[llvm] [VPlan] Consolidate logic for narrow to single scalars (PR #151506)

Ramkumar Ramachandra via llvm-commits llvm-commits at lists.llvm.org
Wed Sep 10 07:39:53 PDT 2025


https://github.com/artagnon updated https://github.com/llvm/llvm-project/pull/151506

>From 02d9c7149a12f9f5defe3feb0c07de3a19956573 Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Wed, 10 Sep 2025 15:29:28 +0100
Subject: [PATCH 1/2] [VPlan] Allow wide-stores in narrow to single scalar

Follow up on 132bacd ([VPlan] Also allow extracts as users when
converting to single scalars.) to also allow WidenStore recipes as users
when converting to single scalars. While at it, refine the
vputils::isSingleScalar check to also check vputils::onlyFirstLaneUsed,
and forbid zero users.

The motivation for this patch is to ease consolidation of the logic to
narrow to single scalar, and the consolidation will be tackled in a
follow-up.
---
 .../Transforms/Vectorize/VPlanTransforms.cpp  |  7 +--
 .../AArch64/conditional-branches-cost.ll      | 49 +++++++++----------
 .../extractvalue-no-scalarization-required.ll | 10 ++--
 .../AArch64/sve-widen-extractvalue.ll         |  8 ++-
 .../LoopVectorize/RISCV/dead-ops-cost.ll      |  6 +--
 llvm/test/Transforms/LoopVectorize/pr50686.ll |  7 +--
 6 files changed, 41 insertions(+), 46 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 6b122e19c0169..099f871f10cad 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -1311,14 +1311,15 @@ static void narrowToSingleScalarRecipes(VPlan &Plan) {
       // Skip recipes that aren't single scalars or don't have only their
       // scalar results used. In the latter case, we would introduce extra
       // broadcasts.
-      if (!vputils::isSingleScalar(RepOrWidenR) ||
+      if ((!vputils::isSingleScalar(RepOrWidenR) &&
+           !vputils::onlyFirstLaneUsed(RepOrWidenR)) ||
+          RepOrWidenR->getNumUsers() == 0 ||
           !all_of(RepOrWidenR->users(), [RepOrWidenR](const VPUser *U) {
-            return U->usesScalars(RepOrWidenR) ||
+            return U->usesScalars(RepOrWidenR) || isa<VPWidenStoreRecipe>(U) ||
                    match(cast<VPRecipeBase>(U),
                          m_ExtractLastElement(m_VPValue()));
           }))
         continue;
-
       auto *Clone = new VPReplicateRecipe(RepOrWidenR->getUnderlyingInstr(),
                                           RepOrWidenR->operands(),
                                           true /*IsSingleScalar*/);
diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/conditional-branches-cost.ll b/llvm/test/Transforms/LoopVectorize/AArch64/conditional-branches-cost.ll
index 884eeac09e1e3..d26a33add96ed 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/conditional-branches-cost.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/conditional-branches-cost.ll
@@ -428,7 +428,7 @@ define i32 @header_mask_and_invariant_compare(ptr %A, ptr %B, ptr %C, ptr %D, pt
 ; DEFAULT-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP0]], [[N_MOD_VF]]
 ; DEFAULT-NEXT:    br label %[[VECTOR_BODY:.*]]
 ; DEFAULT:       [[VECTOR_BODY]]:
-; DEFAULT-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[PRED_STORE_CONTINUE37:.*]] ]
+; DEFAULT-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[PRED_STORE_CONTINUE35:.*]] ]
 ; DEFAULT-NEXT:    [[TMP9:%.*]] = load i32, ptr [[A]], align 4, !alias.scope [[META8:![0-9]+]]
