[llvm] [VPlan] Simplify extract-lane of all single-scalars (PR #194838)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon updated https://github.com/llvm/llvm-project/pull/194838

>From b0f6b6e6549a5487b55ebb7f2aff8c0c07817d8f Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <artagnon at tenstorrent.com>
Date: Wed, 29 Apr 2026 12:22:59 +0100
Subject: [PATCH] [VPlan] Simplify extract-lane of all single-scalars

Checking against vputils::isSingleScalar is sufficient for both
correctness and profitability.
---
 llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp         | 8 +++-----
 .../LoopVectorize/X86/replicating-load-store-costs.ll     | 1 -
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 11e5b18bca871..5facd6e15159a 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -1794,11 +1794,9 @@ static void simplifyRecipe(VPSingleDefRecipe *Def, VPTypeAnalysis &TypeInfo) {
   }
 
   if (match(Def, m_ExtractLastLane(m_VPValue(A))) &&
-      ((isa<VPInstruction>(A) && vputils::isSingleScalar(A)) ||
-       (isa<VPReplicateRecipe>(A) &&
-        cast<VPReplicateRecipe>(A)->isSingleScalar())) &&
-      all_of(A->users(),
-             [Def, A](VPUser *U) { return U->usesScalars(A) || Def == U; })) {
+      vputils::isSingleScalar(A) && all_of(A->users(), [Def, A](VPUser *U) {
+        return U->usesScalars(A) || Def == U;
+      })) {
     return Def->replaceAllUsesWith(A);
   }
 
diff --git a/llvm/test/Transforms/LoopVectorize/X86/replicating-load-store-costs.ll b/llvm/test/Transforms/LoopVectorize/X86/replicating-load-store-costs.ll
index 6f74f7c5154b3..3063207e47b25 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/replicating-load-store-costs.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/replicating-load-store-costs.ll
@@ -477,7 +477,6 @@ define double @test_load_used_by_other_load_scev(ptr %ptr.a, ptr %ptr.b, ptr %pt
 ; I64-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[INDEX_NEXT]], 100
 ; I64-NEXT:    br i1 [[TMP3]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP8:![0-9]+]]
 ; I64:       [[MIDDLE_BLOCK]]:
-; I64-NEXT:    [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <2 x double> [[TMP2]], i64 1
 ; I64-NEXT:    br label %[[SCALAR_PH:.*]]
 ; I64:       [[SCALAR_PH]]:
 ;