[llvm] [VPlan] Expand VPWidenIntOrFpInductionRecipe into separate recipes (PR #118638)

[Florian Hahn via llvm-commits]

================
@@ -2390,6 +2380,129 @@ void VPlanTransforms::createInterleaveGroups(
   }
 }
 
+/// Expand a VPWidenIntOrFpInduction into executable recipes. for the initial
+/// value, phi and backedge value. In the followng example:
+///
+///  vector.ph:
+///  Successor(s): vector loop
+///
+///  <x1> vector loop: {
+///    vector.body:
+///      WIDEN-INDUCTION %i = phi %start, %step, %vf
+///      ...
+///      EMIT branch-on-count ...
+///    No successors
+///  }
+///
+/// WIDEN-INDUCTION will get expanded to:
+///
+///  vector.ph:
+///    ...
+///    vp<%induction> = ...
+///    vp<%inc> = ...
----------------
fhahn wrote:

```suggestion
///    vp<%induction.increment> = ...
```

https://github.com/llvm/llvm-project/pull/118638