// if this is safe. For example, the use could be in dynamically unreached
// code.
if (!V->hasOneUse()) return 0;
-
+
bool MadeChange = false;
// ((1 << A) >>u B) --> (1 << (A-B))
A = IC.Builder->CreateSub(A, B);
return IC.Builder->CreateShl(PowerOf2, A);
}
-
+
// (PowerOfTwo >>u B) --> isExact since shifting out the result would make it
// inexact. Similarly for <<.
if (BinaryOperator *I = dyn_cast<BinaryOperator>(V))
I->setOperand(0, V2);
MadeChange = true;
}
-
+
if (I->getOpcode() == Instruction::LShr && !I->isExact()) {
I->setIsExact();
MadeChange = true;
}
-
+
if (I->getOpcode() == Instruction::Shl && !I->hasNoUnsignedWrap()) {
I->setHasNoUnsignedWrap();
MadeChange = true;
// TODO: Lots more we could do here:
// If V is a phi node, we can call this on each of its operands.
// "select cond, X, 0" can simplify to "X".
-
+
return MadeChange ? V : 0;
}
LHSExt = LHSExt.zext(W * 2);
RHSExt = RHSExt.zext(W * 2);
}
-
+
APInt MulExt = LHSExt * RHSExt;
-
+
if (!sign)
return MulExt.ugt(APInt::getLowBitsSet(W * 2, W));
-
+
APInt Min = APInt::getSignedMinValue(W).sext(W * 2);
APInt Max = APInt::getSignedMaxValue(W).sext(W * 2);
return MulExt.slt(Min) || MulExt.sgt(Max);
}
+/// \brief A helper routine of InstCombiner::visitMul().
+///
+/// If C is a vector of known powers of 2, then this function returns
+/// a new vector obtained from C replacing each element with its logBase2.
+/// Return a null pointer otherwise.
+static Constant *getLogBase2Vector(ConstantDataVector *CV) {
+ const APInt *IVal;
+ SmallVector<Constant *, 4> Elts;
+
+ for (unsigned I = 0, E = CV->getNumElements(); I != E; ++I) {
+ Constant *Elt = CV->getElementAsConstant(I);
+ if (!match(Elt, m_APInt(IVal)) || !IVal->isPowerOf2())
+ return 0;
+ Elts.push_back(ConstantInt::get(Elt->getType(), IVal->logBase2()));
+ }
+
+ return ConstantVector::get(Elts);
+}
+
Instruction *InstCombiner::visitMul(BinaryOperator &I) {
bool Changed = SimplifyAssociativeOrCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (match(Op1, m_AllOnes())) // X * -1 == 0 - X
return BinaryOperator::CreateNeg(Op0, I.getName());
-
- if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
-
- // ((X << C1)*C2) == (X * (C2 << C1))
- if (BinaryOperator *SI = dyn_cast<BinaryOperator>(Op0))
- if (SI->getOpcode() == Instruction::Shl)
- if (Constant *ShOp = dyn_cast<Constant>(SI->getOperand(1)))
- return BinaryOperator::CreateMul(SI->getOperand(0),
- ConstantExpr::getShl(CI, ShOp));
-
- const APInt &Val = CI->getValue();
- if (Val.isPowerOf2()) { // Replace X*(2^C) with X << C
- Constant *NewCst = ConstantInt::get(Op0->getType(), Val.logBase2());
- BinaryOperator *Shl = BinaryOperator::CreateShl(Op0, NewCst);
- if (I.hasNoSignedWrap()) Shl->setHasNoSignedWrap();
- if (I.hasNoUnsignedWrap()) Shl->setHasNoUnsignedWrap();
- return Shl;
+
+ // Also allow combining multiply instructions on vectors.
