[LV] Move all VPlan transforms after initial VPlan construction.

Reorder VPlan transforms slightly so they are all grouped together,
after disabling Value -> VPValue lookup. In terms of codegen impact,
this should be NFC modulo a small number of instruction reorderings.

Preparation to split up tryToBuildVPlanWithVPRecipes in a follow-up.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D154640

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -9053,18 +9053,10 @@ std::optional<VPlanPtr> LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(
   // bring the VPlan to its final state.
   // ---------------------------------------------------------------------------
 
-  VPlanTransforms::removeRedundantCanonicalIVs(*Plan);
-  VPlanTransforms::removeRedundantInductionCasts(*Plan);
-
   // Adjust the recipes for any inloop reductions.
   adjustRecipesForReductions(cast<VPBasicBlock>(TopRegion->getExiting()), Plan,
                              RecipeBuilder, Range.Start);
 
-  // Sink users of fixed-order recurrence past the recipe defining the previous
-  // value and introduce FirstOrderRecurrenceSplice VPInstructions.
-  if (!VPlanTransforms::adjustFixedOrderRecurrences(*Plan, Builder))
-    return std::nullopt;
-
   // Interleave memory: for each Interleave Group we marked earlier as relevant
   // for this VPlan, replace the Recipes widening its memory instructions with a
   // single VPInterleaveRecipe at its insertion point.
@@ -9121,6 +9113,14 @@ std::optional<VPlanPtr> LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(
   // in ways that accessing values using original IR values is incorrect.
   Plan->disableValue2VPValue();
 
+  // Sink users of fixed-order recurrence past the recipe defining the previous
+  // value and introduce FirstOrderRecurrenceSplice VPInstructions.
+  if (!VPlanTransforms::adjustFixedOrderRecurrences(*Plan, Builder))
+    return std::nullopt;
+
+  VPlanTransforms::removeRedundantCanonicalIVs(*Plan);
+  VPlanTransforms::removeRedundantInductionCasts(*Plan);
+
   VPlanTransforms::optimizeInductions(*Plan, *PSE.getSE());
   VPlanTransforms::removeDeadRecipes(*Plan);
 

llvm/test/Transforms/LoopVectorize/interleaved-accesses.ll

@@ -1505,11 +1505,11 @@ define void @PR34743(ptr %a, ptr %b, i64 %n) {
 ; CHECK-NEXT:    [[WIDE_VEC:%.*]] = load <8 x i16>, ptr [[TMP7]], align 4
 ; CHECK-NEXT:    [[STRIDED_VEC:%.*]] = shufflevector <8 x i16> [[WIDE_VEC]], <8 x i16> poison, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
 ; CHECK-NEXT:    [[STRIDED_VEC4]] = shufflevector <8 x i16> [[WIDE_VEC]], <8 x i16> poison, <4 x i32> <i32 1, i32 3, i32 5, i32 7>
-; CHECK-NEXT:    [[TMP8:%.*]] = sext <4 x i16> [[STRIDED_VEC]] to <4 x i32>
-; CHECK-NEXT:    [[TMP9:%.*]] = shufflevector <4 x i16> [[VECTOR_RECUR]], <4 x i16> [[STRIDED_VEC4]], <4 x i32> <i32 3, i32 4, i32 5, i32 6>
-; CHECK-NEXT:    [[TMP10:%.*]] = sext <4 x i16> [[TMP9]] to <4 x i32>
+; CHECK-NEXT:    [[TMP8:%.*]] = shufflevector <4 x i16> [[VECTOR_RECUR]], <4 x i16> [[STRIDED_VEC4]], <4 x i32> <i32 3, i32 4, i32 5, i32 6>
+; CHECK-NEXT:    [[TMP9:%.*]] = sext <4 x i16> [[TMP8]] to <4 x i32>
+; CHECK-NEXT:    [[TMP10:%.*]] = sext <4 x i16> [[STRIDED_VEC]] to <4 x i32>
 ; CHECK-NEXT:    [[TMP11:%.*]] = sext <4 x i16> [[STRIDED_VEC4]] to <4 x i32>
-; CHECK-NEXT:    [[TMP12:%.*]] = mul nsw <4 x i32> [[TMP10]], [[TMP8]]
+; CHECK-NEXT:    [[TMP12:%.*]] = mul nsw <4 x i32> [[TMP9]], [[TMP10]]
 ; CHECK-NEXT:    [[TMP13:%.*]] = mul nsw <4 x i32> [[TMP12]], [[TMP11]]
 ; CHECK-NEXT:    [[TMP14:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
 ; CHECK-NEXT:    store <4 x i32> [[TMP13]], ptr [[TMP14]], align 4, !alias.scope !36, !noalias !39