[llvm] [SLP] Remove -slp-optimize-identity-hor-reduction-ops option (PR #106238)
Philip Reames via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 27 08:50:02 PDT 2024
https://github.com/preames created https://github.com/llvm/llvm-project/pull/106238
This code has been unchanged for two years; let's simplify the code
and remove configurability which makes the code harder to follow.
>From 6746f6ec8352c4c905777052c24466fcc36e15d4 Mon Sep 17 00:00:00 2001
From: Philip Reames <preames at rivosinc.com>
Date: Tue, 27 Aug 2024 08:34:03 -0700
Subject: [PATCH 1/2] [SLP] Remove -slp-optimize-identity-hor-reduction-ops
option
This code has been unchanged for two years; let's simplify the code
and remove configurability which makes the code harder to follow.
---
.../Transforms/Vectorize/SLPVectorizer.cpp | 20 +++++--------------
.../AArch64/buildvector-reduce.ll | 12 -----------
.../SystemZ/minbitwidth-non-vector-root.ll | 16 ---------------
3 files changed, 5 insertions(+), 43 deletions(-)
delete mode 100644 llvm/test/Transforms/SLPVectorizer/SystemZ/minbitwidth-non-vector-root.ll
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index ed47ed661ab946..b0344a99b4ae01 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -136,13 +136,6 @@ static cl::opt<bool> ShouldStartVectorizeHorAtStore(
cl::desc(
"Attempt to vectorize horizontal reductions feeding into a store"));
-// NOTE: If AllowHorRdxIdenityOptimization is true, the optimization will run
-// even if we match a reduction but do not vectorize in the end.
-static cl::opt<bool> AllowHorRdxIdenityOptimization(
- "slp-optimize-identity-hor-reduction-ops", cl::init(true), cl::Hidden,
- cl::desc("Allow optimization of original scalar identity operations on "
- "matched horizontal reductions."));
-
static cl::opt<int>
MaxVectorRegSizeOption("slp-max-reg-size", cl::init(128), cl::Hidden,
cl::desc("Attempt to vectorize for this register size in bits"));
@@ -17565,10 +17558,9 @@ class HorizontalReduction {
return Num + Vals.size();
});
if (NumReducedVals < ReductionLimit &&
- (!AllowHorRdxIdenityOptimization ||
- all_of(ReducedVals, [](ArrayRef<Value *> RedV) {
+ all_of(ReducedVals, [](ArrayRef<Value *> RedV) {
return RedV.size() < 2 || !allConstant(RedV) || !isSplat(RedV);
- }))) {
+ })) {
for (ReductionOpsType &RdxOps : ReductionOps)
for (Value *RdxOp : RdxOps)
V.analyzedReductionRoot(cast<Instruction>(RdxOp));
@@ -17698,8 +17690,7 @@ class HorizontalReduction {
}
// Emit code for constant values.
- if (AllowHorRdxIdenityOptimization && Candidates.size() > 1 &&
- allConstant(Candidates)) {
+ if (Candidates.size() > 1 && allConstant(Candidates)) {
Value *Res = Candidates.front();
++VectorizedVals.try_emplace(Candidates.front(), 0).first->getSecond();
for (Value *VC : ArrayRef(Candidates).drop_front()) {
@@ -17714,14 +17705,13 @@ class HorizontalReduction {
unsigned NumReducedVals = Candidates.size();
if (NumReducedVals < ReductionLimit &&
- (NumReducedVals < 2 || !AllowHorRdxIdenityOptimization ||
- !isSplat(Candidates)))
+ (NumReducedVals < 2 || !isSplat(Candidates)))
continue;
// Check if we support repeated scalar values processing (optimization of
// original scalar identity operations on matched horizontal reductions).
IsSupportedHorRdxIdentityOp =
- AllowHorRdxIdenityOptimization && RdxKind != RecurKind::Mul &&
+ RdxKind != RecurKind::Mul &&
RdxKind != RecurKind::FMul && RdxKind != RecurKind::FMulAdd;
// Gather same values.
