[llvm] Scalarizer : Fix vector shuffle issue when can't aligned to customized minBits. (PR #163912)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Dec 4 00:38:32 PST 2025
https://github.com/ShchchowAMD updated https://github.com/llvm/llvm-project/pull/163912
>From cca6c72c4cfb43a13231c423948f9139dcb4c22f Mon Sep 17 00:00:00 2001
From: "Zhou, Shaochi(AMD)" <shaozhou at amd.com>
Date: Fri, 17 Oct 2025 14:09:47 +0800
Subject: [PATCH 1/2] Scalarizer : Fix vector shuffle issue when can't aligned
to customized minBits.
When set a value to minBits, when doing scalarizer pass, if last remained
boolean vector size can't be aligned to min bits, remained bits should be processed each by each, and not allowed to do a direct shuffle.
---
llvm/lib/Transforms/Scalar/Scalarizer.cpp | 20 +++++++++--
.../vector-bool-not-aligned-min-bits.ll | 34 +++++++++++++++++++
2 files changed, 52 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll
diff --git a/llvm/lib/Transforms/Scalar/Scalarizer.cpp b/llvm/lib/Transforms/Scalar/Scalarizer.cpp
index 25a531ca33214..57395d375d177 100644
--- a/llvm/lib/Transforms/Scalar/Scalarizer.cpp
+++ b/llvm/lib/Transforms/Scalar/Scalarizer.cpp
@@ -252,14 +252,30 @@ static Value *concatenate(IRBuilder<> &Builder, ArrayRef<Value *> Fragments,
Res = Builder.CreateInsertElement(Res, Fragment, I * VS.NumPacked,
Name + ".upto" + Twine(I));
} else {
+ if (NumPacked < VS.NumPacked) {
+ // If last pack of remained bits not aligned to target pack size.
+ ExtendMask.resize(NumPacked);
+ }
+
Fragment = Builder.CreateShuffleVector(Fragment, Fragment, ExtendMask);
if (I == 0) {
Res = Fragment;
} else {
for (unsigned J = 0; J < NumPacked; ++J)
InsertMask[I * VS.NumPacked + J] = NumElements + J;
- Res = Builder.CreateShuffleVector(Res, Fragment, InsertMask,
- Name + ".upto" + Twine(I));
+
+ if (NumPacked < VS.NumPacked) {
+ for (unsigned J = 0; J < NumPacked; ++J) {
+ auto FragmentBit = Builder.CreateExtractElement(Fragment, J);
+ Res = Builder.CreateInsertElement(Res, FragmentBit,
+ I * VS.NumPacked + J);
+ }
+ Res->setName(Name + ".upto" + Twine(I));
+ } else {
+ Res = Builder.CreateShuffleVector(Res, Fragment, InsertMask,
+ Name + ".upto" + Twine(I));
+ }
+
for (unsigned J = 0; J < NumPacked; ++J)
InsertMask[I * VS.NumPacked + J] = I * VS.NumPacked + J;
}
diff --git a/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll b/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll
new file mode 100644
index 0000000000000..30fe3f5614ace
--- /dev/null
+++ b/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll
@@ -0,0 +1,34 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -passes="scalarizer<min-bits=8>" -S | FileCheck %s
+
+define void @vector_scalar_not_aligned(ptr addrspace(1) %arg0, ptr addrspace(1) %arg1) {
+; CHECK-LABEL: @vector_scalar_not_aligned(
+; CHECK-NEXT: [[VAL_I1:%.*]] = load <11 x i32>, ptr addrspace(1) [[ARG_0:%.*]], align 4
+; CHECK-NEXT: [[VAL_I2:%.*]] = load <11 x i32>, ptr addrspace(1) [[ARG_1:%.*]], align 4
+; CHECK-NEXT: [[BOOL_VEC_B1:%.*]] = icmp ne <11 x i32> [[VAL_I1]], zeroinitializer
