[llvm] [VPlan] Run narrowInterleaveGroups during general VPlan optimizations. (PR #149706)

[David Sherwood via llvm-commits]

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@@ -8336,6 +8333,14 @@ void LoopVectorizationPlanner::buildVPlansWithVPRecipes(ElementCount MinVF,
       if (CM.foldTailWithEVL() && !HasScalarVF)
         VPlanTransforms::runPass(VPlanTransforms::addExplicitVectorLength,
                                  *Plan, CM.getMaxSafeElements());
+
+      if (auto P = VPlanTransforms::narrowInterleaveGroups(
+              *Plan,
+              TTI.getRegisterBitWidth(
+                  TargetTransformInfo::RGK_FixedWidthVector),
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david-arm wrote:

How does this work if `Plan` is for a scalable vector? I thought with https://github.com/llvm/llvm-project/pull/154842 we now supported narrow interleaving groups for scalable VFs?

https://github.com/llvm/llvm-project/pull/149706