sign or zero extend operation. This is used to determine
/// the final width of the IV before actually widening it.
void WideIVVisitor::visitCast(CastInst *Cast) {
static void visitIVCast(CastInst *Cast, WideIVInfo &WI, ScalarEvolution *SE,
const DataLayout *TD) {
bool IsSigned = Cast->getOpcode() == Instruction::SExt;
if (!IsSigned && Cast->getOpcode() != Instruction::ZExt)
return;
@ -1092,10 +1075,37 @@ PHINode *WidenIV::CreateWideIV(SCEVExpander &Rewriter) {
return WidePhi;
}
//===----------------------------------------------------------------------===//
// Live IV Reduction - Minimize IVs live across the loop.
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Simplification of IV users based on SCEV evaluation.
//===----------------------------------------------------------------------===//
namespace {
class IndVarSimplifyVisitor : public IVVisitor {
ScalarEvolution *SE;
const DataLayout *TD;
PHINode *IVPhi;
public:
WideIVInfo WI;
IndVarSimplifyVisitor(PHINode *IV, ScalarEvolution *SCEV,
const DataLayout *TData, const DominatorTree *DTree):
SE(SCEV), TD(TData), IVPhi(IV) {
DT = DTree;
WI.NarrowIV = IVPhi;
if (ReduceLiveIVs)
setSplitOverflowIntrinsics();
}
// Implement the interface used by simplifyUsersOfIV.
virtual void visitCast(CastInst *Cast) { visitIVCast(Cast, WI, SE, TD); }
};
}
/// SimplifyAndExtend - Iteratively perform simplification on a worklist of IV
/// users. Each successive simplification may push more users which may
@ -1127,14 +1137,12 @@ void IndVarSimplify::SimplifyAndExtend(Loop *L,
PHINode *CurrIV = LoopPhis.pop_back_val();
// Information about sign/zero extensions of CurrIV.
WideIVVisitor WIV(CurrIV, SE, TD, DT);
if (ReduceLiveIVs)
WIV.setSplitOverflowIntrinsics();
IndVarSimplifyVisitor Visitor(CurrIV, SE, TD, DT);
Changed |= simplifyUsersOfIV(CurrIV, SE, &LPM, DeadInsts, &WIV);
Changed |= simplifyUsersOfIV(CurrIV, SE, &LPM, DeadInsts, &Visitor);
if (WIV.WI.WidestNativeType) {
WideIVs.push_back(WIV.WI);
if (Visitor.WI.WidestNativeType) {
WideIVs.push_back(Visitor.WI);
}
} while(!LoopPhis.empty());