+; CHECK-NEXT: [[BOOL_VEC_B1_I0:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B1]], <11 x i1> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT: [[BOOL_VEC_B1_I1:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B1]], <11 x i1> poison, <3 x i32> <i32 8, i32 9, i32 10>
+; CHECK-NEXT: [[BOOL_VEC_B2:%.*]] = icmp ne <11 x i32> [[VAL_I2]], zeroinitializer
+; CHECK-NEXT: [[BOOL_VEC_B2_I0:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B2]], <11 x i1> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT: [[BOOL_RESULT_I0:%.*]] = xor <8 x i1> [[BOOL_VEC_B1_I0]], [[BOOL_VEC_B2_I0]]
+; CHECK-NEXT: [[BOOL_VEC_B2_I1:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B2]], <11 x i1> poison, <3 x i32> <i32 8, i32 9, i32 10>
+; CHECK-NEXT: [[BOOL_RESULT_I1:%.*]] = xor <3 x i1> [[BOOL_VEC_B1_I1]], [[BOOL_VEC_B2_I1]]
+; CHECK-NEXT: [[ELEM_1:%.*]] = shufflevector <8 x i1> [[BOOL_RESULT_I0]], <8 x i1> [[BOOL_RESULT_I0]], <11 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 poison, i32 poison, i32 poison>
+; CHECK-NEXT: [[ELEM_2:%.*]] = shufflevector <3 x i1> [[BOOL_RESULT_I1]], <3 x i1> [[BOOL_RESULT_I1]], <3 x i32> <i32 0, i32 1, i32 2>
+; CHECK-NEXT: [[ELEM_3:%.*]] = extractelement <3 x i1> [[ELEM_2]], i64 0
+; CHECK-NEXT: [[ELEM_4:%.*]] = insertelement <11 x i1> [[ELEM_1]], i1 [[ELEM_3]], i64 8
+; CHECK-NEXT: [[ELEM_5:%.*]] = extractelement <3 x i1> [[ELEM_2]], i64 1
+; CHECK-NEXT: [[ELEM_6:%.*]] = insertelement <11 x i1> [[ELEM_4]], i1 [[ELEM_5]], i64 9
+; CHECK-NEXT: [[ELEM_7:%.*]] = extractelement <3 x i1> [[ELEM_2]], i64 2
+; CHECK-NEXT: [[BOOL_RESULT:%.*]] = insertelement <11 x i1> [[ELEM_6]], i1 [[ELEM_7]], i64 10
+; CHECK-NEXT: [[EXT:%.*]] = zext <11 x i1> [[BOOL_RESULT]] to <11 x i32>
+; CHECK-NEXT: ret void
+
+ %val1 = load <11 x i32>, ptr addrspace(1) %arg0, align 4
+ %val2 = load <11 x i32>, ptr addrspace(1) %arg1, align 4
+ %boolVec1 = icmp ne <11 x i32> %val1, zeroinitializer
+ %boolVec2 = icmp ne <11 x i32> %val2, zeroinitializer
+ %boolResult = xor <11 x i1> %boolVec1, %boolVec2
+ %ext = zext <11 x i1> %boolResult to <11 x i32>
+ ret void
+}
\ No newline at end of file
>From 01c4fd3c20194694776fef369f6aad2f91ef1cec Mon Sep 17 00:00:00 2001
From: "Zhou, Shaochi(AMD)" <shaozhou at amd.com>
Date: Thu, 4 Dec 2025 16:33:41 +0800
Subject: [PATCH 2/2] Refine code to use shuffleVector to let too small
fragments be albe to insert into final scalarized results.
---
llvm/lib/Transforms/Scalar/Scalarizer.cpp | 26 +++++++---------
.../vector-bool-not-aligned-min-bits.ll | 30 ++++++++-----------
2 files changed, 24 insertions(+), 32 deletions(-)
diff --git a/llvm/lib/Transforms/Scalar/Scalarizer.cpp b/llvm/lib/Transforms/Scalar/Scalarizer.cpp
index 57395d375d177..ad8fd9b781a55 100644
--- a/llvm/lib/Transforms/Scalar/Scalarizer.cpp
+++ b/llvm/lib/Transforms/Scalar/Scalarizer.cpp
@@ -252,9 +252,16 @@ static Value *concatenate(IRBuilder<> &Builder, ArrayRef<Value *> Fragments,
Res = Builder.CreateInsertElement(Res, Fragment, I * VS.NumPacked,
Name + ".upto" + Twine(I));
} else {
- if (NumPacked < VS.NumPacked) {
+ unsigned remainedSize = NumPacked;
+ while (remainedSize <= VS.NumPacked / 2) {
// If last pack of remained bits not aligned to target pack size.
