// Calculate Edge Weights using "Pointer Heuristics". Predict a comparsion
// between two pointer or pointer and NULL will fail.
bool BranchProbabilityInfo::calcPointerHeuristics(const BasicBlock *BB) {
const BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator());
if (!BI || !BI->isConditional())
return false;
Value *Cond = BI->getCondition();
ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
if (!CI || !CI->isEquality())
return false;
Value *LHS = CI->getOperand(0);
if (!LHS->getType()->isPointerTy())
return false;
assert(CI->getOperand(1)->getType()->isPointerTy());
// p != 0 -> isProb = true
// p == 0 -> isProb = false
// p != q -> isProb = true
// p == q -> isProb = false;
unsigned TakenIdx = 0, NonTakenIdx = 1;
bool isProb = CI->getPredicate() == ICmpInst::ICMP_NE;
if (!isProb)
std::swap(TakenIdx, NonTakenIdx);
BranchProbability TakenProb(PH_TAKEN_WEIGHT,
PH_TAKEN_WEIGHT + PH_NONTAKEN_WEIGHT);
setEdgeProbability(BB, TakenIdx, TakenProb);
setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
return true;
}
// Calculate Edge Weights using "Pointer Heuristics". Predict a comparsion
// between two pointer or pointer and NULL will fail.
bool BranchProbabilityAnalysis::calcPointerHeuristics(BasicBlock *BB) {
BranchInst * BI = dyn_cast<BranchInst>(BB->getTerminator());
if (!BI || !BI->isConditional())
return false;
Value *Cond = BI->getCondition();
ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
if (!CI || !CI->isEquality())
return false;
Value *LHS = CI->getOperand(0);
if (!LHS->getType()->isPointerTy())
return false;
assert(CI->getOperand(1)->getType()->isPointerTy());
BasicBlock *Taken = BI->getSuccessor(0);
BasicBlock *NonTaken = BI->getSuccessor(1);
// p != 0 -> isProb = true
// p == 0 -> isProb = false
// p != q -> isProb = true
// p == q -> isProb = false;
bool isProb = CI->getPredicate() == ICmpInst::ICMP_NE;
if (!isProb)
std::swap(Taken, NonTaken);
BP->setEdgeWeight(BB, Taken, PH_TAKEN_WEIGHT);
BP->setEdgeWeight(BB, NonTaken, PH_NONTAKEN_WEIGHT);
return true;
}
bool BranchProbabilityInfo::calcZeroHeuristics(BasicBlock *BB) {
BranchInst * BI = dyn_cast<BranchInst>(BB->getTerminator());
if (!BI || !BI->isConditional())
return false;
Value *Cond = BI->getCondition();
ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
if (!CI)
return false;
Value *RHS = CI->getOperand(1);
ConstantInt *CV = dyn_cast<ConstantInt>(RHS);
if (!CV)
return false;
bool isProb;
if (CV->isZero()) {
switch (CI->getPredicate()) {
case CmpInst::ICMP_EQ:
// X == 0 -> Unlikely
isProb = false;
break;
case CmpInst::ICMP_NE:
// X != 0 -> Likely
isProb = true;
break;
case CmpInst::ICMP_SLT:
// X < 0 -> Unlikely
isProb = false;
break;
case CmpInst::ICMP_SGT:
// X > 0 -> Likely
isProb = true;
break;
default:
return false;
}
} else if (CV->isOne() && CI->getPredicate() == CmpInst::ICMP_SLT) {
// InstCombine canonicalizes X <= 0 into X < 1.
// X <= 0 -> Unlikely
isProb = false;
} else if (CV->isAllOnesValue() && CI->getPredicate() == CmpInst::ICMP_SGT) {
// InstCombine canonicalizes X >= 0 into X > -1.
// X >= 0 -> Likely
isProb = true;
} else {
return false;
}
unsigned TakenIdx = 0, NonTakenIdx = 1;
if (!isProb)
std::swap(TakenIdx, NonTakenIdx);
setEdgeWeight(BB, TakenIdx, ZH_TAKEN_WEIGHT);
setEdgeWeight(BB, NonTakenIdx, ZH_NONTAKEN_WEIGHT);
return true;
}
/// Given a LoadInst LI this adds assume(LI != null) after it.
static void addAssumeNonNull(AssumptionCache *AC, LoadInst *LI) {
Function *AssumeIntrinsic =
Intrinsic::getDeclaration(LI->getModule(), Intrinsic::assume);
ICmpInst *LoadNotNull = new ICmpInst(ICmpInst::ICMP_NE, LI,
Constant::getNullValue(LI->getType()));
LoadNotNull->insertAfter(LI);
CallInst *CI = CallInst::Create(AssumeIntrinsic, {LoadNotNull});
CI->insertAfter(LoadNotNull);
AC->registerAssumption(CI);
}
void IndVarSimplify::EliminateIVComparisons() {
// Look for ICmp users.
for (IVUsers::iterator I = IU->begin(), E = IU->end(); I != E; ++I) {
IVStrideUse &UI = *I;
ICmpInst *ICmp = dyn_cast<ICmpInst>(UI.getUser());
if (!ICmp) continue;
bool Swapped = UI.getOperandValToReplace() == ICmp->getOperand(1);
ICmpInst::Predicate Pred = ICmp->getPredicate();
if (Swapped) Pred = ICmpInst::getSwappedPredicate(Pred);
// Get the SCEVs for the ICmp operands.
const SCEV *S = IU->getReplacementExpr(UI);
const SCEV *X = SE->getSCEV(ICmp->getOperand(!Swapped));
// Simplify unnecessary loops away.
const Loop *ICmpLoop = LI->getLoopFor(ICmp->getParent());
S = SE->getSCEVAtScope(S, ICmpLoop);
X = SE->getSCEVAtScope(X, ICmpLoop);
// If the condition is always true or always false, replace it with
// a constant value.
if (SE->isKnownPredicate(Pred, S, X))
ICmp->replaceAllUsesWith(ConstantInt::getTrue(ICmp->getContext()));
else if (SE->isKnownPredicate(ICmpInst::getInversePredicate(Pred), S, X))
ICmp->replaceAllUsesWith(ConstantInt::getFalse(ICmp->getContext()));
else
continue;
DEBUG(dbgs() << "INDVARS: Eliminated comparison: " << *ICmp << '\n');
DeadInsts.push_back(ICmp);
}
}
bool AMDGPUCodeGenPrepare::promoteUniformOpToI32(ICmpInst &I) const {
assert(needsPromotionToI32(I.getOperand(0)->getType()) &&
"I does not need promotion to i32");
IRBuilder<> Builder(&I);
Builder.SetCurrentDebugLocation(I.getDebugLoc());
Type *I32Ty = getI32Ty(Builder, I.getOperand(0)->getType());
Value *ExtOp0 = nullptr;
Value *ExtOp1 = nullptr;
Value *NewICmp = nullptr;
if (I.isSigned()) {
ExtOp0 = Builder.CreateSExt(I.getOperand(0), I32Ty);
ExtOp1 = Builder.CreateSExt(I.getOperand(1), I32Ty);
} else {
ExtOp0 = Builder.CreateZExt(I.getOperand(0), I32Ty);
ExtOp1 = Builder.CreateZExt(I.getOperand(1), I32Ty);
}
NewICmp = Builder.CreateICmp(I.getPredicate(), ExtOp0, ExtOp1);
I.replaceAllUsesWith(NewICmp);
I.eraseFromParent();
return true;
}
bool BranchProbabilityAnalysis::calcZeroHeuristics(BasicBlock *BB) {
BranchInst * BI = dyn_cast<BranchInst>(BB->getTerminator());
if (!BI || !BI->isConditional())
return false;
Value *Cond = BI->getCondition();
ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
if (!CI)
return false;
Value *RHS = CI->getOperand(1);
ConstantInt *CV = dyn_cast<ConstantInt>(RHS);
if (!CV || !CV->isZero())
return false;
bool isProb;
switch (CI->getPredicate()) {
case CmpInst::ICMP_EQ:
// Equal to zero is not expected to be taken.
isProb = false;
break;
case CmpInst::ICMP_NE:
// Not equal to zero is expected.
isProb = true;
break;
case CmpInst::ICMP_SLT:
// Less or equal to zero is not expected.
// X < 0 -> Unlikely
isProb = false;
break;
case CmpInst::ICMP_UGT:
case CmpInst::ICMP_SGT:
// Greater or equal to zero is expected.
