From: Zvi Rackover <zvi.rackover@intel.com>
Date: Tue, 4 Apr 2017 04:47:57 +0000 (+0000)
Subject: InstCombine: Use the InstSimplify hook for shufflevector
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c7f9b76a740e1a7b3d5dc7436fc85e4a3bc3bb98;p=llvm

InstCombine: Use the InstSimplify hook for shufflevector

Summary: Start using the recently added InstSimplify hook for shuffles in the respective InstCombine visitor.

Reviewers: spatel, RKSimon, craig.topper, majnemer

Reviewed By: majnemer

Subscribers: majnemer, llvm-commits

Differential Revision: https://reviews.llvm.org/D31526

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299412 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index c29d3276526..e89b400a4af 100644
--- a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -1140,12 +1140,11 @@ Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
   SmallVector<int, 16> Mask = SVI.getShuffleMask();
   Type *Int32Ty = Type::getInt32Ty(SVI.getContext());
 
-  bool MadeChange = false;
-
-  // Undefined shuffle mask -> undefined value.
-  if (isa<UndefValue>(SVI.getOperand(2)))
-    return replaceInstUsesWith(SVI, UndefValue::get(SVI.getType()));
+  if (auto *V = SimplifyShuffleVectorInst(LHS, RHS, SVI.getMask(),
+                                          SVI.getType(), DL, &TLI, &DT, &AC))
+    return replaceInstUsesWith(SVI, V);
 
+  bool MadeChange = false;
   unsigned VWidth = SVI.getType()->getVectorNumElements();
 
   APInt UndefElts(VWidth, 0);