- ExtendMask.resize(NumPacked);
+ remainedSize = remainedSize * 2;
+ SmallVector<int> SmallExtendMask;
+ SmallExtendMask.resize(remainedSize, -1);
+ for (unsigned I = 0; I < remainedSize; ++I)
+ SmallExtendMask[I] = I;
+ Fragment =
+ Builder.CreateShuffleVector(Fragment, Fragment, SmallExtendMask);
}
Fragment = Builder.CreateShuffleVector(Fragment, Fragment, ExtendMask);
@@ -263,19 +270,8 @@ static Value *concatenate(IRBuilder<> &Builder, ArrayRef<Value *> Fragments,
} else {
for (unsigned J = 0; J < NumPacked; ++J)
InsertMask[I * VS.NumPacked + J] = NumElements + J;
-
- if (NumPacked < VS.NumPacked) {
- for (unsigned J = 0; J < NumPacked; ++J) {
- auto FragmentBit = Builder.CreateExtractElement(Fragment, J);
- Res = Builder.CreateInsertElement(Res, FragmentBit,
- I * VS.NumPacked + J);
- }
- Res->setName(Name + ".upto" + Twine(I));
- } else {
- Res = Builder.CreateShuffleVector(Res, Fragment, InsertMask,
- Name + ".upto" + Twine(I));
- }
-
+ Res = Builder.CreateShuffleVector(Res, Fragment, InsertMask,
+ Name + ".upto" + Twine(I));
for (unsigned J = 0; J < NumPacked; ++J)
InsertMask[I * VS.NumPacked + J] = I * VS.NumPacked + J;
}
diff --git a/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll b/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll
index 30fe3f5614ace..3ac91342c7c59 100644
--- a/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll
+++ b/llvm/test/Transforms/Scalarizer/vector-bool-not-aligned-min-bits.ll
@@ -5,23 +5,19 @@ define void @vector_scalar_not_aligned(ptr addrspace(1) %arg0, ptr addrspace(1)
; CHECK-LABEL: @vector_scalar_not_aligned(
; CHECK-NEXT: [[VAL_I1:%.*]] = load <11 x i32>, ptr addrspace(1) [[ARG_0:%.*]], align 4
; CHECK-NEXT: [[VAL_I2:%.*]] = load <11 x i32>, ptr addrspace(1) [[ARG_1:%.*]], align 4
-; CHECK-NEXT: [[BOOL_VEC_B1:%.*]] = icmp ne <11 x i32> [[VAL_I1]], zeroinitializer
-; CHECK-NEXT: [[BOOL_VEC_B1_I0:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B1]], <11 x i1> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
-; CHECK-NEXT: [[BOOL_VEC_B1_I1:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B1]], <11 x i1> poison, <3 x i32> <i32 8, i32 9, i32 10>
-; CHECK-NEXT: [[BOOL_VEC_B2:%.*]] = icmp ne <11 x i32> [[VAL_I2]], zeroinitializer
-; CHECK-NEXT: [[BOOL_VEC_B2_I0:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B2]], <11 x i1> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
-; CHECK-NEXT: [[BOOL_RESULT_I0:%.*]] = xor <8 x i1> [[BOOL_VEC_B1_I0]], [[BOOL_VEC_B2_I0]]
-; CHECK-NEXT: [[BOOL_VEC_B2_I1:%.*]] = shufflevector <11 x i1> [[BOOL_VEC_B2]], <11 x i1> poison, <3 x i32> <i32 8, i32 9, i32 10>
-; CHECK-NEXT: [[BOOL_RESULT_I1:%.*]] = xor <3 x i1> [[BOOL_VEC_B1_I1]], [[BOOL_VEC_B2_I1]]