// X > 0 -> Likely
isProb = true;
break;
default:
return false;
};
BasicBlock *Taken = BI->getSuccessor(0);
BasicBlock *NonTaken = BI->getSuccessor(1);
if (!isProb)
std::swap(Taken, NonTaken);
BP->setEdgeWeight(BB, Taken, ZH_TAKEN_WEIGHT);
BP->setEdgeWeight(BB, NonTaken, ZH_NONTAKEN_WEIGHT);
return true;
}
bool LowerExpectIntrinsic::HandleIfExpect(BranchInst *BI) {
if (BI->isUnconditional())
return false;
// Handle non-optimized IR code like:
// %expval = call i64 @llvm.expect.i64(i64 %conv1, i64 1)
// %tobool = icmp ne i64 %expval, 0
// br i1 %tobool, label %if.then, label %if.end
//
// Or the following simpler case:
// %expval = call i1 @llvm.expect.i1(i1 %cmp, i1 1)
// br i1 %expval, label %if.then, label %if.end
CallInst *CI;
ICmpInst *CmpI = dyn_cast<ICmpInst>(BI->getCondition());
if (!CmpI) {
CI = dyn_cast<CallInst>(BI->getCondition());
} else {
if (CmpI->getPredicate() != CmpInst::ICMP_NE)
return false;
CI = dyn_cast<CallInst>(CmpI->getOperand(0));
}
if (!CI)
return false;
Function *Fn = CI->getCalledFunction();
if (!Fn || Fn->getIntrinsicID() != Intrinsic::expect)
return false;
Value *ArgValue = CI->getArgOperand(0);
ConstantInt *ExpectedValue = dyn_cast<ConstantInt>(CI->getArgOperand(1));
if (!ExpectedValue)
return false;
MDBuilder MDB(CI->getContext());
MDNode *Node;
// If expect value is equal to 1 it means that we are more likely to take
// branch 0, in other case more likely is branch 1.
if (ExpectedValue->isOne())
Node = MDB.createBranchWeights(LikelyBranchWeight, UnlikelyBranchWeight);
else
Node = MDB.createBranchWeights(UnlikelyBranchWeight, LikelyBranchWeight);
BI->setMetadata(LLVMContext::MD_prof, Node);
if (CmpI)
CmpI->setOperand(0, ArgValue);
else
BI->setCondition(ArgValue);
return true;
}
void TempScopInfo::buildAffineCondition(Value &V, bool inverted,
Comparison **Comp,
TempScop &Scop) const {
Region &R = Scop.getMaxRegion();
ParamSetType &Params = Scop.getParamSet();
if (ConstantInt *C = dyn_cast<ConstantInt>(&V)) {
// If this is always true condition, we will create 1 >= 0,
// otherwise we will create 1 == 0.
SCEVAffFunc *AffLHS = new SCEVAffFunc(SE->getConstant(C->getType(), 0),
SCEVAffFunc::Eq, R, Params, LI, SE);
SCEVAffFunc *AffRHS = new SCEVAffFunc(SE->getConstant(C->getType(), 1),
SCEVAffFunc::Eq, R, Params, LI, SE);
if (C->isOne() == inverted)
*Comp = new Comparison(AffRHS, AffLHS, ICmpInst::ICMP_NE);
else
*Comp = new Comparison(AffLHS, AffLHS, ICmpInst::ICMP_EQ);
return;
}
ICmpInst *ICmp = dyn_cast<ICmpInst>(&V);
assert(ICmp && "Only ICmpInst of constant as condition supported!");
const SCEV *LHS = SE->getSCEV(ICmp->getOperand(0)),
*RHS = SE->getSCEV(ICmp->getOperand(1));
ICmpInst::Predicate Pred = ICmp->getPredicate();
// Invert the predicate if needed.
if (inverted)
Pred = ICmpInst::getInversePredicate(Pred);
SCEVAffFunc *AffLHS = new SCEVAffFunc(LHS, SCEVAffFunc::Eq, R, Params, LI,
SE);
SCEVAffFunc *AffRHS = new SCEVAffFunc(RHS, SCEVAffFunc::Eq, R, Params, LI,
SE);
switch (Pred) {
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
// TODO: At the moment we need to see everything as signed. This is an
// correctness issue that needs to be solved.
//AffLHS->setUnsigned();
//AffRHS->setUnsigned();
break;
default:
break;
}
*Comp = new Comparison(AffLHS, AffRHS, Pred);
}
bool visitICmpInst(ICmpInst& inst) {
// errs() << "got icmp instruction! " << inst << '\n';
bool changed = false;
if (inst.getPredicate() == CmpInst::ICMP_EQ) {
assert(inst.getNumOperands() == 2);
if (inst.getOperand(1) == processing) {
inst.swapOperands();
changed = true;
any_changes = true;
}
assert(dyn_cast<Instruction>(inst.getOperand(0)) == processing);
Value* other = inst.getOperand(1);
if (isa<ConstantPointerNull>(other)) {
if (VERBOSITY("opt") >= 2) {
errs() << inst << '\n';
errs() << "replacing with false!\n";
}
Value* new_value = ConstantInt::getFalse(other->getContext());
inst.replaceAllUsesWith(new_value);
inst.eraseFromParent();
changed = true;
any_changes = true;
}
}
return changed;
}
/// restrictLoopBound - Op dominates loop body. Op compares an IV based value
/// with a loop invariant value. Update loop's lower and upper bound based on
/// the loop invariant value.
bool LoopIndexSplit::restrictLoopBound(ICmpInst &Op) {
bool Sign = Op.isSigned();
Instruction *PHTerm = L->getLoopPreheader()->getTerminator();
if (IVisGT(*ExitCondition) || IVisGE(*ExitCondition)) {
BranchInst *EBR =
cast<BranchInst>(ExitCondition->getParent()->getTerminator());
ExitCondition->setPredicate(ExitCondition->getInversePredicate());
BasicBlock *T = EBR->getSuccessor(0);
EBR->setSuccessor(0, EBR->getSuccessor(1));
EBR->setSuccessor(1, T);
}
LLVMContext &Context = Op.getContext();
// New upper and lower bounds.
Value *NLB = NULL;
Value *NUB = NULL;
if (Value *V = IVisLT(Op)) {
// Restrict upper bound.
if (IVisLE(*ExitCondition))
V = getMinusOne(V, Sign, PHTerm, Context);
NUB = getMin(V, IVExitValue, Sign, PHTerm);
} else if (Value *V = IVisLE(Op)) {
// Restrict upper bound.
if (IVisLT(*ExitCondition))
V = getPlusOne(V, Sign, PHTerm, Context);
NUB = getMin(V, IVExitValue, Sign, PHTerm);
} else if (Value *V = IVisGT(Op)) {
// Restrict lower bound.
V = getPlusOne(V, Sign, PHTerm, Context);
NLB = getMax(V, IVStartValue, Sign, PHTerm);
} else if (Value *V = IVisGE(Op))
// Restrict lower bound.
NLB = getMax(V, IVStartValue, Sign, PHTerm);
if (!NLB && !NUB)
return false;
if (NLB) {
unsigned i = IndVar->getBasicBlockIndex(L->getLoopPreheader());
IndVar->setIncomingValue(i, NLB);
}
if (NUB) {
unsigned i = (ExitCondition->getOperand(0) != IVExitValue);
ExitCondition->setOperand(i, NUB);
}
return true;
}
/// Creates the graphs for this function.
/// It will look for all comparators used in branches, and create them.
/// These comparators will create constraints for any instruction as an
/// operand.
void ABCD::executeABCD(Function &F) {
for (Function::iterator begin = F.begin(), end = F.end();
begin != end; ++begin) {
BasicBlock *BB = begin;
TerminatorInst *TI = BB->getTerminator();
if (TI->getNumOperands() == 0)
continue;
ICmpInst *ICI = dyn_cast<ICmpInst>(TI->getOperand(0));
if (!ICI || !isa<IntegerType>(ICI->getOperand(0)->getType()))
continue;
createConstraintCmpInst(ICI, TI);
seekRedundancy(ICI, TI);
}
}
void TempScopInfo::buildAffineCondition(Value &V, bool inverted,
Comparison **Comp) const {
if (ConstantInt *C = dyn_cast<ConstantInt>(&V)) {
// If this is always true condition, we will create 0 <= 1,
// otherwise we will create 0 >= 1.
const SCEV *LHS = SE->getConstant(C->getType(), 0);
const SCEV *RHS = SE->getConstant(C->getType(), 1);
if (C->isOne() == inverted)
*Comp = new Comparison(LHS, RHS, ICmpInst::ICMP_SLE);
else
*Comp = new Comparison(LHS, RHS, ICmpInst::ICMP_SGE);
return;
}
ICmpInst *ICmp = dyn_cast<ICmpInst>(&V);
assert(ICmp && "Only ICmpInst of constant as condition supported!");
Loop *L = LI->getLoopFor(ICmp->getParent());
const SCEV *LHS = SE->getSCEVAtScope(ICmp->getOperand(0), L);
const SCEV *RHS = SE->getSCEVAtScope(ICmp->getOperand(1), L);
ICmpInst::Predicate Pred = ICmp->getPredicate();
// Invert the predicate if needed.
if (inverted)
Pred = ICmpInst::getInversePredicate(Pred);
switch (Pred) {
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
// TODO: At the moment we need to see everything as signed. This is an
// correctness issue that needs to be solved.