 ; DEFAULT-NEXT:    [[BROADCAST_SPLATINSERT28:%.*]] = insertelement <4 x i32> poison, i32 [[TMP9]], i64 0
 ; DEFAULT-NEXT:    [[BROADCAST_SPLAT29:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT28]], <4 x i32> poison, <4 x i32> zeroinitializer
@@ -436,40 +436,37 @@ define i32 @header_mask_and_invariant_compare(ptr %A, ptr %B, ptr %C, ptr %D, pt
 ; DEFAULT-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i32> poison, i32 [[TMP19]], i64 0
 ; DEFAULT-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; DEFAULT-NEXT:    [[TMP6:%.*]] = or <4 x i32> [[BROADCAST_SPLAT]], [[BROADCAST_SPLAT29]]
-; DEFAULT-NEXT:    [[TMP7:%.*]] = load i32, ptr [[C]], align 4, !alias.scope [[META13:![0-9]+]]
-; DEFAULT-NEXT:    [[BROADCAST_SPLATINSERT30:%.*]] = insertelement <4 x i32> poison, i32 [[TMP7]], i64 0
-; DEFAULT-NEXT:    [[BROADCAST_SPLAT31:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT30]], <4 x i32> poison, <4 x i32> zeroinitializer
-; DEFAULT-NEXT:    [[TMP8:%.*]] = icmp ugt <4 x i32> [[BROADCAST_SPLAT31]], [[TMP6]]
+; DEFAULT-NEXT:    [[TMP10:%.*]] = load i32, ptr [[C]], align 4, !alias.scope [[META13:![0-9]+]]
+; DEFAULT-NEXT:    [[TMP7:%.*]] = extractelement <4 x i32> [[TMP6]], i32 0
+; DEFAULT-NEXT:    [[TMP8:%.*]] = icmp ugt i32 [[TMP10]], [[TMP7]]
+; DEFAULT-NEXT:    [[BROADCAST_SPLATINSERT36:%.*]] = insertelement <4 x i1> poison, i1 [[TMP8]], i64 0
+; DEFAULT-NEXT:    [[BROADCAST_SPLAT37:%.*]] = shufflevector <4 x i1> [[BROADCAST_SPLATINSERT36]], <4 x i1> poison, <4 x i32> zeroinitializer
 ; DEFAULT-NEXT:    [[TMP16:%.*]] = getelementptr i32, ptr [[D]], i64 [[INDEX]]
-; DEFAULT-NEXT:    [[TMP20:%.*]] = extractelement <4 x i1> [[TMP8]], i32 0
-; DEFAULT-NEXT:    br i1 [[TMP20]], label %[[PRED_STORE_IF:.*]], label %[[PRED_STORE_CONTINUE:.*]]
+; DEFAULT-NEXT:    br i1 [[TMP8]], label %[[PRED_STORE_IF:.*]], label %[[PRED_STORE_CONTINUE:.*]]
 ; DEFAULT:       [[PRED_STORE_IF]]:
 ; DEFAULT-NEXT:    [[TMP11:%.*]] = extractelement <4 x i32> [[TMP6]], i32 0
 ; DEFAULT-NEXT:    store i32 [[TMP11]], ptr [[E]], align 4, !alias.scope [[META15:![0-9]+]], !noalias [[META17:![0-9]+]]
 ; DEFAULT-NEXT:    br label %[[PRED_STORE_CONTINUE]]
 ; DEFAULT:       [[PRED_STORE_CONTINUE]]:
-; DEFAULT-NEXT:    [[TMP12:%.*]] = extractelement <4 x i1> [[TMP8]], i32 1
-; DEFAULT-NEXT:    br i1 [[TMP12]], label %[[PRED_STORE_IF32:.*]], label %[[PRED_STORE_CONTINUE33:.*]]
-; DEFAULT:       [[PRED_STORE_IF32]]:
+; DEFAULT-NEXT:    br i1 [[TMP8]], label %[[PRED_STORE_IF30:.*]], label %[[PRED_STORE_CONTINUE31:.*]]
+; DEFAULT:       [[PRED_STORE_IF30]]:
 ; DEFAULT-NEXT:    [[TMP13:%.*]] = extractelement <4 x i32> [[TMP6]], i32 0
 ; DEFAULT-NEXT:    store i32 [[TMP13]], ptr [[E]], align 4, !alias.scope [[META15]], !noalias [[META17]]
+; DEFAULT-NEXT:    br label %[[PRED_STORE_CONTINUE31]]
+; DEFAULT:       [[PRED_STORE_CONTINUE31]]:
+; DEFAULT-NEXT:    br i1 [[TMP8]], label %[[PRED_STORE_IF32:.*]], label %[[PRED_STORE_CONTINUE33:.*]]
+; DEFAULT:       [[PRED_STORE_IF32]]:
+; DEFAULT-NEXT:    [[TMP15:%.*]] = extractelement <4 x i32> [[TMP6]], i32 0
+; DEFAULT-NEXT:    store i32 [[TMP15]], ptr [[E]], align 4, !alias.scope [[META15]], !noalias [[META17]]
 ; DEFAULT-NEXT:    br label %[[PRED_STORE_CONTINUE33]]
 ; DEFAULT:       [[PRED_STORE_CONTINUE33]]:
-; DEFAULT-NEXT:    [[TMP14:%.*]] = extractelement <4 x i1> [[TMP8]], i32 2
