}
}
+ bool isSigned = Opcode == Instruction::SDiv;
+
// X / undef -> undef
if (isa<UndefValue>(Op1))
return Op1;
if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
BinaryOperator *Mul = dyn_cast<BinaryOperator>(Op0);
// If the Mul knows it does not overflow, then we are good to go.
- bool isSigned = Opcode == Instruction::SDiv;
if ((isSigned && Mul->hasNoSignedWrap()) ||
(!isSigned && Mul->hasNoUnsignedWrap()))
return X;
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;
}
if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, TD, DT, MaxRecurse))
return V;
- // (X rem Y) / Y -> 0
- if (match(Op0, m_SRem(m_Value(), m_Specific(Op1))))
- return Constant::getNullValue(Op0->getType());
-
return 0;
}
if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, TD, DT, MaxRecurse))
return V;
- // (X rem Y) / Y -> 0
- if (match(Op0, m_URem(m_Value(), m_Specific(Op1))))
- return Constant::getNullValue(Op0->getType());
-
return 0;
}