// AffLHS->setUnsigned();
// AffRHS->setUnsigned();
break;
default:
break;
}
*Comp = new Comparison(LHS, RHS, Pred);
}
bool AMDGPUCodeGenPrepare::visitICmpInst(ICmpInst &I) {
bool Changed = false;
if (ST->has16BitInsts() && needsPromotionToI32(I.getOperand(0)->getType()) &&
DA->isUniform(&I))
Changed |= promoteUniformOpToI32(I);
return Changed;
}
/// If From has a conditional jump to To, add the condition to Conditions,
/// if it is relevant to any argument at CS.
static void recordCondition(CallSite CS, BasicBlock *From, BasicBlock *To,
ConditionsTy &Conditions) {
auto *BI = dyn_cast<BranchInst>(From->getTerminator());
if (!BI || !BI->isConditional())
return;
CmpInst::Predicate Pred;
Value *Cond = BI->getCondition();
if (!match(Cond, m_ICmp(Pred, m_Value(), m_Constant())))
return;
ICmpInst *Cmp = cast<ICmpInst>(Cond);
if (Pred == ICmpInst::ICMP_EQ || Pred == ICmpInst::ICMP_NE)
if (isCondRelevantToAnyCallArgument(Cmp, CS))
Conditions.push_back({Cmp, From->getTerminator()->getSuccessor(0) == To
? Pred
: Cmp->getInversePredicate()});
}
bool LowerExpectIntrinsic::HandleIfExpect(BranchInst *BI) {
if (BI->isUnconditional())
return false;
// Handle non-optimized IR code like:
// %expval = call i64 @llvm.expect.i64.i64(i64 %conv1, i64 1)
// %tobool = icmp ne i64 %expval, 0
// br i1 %tobool, label %if.then, label %if.end
ICmpInst *CmpI = dyn_cast<ICmpInst>(BI->getCondition());
if (!CmpI || CmpI->getPredicate() != CmpInst::ICMP_NE)
return false;
CallInst *CI = dyn_cast<CallInst>(CmpI->getOperand(0));
if (!CI)
return false;
Function *Fn = CI->getCalledFunction();
if (!Fn || Fn->getIntrinsicID() != Intrinsic::expect)
return false;
Value *ArgValue = CI->getArgOperand(0);
ConstantInt *ExpectedValue = dyn_cast<ConstantInt>(CI->getArgOperand(1));
if (!ExpectedValue)
return false;
LLVMContext &Context = CI->getContext();
const Type *Int32Ty = Type::getInt32Ty(Context);
bool Likely = ExpectedValue->isOne();
// If expect value is equal to 1 it means that we are more likely to take
// branch 0, in other case more likely is branch 1.
Value *Ops[] = {
MDString::get(Context, "branch_weights"),
ConstantInt::get(Int32Ty, Likely ? LikelyBranchWeight : UnlikelyBranchWeight),
ConstantInt::get(Int32Ty, Likely ? UnlikelyBranchWeight : LikelyBranchWeight)
};
MDNode *WeightsNode = MDNode::get(Context, Ops);
BI->setMetadata(LLVMContext::MD_prof, WeightsNode);
CmpI->setOperand(0, ArgValue);
return true;
}
/// MatchPointerHeuristic - Predict that a comparison of a pointer against
/// null or of two pointers will fail.
/// @returns a Prediction that is a pair in which the first element is the
/// successor taken, and the second the successor not taken.
Prediction BranchHeuristicsInfo::MatchPointerHeuristic(BasicBlock *root) const {
// Last instruction of basic block.
TerminatorInst *TI = root->getTerminator();
// Basic block successors. True and False branches.
BasicBlock *trueSuccessor = TI->getSuccessor(0);
BasicBlock *falseSuccessor = TI->getSuccessor(1);
// Is the last instruction a Branch Instruction?
BranchInst *BI = dyn_cast<BranchInst>(TI);
if (!BI || !BI->isConditional())
return empty;
// Conditional instruction.
Value *cond = BI->getCondition();
// Pointer comparisons are integer comparisons.
ICmpInst *II = dyn_cast<ICmpInst>(cond);
if (!II)
return empty;
// An integer comparison has always two operands.
Value *operand1 = II->getOperand(0);
Value *operand2 = II->getOperand(1);
// Obtain the type of comparison.
enum ICmpInst::Predicate signedPred = II->getSignedPredicate();
// The heuristic states that it must be compared against null,
// but in LLVM, null is also a PointerType, so it only requires
// to test if there is a comparison between two pointers.
if (signedPred == ICmpInst::ICMP_EQ &&
isa<PointerType>(operand1->getType()) && // NULL is a pointer type too
isa<PointerType>(operand2->getType())) { // NULL is a pointer type too
return std::make_pair(falseSuccessor, trueSuccessor);
} else if (signedPred != ICmpInst::ICMP_EQ &&
isa<PointerType>(operand1->getType()) &&
isa<PointerType>(operand2->getType())) {
return std::make_pair(trueSuccessor, falseSuccessor);
}
return empty;
}
// createSigmasForCondBranch
void Redefinition::createSigmasForCondBranch(BranchInst *BI) {
assert(BI->isConditional() && "Expected conditional branch");
ICmpInst *ICI = dyn_cast<ICmpInst>(BI->getCondition());
if (!ICI || !ICI->getOperand(0)->getType()->isIntegerTy())
return;
RDEF_DEBUG(dbgs() << "createSigmasForCondBranch: " << *BI << "\n");
Value *Left = ICI->getOperand(0);
Value *Right = ICI->getOperand(1);
BasicBlock *TB = BI->getSuccessor(0);
BasicBlock *FB = BI->getSuccessor(1);
bool HasSinglePredTB = TB->getSinglePredecessor() != NULL;
bool HasSinglePredFB = FB->getSinglePredecessor() != NULL;
bool IsRedefinableRight = IsRedefinable(Right);
bool SameBranchOperands = Left == Right;
//errs() << HasSinglePredTB << ", " << HasSinglePredFB << "\n";
//errs() << IsRedefinable(Left) << ", " << IsRedefinableRight << "\n";
if (IsRedefinable(Left)) {
// We don't want to place extranius definitions of a value, so the only
// place the sigma once if the branch operands are the same.
Value *Second = SameBranchOperands && IsRedefinableRight ? Right : NULL;
if (HasSinglePredTB)
createSigmaNodesForValueAt(Left, Second, TB);
if (HasSinglePredFB)
createSigmaNodesForValueAt(Left, Second, FB);
}
// Left isn't definable down here.
else if (IsRedefinable(Right)) {
if (HasSinglePredTB)
createSigmaNodesForValueAt(Right, NULL, TB);
if (HasSinglePredFB)
createSigmaNodesForValueAt(Right, NULL, FB);
}
}
void IndVarSimplify::EliminateIVComparisons() {
SmallVector<WeakVH, 16> DeadInsts;
// Look for ICmp users.
for (IVUsers::iterator I = IU->begin(), E = IU->end(); I != E; ++I) {
IVStrideUse &UI = *I;
ICmpInst *ICmp = dyn_cast<ICmpInst>(UI.getUser());
if (!ICmp) continue;
bool Swapped = UI.getOperandValToReplace() == ICmp->getOperand(1);
ICmpInst::Predicate Pred = ICmp->getPredicate();
if (Swapped) Pred = ICmpInst::getSwappedPredicate(Pred);
// Get the SCEVs for the ICmp operands.
const SCEV *S = IU->getReplacementExpr(UI);
const SCEV *X = SE->getSCEV(ICmp->getOperand(!Swapped));
// Simplify unnecessary loops away.
const Loop *ICmpLoop = LI->getLoopFor(ICmp->getParent());
S = SE->getSCEVAtScope(S, ICmpLoop);
X = SE->getSCEVAtScope(X, ICmpLoop);
// If the condition is always true or always false, replace it with
// a constant value.
if (SE->isKnownPredicate(Pred, S, X))
ICmp->replaceAllUsesWith(ConstantInt::getTrue(ICmp->getContext()));
else if (SE->isKnownPredicate(ICmpInst::getInversePredicate(Pred), S, X))
ICmp->replaceAllUsesWith(ConstantInt::getFalse(ICmp->getContext()));
else
continue;
DEBUG(dbgs() << "INDVARS: Eliminated comparison: " << *ICmp << '\n');
DeadInsts.push_back(ICmp);
}
// Now that we're done iterating through lists, clean up any instructions
// which are now dead.
while (!DeadInsts.empty())
if (Instruction *Inst =
dyn_cast_or_null<Instruction>(&*DeadInsts.pop_back_val()))
RecursivelyDeleteTriviallyDeadInstructions(Inst);
}
/// MatchSelectPattern - Pattern match integer [SU]MIN, [SU]MAX, and ABS idioms,
/// returning the kind and providing the out parameter results if we
/// successfully match.
static SelectPatternFlavor
MatchSelectPattern(Value *V, Value *&LHS, Value *&RHS) {
SelectInst *SI = dyn_cast<SelectInst>(V);
if (SI == 0) return SPF_UNKNOWN;
ICmpInst *ICI = dyn_cast<ICmpInst>(SI->getCondition());
if (ICI == 0) return SPF_UNKNOWN;
LHS = ICI->getOperand(0);
RHS = ICI->getOperand(1);
// (icmp X, Y) ? X : Y
if (SI->getTrueValue() == ICI->getOperand(0) &&
SI->getFalseValue() == ICI->getOperand(1)) {
switch (ICI->getPredicate()) {
default: return SPF_UNKNOWN; // Equality.
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE: return SPF_UMAX;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE: return SPF_SMAX;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE: return SPF_UMIN;
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE: return SPF_SMIN;
}
}
// (icmp X, Y) ? Y : X
if (SI->getTrueValue() == ICI->getOperand(1) &&
SI->getFalseValue() == ICI->getOperand(0)) {
switch (ICI->getPredicate()) {
default: return SPF_UNKNOWN; // Equality.