+ {
+ Value *NewOp;
+ Constant *C1, *C2;
+ const APInt *IVal;
+ if (match(&I, m_Mul(m_Shl(m_Value(NewOp), m_Constant(C2)),
+ m_Constant(C1))) &&
+ match(C1, m_APInt(IVal)))
+ // ((X << C1)*C2) == (X * (C2 << C1))
+ return BinaryOperator::CreateMul(NewOp, ConstantExpr::getShl(C1, C2));
+
+ if (match(&I, m_Mul(m_Value(NewOp), m_Constant(C1)))) {
+ Constant *NewCst = 0;
+ if (match(C1, m_APInt(IVal)) && IVal->isPowerOf2())
+ // Replace X*(2^C) with X << C, where C is either a scalar or a splat.
+ NewCst = ConstantInt::get(NewOp->getType(), IVal->logBase2());
+ else if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(C1))
+ // Replace X*(2^C) with X << C, where C is a vector of known
+ // constant powers of 2.
+ NewCst = getLogBase2Vector(CV);
+
+ if (NewCst) {
+ BinaryOperator *Shl = BinaryOperator::CreateShl(NewOp, NewCst);
+ if (I.hasNoSignedWrap()) Shl->setHasNoSignedWrap();
+ if (I.hasNoUnsignedWrap()) Shl->setHasNoUnsignedWrap();
+ return Shl;
+ }
}
-
+ }
+
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
// Canonicalize (X+C1)*CI -> X*CI+C1*CI.
{ Value *X; ConstantInt *C1;
if (Op0->hasOneUse() &&
}
}
}
-
+
// Simplify mul instructions with a constant RHS.
- if (isa<Constant>(Op1)) {
+ if (isa<Constant>(Op1)) {
// Try to fold constant mul into select arguments.
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
if (Instruction *R = FoldOpIntoSelect(I, SI))
Value *Op1C = Op1;
BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0);
if (!BO ||
- (BO->getOpcode() != Instruction::UDiv &&
+ (BO->getOpcode() != Instruction::UDiv &&
BO->getOpcode() != Instruction::SDiv)) {
Op1C = Op0;
BO = dyn_cast<BinaryOperator>(Op1);
if (match(Op1, m_Shl(m_One(), m_Value(Y))))
return BinaryOperator::CreateShl(Op0, Y);
}
-
+
// If one of the operands of the multiply is a cast from a boolean value, then
// we know the bool is either zero or one, so this is a 'masking' multiply.
// X * Y (where Y is 0 or 1) -> X & (0-Y)
if (!I.getType()->isVectorTy()) {
// -2 is "-1 << 1" so it is all bits set except the low one.
APInt Negative2(I.getType()->getPrimitiveSizeInBits(), (uint64_t)-2, true);
-
+
Value *BoolCast = 0, *OtherOp = 0;
if (MaskedValueIsZero(Op0, Negative2))
BoolCast = Op0, OtherOp = Op1;
return;
if (I->getOpcode() != Instruction::FMul || !I->hasUnsafeAlgebra())
return;
-
+
ConstantFP *CFP = dyn_cast<ConstantFP>(I->getOperand(0));
if (CFP && CFP->isExactlyValue(0.5)) {
Y = I->getOperand(1);
CFP = dyn_cast<ConstantFP>(I->getOperand(1));
if (CFP && CFP->isExactlyValue(0.5))
Y = I->getOperand(0);
-}
+}
/// Helper function of InstCombiner::visitFMul(BinaryOperator(). It returns
/// true iff the given value is FMul or FDiv with one and only one operand
/// being a normal constant (i.e. not Zero/NaN/Infinity).
static bool isFMulOrFDivWithConstant(Value *V) {
Instruction *I = dyn_cast<Instruction>(V);
- if (!I || (I->getOpcode() != Instruction::FMul &&
+ if (!I || (I->getOpcode() != Instruction::FMul &&
I->getOpcode() != Instruction::FDiv))
return false;
if (C0 && C1)
return false;
- return (C0 && C0->getValueAPF().isNormal()) ||
- (C1 && C1->getValueAPF().isNormal());
+ return (C0 && C0->getValueAPF().isFiniteNonZero()) ||
+ (C1 && C1->getValueAPF().isFiniteNonZero());
}
static bool isNormalFp(const ConstantFP *C) {
const APFloat &Flt = C->getValueAPF();
- return Flt.isNormal() && !Flt.isDenormal();
+ return Flt.isNormal();
}
/// foldFMulConst() is a helper routine of InstCombiner::visitFMul().
