[llvm] [VPlan] Impl VPlan-based pattern match for ExtendedRed and MulAccRed (NFCI) (PR #113903)

[Florian Hahn via llvm-commits]

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@@ -9518,9 +9626,21 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
       if (CM.blockNeedsPredicationForAnyReason(BB))
         CondOp = RecipeBuilder.getBlockInMask(BB);
 
-      VPReductionRecipe *RedRecipe =
-          new VPReductionRecipe(RdxDesc, CurrentLinkI, PreviousLink, VecOp,
-                                CondOp, CM.useOrderedReductions(RdxDesc));
+      VPReductionRecipe *RedRecipe;
+      VPCostContext CostCtx(CM.TTI, *CM.TLI, Legal->getWidestInductionType(),
+                            CM);
+      if (auto *MulAcc =
+              tryToMatchAndCreateMulAcc(RdxDesc, CurrentLinkI, PreviousLink,
+                                        VecOp, CondOp, CM, CostCtx, Range))
+        RedRecipe = MulAcc;
+      else if (auto *ExtRed = tryToMatchAndCreateExtendedReduction(
+                   RdxDesc, CurrentLinkI, PreviousLink, VecOp, CondOp, CM,
+                   CostCtx, Range))
+        RedRecipe = ExtRed;
+      else
+        RedRecipe =
+            new VPReductionRecipe(RdxDesc, CurrentLinkI, PreviousLink, VecOp,
+                                  CondOp, CM.useOrderedReductions(RdxDesc));
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fhahn wrote:

Could we move the complexity to create the new, optimized recipes to a separate VPlan transform instead of adding it here? 

https://github.com/llvm/llvm-project/pull/113903