-; CHECK-NEXT: [[ELEM_1:%.*]] = shufflevector <8 x i1> [[BOOL_RESULT_I0]], <8 x i1> [[BOOL_RESULT_I0]], <11 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 poison, i32 poison, i32 poison>
-; CHECK-NEXT: [[ELEM_2:%.*]] = shufflevector <3 x i1> [[BOOL_RESULT_I1]], <3 x i1> [[BOOL_RESULT_I1]], <3 x i32> <i32 0, i32 1, i32 2>
-; CHECK-NEXT: [[ELEM_3:%.*]] = extractelement <3 x i1> [[ELEM_2]], i64 0
-; CHECK-NEXT: [[ELEM_4:%.*]] = insertelement <11 x i1> [[ELEM_1]], i1 [[ELEM_3]], i64 8
-; CHECK-NEXT: [[ELEM_5:%.*]] = extractelement <3 x i1> [[ELEM_2]], i64 1
-; CHECK-NEXT: [[ELEM_6:%.*]] = insertelement <11 x i1> [[ELEM_4]], i1 [[ELEM_5]], i64 9
-; CHECK-NEXT: [[ELEM_7:%.*]] = extractelement <3 x i1> [[ELEM_2]], i64 2
-; CHECK-NEXT: [[BOOL_RESULT:%.*]] = insertelement <11 x i1> [[ELEM_6]], i1 [[ELEM_7]], i64 10
-; CHECK-NEXT: [[EXT:%.*]] = zext <11 x i1> [[BOOL_RESULT]] to <11 x i32>
+; CHECK-NEXT: [[BOOLVEC1:%.*]] = icmp ne <11 x i32> [[VAL_I1]], zeroinitializer
+; CHECK-NEXT: [[BOOLVEC1_I0:%.*]] = shufflevector <11 x i1> [[BOOLVEC1]] <11 x i1> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT: [[BOOLVEC1_I1:%.*]] = shufflevector <11 x i1> [[BOOLVEC1]], <11 x i1> poison, <3 x i32> <i32 8, i32 9, i32 10>
+; CHECK-NEXT: [[BOOLVEC2:%.*]] = icmp ne <11 x i32> [[VAL_I2]], zeroinitializer
+; CHECK-NEXT: [[BOOLVEC2_I0:%.*]] = shufflevector <11 x i1> [[BOOLVEC2]], <11 x i1> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT: [[BOOLRESULT_I0:%.*]] = xor <8 x i1> [[BOOLVEC1_I0]], [[BOOLVEC2_I0]]
+; CHECK-NEXT: [[BOOLVEC2_I1:%.*]] = shufflevector <11 x i1> [[BOOLVEC2]], <11 x i1> poison, <3 x i32> <i32 8, i32 9, i32 10>
+; CHECK-NEXT: [[BOOLRESULT_I1:%.*]] = xor <3 x i1> [[BOOLVEC1_I1]], [[BOOLVEC2_I1]]
+; CHECK-NEXT: [[SSA1:%.*]] = shufflevector <8 x i1> [[BOOLRESULT_I0]], <8 x i1> [[BOOLRESULT_I0]], <11 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 poison, i32 poison, i32 poison>
+; CHECK-NEXT: [[SSA2:%.*]] = shufflevector <3 x i1> [[BOOLRESULT_I1]], <3 x i1> [[BOOLRESULT_I1]], <6 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5>
+; CHECK-NEXT: [[SSA3:%.*]] = shufflevector <6 x i1> [[SSA2]], <6 x i1> [[SSA2]], <11 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 poison, i32 poison, i32 poison>
+; CHECK-NEXT: [[BOOLRESULT:%.*]] = shufflevector <11 x i1> [[SSA1]], <11 x i1> [[SSA3]], <11 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 11, i32 12, i32 13>
+; CHECK-NEXT: [[EXT:%.*]] = zext <11 x i1> [[BOOLRESULT]] to <11 x i32>
; CHECK-NEXT: ret void
%val1 = load <11 x i32>, ptr addrspace(1) %arg0, align 4
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