/// The input \p FMulOrDiv is a FMul/FDiv with one and only one operand
/// being a constant (i.e. isFMulOrFDivWithConstant(FMulOrDiv) == true).
-/// This function is to simplify "FMulOrDiv * C" and returns the
+/// This function is to simplify "FMulOrDiv * C" and returns the
/// resulting expression. Note that this function could return NULL in
/// case the constants cannot be folded into a normal floating-point.
-///
+///
Value *InstCombiner::foldFMulConst(Instruction *FMulOrDiv, ConstantFP *C,
Instruction *InsertBefore) {
assert(isFMulOrFDivWithConstant(FMulOrDiv) && "V is invalid");
} else {
if (C0) {
// (C0 / X) * C => (C0 * C) / X
- ConstantFP *F = cast<ConstantFP>(ConstantExpr::getFMul(C0, C));
- if (isNormalFp(F))
- R = BinaryOperator::CreateFDiv(F, Opnd1);
+ if (FMulOrDiv->hasOneUse()) {
+ // It would otherwise introduce another div.
+ ConstantFP *F = cast<ConstantFP>(ConstantExpr::getFMul(C0, C));
+ if (isNormalFp(F))
+ R = BinaryOperator::CreateFDiv(F, Opnd1);
+ }
} else {
// (X / C1) * C => X * (C/C1) if C/C1 is not a denormal
ConstantFP *F = cast<ConstantFP>(ConstantExpr::getFDiv(C, C1));
if (isNormalFp(F)) {
R = BinaryOperator::CreateFMul(Opnd0, F);
} else {
- // (X / C1) * C => X / (C1/C)
+ // (X / C1) * C => X / (C1/C)
Constant *F = ConstantExpr::getFDiv(C1, C);
if (isNormalFp(cast<ConstantFP>(F)))
R = BinaryOperator::CreateFDiv(Opnd0, F);
return NV;
ConstantFP *C = dyn_cast<ConstantFP>(Op1);
- if (C && AllowReassociate && C->getValueAPF().isNormal()) {
+ if (C && AllowReassociate && C->getValueAPF().isFiniteNonZero()) {
// Let MDC denote an expression in one of these forms:
// X * C, C/X, X/C, where C is a constant.
//
return ReplaceInstUsesWith(I, V);
}
- // (MDC +/- C1) * C2 => (MDC * C2) +/- (C1 * C2)
+ // (MDC +/- C1) * C => (MDC * C) +/- (C1 * C)
Instruction *FAddSub = dyn_cast<Instruction>(Op0);
if (FAddSub &&
(FAddSub->getOpcode() == Instruction::FAdd ||
if (C0) {
std::swap(C0, C1);
std::swap(Opnd0, Opnd1);
- Swap = true;
+ Swap = true;
}
- if (C1 && C1->getValueAPF().isNormal() &&
+ if (C1 && C1->getValueAPF().isFiniteNonZero() &&
isFMulOrFDivWithConstant(Opnd0)) {
- Value *M0 = ConstantExpr::getFMul(C1, C);
- Value *M1 = isNormalFp(cast<ConstantFP>(M0)) ?
+ Value *M1 = ConstantExpr::getFMul(C1, C);
+ Value *M0 = isNormalFp(cast<ConstantFP>(M1)) ?
foldFMulConst(cast<Instruction>(Opnd0), C, &I) :
0;
if (M0 && M1) {
}
// (X*Y) * X => (X*X) * Y where Y != X
- // The purpose is two-fold:
+ // The purpose is two-fold:
// 1) to form a power expression (of X).
