[llvm] [VPlan] Add VPInstruction to unpack vector values to scalars. (PR #155670)

[via llvm-commits]

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@@ -326,8 +326,9 @@ struct VPlanTransforms {
                                             VPBasicBlock *VectorPH);
 
   /// Add explicit Build[Struct]Vector recipes that combine multiple scalar
-  /// values into single vectors.
-  static void materializeBuildVectors(VPlan &Plan);
+  /// values into single vectors and Unpack recipes to extract scalars from a
+  /// vector as needed.
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ayalz wrote:

```
  /// Add explicit Build[Struct]Vector recipes to Pack multiple scalar values
  /// into vectors and Unpack recipes to extract scalars from vectors as needed.
```

https://github.com/llvm/llvm-project/pull/155670