MapVector<Value *, unsigned> SameValuesCounter;
diff --git a/llvm/test/Transforms/SLPVectorizer/AArch64/buildvector-reduce.ll b/llvm/test/Transforms/SLPVectorizer/AArch64/buildvector-reduce.ll
index 2c417804c83e0d..bbc2bfdcb6c160 100644
--- a/llvm/test/Transforms/SLPVectorizer/AArch64/buildvector-reduce.ll
+++ b/llvm/test/Transforms/SLPVectorizer/AArch64/buildvector-reduce.ll
@@ -1,6 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -passes=slp-vectorizer < %s -mtriple=arm64-apple-macosx | FileCheck %s
-; RUN: opt -S -passes=slp-vectorizer < %s -mtriple=arm64-apple-macosx -slp-optimize-identity-hor-reduction-ops=false | FileCheck %s --check-prefix=NO-IDENTITY
define i8 @test() {
; CHECK-LABEL: @test(
@@ -12,17 +11,6 @@ define i8 @test() {
; CHECK-NEXT: [[TMP0]] = mul i32 [[CALL278]], 8
; CHECK-NEXT: br label [[FOR_BODY]]
;
-; NO-IDENTITY-LABEL: @test(
-; NO-IDENTITY-NEXT: entry:
-; NO-IDENTITY-NEXT: br label [[FOR_BODY:%.*]]
-; NO-IDENTITY: for.body:
-; NO-IDENTITY-NEXT: [[SUM:%.*]] = phi i32 [ [[TMP2:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ]
-; NO-IDENTITY-NEXT: [[CALL278:%.*]] = call i32 @fn(i32 [[SUM]])
-; NO-IDENTITY-NEXT: [[TMP0:%.*]] = insertelement <8 x i32> poison, i32 [[CALL278]], i32 0
-; NO-IDENTITY-NEXT: [[TMP1:%.*]] = shufflevector <8 x i32> [[TMP0]], <8 x i32> poison, <8 x i32> zeroinitializer
-; NO-IDENTITY-NEXT: [[TMP2]] = call i32 @llvm.vector.reduce.add.v8i32(<8 x i32> [[TMP1]])
-; NO-IDENTITY-NEXT: br label [[FOR_BODY]]
-;
entry:
br label %for.body
diff --git a/llvm/test/Transforms/SLPVectorizer/SystemZ/minbitwidth-non-vector-root.ll b/llvm/test/Transforms/SLPVectorizer/SystemZ/minbitwidth-non-vector-root.ll
deleted file mode 100644
index 6524b378f3d8bb..00000000000000
--- a/llvm/test/Transforms/SLPVectorizer/SystemZ/minbitwidth-non-vector-root.ll
+++ /dev/null
@@ -1,16 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
-; RUN: opt -passes=slp-vectorizer -S -slp-optimize-identity-hor-reduction-ops=false < %s -mtriple=s390x-ibm-linux -mcpu=arch13 | FileCheck %s
-
-define void @foo() {
-; CHECK-LABEL: define void @foo(
-; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
-; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> zeroinitializer)
-; CHECK-NEXT: store i32 [[TMP1]], ptr null, align 4
-; CHECK-NEXT: ret void
-;
- %1 = add i32 0, 0
- %2 = add i32 %1, 0
- %3 = add i32 %2, 0
- store i32 %3, ptr null, align 4
- ret void
-}
>From c387be4e77e14771d933616817c60a6432e16cec Mon Sep 17 00:00:00 2001
From: Philip Reames <preames at rivosinc.com>
Date: Tue, 27 Aug 2024 08:46:26 -0700
Subject: [PATCH 2/2] clang-format
---
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index b0344a99b4ae01..1c57855b57149c 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -17559,7 +17559,7 @@ class HorizontalReduction {
});
if (NumReducedVals < ReductionLimit &&
all_of(ReducedVals, [](ArrayRef<Value *> RedV) {
- return RedV.size() < 2 || !allConstant(RedV) || !isSplat(RedV);
+ return RedV.size() < 2 || !allConstant(RedV) || !isSplat(RedV);
})) {
for (ReductionOpsType &RdxOps : ReductionOps)
for (Value *RdxOp : RdxOps)
@@ -17710,9 +17710,9 @@ class HorizontalReduction {
// Check if we support repeated scalar values processing (optimization of
// original scalar identity operations on matched horizontal reductions).
- IsSupportedHorRdxIdentityOp =
- RdxKind != RecurKind::Mul &&
- RdxKind != RecurKind::FMul && RdxKind != RecurKind::FMulAdd;
+ IsSupportedHorRdxIdentityOp = RdxKind != RecurKind::Mul &&
+ RdxKind != RecurKind::FMul &&
+ RdxKind != RecurKind::FMulAdd;
// Gather same values.
MapVector<Value *, unsigned> SameValuesCounter;
if (IsSupportedHorRdxIdentityOp)
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