-; DEFAULT-NEXT:    br i1 [[TMP14]], label %[[PRED_STORE_IF34:.*]], label %[[PRED_STORE_CONTINUE35:.*]]
+; DEFAULT-NEXT:    br i1 [[TMP8]], label %[[PRED_STORE_IF34:.*]], label %[[PRED_STORE_CONTINUE35]]
 ; DEFAULT:       [[PRED_STORE_IF34]]:
-; DEFAULT-NEXT:    [[TMP15:%.*]] = extractelement <4 x i32> [[TMP6]], i32 0
-; DEFAULT-NEXT:    store i32 [[TMP15]], ptr [[E]], align 4, !alias.scope [[META15]], !noalias [[META17]]
-; DEFAULT-NEXT:    br label %[[PRED_STORE_CONTINUE35]]
-; DEFAULT:       [[PRED_STORE_CONTINUE35]]:
-; DEFAULT-NEXT:    [[TMP21:%.*]] = extractelement <4 x i1> [[TMP8]], i32 3
-; DEFAULT-NEXT:    br i1 [[TMP21]], label %[[PRED_STORE_IF36:.*]], label %[[PRED_STORE_CONTINUE37]]
-; DEFAULT:       [[PRED_STORE_IF36]]:
 ; DEFAULT-NEXT:    [[TMP22:%.*]] = extractelement <4 x i32> [[TMP6]], i32 0
 ; DEFAULT-NEXT:    store i32 [[TMP22]], ptr [[E]], align 4, !alias.scope [[META15]], !noalias [[META17]]
-; DEFAULT-NEXT:    br label %[[PRED_STORE_CONTINUE37]]
-; DEFAULT:       [[PRED_STORE_CONTINUE37]]:
-; DEFAULT-NEXT:    call void @llvm.masked.store.v4i32.p0(<4 x i32> zeroinitializer, ptr [[TMP16]], i32 4, <4 x i1> [[TMP8]]), !alias.scope [[META19:![0-9]+]], !noalias [[META20:![0-9]+]]
+; DEFAULT-NEXT:    br label %[[PRED_STORE_CONTINUE35]]
+; DEFAULT:       [[PRED_STORE_CONTINUE35]]:
+; DEFAULT-NEXT:    call void @llvm.masked.store.v4i32.p0(<4 x i32> zeroinitializer, ptr [[TMP16]], i32 4, <4 x i1> [[BROADCAST_SPLAT37]]), !alias.scope [[META19:![0-9]+]], !noalias [[META20:![0-9]+]]
 ; DEFAULT-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
 ; DEFAULT-NEXT:    [[TMP18:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
 ; DEFAULT-NEXT:    br i1 [[TMP18]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP21:![0-9]+]]
@@ -658,15 +655,15 @@ define void @low_trip_count_fold_tail_scalarized_store(ptr %dst) {
 ; COMMON-NEXT:    store i8 6, ptr [[TMP6]], align 1
 ; COMMON-NEXT:    br label %[[PRED_STORE_CONTINUE12]]
 ; COMMON:       [[PRED_STORE_CONTINUE12]]:
-; COMMON-NEXT:    br i1 false, label %[[PRED_STORE_IF13:.*]], label %[[EXIT:.*]]
+; COMMON-NEXT:    br i1 false, label %[[PRED_STORE_IF13:.*]], label %[[EXIT1:.*]]
 ; COMMON:       [[PRED_STORE_IF13]]:
 ; COMMON-NEXT:    [[TMP7:%.*]] = getelementptr i8, ptr [[DST]], i64 7
 ; COMMON-NEXT:    store i8 7, ptr [[TMP7]], align 1
-; COMMON-NEXT:    br label %[[EXIT]]
-; COMMON:       [[EXIT]]:
+; COMMON-NEXT:    br label %[[EXIT1]]
+; COMMON:       [[EXIT1]]:
 ; COMMON-NEXT:    br label %[[MIDDLE_BLOCK:.*]]
 ; COMMON:       [[MIDDLE_BLOCK]]:
-; COMMON-NEXT:    br [[EXIT1:label %.*]]
+; COMMON-NEXT:    br [[EXIT:label %.*]]
 ; COMMON:       [[SCALAR_PH]]:
 ;
 entry:
diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/extractvalue-no-scalarization-required.ll b/llvm/test/Transforms/LoopVectorize/AArch64/extractvalue-no-scalarization-required.ll
index efcd810203a44..379825bbbab88 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/extractvalue-no-scalarization-required.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/extractvalue-no-scalarization-required.ll
@@ -16,7 +16,7 @@
 ; CM: vector.ph:
 ; CM:  CLONE ir<%a> = extractvalue ir<%sv>
 ; CM:  CLONE ir<%b> = extractvalue ir<%sv>
-; CM:  WIDEN ir<%add> = add ir<%a>, ir<%b>
+; CM:  CLONE ir<%add> = add ir<%a>, ir<%b>
 ; CM:  Successor(s): vector loop
 
