+/// SimplifyAddInst - Given operands for an Add, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const DominatorTree *DT,
+ unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(),
+ Ops, TD);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ // X + undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // X + 0 -> X
+ if (match(Op1, m_Zero()))
+ return Op0;
+
+ // X + (Y - X) -> Y
+ // (Y - X) + X -> Y
+ // Eg: X + -X -> 0
+ Value *Y = 0;
+ if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) ||
+ match(Op0, m_Sub(m_Value(Y), m_Specific(Op1))))
+ return Y;
+
+ // X + ~X -> -1 since ~X = -X-1
+ if (match(Op0, m_Not(m_Specific(Op1))) ||
+ match(Op1, m_Not(m_Specific(Op0))))
+ return Constant::getAllOnesValue(Op0->getType());
+
+ /// i1 add -> xor.
+ if (MaxRecurse && Op0->getType()->isIntegerTy(1))
+ if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1))
+ return V;
+
+ // Try some generic simplifications for associative operations.
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, TD, DT,
+ MaxRecurse))
+ return V;
+
+ // Mul distributes over Add. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul,
+ TD, DT, MaxRecurse))
+ return V;
+
+ // Threading Add over selects and phi nodes is pointless, so don't bother.
+ // Threading over the select in "A + select(cond, B, C)" means evaluating
+ // "A+B" and "A+C" and seeing if they are equal; but they are equal if and
+ // only if B and C are equal. If B and C are equal then (since we assume
+ // that operands have already been simplified) "select(cond, B, C)" should
+ // have been simplified to the common value of B and C already. Analysing
+ // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
+ // for threading over phi nodes.
+
+ return 0;
+}
+
+Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const DominatorTree *DT) {
+ return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+}
+
+/// SimplifySubInst - Given operands for a Sub, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const DominatorTree *DT,
+ unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0))
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(),
+ Ops, TD);
+ }
+
+ // X - undef -> undef
+ // undef - X -> undef
+ if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
+ return UndefValue::get(Op0->getType());
+
+ // X - 0 -> X
+ if (match(Op1, m_Zero()))
+ return Op0;
+
+ // X - X -> 0
+ if (Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
+ // (X*2) - X -> X
+ // (X<<1) - X -> X
+ Value *X = 0;
+ if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) ||
+ match(Op0, m_Shl(m_Specific(Op1), m_One())))
+ return Op1;
+
+ // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
+ // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
+ Value *Y = 0, *Z = Op1;
+ if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
+ // See if "V === Y - Z" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, TD, DT, MaxRecurse-1))
+ // It does! Now see if "X + V" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Add, X, V, TD, DT,
+ MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ // See if "V === X - Z" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1))
+ // It does! Now see if "Y + V" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, TD, DT,
+ MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ }
+
+ // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
+ // For example, X - (X + 1) -> -1
+ X = Op0;
+ if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
+ // See if "V === X - Y" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, TD, DT, MaxRecurse-1))
+ // It does! Now see if "V - Z" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, TD, DT,
+ MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ // See if "V === X - Z" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1))
+ // It does! Now see if "V - Y" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, TD, DT,
+ MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+ }
+
+ // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
+ // For example, X - (X - Y) -> Y.
+ Z = Op0;
+ if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
+ // See if "V === Z - X" simplifies.
+ if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, TD, DT, MaxRecurse-1))
+ // It does! Now see if "V + Y" simplifies.
+ if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, TD, DT,
+ MaxRecurse-1)) {
+ // It does, we successfully reassociated!
+ ++NumReassoc;
+ return W;
+ }
+
+ // Mul distributes over Sub. Try some generic simplifications based on this.
+ if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul,
+ TD, DT, MaxRecurse))
+ return V;
+
+ // i1 sub -> xor.
+ if (MaxRecurse && Op0->getType()->isIntegerTy(1))
+ if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1))
+ return V;
+
+ // Threading Sub over selects and phi nodes is pointless, so don't bother.
+ // Threading over the select in "A - select(cond, B, C)" means evaluating
+ // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
+ // only if B and C are equal. If B and C are equal then (since we assume
+ // that operands have already been simplified) "select(cond, B, C)" should
+ // have been simplified to the common value of B and C already. Analysing
+ // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
+ // for threading over phi nodes.
+
+ return 0;
+}
+
+Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const DominatorTree *DT) {
+ return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit);
+}
+
+/// SimplifyMulInst - Given operands for a Mul, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT, unsigned MaxRecurse) {
+ if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
+ if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { CLHS, CRHS };
+ return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(),
+ Ops, TD);
+ }
+
+ // Canonicalize the constant to the RHS.
+ std::swap(Op0, Op1);
+ }
+
+ // X * undef -> 0
+ if (match(Op1, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // X * 0 -> 0
+ if (match(Op1, m_Zero()))
+ return Op1;
+
+ // X * 1 -> X
+ if (match(Op1, m_One()))
+ return Op0;
+
+ // (X / Y) * Y -> X if the division is exact.
+ Value *X = 0, *Y = 0;
+ if ((match(Op0, m_IDiv(m_Value(X), m_Value(Y))) && Y == Op1) || // (X / Y) * Y
+ (match(Op1, m_IDiv(m_Value(X), m_Value(Y))) && Y == Op0)) { // Y * (X / Y)
+ BinaryOperator *Div = cast<BinaryOperator>(Y == Op1 ? Op0 : Op1);
+ if (Div->isExact())
+ return X;
+ }
+
+ // i1 mul -> and.
