Handle floating point ivs during doInitialization().
llvm-svn: 59466
This commit is contained in:
Devang Patel
parent
92a36d7a78
commit
aa3d68d301
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@ -96,7 +96,8 @@ namespace {
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void DeleteTriviallyDeadInstructions(SmallPtrSet<Instruction*, 16> &Insts);
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void OptimizeCanonicalIVType(Loop *L);
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void HandleFloatingPointIV(Loop *L);
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void HandleFloatingPointIV(Loop *L, PHINode *PH,
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SmallPtrSet<Instruction*, 16> &DeadInsts);
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};
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}
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@ -433,6 +434,8 @@ bool IndVarSimplify::doInitialization(Loop *L, LPPassManager &LPM) {
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PHINode *PN = cast<PHINode>(I);
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if (isa<PointerType>(PN->getType()))
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EliminatePointerRecurrence(PN, Preheader, DeadInsts);
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else
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HandleFloatingPointIV(L, PN, DeadInsts);
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}
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if (!DeadInsts.empty())
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@ -468,7 +471,6 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
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// auxillary induction variables.
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std::vector<std::pair<PHINode*, SCEVHandle> > IndVars;
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HandleFloatingPointIV(L);
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for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) {
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PHINode *PN = cast<PHINode>(I);
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if (PN->getType()->isInteger()) { // FIXME: when we have fast-math, enable!
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@ -723,149 +725,133 @@ void IndVarSimplify::OptimizeCanonicalIVType(Loop *L) {
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/// HandleFloatingPointIV - If the loop has floating induction variable
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/// then insert corresponding integer induction variable if possible.
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void IndVarSimplify::HandleFloatingPointIV(Loop *L) {
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BasicBlock *Header = L->getHeader();
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SmallVector <PHINode *, 4> FPHIs;
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Instruction *NonPHIInsn = NULL;
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/// For example,
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/// for(double i = 0; i < 10000; ++i)
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/// bar(i)
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/// is converted into
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/// for(int i = 0; i < 10000; ++i)
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/// bar((double)i);
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///
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void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PH,
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SmallPtrSet<Instruction*, 16> &DeadInsts) {
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// Collect all floating point IVs first.
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BasicBlock::iterator I = Header->begin();
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while(true) {
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if (!isa<PHINode>(I)) {
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NonPHIInsn = I;
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break;
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}
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PHINode *PH = cast<PHINode>(I);
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if (PH->getType()->isFloatingPoint())
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FPHIs.push_back(PH);
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++I;
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unsigned IncomingEdge = L->contains(PH->getIncomingBlock(0));
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unsigned BackEdge = IncomingEdge^1;
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// Check incoming value.
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ConstantFP *CZ = dyn_cast<ConstantFP>(PH->getIncomingValue(IncomingEdge));
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if (!CZ) return;
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APFloat PHInit = CZ->getValueAPF();
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if (!PHInit.isPosZero()) return;
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// Check IV increment.
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BinaryOperator *Incr =
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dyn_cast<BinaryOperator>(PH->getIncomingValue(BackEdge));
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if (!Incr) return;
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if (Incr->getOpcode() != Instruction::Add) return;
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ConstantFP *IncrValue = NULL;
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unsigned IncrVIndex = 1;
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if (Incr->getOperand(1) == PH)
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IncrVIndex = 0;
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IncrValue = dyn_cast<ConstantFP>(Incr->getOperand(IncrVIndex));
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if (!IncrValue) return;
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APFloat IVAPF = IncrValue->getValueAPF();
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APFloat One = APFloat(IVAPF.getSemantics(), 1);
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if (!IVAPF.bitwiseIsEqual(One)) return;
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// Check Incr uses.
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Value::use_iterator IncrUse = Incr->use_begin();
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Instruction *U1 = cast<Instruction>(IncrUse++);
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if (IncrUse == Incr->use_end()) return;
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Instruction *U2 = cast<Instruction>(IncrUse++);
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if (IncrUse != Incr->use_end()) return;
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// Find exit condition.
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FCmpInst *EC = dyn_cast<FCmpInst>(U1);
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if (!EC)
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EC = dyn_cast<FCmpInst>(U2);
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if (!EC) return;
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if (BranchInst *BI = dyn_cast<BranchInst>(EC->getParent()->getTerminator())) {
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if (!BI->isConditional()) return;
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if (BI->getCondition() != EC) return;
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}
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for (SmallVector<PHINode *, 4>::iterator I = FPHIs.begin(), E = FPHIs.end();
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I != E; ++I) {
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PHINode *PH = *I;
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unsigned IncomingEdge = L->contains(PH->getIncomingBlock(0));
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unsigned BackEdge = IncomingEdge^1;
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// Check incoming value.