// 2) potentially shorten the critical path: After transformation, the
// latency of the instruction Y is amortized by the expression of X*X,
}
}
+ // B * (uitofp i1 C) -> select C, B, 0
+ if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
+ Value *LHS = Op0, *RHS = Op1;
+ Value *B, *C;
+ if (!match(RHS, m_UIToFP(m_Value(C))))
+ std::swap(LHS, RHS);
+
+ if (match(RHS, m_UIToFP(m_Value(C))) && C->getType()->isIntegerTy(1)) {
+ B = LHS;
+ Value *Zero = ConstantFP::getNegativeZero(B->getType());
+ return SelectInst::Create(C, B, Zero);
+ }
+ }
+
+ // A * (1 - uitofp i1 C) -> select C, 0, A
+ if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
+ Value *LHS = Op0, *RHS = Op1;
+ Value *A, *C;
+ if (!match(RHS, m_FSub(m_FPOne(), m_UIToFP(m_Value(C)))))
+ std::swap(LHS, RHS);
+
+ if (match(RHS, m_FSub(m_FPOne(), m_UIToFP(m_Value(C)))) &&
+ C->getType()->isIntegerTy(1)) {
+ A = LHS;
+ Value *Zero = ConstantFP::getNegativeZero(A->getType());
+ return SelectInst::Create(C, Zero, A);
+ }
+ }
+
if (!isa<Constant>(Op1))
std::swap(Opnd0, Opnd1);
else
/// instruction.
bool InstCombiner::SimplifyDivRemOfSelect(BinaryOperator &I) {
SelectInst *SI = cast<SelectInst>(I.getOperand(1));
-
+
// div/rem X, (Cond ? 0 : Y) -> div/rem X, Y
int NonNullOperand = -1;
if (Constant *ST = dyn_cast<Constant>(SI->getOperand(1)))
if (Constant *ST = dyn_cast<Constant>(SI->getOperand(2)))
if (ST->isNullValue())
NonNullOperand = 1;
-
+
if (NonNullOperand == -1)
return false;
-
+
Value *SelectCond = SI->getOperand(0);
-
+
// Change the div/rem to use 'Y' instead of the select.
I.setOperand(1, SI->getOperand(NonNullOperand));
-
+
// Okay, we know we replace the operand of the div/rem with 'Y' with no
// problem. However, the select, or the condition of the select may have
// multiple uses. Based on our knowledge that the operand must be non-zero,
// propagate the known value for the select into other uses of it, and
// propagate a known value of the condition into its other users.
-
+
// If the select and condition only have a single use, don't bother with this,
// early exit.
if (SI->use_empty() && SelectCond->hasOneUse())
return true;
-
+
// Scan the current block backward, looking for other uses of SI.
BasicBlock::iterator BBI = &I, BBFront = I.getParent()->begin();
-
+
while (BBI != BBFront) {
--BBI;
// If we found a call to a function, we can't assume it will return, so
// information from below it cannot be propagated above it.
if (isa<CallInst>(BBI) && !isa<IntrinsicInst>(BBI))
break;
-
+
// Replace uses of the select or its condition with the known values.
for (Instruction::op_iterator I = BBI->op_begin(), E = BBI->op_end();
I != E; ++I) {
*I = SI->getOperand(NonNullOperand);
Worklist.Add(BBI);
} else if (*I == SelectCond) {
- *I = NonNullOperand == 1 ? ConstantInt::getTrue(BBI->getContext()) :
- ConstantInt::getFalse(BBI->getContext());
+ *I = Builder->getInt1(NonNullOperand == 1);
Worklist.Add(BBI);
}
}
-
+
// If we past the instruction, quit looking for it.
if (&*BBI == SI)
SI = 0;
if (&*BBI == SelectCond)
SelectCond = 0;
-
+
// If we ran out of things to eliminate, break out of the loop.
if (SelectCond == 0 && SI == 0)
break;
-
+
}
return true;
}
I.setOperand(1, V);
return &I;
}
-
+
// Handle cases involving: [su]div X, (select Cond, Y, Z)
// This does not apply for fdiv.
if (isa<SelectInst>(Op1) && SimplifyDivRemOfSelect(I))
return 0;
}
+namespace {
+const unsigned MaxDepth = 6;
+typedef Instruction *(*FoldUDivOperandCb)(Value *Op0, Value *Op1,
+ const BinaryOperator &I,
+ InstCombiner &IC);
+
+/// \brief Used to maintain state for visitUDivOperand().
