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Revert 54821. It's miscompiling 252.eon and 447.dealII

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54878 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2008-08-17 08:07:31 +00:00
parent cbe23e33ba
commit ee2aa85f44
1 changed files with 1 additions and 118 deletions
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117
lib/Transforms/Scalar/LoopStrengthReduce.cpp
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@ -45,7 +45,6 @@ STATISTIC(NumReduced , "Number of GEPs strength reduced");
STATISTIC(NumInserted, "Number of PHIs inserted");
STATISTIC(NumVariable, "Number of PHIs with variable strides");
STATISTIC(NumEliminated , "Number of strides eliminated");
STATISTIC(NumShadow , "Number of Shadow IVs optimized");
namespace {
@ -178,11 +177,6 @@ private:
IVStrideUse* &CondUse,
const SCEVHandle* &CondStride);
void OptimizeIndvars(Loop *L);
/// OptimizeShadowIV - If IV is used in a int-to-float cast
/// inside the loop then try to eliminate the cast opeation.
void OptimizeShadowIV(Loop *L, ICmpInst *Cond,
const SCEVHandle *&CondStride);
bool FindIVUserForCond(ICmpInst *Cond, IVStrideUse *&CondUse,
const SCEVHandle *&CondStride);
bool RequiresTypeConversion(const Type *Ty, const Type *NewTy);
@ -1695,115 +1689,6 @@ ICmpInst *LoopStrengthReduce::ChangeCompareStride(Loop *L, ICmpInst *Cond,
return Cond;
}
/// OptimizeShadowIV - If IV is used in a int-to-float cast
/// inside the loop then try to eliminate the cast opeation.
void LoopStrengthReduce::OptimizeShadowIV(Loop *L, ICmpInst *Cond,
const SCEVHandle *&CondStride) {
const SCEVConstant *SC = dyn_cast<SCEVConstant>(*CondStride);
if (!SC) return;
SCEVHandle IterationCount = SE->getIterationCount(L);
if (isa<SCEVCouldNotCompute>(IterationCount))
return;
for (unsigned Stride = 0, e = StrideOrder.size(); Stride != e;
++Stride) {
std::map<SCEVHandle, IVUsersOfOneStride>::iterator SI =
IVUsesByStride.find(StrideOrder[Stride]);
assert(SI != IVUsesByStride.end() && "Stride doesn't exist!");
for (std::vector<IVStrideUse>::iterator UI = SI->second.Users.begin(),
E = SI->second.Users.end(); UI != E; /* empty */) {
std::vector<IVStrideUse>::iterator CandidateUI = UI;
UI++;
Instruction *ShadowUse = CandidateUI->User;
const Type *DestTy = NULL;
/* If shadow use is a int->float cast then insert a second IV
to elminate this cast.
for (unsigned i = 0; i < n; ++i)
foo((double)i);
is trnasformed into
double d = 0.0;
for (unsigned i = 0; i < n; ++i, ++d)
foo(d);
*/
UIToFPInst *UCast = dyn_cast<UIToFPInst>(CandidateUI->User);
if (UCast)
DestTy = UCast->getDestTy();
else {
SIToFPInst *SCast = dyn_cast<SIToFPInst>(CandidateUI->User);
if (!SCast) continue;
DestTy = SCast->getDestTy();
}
PHINode *PH = dyn_cast<PHINode>(ShadowUse->getOperand(0));
if (!PH) continue;
if (PH->getNumIncomingValues() != 2) continue;
const Type *SrcTy = PH->getType();
int Mantissa = DestTy->getFPMantissaWidth();
if (Mantissa == -1) continue;
if ((int)TD->getTypeSizeInBits(SrcTy) > Mantissa)
continue;
unsigned Entry, Latch;
if (PH->getIncomingBlock(0) == L->getLoopPreheader()) {
Entry = 0;
Latch = 1;
} else {
Entry = 1;
Latch = 0;
}
ConstantInt *Init = dyn_cast<ConstantInt>(PH->getIncomingValue(Entry));
if (!Init) continue;
ConstantFP *NewInit = ConstantFP::get(DestTy, Init->getZExtValue());
BinaryOperator *Incr =
dyn_cast<BinaryOperator>(PH->getIncomingValue(Latch));
if (!Incr) continue;
if (Incr->getOpcode() != Instruction::Add
&& Incr->getOpcode() != Instruction::Sub)
continue;
/* Initialize new IV, double d = 0.0 in above example. */
ConstantInt *C = NULL;
if (Incr->getOperand(0) == PH)
C = dyn_cast<ConstantInt>(Incr->getOperand(1));
else if (Incr->getOperand(1) == PH)
C = dyn_cast<ConstantInt>(Incr->getOperand(0));
else
continue;
if (!C) continue;
/* Add new PHINode. */
PHINode *NewPH = PHINode::Create(DestTy, "IV.S.", PH);
/* create new icnrement. '++d' in above example. */
ConstantFP *CFP = ConstantFP::get(DestTy, C->getZExtValue());
BinaryOperator *NewIncr =
BinaryOperator::Create(Incr->getOpcode(),
NewPH, CFP, "IV.S.next.", Incr);
NewPH->addIncoming(NewInit, PH->getIncomingBlock(Entry));
NewPH->addIncoming(NewIncr, PH->getIncomingBlock(Latch));
/* Remove cast operation */
ShadowUse->replaceAllUsesWith(NewPH);
ShadowUse->eraseFromParent();
SI->second.Users.erase(CandidateUI);
NumShadow++;
break;
}
}
}
// OptimizeIndvars - Now that IVUsesByStride is set up with all of the indvar
// uses in the loop, look to see if we can eliminate some, in favor of using
// common indvars for the different uses.
@ -1831,8 +1716,6 @@ void LoopStrengthReduce::OptimizeIndvars(Loop *L) {
if (!FindIVUserForCond(Cond, CondUse, CondStride))
return; // setcc doesn't use the IV.
OptimizeShadowIV(L, Cond, CondStride);
// If possible, change stride and operands of the compare instruction to
// eliminate one stride.
Cond = ChangeCompareStride(L, Cond, CondUse, CondStride);