[llvm-commits] [llvm] r128627 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineCompares.cpp test/Transforms/InstCombine/fcmp.ll

[Benjamin Kramer]

Author: d0k
Date: Thu Mar 31 05:12:22 2011
New Revision: 128627

URL: http://llvm.org/viewvc/llvm-project?rev=128627&view=rev
Log:
InstCombine: fold fcmp (fneg x), (fneg y) -> fcmp x, y

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
    llvm/trunk/test/Transforms/InstCombine/fcmp.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=128627&r1=128626&r2=128627&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Thu Mar 31 05:12:22 2011
@@ -2855,6 +2855,11 @@
       }
   }
 
+  // fcmp (fneg x), (fneg y) -> fcmp x, y
+  Value *X, *Y;
+  if (match(Op0, m_FNeg(m_Value(X))) && match(Op1, m_FNeg(m_Value(Y))))
+    return new FCmpInst(I.getPredicate(), X, Y);
+
   // fcmp (fpext x), (fpext y) -> fcmp x, y
   if (FPExtInst *LHSExt = dyn_cast<FPExtInst>(Op0))
     if (FPExtInst *RHSExt = dyn_cast<FPExtInst>(Op1))

Modified: llvm/trunk/test/Transforms/InstCombine/fcmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fcmp.ll?rev=128627&r1=128626&r2=128627&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fcmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fcmp.ll Thu Mar 31 05:12:22 2011
@@ -40,3 +40,12 @@
 ; CHECK: @test5
 ; CHECK-NEXT: fcmp olt float %a, -1.0
 }
+
+define i1 @test6(float %x, float %y) nounwind {
+  %neg1 = fsub float -0.000000e+00, %x
+  %neg2 = fsub float -0.000000e+00, %y
+  %cmp = fcmp ogt float %neg1, %neg2
+  ret i1 %cmp
+; CHECK: @test6
+; CHECK-NEXT: fcmp ogt float %x, %y
+}