+struct UDivFoldAction {
+ FoldUDivOperandCb FoldAction; ///< Informs visitUDiv() how to fold this
+ ///< operand. This can be zero if this action
+ ///< joins two actions together.
+
+ Value *OperandToFold; ///< Which operand to fold.
+ union {
+ Instruction *FoldResult; ///< The instruction returned when FoldAction is
+ ///< invoked.
+
+ size_t SelectLHSIdx; ///< Stores the LHS action index if this action
+ ///< joins two actions together.
+ };
+
+ UDivFoldAction(FoldUDivOperandCb FA, Value *InputOperand)
+ : FoldAction(FA), OperandToFold(InputOperand), FoldResult(0) {}
+ UDivFoldAction(FoldUDivOperandCb FA, Value *InputOperand, size_t SLHS)
+ : FoldAction(FA), OperandToFold(InputOperand), SelectLHSIdx(SLHS) {}
+};
+}
+
+// X udiv 2^C -> X >> C
+static Instruction *foldUDivPow2Cst(Value *Op0, Value *Op1,
+ const BinaryOperator &I, InstCombiner &IC) {
+ const APInt &C = cast<Constant>(Op1)->getUniqueInteger();
+ BinaryOperator *LShr = BinaryOperator::CreateLShr(
+ Op0, ConstantInt::get(Op0->getType(), C.logBase2()));
+ if (I.isExact()) LShr->setIsExact();
+ return LShr;
+}
+
+// X udiv C, where C >= signbit
+static Instruction *foldUDivNegCst(Value *Op0, Value *Op1,
+ const BinaryOperator &I, InstCombiner &IC) {
+ Value *ICI = IC.Builder->CreateICmpULT(Op0, cast<ConstantInt>(Op1));
+
+ return SelectInst::Create(ICI, Constant::getNullValue(I.getType()),
+ ConstantInt::get(I.getType(), 1));
+}
+
+// X udiv (C1 << N), where C1 is "1<<C2" --> X >> (N+C2)
+static Instruction *foldUDivShl(Value *Op0, Value *Op1, const BinaryOperator &I,
+ InstCombiner &IC) {
+ Instruction *ShiftLeft = cast<Instruction>(Op1);
+ if (isa<ZExtInst>(ShiftLeft))
+ ShiftLeft = cast<Instruction>(ShiftLeft->getOperand(0));
+
+ const APInt &CI =
+ cast<Constant>(ShiftLeft->getOperand(0))->getUniqueInteger();
+ Value *N = ShiftLeft->getOperand(1);
+ if (CI != 1)
+ N = IC.Builder->CreateAdd(N, ConstantInt::get(N->getType(), CI.logBase2()));
+ if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1))
+ N = IC.Builder->CreateZExt(N, Z->getDestTy());
+ BinaryOperator *LShr = BinaryOperator::CreateLShr(Op0, N);
+ if (I.isExact()) LShr->setIsExact();
+ return LShr;
+}
+
+// \brief Recursively visits the possible right hand operands of a udiv
+// instruction, seeing through select instructions, to determine if we can
+// replace the udiv with something simpler. If we find that an operand is not
+// able to simplify the udiv, we abort the entire transformation.
+static size_t visitUDivOperand(Value *Op0, Value *Op1, const BinaryOperator &I,
+ SmallVectorImpl<UDivFoldAction> &Actions,
+ unsigned Depth = 0) {
+ // Check to see if this is an unsigned division with an exact power of 2,
+ // if so, convert to a right shift.