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE: return SPF_UMIN;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE: return SPF_SMIN;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE: return SPF_UMAX;
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE: return SPF_SMAX;
}
}
// TODO: (X > 4) ? X : 5 --> (X >= 5) ? X : 5 --> MAX(X, 5)
return SPF_UNKNOWN;
}
int BranchProbabilities::CheckPointerHeuristic()
{
// Heuristic fails if the last instruction is not a conditional branch
BranchInst *BI = dyn_cast<BranchInst>(_TI);
if ((!BI) || (BI->isUnconditional()))
return -1;
// All pointer comparisons are done with the icmp instruction
ICmpInst *icmp = dyn_cast<ICmpInst>(BI->getCondition());
if (!icmp)
return -1;
Value *v[2];
v[0] = icmp->getOperand(0);
v[1] = icmp->getOperand(1);
// Make sure we're comparing pointers
if (isa<PointerType>(v[0]->getType()))
{
assert(isa<PointerType>(v[1]->getType()) && "v[1] is not a pointer!");
// Choose the prefered branch depending on if this is an eq or neq comp
switch (icmp->getPredicate())
{
case ICmpInst::ICMP_EQ:
return 1;
case ICmpInst::ICMP_NE:
return 0;
default:
assert("non-equality comparison of pointers");
return -1;
}
}
return -1;
}
bool CallAnalyzer::visitICmp(ICmpInst &I) {
Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
// First try to handle simplified comparisons.
if (!isa<Constant>(LHS))
if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
LHS = SimpleLHS;
if (!isa<Constant>(RHS))
if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
RHS = SimpleRHS;
if (Constant *CLHS = dyn_cast<Constant>(LHS))
if (Constant *CRHS = dyn_cast<Constant>(RHS))
if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
SimplifiedValues[&I] = C;
return true;
}
// Otherwise look for a comparison between constant offset pointers with
// a common base.
Value *LHSBase, *RHSBase;
APInt LHSOffset, RHSOffset;
llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
if (LHSBase) {
llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
if (RHSBase && LHSBase == RHSBase) {
// We have common bases, fold the icmp to a constant based on the
// offsets.
Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
SimplifiedValues[&I] = C;
++NumConstantPtrCmps;
return true;
}
}
}
// If the comparison is an equality comparison with null, we can simplify it
// for any alloca-derived argument.
if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1)))
if (isAllocaDerivedArg(I.getOperand(0))) {
// We can actually predict the result of comparisons between an
// alloca-derived value and null. Note that this fires regardless of
// SROA firing.
bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE;
SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType())
: ConstantInt::getFalse(I.getType());
return true;
}
// Finally check for SROA candidates in comparisons.
Value *SROAArg;
DenseMap<Value *, int>::iterator CostIt;
if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
if (isa<ConstantPointerNull>(I.getOperand(1))) {
accumulateSROACost(CostIt, InlineConstants::InstrCost);
return true;
}
disableSROA(CostIt);
}
return false;
}
bool BranchProbabilityInfo::calcZeroHeuristics(BasicBlock *BB) {
BranchInst * BI = dyn_cast<BranchInst>(BB->getTerminator());
if (!BI || !BI->isConditional())
return false;
Value *Cond = BI->getCondition();
ICmpInst *CI = dyn_cast<ICmpInst>(Cond);
if (!CI)
return false;
Value *RHS = CI->getOperand(1);
ConstantInt *CV = dyn_cast<ConstantInt>(RHS);
if (!CV)
return false;
// If the LHS is the result of AND'ing a value with a single bit bitmask,
// we don't have information about probabilities.
if (Instruction *LHS = dyn_cast<Instruction>(CI->getOperand(0)))
if (LHS->getOpcode() == Instruction::And)
if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(LHS->getOperand(1)))
if (AndRHS->getUniqueInteger().isPowerOf2())
return false;
bool isProb;
if (CV->isZero()) {
switch (CI->getPredicate()) {
case CmpInst::ICMP_EQ:
// X == 0 -> Unlikely
isProb = false;
break;
case CmpInst::ICMP_NE:
// X != 0 -> Likely
isProb = true;
break;
case CmpInst::ICMP_SLT:
// X < 0 -> Unlikely
isProb = false;
break;
case CmpInst::ICMP_SGT:
// X > 0 -> Likely
isProb = true;
break;
default:
return false;
}
} else if (CV->isOne() && CI->getPredicate() == CmpInst::ICMP_SLT) {
// InstCombine canonicalizes X <= 0 into X < 1.
// X <= 0 -> Unlikely
isProb = false;
} else if (CV->isAllOnesValue()) {
switch (CI->getPredicate()) {
case CmpInst::ICMP_EQ:
// X == -1 -> Unlikely
isProb = false;
break;
case CmpInst::ICMP_NE:
// X != -1 -> Likely
isProb = true;
break;
case CmpInst::ICMP_SGT:
// InstCombine canonicalizes X >= 0 into X > -1.
// X >= 0 -> Likely
isProb = true;
break;
default:
return false;
}
} else {
return false;
}
unsigned TakenIdx = 0, NonTakenIdx = 1;
if (!isProb)
std::swap(TakenIdx, NonTakenIdx);
BranchProbability TakenProb(ZH_TAKEN_WEIGHT,
ZH_TAKEN_WEIGHT + ZH_NONTAKEN_WEIGHT);
setEdgeProbability(BB, TakenIdx, TakenProb);
setEdgeProbability(BB, NonTakenIdx, TakenProb.getCompl());
return true;
}
bool LoopIndexSplit::splitLoop() {
SplitCondition = NULL;
if (ExitCondition->getPredicate() == ICmpInst::ICMP_NE
|| ExitCondition->getPredicate() == ICmpInst::ICMP_EQ)
return false;
BasicBlock *Header = L->getHeader();
BasicBlock *Latch = L->getLoopLatch();
BranchInst *SBR = NULL; // Split Condition Branch
BranchInst *EBR = cast<BranchInst>(ExitCondition->getParent()->getTerminator());
// If Exiting block includes loop variant instructions then this
// loop may not be split safely.
BasicBlock *ExitingBlock = ExitCondition->getParent();
if (!cleanBlock(ExitingBlock)) return false;
LLVMContext &Context = Header->getContext();
for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
I != E; ++I) {
BranchInst *BR = dyn_cast<BranchInst>((*I)->getTerminator());
if (!BR || BR->isUnconditional()) continue;
ICmpInst *CI = dyn_cast<ICmpInst>(BR->getCondition());
if (!CI || CI == ExitCondition
|| CI->getPredicate() == ICmpInst::ICMP_NE
|| CI->getPredicate() == ICmpInst::ICMP_EQ)
continue;
// Unable to handle triangle loops at the moment.
// In triangle loop, split condition is in header and one of the
// the split destination is loop latch. If split condition is EQ
// then such loops are already handle in processOneIterationLoop().
if (Header == (*I)
&& (Latch == BR->getSuccessor(0) || Latch == BR->getSuccessor(1)))
continue;
// If the block does not dominate the latch then this is not a diamond.
// Such loop may not benefit from index split.
if (!DT->dominates((*I), Latch))
continue;
// If split condition branches heads do not have single predecessor,
// SplitCondBlock, then is not possible to remove inactive branch.
if (!BR->getSuccessor(0)->getSinglePredecessor()
|| !BR->getSuccessor(1)->getSinglePredecessor())
return false;
// If the merge point for BR is not loop latch then skip this condition.
if (BR->getSuccessor(0) != Latch) {
DominanceFrontier::iterator DF0 = DF->find(BR->getSuccessor(0));
assert (DF0 != DF->end() && "Unable to find dominance frontier");
if (!DF0->second.count(Latch))
continue;
}
if (BR->getSuccessor(1) != Latch) {
DominanceFrontier::iterator DF1 = DF->find(BR->getSuccessor(1));
assert (DF1 != DF->end() && "Unable to find dominance frontier");
if (!DF1->second.count(Latch))
continue;
}
SplitCondition = CI;
SBR = BR;
break;
}
if (!SplitCondition)
return false;
// If the predicate sign does not match then skip.
if (ExitCondition->isSigned() != SplitCondition->isSigned())
return false;
unsigned EVOpNum = (ExitCondition->getOperand(1) == IVExitValue);
unsigned SVOpNum = IVBasedValues.count(SplitCondition->getOperand(0));
Value *SplitValue = SplitCondition->getOperand(SVOpNum);
if (!L->isLoopInvariant(SplitValue))
return false;
if (!IVBasedValues.count(SplitCondition->getOperand(!SVOpNum)))
return false;
// Normalize loop conditions so that it is easier to calculate new loop
// bounds.
if (IVisGT(*ExitCondition) || IVisGE(*ExitCondition)) {
ExitCondition->setPredicate(ExitCondition->getInversePredicate());
BasicBlock *T = EBR->getSuccessor(0);
EBR->setSuccessor(0, EBR->getSuccessor(1));
EBR->setSuccessor(1, T);
}
if (IVisGT(*SplitCondition) || IVisGE(*SplitCondition)) {
SplitCondition->setPredicate(SplitCondition->getInversePredicate());
BasicBlock *T = SBR->getSuccessor(0);
SBR->setSuccessor(0, SBR->getSuccessor(1));
SBR->setSuccessor(1, T);
}
//[*] Calculate new loop bounds.
Value *AEV = SplitValue;
Value *BSV = SplitValue;
bool Sign = SplitCondition->isSigned();
Instruction *PHTerm = L->getLoopPreheader()->getTerminator();
if (IVisLT(*ExitCondition)) {
if (IVisLT(*SplitCondition)) {
/* Do nothing */
}
else if (IVisLE(*SplitCondition)) {
AEV = getPlusOne(SplitValue, Sign, PHTerm, Context);
BSV = getPlusOne(SplitValue, Sign, PHTerm, Context);
} else {
assert (0 && "Unexpected split condition!");
}
}
else if (IVisLE(*ExitCondition)) {
if (IVisLT(*SplitCondition)) {
AEV = getMinusOne(SplitValue, Sign, PHTerm, Context);
}
else if (IVisLE(*SplitCondition)) {
BSV = getPlusOne(SplitValue, Sign, PHTerm, Context);
} else {
assert (0 && "Unexpected split condition!");
}
} else {
assert (0 && "Unexpected exit condition!");
}
AEV = getMin(AEV, IVExitValue, Sign, PHTerm);
BSV = getMax(BSV, IVStartValue, Sign, PHTerm);
// [*] Clone Loop
DenseMap<const Value *, Value *> ValueMap;
Loop *BLoop = CloneLoop(L, LPM, LI, ValueMap, this);
Loop *ALoop = L;
// [*] ALoop's exiting edge enters BLoop's header.
