[llvm] 5e963a2 - Rehome an orphaned comment [NFC]

[Sanne Wouda via llvm-commits]

Author: Sanne Wouda
Date: 2021-03-08T16:32:30Z
New Revision: 5e963a24415eb88d512eb74c8addf87051f7969a

URL: https://github.com/llvm/llvm-project/commit/5e963a24415eb88d512eb74c8addf87051f7969a
DIFF: https://github.com/llvm/llvm-project/commit/5e963a24415eb88d512eb74c8addf87051f7969a.diff

LOG: Rehome an orphaned comment [NFC]

As seen in 35827164c4, the "shuffle x, x, mask" comment has drifted away
from the implementation of the pattern. Put it back.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index 06f22cdfb63d..d7474e3072f0 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -2287,7 +2287,6 @@ Instruction *InstCombinerImpl::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
   if (isa<ScalableVectorType>(LHS->getType()))
     return nullptr;
 
-  // shuffle x, x, mask --> shuffle x, undef, mask'
   unsigned VWidth = cast<FixedVectorType>(SVI.getType())->getNumElements();
   unsigned LHSWidth = cast<FixedVectorType>(LHS->getType())->getNumElements();
   ArrayRef<int> Mask = SVI.getShuffleMask();
@@ -2323,6 +2322,7 @@ Instruction *InstCombinerImpl::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
     }
   }
 
+  // shuffle x, x, mask --> shuffle x, undef, mask'
   if (LHS == RHS) {
     assert(!isa<UndefValue>(RHS) && "Shuffle with 2 undef ops not simplified?");
     // Remap any references to RHS to use LHS.