From 688d668e5c18607cbf1832402e0435f1e886f5e4 Mon Sep 17 00:00:00 2001
From: Nick Lewycky <nicholas@mxc.ca>
Date: Mon, 3 Jun 2013 23:15:20 +0000
Subject: [PATCH] Delete dead safety check.

llvm-svn: 183167
---
 llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index c76aa4c2e6cf..d43093d83165 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -820,12 +820,7 @@ Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
     if (isRHSID) return ReplaceInstUsesWith(SVI, RHS);
   }
 
-  if (isa<UndefValue>(RHS) &&
-      // This isn't necessary for correctness, but the comment block below
-      // claims that there are cases where folding two shuffles into one would
-      // cause worse codegen on some targets.
-      !isa<ShuffleVectorInst>(LHS) &&
-      CanEvaluateShuffled(LHS, Mask)) {
+  if (isa<UndefValue>(RHS) && CanEvaluateShuffled(LHS, Mask)) {
     Value *V = EvaluateInDifferentElementOrder(LHS, Mask);
     return ReplaceInstUsesWith(SVI, V);
   }