// ALoop's original exit block becomes BLoop's exit block.
PHINode *B_IndVar = cast<PHINode>(ValueMap[IndVar]);
BasicBlock *A_ExitingBlock = ExitCondition->getParent();
BranchInst *A_ExitInsn =
dyn_cast<BranchInst>(A_ExitingBlock->getTerminator());
assert (A_ExitInsn && "Unable to find suitable loop exit branch");
BasicBlock *B_ExitBlock = A_ExitInsn->getSuccessor(1);
BasicBlock *B_Header = BLoop->getHeader();
if (ALoop->contains(B_ExitBlock)) {
B_ExitBlock = A_ExitInsn->getSuccessor(0);
A_ExitInsn->setSuccessor(0, B_Header);
} else
A_ExitInsn->setSuccessor(1, B_Header);
// [*] Update ALoop's exit value using new exit value.
ExitCondition->setOperand(EVOpNum, AEV);
// [*] Update BLoop's header phi nodes. Remove incoming PHINode's from
// original loop's preheader. Add incoming PHINode values from
// ALoop's exiting block. Update BLoop header's domiantor info.
// Collect inverse map of Header PHINodes.
DenseMap<Value *, Value *> InverseMap;
for (BasicBlock::iterator BI = ALoop->getHeader()->begin(),
BE = ALoop->getHeader()->end(); BI != BE; ++BI) {
if (PHINode *PN = dyn_cast<PHINode>(BI)) {
PHINode *PNClone = cast<PHINode>(ValueMap[PN]);
InverseMap[PNClone] = PN;
} else
break;
}
BasicBlock *A_Preheader = ALoop->getLoopPreheader();
for (BasicBlock::iterator BI = B_Header->begin(), BE = B_Header->end();
BI != BE; ++BI) {
if (PHINode *PN = dyn_cast<PHINode>(BI)) {
// Remove incoming value from original preheader.
PN->removeIncomingValue(A_Preheader);
// Add incoming value from A_ExitingBlock.
if (PN == B_IndVar)
PN->addIncoming(BSV, A_ExitingBlock);
else {
PHINode *OrigPN = cast<PHINode>(InverseMap[PN]);
Value *V2 = NULL;
// If loop header is also loop exiting block then
// OrigPN is incoming value for B loop header.
if (A_ExitingBlock == ALoop->getHeader())
V2 = OrigPN;
else
V2 = OrigPN->getIncomingValueForBlock(A_ExitingBlock);
PN->addIncoming(V2, A_ExitingBlock);
}
} else
break;
}
DT->changeImmediateDominator(B_Header, A_ExitingBlock);
DF->changeImmediateDominator(B_Header, A_ExitingBlock, DT);
// [*] Update BLoop's exit block. Its new predecessor is BLoop's exit
// block. Remove incoming PHINode values from ALoop's exiting block.
// Add new incoming values from BLoop's incoming exiting value.
// Update BLoop exit block's dominator info..
BasicBlock *B_ExitingBlock = cast<BasicBlock>(ValueMap[A_ExitingBlock]);
for (BasicBlock::iterator BI = B_ExitBlock->begin(), BE = B_ExitBlock->end();
BI != BE; ++BI) {
if (PHINode *PN = dyn_cast<PHINode>(BI)) {
PN->addIncoming(ValueMap[PN->getIncomingValueForBlock(A_ExitingBlock)],
B_ExitingBlock);
PN->removeIncomingValue(A_ExitingBlock);
} else
break;
}
DT->changeImmediateDominator(B_ExitBlock, B_ExitingBlock);
DF->changeImmediateDominator(B_ExitBlock, B_ExitingBlock, DT);
//[*] Split ALoop's exit edge. This creates a new block which
// serves two purposes. First one is to hold PHINode defnitions
// to ensure that ALoop's LCSSA form. Second use it to act
// as a preheader for BLoop.
BasicBlock *A_ExitBlock = SplitEdge(A_ExitingBlock, B_Header, this);
//[*] Preserve ALoop's LCSSA form. Create new forwarding PHINodes
// in A_ExitBlock to redefine outgoing PHI definitions from ALoop.
for(BasicBlock::iterator BI = B_Header->begin(), BE = B_Header->end();
BI != BE; ++BI) {
if (PHINode *PN = dyn_cast<PHINode>(BI)) {
Value *V1 = PN->getIncomingValueForBlock(A_ExitBlock);
PHINode *newPHI = PHINode::Create(PN->getType(), PN->getName());
newPHI->addIncoming(V1, A_ExitingBlock);
A_ExitBlock->getInstList().push_front(newPHI);
PN->removeIncomingValue(A_ExitBlock);
PN->addIncoming(newPHI, A_ExitBlock);
} else
break;
}
//[*] Eliminate split condition's inactive branch from ALoop.
BasicBlock *A_SplitCondBlock = SplitCondition->getParent();
BranchInst *A_BR = cast<BranchInst>(A_SplitCondBlock->getTerminator());
BasicBlock *A_InactiveBranch = NULL;
BasicBlock *A_ActiveBranch = NULL;
A_ActiveBranch = A_BR->getSuccessor(0);
A_InactiveBranch = A_BR->getSuccessor(1);
A_BR->setUnconditionalDest(A_ActiveBranch);
removeBlocks(A_InactiveBranch, L, A_ActiveBranch);
//[*] Eliminate split condition's inactive branch in from BLoop.
BasicBlock *B_SplitCondBlock = cast<BasicBlock>(ValueMap[A_SplitCondBlock]);
BranchInst *B_BR = cast<BranchInst>(B_SplitCondBlock->getTerminator());
BasicBlock *B_InactiveBranch = NULL;
BasicBlock *B_ActiveBranch = NULL;
B_ActiveBranch = B_BR->getSuccessor(1);
B_InactiveBranch = B_BR->getSuccessor(0);
B_BR->setUnconditionalDest(B_ActiveBranch);
removeBlocks(B_InactiveBranch, BLoop, B_ActiveBranch);
BasicBlock *A_Header = ALoop->getHeader();
if (A_ExitingBlock == A_Header)
return true;
//[*] Move exit condition into split condition block to avoid
// executing dead loop iteration.
ICmpInst *B_ExitCondition = cast<ICmpInst>(ValueMap[ExitCondition]);
Instruction *B_IndVarIncrement = cast<Instruction>(ValueMap[IVIncrement]);
ICmpInst *B_SplitCondition = cast<ICmpInst>(ValueMap[SplitCondition]);
moveExitCondition(A_SplitCondBlock, A_ActiveBranch, A_ExitBlock, ExitCondition,
cast<ICmpInst>(SplitCondition), IndVar, IVIncrement,
ALoop, EVOpNum);
moveExitCondition(B_SplitCondBlock, B_ActiveBranch,
B_ExitBlock, B_ExitCondition,
B_SplitCondition, B_IndVar, B_IndVarIncrement,
BLoop, EVOpNum);
NumIndexSplit++;
return true;
}
/// HandleFloatingPointIV - If the loop has floating induction variable
/// then insert corresponding integer induction variable if possible.
/// For example,
/// for(double i = 0; i < 10000; ++i)
/// bar(i)
/// is converted into
/// for(int i = 0; i < 10000; ++i)
/// bar((double)i);
///
void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PN) {
unsigned IncomingEdge = L->contains(PN->getIncomingBlock(0));
unsigned BackEdge = IncomingEdge^1;
// Check incoming value.
ConstantFP *InitValueVal =
dyn_cast<ConstantFP>(PN->getIncomingValue(IncomingEdge));
int64_t InitValue;
if (!InitValueVal || !ConvertToSInt(InitValueVal->getValueAPF(), InitValue))
return;
// Check IV increment. Reject this PN if increment operation is not
// an add or increment value can not be represented by an integer.
BinaryOperator *Incr =
dyn_cast<BinaryOperator>(PN->getIncomingValue(BackEdge));
if (Incr == 0 || Incr->getOpcode() != Instruction::FAdd) return;
// If this is not an add of the PHI with a constantfp, or if the constant fp
// is not an integer, bail out.
ConstantFP *IncValueVal = dyn_cast<ConstantFP>(Incr->getOperand(1));
int64_t IncValue;
if (IncValueVal == 0 || Incr->getOperand(0) != PN ||
!ConvertToSInt(IncValueVal->getValueAPF(), IncValue))
return;
// Check Incr uses. One user is PN and the other user is an 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;
Instruction *U2 = cast<Instruction>(IncrUse++);
if (IncrUse != Incr->use_end()) return;
// Find exit condition, which is an fcmp. If it doesn't exist, or if it isn't
// only used by a branch, we can't transform it.
FCmpInst *Compare = dyn_cast<FCmpInst>(U1);
if (!Compare)
Compare = dyn_cast<FCmpInst>(U2);
if (Compare == 0 || !Compare->hasOneUse() ||
!isa<BranchInst>(Compare->use_back()))
return;
BranchInst *TheBr = cast<BranchInst>(Compare->use_back());
// We need to verify that the branch actually controls the iteration count
// of the loop. If not, the new IV can overflow and no one will notice.