 ; CM: LV: Scalar loop costs: 5.
@@ -30,17 +30,15 @@ define void @test1(ptr %dst, {i64, i64} %sv) {
 ; FORCED-NEXT:    br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
 ; FORCED:       [[VECTOR_PH]]:
 ; FORCED-NEXT:    [[TMP0:%.*]] = extractvalue { i64, i64 } [[SV]], 0
-; FORCED-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <2 x i64> poison, i64 [[TMP0]], i64 0
-; FORCED-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <2 x i64> [[BROADCAST_SPLATINSERT]], <2 x i64> poison, <2 x i32> zeroinitializer
 ; FORCED-NEXT:    [[TMP4:%.*]] = extractvalue { i64, i64 } [[SV]], 1
-; FORCED-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <2 x i64> poison, i64 [[TMP4]], i64 0
+; FORCED-NEXT:    [[TMP5:%.*]] = add i64 [[TMP0]], [[TMP4]]
+; FORCED-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <2 x i64> poison, i64 [[TMP5]], i64 0
 ; FORCED-NEXT:    [[BROADCAST_SPLAT2:%.*]] = shufflevector <2 x i64> [[BROADCAST_SPLATINSERT1]], <2 x i64> poison, <2 x i32> zeroinitializer
-; FORCED-NEXT:    [[TMP1:%.*]] = add <2 x i64> [[BROADCAST_SPLAT]], [[BROADCAST_SPLAT2]]
 ; FORCED-NEXT:    br label %[[VECTOR_BODY:.*]]
 ; FORCED:       [[VECTOR_BODY]]:
 ; FORCED-NEXT:    [[INDEX:%.*]] = phi i32 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
 ; FORCED-NEXT:    [[TMP2:%.*]] = getelementptr i64, ptr [[DST]], i32 [[INDEX]]
-; FORCED-NEXT:    store <2 x i64> [[TMP1]], ptr [[TMP2]], align 4
+; FORCED-NEXT:    store <2 x i64> [[BROADCAST_SPLAT2]], ptr [[TMP2]], align 4
 ; FORCED-NEXT:    [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 2
 ; FORCED-NEXT:    [[TMP3:%.*]] = icmp eq i32 [[INDEX_NEXT]], 1000
 ; FORCED-NEXT:    br i1 [[TMP3]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/sve-widen-extractvalue.ll b/llvm/test/Transforms/LoopVectorize/AArch64/sve-widen-extractvalue.ll
index 0c6a490ddf4ba..eceda0897b174 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/sve-widen-extractvalue.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/sve-widen-extractvalue.ll
@@ -17,17 +17,15 @@ define void @widen_extractvalue(ptr %dst, {i64, i64} %sv) #0 {
 ; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i32 1000, [[TMP3]]
 ; CHECK-NEXT:    [[N_VEC:%.*]] = sub i32 1000, [[N_MOD_VF]]
 ; CHECK-NEXT:    [[EXTRACT0:%.*]] = extractvalue { i64, i64 } [[SV]], 0
-; CHECK-NEXT:    [[DOTSPLATINSERT1:%.*]] = insertelement <vscale x 2 x i64> poison, i64 [[EXTRACT0]], i64 0
-; CHECK-NEXT:    [[DOTSPLAT2:%.*]] = shufflevector <vscale x 2 x i64> [[DOTSPLATINSERT1]], <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer
 ; CHECK-NEXT:    [[TMP10:%.*]] = extractvalue { i64, i64 } [[SV]], 1
-; CHECK-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <vscale x 2 x i64> poison, i64 [[TMP10]], i64 0
+; CHECK-NEXT:    [[TMP6:%.*]] = add i64 [[EXTRACT0]], [[TMP10]]
+; CHECK-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <vscale x 2 x i64> poison, i64 [[TMP6]], i64 0
 ; CHECK-NEXT:    [[BROADCAST_SPLAT2:%.*]] = shufflevector <vscale x 2 x i64> [[BROADCAST_SPLATINSERT1]], <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer
-; CHECK-NEXT:    [[TMP7:%.*]] = add <vscale x 2 x i64> [[DOTSPLAT2]], [[BROADCAST_SPLAT2]]
 ; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
 ; CHECK:       [[VECTOR_BODY]]:
 ; CHECK-NEXT:    [[INDEX:%.*]] = phi i32 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[TMP8:%.*]] = getelementptr i64, ptr [[DST]], i32 [[INDEX]]
-; CHECK-NEXT:    store <vscale x 2 x i64> [[TMP7]], ptr [[TMP8]], align 8
+; CHECK-NEXT:    store <vscale x 2 x i64> [[BROADCAST_SPLAT2]], ptr [[TMP8]], align 8
 ; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i32 [[INDEX]], [[TMP3]]
 ; CHECK-NEXT:    [[TMP9:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]]
 ; CHECK-NEXT:    br i1 [[TMP9]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/dead-ops-cost.ll b/llvm/test/Transforms/LoopVectorize/RISCV/dead-ops-cost.ll
index e014b9ddbcd0e..95e68d6cc300a 100644
--- a/llvm/test/Transforms/LoopVectorize/RISCV/dead-ops-cost.ll
