Commit 599b06e2 authored by Pawel Wodnicki's avatar Pawel Wodnicki
Browse files

Merging r168186: into the 3.2 release branch. 

InstructionSimplify should be able to simplify A+B==B+A to 'true'
but wasn't due to the same logic bug that caused PR14361.

llvm-svn: 168593
parent 5dc26cea

llvm/lib/Analysis/InstructionSimplify.cpp

+14 −2
Original line number Diff line number Diff line
@@ -2065,8 +2065,20 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 
    if (A && C && (A == C || A == D || B == C || B == D) &&

        NoLHSWrapProblem && NoRHSWrapProblem) {

      // Determine Y and Z in the form icmp (X+Y), (X+Z).

      Value *Y = (A == C || A == D) ? B : A;

      Value *Z = (C == A || C == B) ? D : C;

      Value *Y, *Z;

      if (A == C) {

        Y = B;

        Z = D;

      } else if (A == D) {

        Y = B;

        Z = C;

      } else if (B == C) {

        Y = A;

        Z = D;

      } else if (B == D) {

        Y = A;

        Z = C;

      }

      if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))

        return V;

    }

llvm/test/Transforms/InstSimplify/compare.ll

+9 −0
Original line number Diff line number Diff line
@@ -266,6 +266,15 @@ define i1 @add5(i32 %x, i32 %y) { 
; CHECK: ret i1 true

}



define i1 @add6(i64 %A, i64 %B) {

; CHECK: @add6

  %s1 = add i64 %A, %B

  %s2 = add i64 %B, %A

  %cmp = icmp eq i64 %s1, %s2

  ret i1 %cmp

; CHECK: ret i1 true

}



define i1 @addpowtwo(i32 %x, i32 %y) {

; CHECK: @addpowtwo

  %l = lshr i32 %x, 1