// The branch block must be in the loop and one of the successors must be out
// of the loop.
assert(TheBr->isConditional() && "Can't use fcmp if not conditional");
if (!L->contains(TheBr->getParent()) ||
(L->contains(TheBr->getSuccessor(0)) &&
L->contains(TheBr->getSuccessor(1))))
return;
// If it isn't a comparison with an integer-as-fp (the exit value), we can't
// transform it.
ConstantFP *ExitValueVal = dyn_cast<ConstantFP>(Compare->getOperand(1));
int64_t ExitValue;
if (ExitValueVal == 0 ||
!ConvertToSInt(ExitValueVal->getValueAPF(), ExitValue))
return;
// Find new predicate for integer comparison.
CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
switch (Compare->getPredicate()) {
default: return; // Unknown comparison.
case CmpInst::FCMP_OEQ:
case CmpInst::FCMP_UEQ: NewPred = CmpInst::ICMP_EQ; break;
case CmpInst::FCMP_ONE:
case CmpInst::FCMP_UNE: NewPred = CmpInst::ICMP_NE; break;
case CmpInst::FCMP_OGT:
case CmpInst::FCMP_UGT: NewPred = CmpInst::ICMP_SGT; break;
case CmpInst::FCMP_OGE:
case CmpInst::FCMP_UGE: NewPred = CmpInst::ICMP_SGE; break;
case CmpInst::FCMP_OLT:
case CmpInst::FCMP_ULT: NewPred = CmpInst::ICMP_SLT; break;
case CmpInst::FCMP_OLE:
case CmpInst::FCMP_ULE: NewPred = CmpInst::ICMP_SLE; break;
}
// We convert the floating point induction variable to a signed i32 value if
// we can. This is only safe if the comparison will not overflow in a way
// that won't be trapped by the integer equivalent operations. Check for this
// now.
// TODO: We could use i64 if it is native and the range requires it.
// The start/stride/exit values must all fit in signed i32.
if (!isInt<32>(InitValue) || !isInt<32>(IncValue) || !isInt<32>(ExitValue))
return;
// If not actually striding (add x, 0.0), avoid touching the code.
if (IncValue == 0)
return;
// Positive and negative strides have different safety conditions.
if (IncValue > 0) {
// If we have a positive stride, we require the init to be less than the
// exit value and an equality or less than comparison.
if (InitValue >= ExitValue ||
NewPred == CmpInst::ICMP_SGT || NewPred == CmpInst::ICMP_SGE)
return;
uint32_t Range = uint32_t(ExitValue-InitValue);
if (NewPred == CmpInst::ICMP_SLE) {
// Normalize SLE -> SLT, check for infinite loop.
if (++Range == 0) return; // Range overflows.
}
unsigned Leftover = Range % uint32_t(IncValue);
// If this is an equality comparison, we require that the strided value
// exactly land on the exit value, otherwise the IV condition will wrap
// around and do things the fp IV wouldn't.
if ((NewPred == CmpInst::ICMP_EQ || NewPred == CmpInst::ICMP_NE) &&
Leftover != 0)
return;
// If the stride would wrap around the i32 before exiting, we can't
// transform the IV.
if (Leftover != 0 && int32_t(ExitValue+IncValue) < ExitValue)
return;
} else {
// If we have a negative stride, we require the init to be greater than the
// exit value and an equality or greater than comparison.
if (InitValue >= ExitValue ||
NewPred == CmpInst::ICMP_SLT || NewPred == CmpInst::ICMP_SLE)
return;
uint32_t Range = uint32_t(InitValue-ExitValue);
if (NewPred == CmpInst::ICMP_SGE) {
// Normalize SGE -> SGT, check for infinite loop.
if (++Range == 0) return; // Range overflows.
}
unsigned Leftover = Range % uint32_t(-IncValue);
// If this is an equality comparison, we require that the strided value
// exactly land on the exit value, otherwise the IV condition will wrap
// around and do things the fp IV wouldn't.
if ((NewPred == CmpInst::ICMP_EQ || NewPred == CmpInst::ICMP_NE) &&
Leftover != 0)
return;
// If the stride would wrap around the i32 before exiting, we can't
// transform the IV.
if (Leftover != 0 && int32_t(ExitValue+IncValue) > ExitValue)
return;
}
const IntegerType *Int32Ty = Type::getInt32Ty(PN->getContext());
// Insert new integer induction variable.
PHINode *NewPHI = PHINode::Create(Int32Ty, PN->getName()+".int", PN);
NewPHI->addIncoming(ConstantInt::get(Int32Ty, InitValue),
PN->getIncomingBlock(IncomingEdge));
Value *NewAdd =
BinaryOperator::CreateAdd(NewPHI, ConstantInt::get(Int32Ty, IncValue),
Incr->getName()+".int", Incr);
NewPHI->addIncoming(NewAdd, PN->getIncomingBlock(BackEdge));
ICmpInst *NewCompare = new ICmpInst(TheBr, NewPred, NewAdd,
ConstantInt::get(Int32Ty, ExitValue),
Compare->getName());
// In the following deletions, PN may become dead and may be deleted.
// Use a WeakVH to observe whether this happens.
WeakVH WeakPH = PN;
// Delete the old floating point exit comparison. The branch starts using the
// new comparison.
NewCompare->takeName(Compare);
Compare->replaceAllUsesWith(NewCompare);
RecursivelyDeleteTriviallyDeadInstructions(Compare);
// Delete the old floating point increment.
Incr->replaceAllUsesWith(UndefValue::get(Incr->getType()));
RecursivelyDeleteTriviallyDeadInstructions(Incr);
// If the FP induction variable still has uses, this is because something else
// in the loop uses its value. In order to canonicalize the induction
// variable, we chose to eliminate the IV and rewrite it in terms of an
// int->fp cast.
//
// We give preference to sitofp over uitofp because it is faster on most
// platforms.
if (WeakPH) {
Value *Conv = new SIToFPInst(NewPHI, PN->getType(), "indvar.conv",
PN->getParent()->getFirstNonPHI());
PN->replaceAllUsesWith(Conv);
RecursivelyDeleteTriviallyDeadInstructions(PN);
}
// Add a new IVUsers entry for the newly-created integer PHI.
IU->AddUsersIfInteresting(NewPHI);
}
bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
IU = &getAnalysis<IVUsers>();
LI = &getAnalysis<LoopInfo>();
SE = &getAnalysis<ScalarEvolution>();
DT = &getAnalysis<DominatorTree>();
Changed = false;
// If there are any floating-point recurrences, attempt to
// transform them to use integer recurrences.
RewriteNonIntegerIVs(L);
BasicBlock *ExitingBlock = L->getExitingBlock(); // may be null
const SCEV *BackedgeTakenCount = SE->getBackedgeTakenCount(L);
// Create a rewriter object which we'll use to transform the code with.
SCEVExpander Rewriter(*SE);
// Check to see if this loop has a computable loop-invariant execution count.
// If so, this means that we can compute the final value of any expressions
// that are recurrent in the loop, and substitute the exit values from the
// loop into any instructions outside of the loop that use the final values of
// the current expressions.
//
if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount))
RewriteLoopExitValues(L, Rewriter);
// Compute the type of the largest recurrence expression, and decide whether
// a canonical induction variable should be inserted.
const Type *LargestType = 0;
bool NeedCannIV = false;
if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount)) {
LargestType = BackedgeTakenCount->getType();
LargestType = SE->getEffectiveSCEVType(LargestType);
// If we have a known trip count and a single exit block, we'll be
// rewriting the loop exit test condition below, which requires a
// canonical induction variable.
if (ExitingBlock)
NeedCannIV = true;
}
for (IVUsers::const_iterator I = IU->begin(), E = IU->end(); I != E; ++I) {
const Type *Ty =
SE->getEffectiveSCEVType(I->getOperandValToReplace()->getType());
if (!LargestType ||
SE->getTypeSizeInBits(Ty) >
SE->getTypeSizeInBits(LargestType))
LargestType = Ty;
NeedCannIV = true;
}
// Now that we know the largest of the induction variable expressions
// in this loop, insert a canonical induction variable of the largest size.
Value *IndVar = 0;
if (NeedCannIV) {
// Check to see if the loop already has any canonical-looking induction
// variables. If any are present and wider than the planned canonical
// induction variable, temporarily remove them, so that the Rewriter
// doesn't attempt to reuse them.
SmallVector<PHINode *, 2> OldCannIVs;
while (PHINode *OldCannIV = L->getCanonicalInductionVariable()) {
if (SE->getTypeSizeInBits(OldCannIV->getType()) >
SE->getTypeSizeInBits(LargestType))
OldCannIV->removeFromParent();
else
break;
OldCannIVs.push_back(OldCannIV);
}
IndVar = Rewriter.getOrInsertCanonicalInductionVariable(L, LargestType);
++NumInserted;
Changed = true;
DEBUG(dbgs() << "INDVARS: New CanIV: " << *IndVar << '\n');
// Now that the official induction variable is established, reinsert
// any old canonical-looking variables after it so that the IR remains
// consistent. They will be deleted as part of the dead-PHI deletion at
// the end of the pass.
while (!OldCannIVs.empty()) {
PHINode *OldCannIV = OldCannIVs.pop_back_val();
OldCannIV->insertBefore(L->getHeader()->getFirstNonPHI());
}
}
// If we have a trip count expression, rewrite the loop's exit condition
// using it. We can currently only handle loops with a single exit.
