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-Tag: llvmorg-5.0.0-rc1~8578
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=82bf48d8b955c8b06eabc374196042d8ae14010d;p=platform%2Fupstream%2Fllvm.git

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

llvm-svn: 299412
---

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index c29d327..e89b400 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/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);