+ if (MaxRecurse && Op0->getType()->isIntegerTy(1))
+ if (Value *V = SimplifyAndInst(Op0, Op1, TD, DT, MaxRecurse-1))
+ return V;
+
+ // Try some generic simplifications for associative operations.
+ if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, TD, DT,
+ MaxRecurse))
+ return V;
+
+ // Mul distributes over Add. Try some generic simplifications based on this.
+ if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
+ TD, DT, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, TD, DT,
+ MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, TD, DT,
+ MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifyMulInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
+ const TargetData *TD, const DominatorTree *DT,
+ unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, TD);
+ }
+ }
+
+ bool isSigned = Opcode == Instruction::SDiv;
+
+ // X / undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // undef / X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // 0 / X -> 0, we don't need to preserve faults!
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X / 1 -> X
+ if (match(Op1, m_One()))
+ return Op0;
+
+ if (Op0->getType()->isIntegerTy(1))
+ // It can't be division by zero, hence it must be division by one.
+ return Op0;
+
+ // X / X -> 1
+ if (Op0 == Op1)
+ return ConstantInt::get(Op0->getType(), 1);
+
+ // (X * Y) / Y -> X if the multiplication does not overflow.
+ Value *X = 0, *Y = 0;
+ if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
+ if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
+ BinaryOperator *Mul = cast<BinaryOperator>(Op0);
+ // If the Mul knows it does not overflow, then we are good to go.
+ if ((isSigned && Mul->hasNoSignedWrap()) ||
+ (!isSigned && Mul->hasNoUnsignedWrap()))
+ return X;
+ // If X has the form X = A / Y then X * Y cannot overflow.
+ if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X))
+ if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y)
+ return X;
+ }
+
+ // (X rem Y) / Y -> 0
+ if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
+ (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
+ return Constant::getNullValue(Op0->getType());
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+/// SimplifySDivInst - Given operands for an SDiv, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT, unsigned MaxRecurse) {
+ if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifySDivInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+/// SimplifyUDivInst - Given operands for a UDiv, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT, unsigned MaxRecurse) {
+ if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifyUDivInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *,
+ const DominatorTree *, unsigned) {
+ // undef / X -> undef (the undef could be a snan).
+ if (match(Op0, m_Undef()))
+ return Op0;
+
+ // X / undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ return 0;
+}
+
+Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifyFDivInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+/// SimplifyRem - Given operands for an SRem or URem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
+ const TargetData *TD, const DominatorTree *DT,
+ unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, TD);
+ }
+ }
+
+ // X % undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // undef % X -> 0
+ if (match(Op0, m_Undef()))
+ return Constant::getNullValue(Op0->getType());
+
+ // 0 % X -> 0, we don't need to preserve faults!
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X % 0 -> undef, we don't need to preserve faults!
+ if (match(Op1, m_Zero()))
+ return UndefValue::get(Op0->getType());
+
+ // X % 1 -> 0
+ if (match(Op1, m_One()))
+ return Constant::getNullValue(Op0->getType());
+
+ if (Op0->getType()->isIntegerTy(1))
+ // It can't be remainder by zero, hence it must be remainder by one.
+ return Constant::getNullValue(Op0->getType());
+
+ // X % X -> 0
+ if (Op0 == Op1)
+ return Constant::getNullValue(Op0->getType());
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+/// SimplifySRemInst - Given operands for an SRem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifySRemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT, unsigned MaxRecurse) {
+ if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifySRemInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+/// SimplifyURemInst - Given operands for a URem, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyURemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT, unsigned MaxRecurse) {
+ if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifyURemInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const TargetData *,
+ const DominatorTree *, unsigned) {
+ // undef % X -> undef (the undef could be a snan).
+ if (match(Op0, m_Undef()))
+ return Op0;
+
+ // X % undef -> undef
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ return 0;
+}
+
+Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const TargetData *TD,
+ const DominatorTree *DT) {
+ return ::SimplifyFRemInst(Op0, Op1, TD, DT, RecursionLimit);
+}
+
+/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
+ const TargetData *TD, const DominatorTree *DT,
+ unsigned MaxRecurse) {
+ if (Constant *C0 = dyn_cast<Constant>(Op0)) {
+ if (Constant *C1 = dyn_cast<Constant>(Op1)) {
+ Constant *Ops[] = { C0, C1 };
+ return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, TD);
+ }
+ }
+
+ // 0 shift by X -> 0
+ if (match(Op0, m_Zero()))
+ return Op0;
+
+ // X shift by 0 -> X
+ if (match(Op1, m_Zero()))
+ return Op0;
+
+ // X shift by undef -> undef because it may shift by the bitwidth.
+ if (match(Op1, m_Undef()))
+ return Op1;
+
+ // Shifting by the bitwidth or more is undefined.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1))
+ if (CI->getValue().getLimitedValue() >=
+ Op0->getType()->getScalarSizeInBits())
+ return UndefValue::get(Op0->getType());
+
+ // If the operation is with the result of a select instruction, check whether
+ // operating on either branch of the select always yields the same value.
+ if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
+ if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ // If the operation is with the result of a phi instruction, check whether
+ // operating on all incoming values of the phi always yields the same value.
+ if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
+ if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse))
+ return V;
+
+ return 0;
+}
+
+/// SimplifyShlInst - Given operands for an Shl, see if we can
+/// fold the result. If not, this returns null.
+static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
+ const TargetData *TD, const DominatorTree *DT,
+ unsigned MaxRecurse) {
+ if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, TD, DT, MaxRecurse))
+ return V;