ICmpInst *NewICmp = 0;
if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount) &&
!BackedgeTakenCount->isZero() &&
ExitingBlock) {
assert(NeedCannIV &&
"LinearFunctionTestReplace requires a canonical induction variable");
// Can't rewrite non-branch yet.
if (BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator()))
NewICmp = LinearFunctionTestReplace(L, BackedgeTakenCount, IndVar,
ExitingBlock, BI, Rewriter);
}
// Rewrite IV-derived expressions. Clears the rewriter cache.
RewriteIVExpressions(L, Rewriter);
// The Rewriter may not be used from this point on.
// Loop-invariant instructions in the preheader that aren't used in the
// loop may be sunk below the loop to reduce register pressure.
SinkUnusedInvariants(L);
// For completeness, inform IVUsers of the IV use in the newly-created
// loop exit test instruction.
if (NewICmp)
IU->AddUsersIfInteresting(cast<Instruction>(NewICmp->getOperand(0)));
// Clean up dead instructions.
Changed |= DeleteDeadPHIs(L->getHeader());
// Check a post-condition.
assert(L->isLCSSAForm(*DT) && "Indvars did not leave the loop in lcssa form!");
return Changed;
}
string esp::parseName(Value *value){
// has existed
if(names.find(value) != names.end())
return names[value];
string name = "";
Value *current = value;
/*
bool continueFlag = true;
do{
if(isa<Instruction > (current)){
Instruction* inst = dyn_cast<Instruction>(current);
unsigned op = inst->getOpcode();
switch(op){
case Instruction::Ret :{
break;
}
case Instruction::Br :{
break;
}
case Instruction::Switch :{
break;
}
case Instruction::Call :{
CallInst *callinst = (CallInst*) current;
if (((CallInst*) current)->getCalledFunction() != NULL) {
name += string("@")+((CallInst*) current)->getCalledFunction()->getNameStr() + "(";
} else {
name += string("@[funcPTR](");
name += ((CallInst*) current)->getCalledValue()->getNameStr();
}
for (unsigned i = 1; i < callinst->getNumOperands(); i++) {
name += esp::parseName(callinst->getOperand(i));
}
name += string(")");
continueFlag = false;
break;
}
case Instruction::PHI :{
name += string("PHI[");
name += current->getNameStr();
PHINode *phi = (PHINode*) current;
for (unsigned i = 0; i < phi->getNumIncomingValues(); i++) {
Value *incoming = phi->getIncomingValue(i);
if (i != 0) name += ",";
if (!hasLoop(incoming)) {
if (!incoming->hasName()) {
name += esp::parseName(incoming);
} else {
name += incoming->getNameStr();
}
}
}
name += std::string("]");
continueFlag = false;
break;
}
case Instruction::Select :{
break;
}
case Instruction::Add :{
name += "+";
name += parseBinaryOpName(inst);
break;
}
case Instruction::Sub :{
name += "-";
name += parseBinaryOpName(inst);
break;
}
case Instruction::Mul :{
name += "*";
name += parseBinaryOpName(inst);
break;
}
case Instruction::UDiv :{
name += "/";
name += parseBinaryOpName(inst);
break;
}
case Instruction::SDiv :{
name += "//";
name += parseBinaryOpName(inst);
break;
}
case Instruction::And :{
name += "&";
name += parseBinaryOpName(inst);
break;
}
case Instruction::Or :{
name += "|";
name += parseBinaryOpName(inst);
break;
}
case Instruction::Xor :{
name += "^";
name += parseBinaryOpName(inst);
break;
}
case Instruction::Shl :{
name += "<<";
name += parseBinaryOpName(inst);
break;
}
case Instruction::LShr :{
name += ">>";
name += parseBinaryOpName(inst);
break;
}
case Instruction::AShr :{
name += ">>>";
name += parseBinaryOpName(inst);
break;
}
case Instruction::ICmp :{
ICmpInst * icmp = dyn_cast<ICmpInst>(current);
if (isa<Constant>(icmp->getOperand(0))) {
name += esp::parseName(icmp->getOperand(1));
continueFlag = false;
} else {
name += esp::parseName(icmp->getOperand(0));
continueFlag = false;
}
break;
}
case Instruction::Alloca :{
name += current->getNameStr();
break;
}
case Instruction::Load :{
if (((LoadInst*) inst)->isVolatile())
name += std::string("@VolatileLoad");
name += "*";
name += esp::parseName(inst->getOperand(0));
continueFlag = false;
break;
}
case Instruction::Store :{
// need to handle
continueFlag = false;
break;
}
case Instruction::GetElementPtr :{
GetElementPtrInst * gep = dyn_cast<GetElementPtrInst>(current);
unsigned ops = gep->getNumOperands();
name += "[";
for (unsigned i = 1; i < ops; i++) {
Value *v = gep->getOperand(i);
if (ConstantInt * ci = dyn_cast<ConstantInt>(v)) {
if (i == 1 && ci->equalsInt(0))
continue;
name += ".";
name += ci->getValue().toString(10, false);
} else {
name += ".";
name += esp::parseName(v);
}
}
name += "]";
name += esp::parseName(gep->getOperand(0));
continueFlag = false;
break;
}
case Instruction::BitCast:{
name += esp::parseName(inst->getOperand(0));
continueFlag = false;
break;
}
default :{
// Illegal or unsupported instruction
name += current->getNameStr();
break;
}
}
}else if(isa<Argument>(current)){
if (arguments.find(current) != arguments.end())
name += std::string("$") + current->getNameStr();
}else if(isa<GlobalValue>(current)){
name += std::string("@") + current->getNameStr();
}else if(isa<ConstantInt>(current)){
ConstantInt * cint = dyn_cast<ConstantInt > (current);
name += cint->getValue().toString(10, true);
}else if (isa<Constant > (current)) {
Constant *c = dyn_cast<Constant > (current);
if (c->isNullValue()) {
name += "null";
}
}else{
// Illegal format
}
if(!continueFlag)
break;
current = parents[current];
}while(current);
*/
//Refactor
do {
if (isa<LoadInst > (current)) {
name += "*";
if (parents[current] == NULL)
name += (((LoadInst*) current)->getOperand(0))->getNameStr();
if (((LoadInst*) current)->isVolatile())
name += std::string("@VolatileLoad");
} else if (dyn_cast<GetElementPtrInst > (current)) {
GetElementPtrInst * gep = dyn_cast<GetElementPtrInst > (current);
unsigned ops = gep->getNumOperands();
name += "[";
for (unsigned i = 1; i < ops; i++) {
Value *v = gep->getOperand(i);
if (dyn_cast<ConstantInt > (current)) {
ConstantInt * ci = dyn_cast<ConstantInt > (current);
if (i == 1 && ci->equalsInt(0)) continue;
name += ".";
name += ci->getValue().toString(10, false);
} else {
name += ".";
name += parseName(v);
}
}
name += "]";
name += parseName(gep->getOperand(0));
break;
} else if (isa<AllocaInst > (current)) {
name += current->getNameStr();
} else if (isa<Argument > (current)) {
if (arguments.find(current) != arguments.end())
name += std::string("$") + current->getNameStr();
} else if (isa<GlobalValue > (current)) {
name += std::string("@") + current->getNameStr();
} else if (isa<CallInst > (current)) {
CallInst *callinst = (CallInst*) current;
if (((CallInst*) current)->getCalledFunction() != NULL) {
name += std::string("@")+((CallInst*) current)->getCalledFunction()->getNameStr() + "(";
} else {
name += std::string("@[funcPTR](");
name += ((CallInst*) current)->getCalledValue()->getNameStr();
}
for (unsigned i = 1; i < callinst->getNumOperands(); i++) {
name += parseName(callinst->getOperand(i));
}
name += std::string(")");
break;
} else if (isa<CastInst > (current)) {
} else if (isa<PHINode > (current)) {
/*
name += std::string("PHI[");
s += parent->getNameStr();
PHINode *phi = (PHINode*) parent;
for (unsigned i = 0; i < phi->getNumIncomingValues(); i++) {
//s+=phi->getIncomingBlock(i)->getNameStr();
Value *incoming = phi->getIncomingValue(i);
if (i != 0) s += ",";
if (!hasLoop(incoming)) {
DEBUG(errs() << "incoming#" << i << " no loop(i rather doubt it)\n");
if (!incoming->hasName()) {
s += parseName(incoming);
} else {
s += incoming->getNameStr();
}
}
}
// PHI nodes...ugh
s += std::string("]");
break;
*/
} else if (isa<BinaryOperator > (current)) {
BinaryOperator *bo = dyn_cast<BinaryOperator > (current);
Instruction::BinaryOps opcode = bo->getOpcode();
if (opcode == Instruction::Add) {
name.append("+");
} else if (opcode == Instruction::Sub) {
name.append("-");
} else if (opcode == Instruction::Or) {
name.append("||");
} else if (opcode == Instruction::Mul) {
name.append("*");
} else if (opcode == Instruction::Xor) {
name.append("^");
} else if (opcode == Instruction::And) {
name.append("&&");
} else if (opcode == Instruction::Shl) {
name.append("<<");
} else if (opcode == Instruction::AShr) {
name.append(">>");
} else if (opcode == Instruction::LShr) {
name.append(">>>");
}
Value *v0 = bo->getOperand(0);
