[llvm] r299412 - InstCombine: Use the InstSimplify hook for shufflevector

[Zvi Rackover via llvm-commits]

Author: zvi
Date: Mon Apr  3 23:47:57 2017
New Revision: 299412

URL: http://llvm.org/viewvc/llvm-project?rev=299412&view=rev
Log:
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

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineVectorOps.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineVectorOps.cpp?rev=299412&r1=299411&r2=299412&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineVectorOps.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineVectorOps.cpp Mon Apr  3 23:47:57 2017
@@ -1140,12 +1140,11 @@ Instruction *InstCombiner::visitShuffleV
   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);