While handling floating point IVs lift restrictions on initial value and increment value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59471 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index d580978..ba19fbf 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -446,7 +446,6 @@
bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
-
LI = &getAnalysis<LoopInfo>();
SE = &getAnalysis<ScalarEvolution>();
@@ -723,6 +722,19 @@
Incr->eraseFromParent();
}
+static bool convertToInt(const APFloat &APF, uint64_t *intVal) {
+
+ bool isExact = false;
+ if (APF.convertToInteger(intVal, 32, APF.isNegative(),
+ APFloat::rmTowardZero, &isExact)
+ != APFloat::opOK)
+ return false;
+ if (!isExact)
+ return false;
+ return true;
+
+}
+
/// HandleFloatingPointIV - If the loop has floating induction variable
/// then insert corresponding integer induction variable if possible.
/// For example,
@@ -739,12 +751,14 @@
unsigned BackEdge = IncomingEdge^1;
// Check incoming value.
- ConstantFP *CZ = dyn_cast<ConstantFP>(PH->getIncomingValue(IncomingEdge));
- if (!CZ) return;
- APFloat PHInit = CZ->getValueAPF();
- if (!PHInit.isPosZero()) return;
-
- // Check IV increment.
+ ConstantFP *InitValue = dyn_cast<ConstantFP>(PH->getIncomingValue(IncomingEdge));
+ if (!InitValue) return;
+ uint64_t newInitValue = Type::Int32Ty->getPrimitiveSizeInBits();
+ if (!convertToInt(InitValue->getValueAPF(), &newInitValue))
+ return;
+
+ // Check IV increment. Reject this PH if increement operation is not
+ // an add or increment value can not be represented by an integer.
BinaryOperator *Incr =
dyn_cast<BinaryOperator>(PH->getIncomingValue(BackEdge));
if (!Incr) return;
@@ -755,11 +769,12 @@
IncrVIndex = 0;
IncrValue = dyn_cast<ConstantFP>(Incr->getOperand(IncrVIndex));
if (!IncrValue) return;
- APFloat IVAPF = IncrValue->getValueAPF();
- APFloat One = APFloat(IVAPF.getSemantics(), 1);
- if (!IVAPF.bitwiseIsEqual(One)) return;
+ uint64_t newIncrValue = Type::Int32Ty->getPrimitiveSizeInBits();
+ if (!convertToInt(IncrValue->getValueAPF(), &newIncrValue))
+ return;
- // Check Incr uses.
+ // Check Incr uses. One user is PH and the other users is exit condition used
+ // by the conditional terminator.
Value::use_iterator IncrUse = Incr->use_begin();
Instruction *U1 = cast<Instruction>(IncrUse++);
if (IncrUse == Incr->use_end()) return;
@@ -777,23 +792,17 @@
if (BI->getCondition() != EC) return;
}
- // Find exit value.
+ // Find exit value. If exit value can not be represented as an interger then
+ // do not handle this floating point PH.
ConstantFP *EV = NULL;
unsigned EVIndex = 1;
if (EC->getOperand(1) == Incr)
EVIndex = 0;
EV = dyn_cast<ConstantFP>(EC->getOperand(EVIndex));
if (!EV) return;
- APFloat EVAPF = EV->getValueAPF();
- if (EVAPF.isNegative()) return;
-
- // Find corresponding integer exit value.
uint64_t intEV = Type::Int32Ty->getPrimitiveSizeInBits();
- bool isExact = false;
- if (EVAPF.convertToInteger(&intEV, 32, false, APFloat::rmTowardZero, &isExact)
- != APFloat::opOK)
+ if (!convertToInt(EV->getValueAPF(), &intEV))
return;
- if (!isExact) return;
// Find new predicate for integer comparison.
CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
@@ -826,11 +835,12 @@
// Insert new integer induction variable.
PHINode *NewPHI = PHINode::Create(Type::Int32Ty,
PH->getName()+".int", PH);
- NewPHI->addIncoming(Constant::getNullValue(NewPHI->getType()),
+ NewPHI->addIncoming(ConstantInt::get(Type::Int32Ty, newInitValue),
PH->getIncomingBlock(IncomingEdge));
Value *NewAdd = BinaryOperator::CreateAdd(NewPHI,
- ConstantInt::get(Type::Int32Ty, 1),
+ ConstantInt::get(Type::Int32Ty,
+ newIncrValue),
Incr->getName()+".int", Incr);
NewPHI->addIncoming(NewAdd, PH->getIncomingBlock(BackEdge));
@@ -849,9 +859,16 @@
DeadInsts.insert(Incr);
// Replace floating induction variable.
- UIToFPInst *Conv = new UIToFPInst(NewPHI, PH->getType(), "indvar.conv",
- PH->getParent()->getFirstNonPHI());
- PH->replaceAllUsesWith(Conv);
+ if (EV->getValueAPF().isNegative()
+ || InitValue->getValueAPF().isNegative()) {
+ SIToFPInst *Conv = new SIToFPInst(NewPHI, PH->getType(), "indvar.conv",
+ PH->getParent()->getFirstNonPHI());
+ PH->replaceAllUsesWith(Conv);
+ } else {
+ UIToFPInst *Conv = new UIToFPInst(NewPHI, PH->getType(), "indvar.conv",
+ PH->getParent()->getFirstNonPHI());
+ PH->replaceAllUsesWith(Conv);
+ }
DeadInsts.insert(PH);
}