Value *v1 = bo->getOperand(1);
if (isa<ConstantInt > (v0)) {
name += ((ConstantInt*) v0)->getValue().toString(10, false);
} else if (isa<ConstantInt > (v1)) {
name += ((ConstantInt*) v1)->getValue().toString(10, false);
} else {
printDebugMsg("Binary Operation between non-constants\n");
}
} else if (dyn_cast<GEPOperator > (current)) {
GEPOperator * gep = dyn_cast<GEPOperator > (current);
unsigned ops = gep->getNumOperands();
name += "[";
for (unsigned i = 1; i < ops; i++) {
Value *v = gep->getOperand(i);
if (dyn_cast<ConstantInt > (v)) {
ConstantInt * ci = dyn_cast<ConstantInt > (v);
if (i == 1 && ci->equalsInt(0)) continue;
name += ".";
name += ci->getValue().toString(10, false);
}
}
name += "]";
name += parseName(gep->getOperand(0));
break;
} else if (dyn_cast<ICmpInst > (current)) {
ICmpInst * icmp = dyn_cast<ICmpInst > (current);
if (isa<Constant > (icmp->getOperand(0))) {
name += parseName(icmp->getOperand(1));
break;
} else {
name += parseName(icmp->getOperand(0));
break;
}
} else if (dyn_cast<ConstantInt > (current)) {
ConstantInt * cint = dyn_cast<ConstantInt > (current);
name += cint->getValue().toString(10, true);
} else {
name += current->getNameStr(); // might not work
}
} while ((current = parents[current]));
names[value] = name;
return name;
}
bool GambasPass::runOnFunction(Function &F){
IRBuilder<> Builder(F.getContext());
bool changed = false;
for(Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
for(BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ){
ICmpInst* ICI = dyn_cast<ICmpInst>(I);
CallInst* CI = dyn_cast<CallInst>(I++);
if (ICI && ICI->hasMetadata() && ICI->getMetadata("unref_slt") && dyn_cast<LoadInst>(ICI->getOperand(0))){
ICI->replaceAllUsesWith(ConstantInt::get(ICI->getType(), false));
ICI->eraseFromParent();
changed = true;
continue;
}
if (!CI)
continue;
Function* callee = CI->getCalledFunction();
if (callee == NULL || !callee->isDeclaration())
continue;
StringRef name = callee->getName();
if (name == "JR_release_variant" || name == "JR_borrow_variant"){
ConstantInt* vtype_int = dyn_cast<ConstantInt>(CI->getArgOperand(0));
if (!vtype_int)
continue;
uint64_t vtype = vtype_int->getZExtValue();
if (TYPE_is_string(vtype) || TYPE_is_object(vtype))
continue;
CI->eraseFromParent();
changed = true;
} else if (name == FUNCTION_NAME(__finite)){
ConstantFP* op = dyn_cast<ConstantFP>(CI->getArgOperand(0));
if (!op)
continue;
int val = __finite(op->getValueAPF().convertToDouble());
Constant* res = ConstantInt::get(CI->getType(), val);
CI->replaceAllUsesWith(res);
CI->eraseFromParent();
changed = true;
} else if (name == FUNCTION_NAME(__isnan)){
ConstantFP* op = dyn_cast<ConstantFP>(CI->getArgOperand(0));
if (!op)
continue;
int val = __isnan(op->getValueAPF().convertToDouble());
Constant* res = ConstantInt::get(CI->getType(), val);
CI->replaceAllUsesWith(res);
CI->eraseFromParent();
changed = true;
} else if (name == FUNCTION_NAME(__isinf)){
ConstantFP* op = dyn_cast<ConstantFP>(CI->getArgOperand(0));
if (!op)
continue;
int val = __isinf(op->getValueAPF().convertToDouble());
Constant* res = ConstantInt::get(CI->getType(), val);
CI->replaceAllUsesWith(res);
CI->eraseFromParent();
changed = true;
}
}
}
return changed;
}
void CPFlowFunction::visitBranchInst(BranchInst &BI) {
CPLatticePoint* result = new CPLatticePoint(*(info_in_casted.back()));
info_in_casted.pop_back();
BranchInst* current = &BI;
if (BI.isConditional()) {
Value* cond = BI.getCondition();
if (isa<ICmpInst>(cond)) {
std::pair<Use*, Use *> branches = helper::getOps(BI);
Use* true_branch = branches.first;
Use* false_branch = branches.second;
ICmpInst* cmp = dyn_cast<ICmpInst>(cond);
std::pair<Use*, Use *> operands = helper::getOps(*cmp);
Use* rhs = operands.second;
Use* lhs = operands.first;
ConstantInt* rhs_const = NULL;
ConstantInt* lhs_const = NULL;
// get the rhs/lhs as a constant int
if (isa<ConstantInt>(rhs)) {
rhs_const = dyn_cast<ConstantInt>(rhs);
} else if (result->representation.count(rhs->get()) > 0) {
rhs_const = result->representation[rhs->get()];
} else {
rhs_const = ConstantInt::get(context, llvm::APInt(32, 0, true));
}
if (isa<ConstantInt>(lhs)) {
lhs_const = dyn_cast<ConstantInt>(lhs->get());
} else if (result->representation.count(lhs->get()) > 0) {
lhs_const = result->representation[lhs->get()];
} else {
lhs_const = ConstantInt::get(context, llvm::APInt(32, 0, true));
}
// Create successors
CPLatticePoint* true_branchCLP = new CPLatticePoint(false, false, std::map<Value*,ConstantInt*>(result->representation));
CPLatticePoint* false_branchCLP = new CPLatticePoint(false, false, std::map<Value*,ConstantInt*>(result->representation));
// get the predicate
int predicate = 0;
predicate = cmp->isSigned() ? cmp->getSignedPredicate() : cmp->getUnsignedPredicate();
if (predicate == CmpInst::ICMP_EQ) {
if (isa<ConstantInt>(lhs)) {
true_branchCLP->representation[rhs->get()] = lhs_const;
} else if (isa<ConstantInt>(rhs)) {
true_branchCLP->representation[lhs->get()] = rhs_const;
}
out_map[true_branch->get()] = true_branchCLP;
out_map[false_branch->get()] = false_branchCLP;
} else if (predicate == CmpInst::ICMP_NE) {
if (isa<ConstantInt>(lhs)) {
false_branchCLP->representation[rhs->get()] = lhs_const;
} else if (isa<ConstantInt>(rhs)) {
false_branchCLP->representation[lhs->get()] = rhs_const;
}
out_map[true_branch->get()] = true_branchCLP;
out_map[false_branch->get()] = false_branchCLP;
} else {
for (std::map<Value *, LatticePoint *>::iterator it=out_map.begin(); it != out_map.end(); ++it){
Value* elm = it->first;
out_map[elm] = new CPLatticePoint(*result);
}
}
} else {
for (std::map<Value *, LatticePoint *>::iterator it=out_map.begin(); it != out_map.end(); ++it){
Value* elm = it->first;
out_map[elm] = new CPLatticePoint(*result);
}
}
} else {
for (std::map<Value *, LatticePoint *>::iterator it=out_map.begin(); it != out_map.end(); ++it){
Value* elm = it->first;
out_map[elm] = new CPLatticePoint(*result);
}
}
}
/// MatchSelectPattern - Pattern match integer [SU]MIN, [SU]MAX, and ABS idioms,
/// returning the kind and providing the out parameter results if we
/// successfully match.
static SelectPatternFlavor
MatchSelectPattern(Value *V, Value *&LHS, Value *&RHS) {
SelectInst *SI = dyn_cast<SelectInst>(V);
if (!SI) return SPF_UNKNOWN;
ICmpInst *ICI = dyn_cast<ICmpInst>(SI->getCondition());
if (!ICI) return SPF_UNKNOWN;
ICmpInst::Predicate Pred = ICI->getPredicate();
Value *CmpLHS = ICI->getOperand(0);
Value *CmpRHS = ICI->getOperand(1);
Value *TrueVal = SI->getTrueValue();
Value *FalseVal = SI->getFalseValue();
LHS = CmpLHS;
RHS = CmpRHS;
// (icmp X, Y) ? X : Y
if (TrueVal == CmpLHS && FalseVal == CmpRHS) {
switch (Pred) {
default: return SPF_UNKNOWN; // Equality.
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE: return SPF_UMAX;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE: return SPF_SMAX;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE: return SPF_UMIN;
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE: return SPF_SMIN;
}
}
// (icmp X, Y) ? Y : X
if (TrueVal == CmpRHS && FalseVal == CmpLHS) {
switch (Pred) {
default: return SPF_UNKNOWN; // Equality.
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE: return SPF_UMIN;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE: return SPF_SMIN;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE: return SPF_UMAX;
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE: return SPF_SMAX;
}
}
if (ConstantInt *C1 = dyn_cast<ConstantInt>(CmpRHS)) {
if ((CmpLHS == TrueVal && match(FalseVal, m_Neg(m_Specific(CmpLHS)))) ||
(CmpLHS == FalseVal && match(TrueVal, m_Neg(m_Specific(CmpLHS))))) {
// ABS(X) ==> (X >s 0) ? X : -X and (X >s -1) ? X : -X
// NABS(X) ==> (X >s 0) ? -X : X and (X >s -1) ? -X : X
if (Pred == ICmpInst::ICMP_SGT && (C1->isZero() || C1->isMinusOne())) {
return (CmpLHS == TrueVal) ? SPF_ABS : SPF_NABS;
}
// ABS(X) ==> (X <s 0) ? -X : X and (X <s 1) ? -X : X
// NABS(X) ==> (X <s 0) ? X : -X and (X <s 1) ? X : -X
if (Pred == ICmpInst::ICMP_SLT && (C1->isZero() || C1->isOne())) {
return (CmpLHS == FalseVal) ? SPF_ABS : SPF_NABS;
}
}
}
// TODO: (X > 4) ? X : 5 --> (X >= 5) ? X : 5 --> MAX(X, 5)
return SPF_UNKNOWN;
}