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ConstantFP *CZ = dyn_cast<ConstantFP>(PH->getIncomingValue(IncomingEdge));
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if (!CZ) continue;
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APFloat PHInit = CZ->getValueAPF();
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if (!PHInit.isPosZero()) continue;
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// Check IV increment.
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BinaryOperator *Incr =
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dyn_cast<BinaryOperator>(PH->getIncomingValue(BackEdge));
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if (!Incr) continue;
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if (Incr->getOpcode() != Instruction::Add) continue;
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ConstantFP *IncrValue = NULL;
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unsigned IncrVIndex = 1;
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if (Incr->getOperand(1) == PH)
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IncrVIndex = 0;
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IncrValue = dyn_cast<ConstantFP>(Incr->getOperand(IncrVIndex));
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if (!IncrValue) continue;
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APFloat IVAPF = IncrValue->getValueAPF();
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APFloat One = APFloat(IVAPF.getSemantics(), 1);
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if (!IVAPF.bitwiseIsEqual(One)) continue;
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// Check Incr uses.
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Value::use_iterator IncrUse = Incr->use_begin();
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Instruction *U1 = cast<Instruction>(IncrUse++);
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if (IncrUse == Incr->use_end()) continue;
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Instruction *U2 = cast<Instruction>(IncrUse++);
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if (IncrUse != Incr->use_end()) continue;
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// Find exict condition.
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FCmpInst *EC = dyn_cast<FCmpInst>(U1);
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if (!EC)
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EC = dyn_cast<FCmpInst>(U2);
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if (!EC) continue;
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bool skip = false;
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Instruction *Terminator = EC->getParent()->getTerminator();
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for(Value::use_iterator ECUI = EC->use_begin(), ECUE = EC->use_end();
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ECUI != ECUE; ++ECUI) {
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Instruction *U = cast<Instruction>(ECUI);
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if (U != Terminator) {
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skip = true;
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break;
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}
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}
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if (skip) continue;
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// Find exit value.
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ConstantFP *EV = NULL;
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unsigned EVIndex = 1;
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if (EC->getOperand(1) == Incr)
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EVIndex = 0;
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EV = dyn_cast<ConstantFP>(EC->getOperand(EVIndex));
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if (!EV) continue;
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APFloat EVAPF = EV->getValueAPF();
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if (EVAPF.isNegative()) continue;
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// Find corresponding integer exit value.
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uint64_t integerVal = Type::Int32Ty->getPrimitiveSizeInBits();
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bool isExact = false;
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if (EVAPF.convertToInteger(&integerVal, 32, false, APFloat::rmTowardZero, &isExact)
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!= APFloat::opOK)
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continue;
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if (!isExact) continue;
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// Find new predicate for integer comparison.
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CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
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switch (EC->getPredicate()) {
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case CmpInst::FCMP_OEQ:
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case CmpInst::FCMP_UEQ:
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NewPred = CmpInst::ICMP_EQ;
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break;
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case CmpInst::FCMP_OGT:
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case CmpInst::FCMP_UGT:
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NewPred = CmpInst::ICMP_UGT;
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break;
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case CmpInst::FCMP_OGE:
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case CmpInst::FCMP_UGE:
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NewPred = CmpInst::ICMP_UGE;
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break;
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case CmpInst::FCMP_OLT:
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case CmpInst::FCMP_ULT:
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NewPred = CmpInst::ICMP_ULT;
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break;
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case CmpInst::FCMP_OLE:
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case CmpInst::FCMP_ULE:
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NewPred = CmpInst::ICMP_ULE;
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break;
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default:
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break;
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}
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if (NewPred == CmpInst::BAD_ICMP_PREDICATE) continue;
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// Insert new integer induction variable.
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SCEVExpander Rewriter(*SE, *LI);
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PHINode *NewIV =
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cast<PHINode>(Rewriter.getOrInsertCanonicalInductionVariable(L,Type::Int32Ty));
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ConstantInt *NewEV = ConstantInt::get(Type::Int32Ty, integerVal);
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Value *LHS = (EVIndex == 1 ? NewIV->getIncomingValue(BackEdge) : NewEV);
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Value *RHS = (EVIndex == 1 ? NewEV : NewIV->getIncomingValue(BackEdge));
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ICmpInst *NewEC = new ICmpInst(NewPred, LHS, RHS, EC->getNameStart(),
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EC->getParent()->getTerminator());
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// Delete old, floating point, exit comparision instruction.
