Commit 3fbacb3b authored by Pawel Wodnicki's avatar Pawel Wodnicki
Browse files

Merging r168196: into the 3.2 release branch. 

Make this easier to understand, as suggested by Chandler.

llvm-svn: 168594
parent 599b06e2

llvm/lib/Analysis/InstructionSimplify.cpp

+6 −1
Original line number Diff line number Diff line
@@ -2067,15 +2067,20 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 
      // Determine Y and Z in the form icmp (X+Y), (X+Z).

      Value *Y, *Z;

      if (A == C) {

        // C + B == C + D  ->  B == D

        Y = B;

        Z = D;

      } else if (A == D) {

        // D + B == C + D  ->  B == C

        Y = B;

        Z = C;

      } else if (B == C) {

        // A + C == C + D  ->  A == D

        Y = A;

        Z = D;

      } else if (B == D) {

      } else {

        assert(B == D);

        // A + D == C + D  ->  A == C

        Y = A;

        Z = C;

      }

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

+6 −1
Original line number Diff line number Diff line
@@ -2358,15 +2358,20 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { 
      // Determine Y and Z in the form icmp (X+Y), (X+Z).

      Value *Y, *Z;

      if (A == C) {

        // C + B == C + D  ->  B == D

        Y = B;

        Z = D;

      } else if (A == D) {

        // D + B == C + D  ->  B == C

        Y = B;

        Z = C;

      } else if (B == C) {

        // A + C == C + D  ->  A == D

        Y = A;

        Z = D;

      } else if (B == D) {

      } else {

        assert(B == D);

        // A + D == C + D  ->  A == C

        Y = A;

        Z = C;

      }