+ if (match(Op1, m_Power2())) {
+ Actions.push_back(UDivFoldAction(foldUDivPow2Cst, Op1));
+ return Actions.size();
+ }
+
+ if (ConstantInt *C = dyn_cast<ConstantInt>(Op1))
+ // X udiv C, where C >= signbit
+ if (C->getValue().isNegative()) {
+ Actions.push_back(UDivFoldAction(foldUDivNegCst, C));
+ return Actions.size();
+ }
+
+ // X udiv (C1 << N), where C1 is "1<<C2" --> X >> (N+C2)
+ if (match(Op1, m_Shl(m_Power2(), m_Value())) ||
+ match(Op1, m_ZExt(m_Shl(m_Power2(), m_Value())))) {
+ Actions.push_back(UDivFoldAction(foldUDivShl, Op1));
+ return Actions.size();
+ }
+
+ // The remaining tests are all recursive, so bail out if we hit the limit.
+ if (Depth++ == MaxDepth)
+ return 0;
+
+ if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
+ if (size_t LHSIdx = visitUDivOperand(Op0, SI->getOperand(1), I, Actions))
+ if (visitUDivOperand(Op0, SI->getOperand(2), I, Actions)) {
+ Actions.push_back(UDivFoldAction((FoldUDivOperandCb)0, Op1, LHSIdx-1));
+ return Actions.size();
+ }
+
+ return 0;
+}
+
Instruction *InstCombiner::visitUDiv(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
// Handle the integer div common cases
if (Instruction *Common = commonIDivTransforms(I))
return Common;
-
- {
- // X udiv 2^C -> X >> C
- // Check to see if this is an unsigned division with an exact power of 2,
- // if so, convert to a right shift.
- const APInt *C;
- if (match(Op1, m_Power2(C))) {
- BinaryOperator *LShr =
- BinaryOperator::CreateLShr(Op0,
- ConstantInt::get(Op0->getType(),
- C->logBase2()));
- if (I.isExact()) LShr->setIsExact();
- return LShr;
- }
- }
-
- if (ConstantInt *C = dyn_cast<ConstantInt>(Op1)) {
- // X udiv C, where C >= signbit
- if (C->getValue().isNegative()) {
- Value *IC = Builder->CreateICmpULT(Op0, C);
- return SelectInst::Create(IC, Constant::getNullValue(I.getType()),
- ConstantInt::get(I.getType(), 1));
- }
- }
// (x lshr C1) udiv C2 --> x udiv (C2 << C1)
if (ConstantInt *C2 = dyn_cast<ConstantInt>(Op1)) {
}
}
- // X udiv (C1 << N), where C1 is "1<<C2" --> X >> (N+C2)
- { const APInt *CI; Value *N;
- if (match(Op1, m_Shl(m_Power2(CI), m_Value(N))) ||
- match(Op1, m_ZExt(m_Shl(m_Power2(CI), m_Value(N))))) {
- if (*CI != 1)
- N = Builder->CreateAdd(N,
- ConstantInt::get(N->getType(), CI->logBase2()));
- if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1))
- N = Builder->CreateZExt(N, Z->getDestTy());
- if (I.isExact())
- return BinaryOperator::CreateExactLShr(Op0, N);
- return BinaryOperator::CreateLShr(Op0, N);
- }
- }
-
- // udiv X, (Select Cond, C1, C2) --> Select Cond, (shr X, C1), (shr X, C2)
- // where C1&C2 are powers of two.
- { Value *Cond; const APInt *C1, *C2;
- if (match(Op1, m_Select(m_Value(Cond), m_Power2(C1), m_Power2(C2)))) {
- // Construct the "on true" case of the select
- Value *TSI = Builder->CreateLShr(Op0, C1->logBase2(), Op1->getName()+".t",
- I.isExact());
-
- // Construct the "on false" case of the select
- Value *FSI = Builder->CreateLShr(Op0, C2->logBase2(), Op1->getName()+".f",
- I.isExact());
-
- // construct the select instruction and return it.
- return SelectInst::Create(Cond, TSI, FSI);
- }
- }
-
// (zext A) udiv (zext B) --> zext (A udiv B)
if (ZExtInst *ZOp0 = dyn_cast<ZExtInst>(Op0))
if (Value *ZOp1 = dyn_castZExtVal(Op1, ZOp0->getSrcTy()))
I.isExact()),
I.getType());
+ // (LHS udiv (select (select (...)))) -> (LHS >> (select (select (...))))
