[llvm] [LV] Fix gap mask requirement for interleaved access (PR #151105)
Mel Chen via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 31 03:13:10 PDT 2025
https://github.com/Mel-Chen updated https://github.com/llvm/llvm-project/pull/151105
>From e2449f9a50ddc0f11f87c79e32e20ac62ff7670a Mon Sep 17 00:00:00 2001
From: Mel Chen <mel.chen at sifive.com>
Date: Tue, 29 Jul 2025 01:26:28 -0700
Subject: [PATCH 1/6] fix
---
.../Transforms/Vectorize/VPlanTransforms.cpp | 3 +-
.../RISCV/interleaved-store-with-gap.ll | 65 +++++++++++++++++++
2 files changed, 67 insertions(+), 1 deletion(-)
create mode 100644 llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index ad8235d891c5d..a50f0fb9f1010 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -2570,7 +2570,8 @@ void VPlanTransforms::createInterleaveGroups(
}
bool NeedsMaskForGaps =
- IG->requiresScalarEpilogue() && !ScalarEpilogueAllowed;
+ (IG->requiresScalarEpilogue() && !ScalarEpilogueAllowed) ||
+ (!StoredValues.empty() && (IG->getNumMembers() < IG->getFactor()));
Instruction *IRInsertPos = IG->getInsertPos();
auto *InsertPos =
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
new file mode 100644
index 0000000000000..8f504cba4242f
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
@@ -0,0 +1,65 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -mtriple=riscv64 -mattr=+v -passes=loop-vectorize -mattr=+v \
+; RUN: -scalable-vectorization=off -enable-masked-interleaved-mem-accesses \
+; RUN: -force-vector-interleave=1 -riscv-v-vector-bits-min=1024 -S < %s | FileCheck %s
+
+define void @store_factor_2_with_tail_gap(i64 %n, ptr %a) {
+; CHECK-LABEL: define void @store_factor_2_with_tail_gap(
+; CHECK-SAME: i64 [[N:%.*]], ptr [[A:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT: [[ENTRY:.*]]:
+; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[N]], 16
+; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
+; CHECK: [[VECTOR_PH]]:
+; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[N]], 16
+; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 [[N]], [[N_MOD_VF]]
+; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
+; CHECK: [[VECTOR_BODY]]:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT: [[VEC_IND:%.*]] = phi <16 x i64> [ <i64 0, i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, i64 10, i64 11, i64 12, i64 13, i64 14, i64 15>, %[[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = shl nsw i64 [[INDEX]], 1
+; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i64, ptr [[A]], i64 [[TMP0]]
+; CHECK-NEXT: [[TMP2:%.*]] = shufflevector <16 x i64> [[VEC_IND]], <16 x i64> poison, <32 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+; CHECK-NEXT: [[INTERLEAVED_VEC:%.*]] = shufflevector <32 x i64> [[TMP2]], <32 x i64> poison, <32 x i32> <i32 0, i32 16, i32 1, i32 17, i32 2, i32 18, i32 3, i32 19, i32 4, i32 20, i32 5, i32 21, i32 6, i32 22, i32 7, i32 23, i32 8, i32 24, i32 9, i32 25, i32 10, i32 26, i32 11, i32 27, i32 12, i32 28, i32 13, i32 29, i32 14, i32 30, i32 15, i32 31>
+; CHECK-NEXT: call void @llvm.masked.store.v32i64.p0(<32 x i64> [[INTERLEAVED_VEC]], ptr [[TMP1]], i32 8, <32 x i1> <i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false>)
+; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
+; CHECK-NEXT: [[VEC_IND_NEXT]] = add <16 x i64> [[VEC_IND]], splat (i64 16)
+; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
+; CHECK-NEXT: br i1 [[TMP3]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK: [[MIDDLE_BLOCK]]:
+; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[N]], [[N_VEC]]
+; CHECK-NEXT: br i1 [[CMP_N]], label %[[EXIT:.*]], label %[[SCALAR_PH]]
+; CHECK: [[SCALAR_PH]]:
+; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], %[[MIDDLE_BLOCK]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT: br label %[[FOR_BODY:.*]]
+; CHECK: [[FOR_BODY]]:
+; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[SCALAR_PH]] ], [ [[INDVARS_IV_NEXT:%.*]], %[[FOR_BODY]] ]
+; CHECK-NEXT: [[TMP4:%.*]] = shl nsw i64 [[INDVARS_IV]], 1
+; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i64, ptr [[A]], i64 [[TMP4]]
+; CHECK-NEXT: store i64 [[INDVARS_IV]], ptr [[ARRAYIDX]], align 8
+; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
+; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i64 [[INDVARS_IV_NEXT]], [[N]]
+; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label %[[EXIT]], label %[[FOR_BODY]], !llvm.loop [[LOOP3:![0-9]+]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %for.body
+
+for.body:
+ %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+ %0 = shl nsw i64 %indvars.iv, 1
+ %arrayidx = getelementptr inbounds i64, ptr %a, i64 %0
+ store i64 %indvars.iv, ptr %arrayidx, align 8
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ %exitcond.not = icmp eq i64 %indvars.iv.next, %n
+ br i1 %exitcond.not, label %exit, label %for.body
+
+exit:
+ ret void
+}
+;.
+; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]]}
+; CHECK: [[META1]] = !{!"llvm.loop.isvectorized", i32 1}
+; CHECK: [[META2]] = !{!"llvm.loop.unroll.runtime.disable"}
+; CHECK: [[LOOP3]] = distinct !{[[LOOP3]], [[META2]], [[META1]]}
+;.
>From 3a5d5ad497c4d49562481d5fca3ef0a9844426c7 Mon Sep 17 00:00:00 2001
From: Mel Chen <mel.chen at sifive.com>
Date: Wed, 30 Jul 2025 00:16:04 -0700
Subject: [PATCH 2/6] apply isFull
---
llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index a50f0fb9f1010..20172a788b014 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -2571,7 +2571,7 @@ void VPlanTransforms::createInterleaveGroups(
bool NeedsMaskForGaps =
(IG->requiresScalarEpilogue() && !ScalarEpilogueAllowed) ||
- (!StoredValues.empty() && (IG->getNumMembers() < IG->getFactor()));
+ (!StoredValues.empty() && !IG->isFull());
Instruction *IRInsertPos = IG->getInsertPos();
auto *InsertPos =
>From b2f1b6f2fa4eaa447554699acfb5f679b9740077 Mon Sep 17 00:00:00 2001
From: Mel Chen <mel.chen at sifive.com>
Date: Wed, 30 Jul 2025 00:53:54 -0700
Subject: [PATCH 3/6] harden assertion
---
llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp | 2 ++
1 file changed, 2 insertions(+)
diff --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index 68e7c20a070f4..31e9fa3c32cf1 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -3548,6 +3548,8 @@ void VPInterleaveRecipe::execute(VPTransformState &State) {
// Vectorize the interleaved store group.
Value *MaskForGaps =
createBitMaskForGaps(State.Builder, State.VF.getKnownMinValue(), *Group);
+ assert(((MaskForGaps != nullptr) == NeedsMaskForGaps) &&
+ "Mismatch between NeedsMaskForGaps and MaskForGaps");
assert((!MaskForGaps || !State.VF.isScalable()) &&
"masking gaps for scalable vectors is not yet supported.");
ArrayRef<VPValue *> StoredValues = getStoredValues();
>From 67cccb0fb209f4b3c1d66e48e80bd59a0770735a Mon Sep 17 00:00:00 2001
From: Mel Chen <mel.chen at sifive.com>
Date: Wed, 30 Jul 2025 00:55:51 -0700
Subject: [PATCH 4/6] apply --check-globals=none
---
.../LoopVectorize/RISCV/interleaved-store-with-gap.ll | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
index 8f504cba4242f..27cd87f1bd7f9 100644
--- a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
@@ -1,4 +1,4 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --version 5
; RUN: opt -mtriple=riscv64 -mattr=+v -passes=loop-vectorize -mattr=+v \
; RUN: -scalable-vectorization=off -enable-masked-interleaved-mem-accesses \
; RUN: -force-vector-interleave=1 -riscv-v-vector-bits-min=1024 -S < %s | FileCheck %s
@@ -57,9 +57,3 @@ for.body:
exit:
ret void
}
-;.
-; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]]}
-; CHECK: [[META1]] = !{!"llvm.loop.isvectorized", i32 1}
-; CHECK: [[META2]] = !{!"llvm.loop.unroll.runtime.disable"}
-; CHECK: [[LOOP3]] = distinct !{[[LOOP3]], [[META2]], [[META1]]}
-;.
>From 157e724b82b79d79fb8263fa3877b316ea3d3318 Mon Sep 17 00:00:00 2001
From: Mel Chen <mel.chen at sifive.com>
Date: Thu, 31 Jul 2025 01:11:57 -0700
Subject: [PATCH 5/6] remove dup -mattr
---
.../LoopVectorize/RISCV/interleaved-store-with-gap.ll | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
index 27cd87f1bd7f9..a13da8e77574a 100644
--- a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
@@ -1,5 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --version 5
-; RUN: opt -mtriple=riscv64 -mattr=+v -passes=loop-vectorize -mattr=+v \
+; RUN: opt -mtriple=riscv64 -mattr=+v -passes=loop-vectorize \
; RUN: -scalable-vectorization=off -enable-masked-interleaved-mem-accesses \
; RUN: -force-vector-interleave=1 -riscv-v-vector-bits-min=1024 -S < %s | FileCheck %s
>From 9a53962654d3e9d993b2348c4c64ec093275e379 Mon Sep 17 00:00:00 2001
From: Mel Chen <mel.chen at sifive.com>
Date: Thu, 31 Jul 2025 03:12:04 -0700
Subject: [PATCH 6/6] compress the variable name
---
.../LoopVectorize/RISCV/interleaved-store-with-gap.ll | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
index a13da8e77574a..c5396f26bbe7f 100644
--- a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-store-with-gap.ll
@@ -46,12 +46,12 @@ entry:
br label %for.body
for.body:
- %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
- %0 = shl nsw i64 %indvars.iv, 1
+ %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ]
+ %0 = shl nsw i64 %iv, 1
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %0
- store i64 %indvars.iv, ptr %arrayidx, align 8
- %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
- %exitcond.not = icmp eq i64 %indvars.iv.next, %n
+ store i64 %iv, ptr %arrayidx, align 8
+ %iv.next = add nuw nsw i64 %iv, 1
+ %exitcond.not = icmp eq i64 %iv.next, %n
br i1 %exitcond.not, label %exit, label %for.body
exit:
More information about the llvm-commits
mailing list