[llvm-commits] [llvm] r168186 - in /llvm/trunk: lib/Analysis/InstructionSimplify.cpp test/Transforms/InstSimplify/compare.ll

[Duncan Sands]

Author: baldrick
Date: Fri Nov 16 13:41:26 2012
New Revision: 168186

URL: http://llvm.org/viewvc/llvm-project?rev=168186&view=rev
Log:
InstructionSimplify should be able to simplify A+B==B+A to 'true'
but wasn't due to the same logic bug that caused PR14361.

Modified:
    llvm/trunk/lib/Analysis/InstructionSimplify.cpp
    llvm/trunk/test/Transforms/InstSimplify/compare.ll

Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=168186&r1=168185&r2=168186&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Fri Nov 16 13:41:26 2012
@@ -2065,8 +2065,20 @@
     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;
     }

Modified: llvm/trunk/test/Transforms/InstSimplify/compare.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/compare.ll?rev=168186&r1=168185&r2=168186&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/compare.ll (original)
+++ llvm/trunk/test/Transforms/InstSimplify/compare.ll Fri Nov 16 13:41:26 2012
@@ -266,6 +266,15 @@
 ; 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