[llvm] [LV] Run replaceSymbolicStrides as a VPlan optimization (NFC) (PR #194067)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon updated https://github.com/llvm/llvm-project/pull/194067

>From 5d3ba74ca8d441a03660ab921e0fcd4c2ff577f6 Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <artagnon at tenstorrent.com>
Date: Fri, 24 Apr 2026 22:26:26 +0100
Subject: [PATCH] [LV] Run replaceSymbolicStrides as a VPlan optimization (NFC)

---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp             | 6 ++----
 .../Transforms/LoopVectorize/VPlan/vplan-print-after-all.ll | 2 +-
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 6535f2dc6c72c..c6170bb436f8d 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -6874,6 +6874,8 @@ void LoopVectorizationPlanner::buildVPlansWithVPRecipes(ElementCount MinVF,
     RUN_VPLAN_PASS(VPlanTransforms::sinkPredicatedStores, *Plan, PSE, OrigLoop);
     RUN_VPLAN_PASS(VPlanTransforms::truncateToMinimalBitwidths, *Plan,
                    Config.getMinimalBitwidths());
+    RUN_VPLAN_PASS(VPlanTransforms::replaceSymbolicStrides, *Plan, PSE,
+                   Legal->getLAI()->getSymbolicStrides());
     RUN_VPLAN_PASS(VPlanTransforms::optimize, *Plan);
     // TODO: try to put addExplicitVectorLength close to addActiveLaneMask
     if (CM.foldTailWithEVL()) {
@@ -7099,10 +7101,6 @@ LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(VPlanPtr Plan,
   RUN_VPLAN_PASS(VPlanTransforms::createInterleaveGroups, *Plan,
                  InterleaveGroups, CM.isEpilogueAllowed());
 
-  // Replace VPValues for known constant strides.
-  RUN_VPLAN_PASS(VPlanTransforms::replaceSymbolicStrides, *Plan, PSE,
-                 Legal->getLAI()->getSymbolicStrides());
-
   auto BlockNeedsPredication = [this](BasicBlock *BB) {
     return Legal->blockNeedsPredication(BB);
   };
diff --git a/llvm/test/Transforms/LoopVectorize/VPlan/vplan-print-after-all.ll b/llvm/test/Transforms/LoopVectorize/VPlan/vplan-print-after-all.ll
index 1fb23a06401d4..c74446c7ee994 100644
--- a/llvm/test/Transforms/LoopVectorize/VPlan/vplan-print-after-all.ll
+++ b/llvm/test/Transforms/LoopVectorize/VPlan/vplan-print-after-all.ll
@@ -25,11 +25,11 @@
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::createPartialReductions
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::convertToAbstractRecipes
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::createInterleaveGroups
-; CHECK: VPlan for loop in 'foo' after VPlanTransforms::replaceSymbolicStrides
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::dropPoisonGeneratingRecipes
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::hoistPredicatedLoads
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::sinkPredicatedStores
 ; CHECK: VPlan for loop in 'foo' after VPlanTransforms::truncateToMinimalBitwidths
+; CHECK: VPlan for loop in 'foo' after VPlanTransforms::replaceSymbolicStrides
 ; CHECK: VPlan for loop in 'foo' after removeRedundantCanonicalIVs
 ; CHECK: VPlan for loop in 'foo' after removeRedundantInductionCasts
 ; CHECK: VPlan for loop in 'foo' after reassociateHeaderMask