[llvm] [LoopVectorize] Generate wide active lane masks (PR #147535)

[Florian Hahn via llvm-commits]

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@@ -1432,20 +1433,93 @@ static bool isConditionTrueViaVFAndUF(VPValue *Cond, VPlan &Plan,
   return SE.isKnownPredicate(CmpInst::ICMP_EQ, TripCount, C);
 }
 
+static void extractFromWideActiveLaneMask(VPlan &Plan, ElementCount VF,
+                                          unsigned UF) {
+  VPRegionBlock *VectorRegion = Plan.getVectorLoopRegion();
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fhahn wrote:

IIUC this needs to be cost-driven, to only be done when the wider active-lane-mask is profitable?

https://github.com/llvm/llvm-project/pull/147535