Commit a29dd911 authored by Sanjay Patel's avatar Sanjay Patel
Browse files

[InstSimplify] remove redundant folds 

The 'hasOneUse' check is a giveaway that something's not right.
We never need to check that in InstSimplify because we don't
create new instructions here.

These are all handled as icmp simplifies which then trigger
existing select simplifies, so there's no need to duplicate
a composite fold of the two.
parent fb87eeb3

llvm/lib/Analysis/InstructionSimplify.cpp

+0 −18
Original line number Diff line number Diff line
@@ -3624,24 +3624,6 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal, 
                                              TrueVal, FalseVal))

    return V;



  if (CondVal->hasOneUse()) {

    const APInt *C;

    if (match(CmpRHS, m_APInt(C))) {

      // X < MIN ? T : F  -->  F

      if (Pred == ICmpInst::ICMP_SLT && C->isMinSignedValue())

        return FalseVal;

      // X < MIN ? T : F  -->  F

      if (Pred == ICmpInst::ICMP_ULT && C->isMinValue())

        return FalseVal;

      // X > MAX ? T : F  -->  F

      if (Pred == ICmpInst::ICMP_SGT && C->isMaxSignedValue())

        return FalseVal;

      // X > MAX ? T : F  -->  F

      if (Pred == ICmpInst::ICMP_UGT && C->isMaxValue())

        return FalseVal;

    }

  }



  // If we have an equality comparison, then we know the value in one of the

  // arms of the select. See if substituting this value into the arm and

  // simplifying the result yields the same value as the other arm.