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/dead-ops-cost.ll
@@ -304,9 +304,9 @@ define void @test_phi_in_latch_redundant(ptr %dst, i32 %a) {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
 ; CHECK-NEXT:    br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
 ; CHECK:       [[VECTOR_PH]]:
-; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <vscale x 4 x i32> poison, i32 [[A]], i64 0
+; CHECK-NEXT:    [[TMP0:%.*]] = xor i32 [[A]], -1
+; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <vscale x 4 x i32> poison, i32 [[TMP0]], i64 0
 ; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <vscale x 4 x i32> [[BROADCAST_SPLATINSERT]], <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
-; CHECK-NEXT:    [[TMP19:%.*]] = xor <vscale x 4 x i32> [[BROADCAST_SPLAT]], splat (i32 -1)
 ; CHECK-NEXT:    [[TMP6:%.*]] = call <vscale x 4 x i64> @llvm.stepvector.nxv4i64()
 ; CHECK-NEXT:    [[TMP7:%.*]] = mul <vscale x 4 x i64> [[TMP6]], splat (i64 9)
 ; CHECK-NEXT:    [[INDUCTION:%.*]] = add <vscale x 4 x i64> zeroinitializer, [[TMP7]]
@@ -320,7 +320,7 @@ define void @test_phi_in_latch_redundant(ptr %dst, i32 %a) {
 ; CHECK-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <vscale x 4 x i64> poison, i64 [[TMP9]], i64 0
 ; CHECK-NEXT:    [[BROADCAST_SPLAT2:%.*]] = shufflevector <vscale x 4 x i64> [[BROADCAST_SPLATINSERT1]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
 ; CHECK-NEXT:    [[TMP16:%.*]] = getelementptr i32, ptr [[DST]], <vscale x 4 x i64> [[VEC_IND]]
-; CHECK-NEXT:    call void @llvm.vp.scatter.nxv4i32.nxv4p0(<vscale x 4 x i32> [[TMP19]], <vscale x 4 x ptr> align 4 [[TMP16]], <vscale x 4 x i1> splat (i1 true), i32 [[TMP8]])
+; CHECK-NEXT:    call void @llvm.vp.scatter.nxv4i32.nxv4p0(<vscale x 4 x i32> [[BROADCAST_SPLAT]], <vscale x 4 x ptr> align 4 [[TMP16]], <vscale x 4 x i1> splat (i1 true), i32 [[TMP8]])
 ; CHECK-NEXT:    [[TMP17:%.*]] = zext i32 [[TMP8]] to i64
 ; CHECK-NEXT:    [[AVL_NEXT]] = sub nuw i64 [[AVL]], [[TMP17]]
 ; CHECK-NEXT:    [[VEC_IND_NEXT]] = add <vscale x 4 x i64> [[VEC_IND]], [[BROADCAST_SPLAT2]]
diff --git a/llvm/test/Transforms/LoopVectorize/pr50686.ll b/llvm/test/Transforms/LoopVectorize/pr50686.ll
index 14bcfde5b4423..dbe7f5874f53e 100644
--- a/llvm/test/Transforms/LoopVectorize/pr50686.ll
+++ b/llvm/test/Transforms/LoopVectorize/pr50686.ll
@@ -26,12 +26,13 @@ define void @m(ptr nocapture %p, ptr nocapture %p2, i32 %q) {
 ; CHECK-NEXT:    [[BROADCAST_SPLATINSERT2:%.*]] = insertelement <4 x i32> poison, i32 [[TMP3]], i64 0
 ; CHECK-NEXT:    [[BROADCAST_SPLAT3:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT2]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    [[TMP4:%.*]] = sub nsw <4 x i32> [[TMP2]], [[BROADCAST_SPLAT3]]
-; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr [[ARRAYIDX9_2]], align 4, !alias.scope [[META0]]
+; CHECK-NEXT:    [[TMP6:%.*]] = load i32, ptr [[ARRAYIDX9_2]], align 4, !alias.scope [[META0]]
+; CHECK-NEXT:    [[TMP9:%.*]] = extractelement <4 x i32> [[TMP4]], i32 0
+; CHECK-NEXT:    [[TMP5:%.*]] = sub nsw i32 [[TMP9]], [[TMP6]]
 ; CHECK-NEXT:    [[BROADCAST_SPLATINSERT4:%.*]] = insertelement <4 x i32> poison, i32 [[TMP5]], i64 0
 ; CHECK-NEXT:    [[BROADCAST_SPLAT5:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT4]], <4 x i32> poison, <4 x i32> zeroinitializer
-; CHECK-NEXT:    [[TMP6:%.*]] = sub nsw <4 x i32> [[TMP4]], [[BROADCAST_SPLAT5]]
 ; CHECK-NEXT:    [[TMP7:%.*]] = getelementptr inbounds i32, ptr [[P]], i64 [[INDEX]]
-; CHECK-NEXT:    store <4 x i32> [[TMP6]], ptr [[TMP7]], align 4, !alias.scope [[META3:![0-9]+]], !noalias [[META0]]
+; CHECK-NEXT:    store <4 x i32> [[BROADCAST_SPLAT5]], ptr [[TMP7]], align 4, !alias.scope [[META3:![0-9]+]], !noalias [[META0]]
 ; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
 ; CHECK-NEXT:    [[TMP8:%.*]] = icmp eq i64 [[INDEX_NEXT]], 60
 ; CHECK-NEXT:    br i1 [[TMP8]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]