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SE->deleteValueFromRecords(EC);
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EC->replaceAllUsesWith(NewEC);
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EC->eraseFromParent();
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// Delete old, floating point, increment instruction.
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SE->deleteValueFromRecords(Incr);
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Incr->replaceAllUsesWith(UndefValue::get(Incr->getType()));
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Incr->eraseFromParent();
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// Replace floating induction variable.
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UIToFPInst *Conv = new UIToFPInst(NewIV, PH->getType(), "indvar.conv",
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NonPHIInsn);
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PH->replaceAllUsesWith(Conv);
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SE->deleteValueFromRecords(PH);
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PH->removeIncomingValue((unsigned)0);
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PH->removeIncomingValue((unsigned)0);
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// Find exit value.
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ConstantFP *EV = NULL;
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unsigned EVIndex = 1;
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if (EC->getOperand(1) == Incr)
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EVIndex = 0;
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EV = dyn_cast<ConstantFP>(EC->getOperand(EVIndex));
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if (!EV) return;
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APFloat EVAPF = EV->getValueAPF();
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if (EVAPF.isNegative()) return;
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// Find corresponding integer exit value.
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uint64_t intEV = Type::Int32Ty->getPrimitiveSizeInBits();
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bool isExact = false;
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if (EVAPF.convertToInteger(&intEV, 32, false, APFloat::rmTowardZero, &isExact)
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!= APFloat::opOK)
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return;
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if (!isExact) return;
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// Find new predicate for integer comparison.
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CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
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switch (EC->getPredicate()) {
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case CmpInst::FCMP_OEQ:
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case CmpInst::FCMP_UEQ:
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NewPred = CmpInst::ICMP_EQ;
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break;
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case CmpInst::FCMP_OGT:
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case CmpInst::FCMP_UGT:
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NewPred = CmpInst::ICMP_UGT;
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break;
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case CmpInst::FCMP_OGE:
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case CmpInst::FCMP_UGE:
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NewPred = CmpInst::ICMP_UGE;
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break;
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case CmpInst::FCMP_OLT:
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case CmpInst::FCMP_ULT:
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NewPred = CmpInst::ICMP_ULT;
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break;
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case CmpInst::FCMP_OLE:
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case CmpInst::FCMP_ULE:
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NewPred = CmpInst::ICMP_ULE;
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break;
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default:
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break;
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}
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if (NewPred == CmpInst::BAD_ICMP_PREDICATE) return;
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// Insert new integer induction variable.
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PHINode *NewPHI = PHINode::Create(Type::Int32Ty,
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PH->getName()+".int", PH);
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NewPHI->addIncoming(Constant::getNullValue(NewPHI->getType()),
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PH->getIncomingBlock(IncomingEdge));
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Value *NewAdd = BinaryOperator::CreateAdd(NewPHI,
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ConstantInt::get(Type::Int32Ty, 1),
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Incr->getName()+".int", Incr);
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NewPHI->addIncoming(NewAdd, PH->getIncomingBlock(BackEdge));
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ConstantInt *NewEV = ConstantInt::get(Type::Int32Ty, intEV);
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Value *LHS = (EVIndex == 1 ? NewPHI->getIncomingValue(BackEdge) : NewEV);
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Value *RHS = (EVIndex == 1 ? NewEV : NewPHI->getIncomingValue(BackEdge));
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ICmpInst *NewEC = new ICmpInst(NewPred, LHS, RHS, EC->getNameStart(),
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EC->getParent()->getTerminator());
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// Delete old, floating point, exit comparision instruction.
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EC->replaceAllUsesWith(NewEC);
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DeadInsts.insert(EC);
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// Delete old, floating point, increment instruction.
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Incr->replaceAllUsesWith(UndefValue::get(Incr->getType()));
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DeadInsts.insert(Incr);
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// Replace floating induction variable.
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UIToFPInst *Conv = new UIToFPInst(NewPHI, PH->getType(), "indvar.conv",
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PH->getParent()->getFirstNonPHI());
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PH->replaceAllUsesWith(Conv);
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DeadInsts.insert(PH);
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}
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