[llvm] [LoopFusion] Fix sink instructions (PR #147501)

[Ryotaro Kasuga via llvm-commits]

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@@ -1176,6 +1176,27 @@ struct LoopFuser {
     return true;
   }
 
+  // This function fixes sunk PHI nodes after fusion.
+  void fixPHINodes(SmallVector<Instruction *, 4> &SafeToSink,
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kasuga-fj wrote:

This is a non-member function, so adding `static` here affects its visibility. It is recommended to use `static` in this case (see [Restrict Visibility](https://llvm.org/docs/CodingStandards.html#restrict-visibility)).

(It may still be preferable to add it even if it is a member function)

https://github.com/llvm/llvm-project/pull/147501