>From 59bce4a4385cb8caf654254879d3f32fa88dd10b Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Thu, 31 Jul 2025 12:58:49 +0100
Subject: [PATCH 2/2] [VPlan] Consolidate logic for narrow to single scalars

The logic for narrowing to single scalar recipes is in two different
places: narrowToSingleScalarRecipes and legalizeAndOptimizeInductions.
Consolidate them, with minor test changes.
---
 .../Transforms/Vectorize/VPlanTransforms.cpp  | 24 -------------------
 1 file changed, 24 deletions(-)

diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 099f871f10cad..d29e49b036f6e 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -648,30 +648,6 @@ static void legalizeAndOptimizeInductions(VPlan &Plan) {
     if (!PhiR)
       continue;
 
-    // Try to narrow wide and replicating recipes to uniform recipes, based on
-    // VPlan analysis.
-    // TODO: Apply to all recipes in the future, to replace legacy uniformity
-    // analysis.
-    auto Users = collectUsersRecursively(PhiR);
-    for (VPUser *U : reverse(Users)) {
-      auto *Def = dyn_cast<VPSingleDefRecipe>(U);
-      auto *RepR = dyn_cast<VPReplicateRecipe>(U);
-      // Skip recipes that shouldn't be narrowed.
-      if (!Def || !isa<VPReplicateRecipe, VPWidenRecipe>(Def) ||
-          Def->getNumUsers() == 0 || !Def->getUnderlyingValue() ||
-          (RepR && (RepR->isSingleScalar() || RepR->isPredicated())))
-        continue;
-
-      // Skip recipes that may have other lanes than their first used.
-      if (!vputils::isSingleScalar(Def) && !vputils::onlyFirstLaneUsed(Def))
-        continue;
-
-      auto *Clone = new VPReplicateRecipe(Def->getUnderlyingInstr(),
-                                          Def->operands(), /*IsUniform*/ true);
-      Clone->insertAfter(Def);
-      Def->replaceAllUsesWith(Clone);
-    }
-
     // Replace wide pointer inductions which have only their scalars used by
     // PtrAdd(IndStart, ScalarIVSteps (0, Step)).
     if (auto *PtrIV = dyn_cast<VPWidenPointerInductionRecipe>(&Phi)) {



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