+ SmallVector<UDivFoldAction, 6> UDivActions;
+ if (visitUDivOperand(Op0, Op1, I, UDivActions))
+ for (unsigned i = 0, e = UDivActions.size(); i != e; ++i) {
+ FoldUDivOperandCb Action = UDivActions[i].FoldAction;
+ Value *ActionOp1 = UDivActions[i].OperandToFold;
+ Instruction *Inst;
+ if (Action)
+ Inst = Action(Op0, ActionOp1, I, *this);
+ else {
+ // This action joins two actions together. The RHS of this action is
+ // simply the last action we processed, we saved the LHS action index in
+ // the joining action.
+ size_t SelectRHSIdx = i - 1;
+ Value *SelectRHS = UDivActions[SelectRHSIdx].FoldResult;
+ size_t SelectLHSIdx = UDivActions[i].SelectLHSIdx;
+ Value *SelectLHS = UDivActions[SelectLHSIdx].FoldResult;
+ Inst = SelectInst::Create(cast<SelectInst>(ActionOp1)->getCondition(),
+ SelectLHS, SelectRHS);
+ }
+
+ // If this is the last action to process, return it to the InstCombiner.
+ // Otherwise, we insert it before the UDiv and record it so that we may
+ // use it as part of a joining action (i.e., a SelectInst).
+ if (e - i != 1) {
+ Inst->insertBefore(&I);
+ UDivActions[i].FoldResult = Inst;
+ } else
+ return Inst;
+ }
+
return 0;
}
// X sdiv Y -> X udiv Y, iff X and Y don't have sign bit set
return BinaryOperator::CreateUDiv(Op0, Op1, I.getName());
}
-
+
if (match(Op1, m_Shl(m_Power2(), m_Value()))) {
// X sdiv (1 << Y) -> X udiv (1 << Y) ( -> X u>> Y)
// Safe because the only negative value (1 << Y) can take on is
}
}
}
-
+
return 0;
}
/// CvtFDivConstToReciprocal tries to convert X/C into X*1/C if C not a special
/// FP value and:
-/// 1) 1/C is exact, or
+/// 1) 1/C is exact, or
/// 2) reciprocal is allowed.
-/// If the convertion was successful, the simplified expression "X * 1/C" is
+/// If the conversion was successful, the simplified expression "X * 1/C" is
/// returned; otherwise, NULL is returned.
///
static Instruction *CvtFDivConstToReciprocal(Value *Dividend,
const APFloat &FpVal = Divisor->getValueAPF();
APFloat Reciprocal(FpVal.getSemantics());
bool Cvt = FpVal.getExactInverse(&Reciprocal);
-
- if (!Cvt && AllowReciprocal && FpVal.isNormal()) {
+
+ if (!Cvt && AllowReciprocal && FpVal.isFiniteNonZero()) {
Reciprocal = APFloat(FpVal.getSemantics(), 1.0f);
(void)Reciprocal.divide(FpVal, APFloat::rmNearestTiesToEven);
Cvt = !Reciprocal.isDenormal();
if (Value *V = SimplifyFDivInst(Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
+ if (isa<Constant>(Op0))
+ if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
+ if (Instruction *R = FoldOpIntoSelect(I, SI))
+ return R;
+
bool AllowReassociate = I.hasUnsafeAlgebra();
bool AllowReciprocal = I.hasAllowReciprocal();
if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
+ if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
+ if (Instruction *R = FoldOpIntoSelect(I, SI))
+ return R;
+
if (AllowReassociate) {
ConstantFP *C1 = 0;
ConstantFP *C2 = Op1C;
//
Constant *C = ConstantExpr::getFDiv(C1, C2);
const APFloat &F = cast<ConstantFP>(C)->getValueAPF();
- if (F.isNormal() && !F.isDenormal())
+ if (F.isNormal())
Res = BinaryOperator::CreateFMul(X, C);
} else if (match(Op0, m_FDiv(m_Value(X), m_ConstantFP(C1)))) {
// (X/C1)/C2 => X /(C2*C1) [=> X * 1/(C2*C1) if reciprocal is allowed]
//
Constant *C = ConstantExpr::getFMul(C1, C2);
const APFloat &F = cast<ConstantFP>(C)->getValueAPF();
- if (F.isNormal() && !F.isDenormal()) {
- Res = CvtFDivConstToReciprocal(X, cast<ConstantFP>(C),
+ if (F.isNormal()) {
+ Res = CvtFDivConstToReciprocal(X, cast<ConstantFP>(C),
AllowReciprocal);
if (!Res)
- Res = BinaryOperator::CreateFDiv(X, C);
+ Res = BinaryOperator::CreateFDiv(X, C);
}
}
if (Fold) {
const APFloat &FoldC = cast<ConstantFP>(Fold)->getValueAPF();
- if (FoldC.isNormal() && !FoldC.isDenormal()) {
- Instruction *R = CreateDiv ?
