[llvm-commits] [llvm] r164814 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineSelect.cpp test/Transforms/InstCombine/vec_shuffle.ll

[Nick Lewycky]

Author: nicholas
Date: Fri Sep 28 04:33:53 2012
New Revision: 164814

URL: http://llvm.org/viewvc/llvm-project?rev=164814&view=rev
Log:
Surprisingly, we missed a trivial case here. Fix that!

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
    llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=164814&r1=164813&r2=164814&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Fri Sep 28 04:33:53 2012
@@ -930,6 +930,10 @@
       Value *V = Builder->CreateShuffleVector(TrueVal, FalseVal, MaskVal);
       return ReplaceInstUsesWith(SI, V);
     }
+
+    if (isa<ConstantAggregateZero>(CondVal)) {
+      return ReplaceInstUsesWith(SI, FalseVal);
+    }
   }
 
   return 0;

Modified: llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll?rev=164814&r1=164813&r2=164814&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll Fri Sep 28 04:33:53 2012
@@ -188,3 +188,11 @@
            <4 x i16> %lhs, <4 x i16> %rhs
   ret <4 x i16> %A
 }
+
+define <4 x i16> @test13e(<4 x i16> %lhs, <4 x i16> %rhs) {
+; CHECK: @test13e
+; CHECK-NEXT: ret <4 x i16> %rhs
+  %A = select <4 x i1> <i1 false, i1 false, i1 false, i1 false>,
+           <4 x i16> %lhs, <4 x i16> %rhs
+  ret <4 x i16> %A
+}