[llvm] [VPlan] Materialize constant vector trip counts before final opts. (PR #142309)

[via llvm-commits]

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@@ -10261,6 +10262,11 @@ bool LoopVectorizePass::processLoop(Loop *L) {
           L, PSE, LI, DT, TLI, TTI, AC, ORE, ElementCount::getFixed(1),
           ElementCount::getFixed(1), IC, &CM, BFI, PSI, Checks, BestPlan);
 
+      // TODO: Move to general VPlan pipeline once epilogue loops are also
+      // supported.
+      VPlanTransforms::runPass(VPlanTransforms::materializeVectorTripCount,
+                               BestPlan, VF.Width, IC, PSE);
+
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ayalz wrote:

This disables materializeVectorTripCount() from running on both main and epilog loops, when both are vectorized, as opposed to running it in LVP.executePlan() under `if (!VectorizingEpilogue)` - which would disable it only when vectorizing the epilog loop?

https://github.com/llvm/llvm-project/pull/142309