+ if (FoldC.isNormal()) {
+ Instruction *R = CreateDiv ?
BinaryOperator::CreateFDiv(Fold, X) :
BinaryOperator::CreateFMul(X, Fold);
R->setFastMathFlags(I.getFastMathFlags());
if (Instruction *common = commonIRemTransforms(I))
return common;
-
- // X urem C^2 -> X and C-1
- { const APInt *C;
- if (match(Op1, m_Power2(C)))
- return BinaryOperator::CreateAnd(Op0,
- ConstantInt::get(I.getType(), *C-1));
- }
- // Turn A % (C << N), where C is 2^k, into A & ((C << N)-1)
- if (match(Op1, m_Shl(m_Power2(), m_Value()))) {
+ // (zext A) urem (zext B) --> zext (A urem B)
+ if (ZExtInst *ZOp0 = dyn_cast<ZExtInst>(Op0))
+ if (Value *ZOp1 = dyn_castZExtVal(Op1, ZOp0->getSrcTy()))
+ return new ZExtInst(Builder->CreateURem(ZOp0->getOperand(0), ZOp1),
+ I.getType());
+
+ // X urem Y -> X and Y-1, where Y is a power of 2,
+ if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true)) {
Constant *N1 = Constant::getAllOnesValue(I.getType());
Value *Add = Builder->CreateAdd(Op1, N1);
return BinaryOperator::CreateAnd(Op0, Add);
}
- // urem X, (select Cond, 2^C1, 2^C2) -->
- // select Cond, (and X, C1-1), (and X, C2-1)
- // when C1&C2 are powers of two.
- { Value *Cond; const APInt *C1, *C2;
- if (match(Op1, m_Select(m_Value(Cond), m_Power2(C1), m_Power2(C2)))) {
- Value *TrueAnd = Builder->CreateAnd(Op0, *C1-1, Op1->getName()+".t");
- Value *FalseAnd = Builder->CreateAnd(Op0, *C2-1, Op1->getName()+".f");
- return SelectInst::Create(Cond, TrueAnd, FalseAnd);
- }
+ // 1 urem X -> zext(X != 1)
+ if (match(Op0, m_One())) {
+ Value *Cmp = Builder->CreateICmpNE(Op1, Op0);
+ Value *Ext = Builder->CreateZExt(Cmp, I.getType());
+ return ReplaceInstUsesWith(I, Ext);
}
- // (zext A) urem (zext B) --> zext (A urem B)
- if (ZExtInst *ZOp0 = dyn_cast<ZExtInst>(Op0))
- if (Value *ZOp1 = dyn_castZExtVal(Op1, ZOp0->getSrcTy()))
- return new ZExtInst(Builder->CreateURem(ZOp0->getOperand(0), ZOp1),
- I.getType());
-
return 0;
}
// Handle the integer rem common cases
if (Instruction *Common = commonIRemTransforms(I))
return Common;
-
+
if (Value *RHSNeg = dyn_castNegVal(Op1))
if (!isa<Constant>(RHSNeg) ||
(isa<ConstantInt>(RHSNeg) &&
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