[llvm-branch-commits] [llvm] [SLP][modularisation][NFC] Add SLPTree.h; move ReductionVectorPart (PR #222545)

[Madhur Amilkanthwar via llvm-branch-commits]

https://github.com/madhur13490 created https://github.com/llvm/llvm-project/pull/222545

Create the internal header SLPVectorizer/SLPTree.h and move the
BoUpSLP-independent ReductionVectorPart struct and the MinScheduleRegionSize
constant into it. Prepares for relocating the BoUpSLP class declaration into
this header in a follow-up. NFC.

Part of the SLPVectorizer.cpp modularization effort:
https://discourse.llvm.org/t/modularizing-slpvectorizer-cpp/90922

>From 4a68f93d61e74d9faa35bf0737cde03575d488e9 Mon Sep 17 00:00:00 2001
From: Madhur Amilkanthwar <madhura at nvidia.com>
Date: Thu, 10 Sep 2026 00:14:33 -0700
Subject: [PATCH] [SLP][modularisation][NFC] Add SLPTree.h; move
 ReductionVectorPart

Create the internal header SLPVectorizer/SLPTree.h and move the
BoUpSLP-independent ReductionVectorPart struct and the MinScheduleRegionSize
constant into it. Prepares for relocating the BoUpSLP class declaration into
this header in a follow-up. NFC.

Part of the SLPVectorizer.cpp modularization effort:
https://discourse.llvm.org/t/modularizing-slpvectorizer-cpp/90922
---
 .../Transforms/Vectorize/SLPVectorizer.cpp    | 26 +---------
 .../Vectorize/SLPVectorizer/SLPTree.h         | 47 +++++++++++++++++++
 2 files changed, 48 insertions(+), 25 deletions(-)
 create mode 100644 llvm/lib/Transforms/Vectorize/SLPVectorizer/SLPTree.h

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index d0332fcaa0936..c5c125aad1fa8 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -22,6 +22,7 @@
 #include "SLPVectorizer/SLPMemoryUtils.h"
 #include "SLPVectorizer/SLPReductionUtils.h"
 #include "SLPVectorizer/SLPShuffleAnalysis.h"
+#include "SLPVectorizer/SLPTree.h"
 #include "SLPVectorizer/SLPTypeUtils.h"
 #include "SLPVectorizer/SLPUtils.h"
 #include "llvm/ADT/DenseMap.h"
@@ -341,34 +342,9 @@ static const unsigned AliasedCheckLimit = 10;
 // This limit is useful for very large basic blocks.
 static const unsigned MaxMemDepDistance = 160;
 
-/// If the ScheduleRegionSizeBudget is exhausted, we allow small scheduling
-/// regions to be handled.
-static const int MinScheduleRegionSize = 16;
-
 /// Maximum allowed number of operands in the PHI nodes.
 static const unsigned MaxPHINumOperands = 128;
 
-namespace {
-/// A vectorized part of a split reduction, combined into the final reduction
-/// result by the horizontal reduction emitter.
-struct ReductionVectorPart {
-  /// The vectorized value, tracked in case it is replaced while other parts
-  /// are vectorized.
-  WeakTrackingVH Vec;
-  /// The number of times each lane is repeated in the reduction (emitted as a
-  /// multiplication by the scale for add/fadd reductions).
-  unsigned Scale = 1;
-  /// Signedness of \p Vec for reductions, operating on truncated types.
-  bool IsSigned = false;
-  /// True if the value was already reduced in-tree.
-  bool ReducedInTree = false;
-  /// True if the part contribution is subtracted from (rather than added to)
-  /// the final reduction result. Used for reassociated fadd reductions,
-  /// flattened through fsub/fneg operations.
-  bool Negated = false;
-};
-} // namespace
-
 /// Bottom Up SLP Vectorizer.
 class slpvectorizer::BoUpSLP {
   class TreeEntry;
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer/SLPTree.h b/llvm/lib/Transforms/Vectorize/SLPVectorizer/SLPTree.h
new file mode 100644
index 0000000000000..4f5a98a7a9047
--- /dev/null
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer/SLPTree.h
@@ -0,0 +1,47 @@
+//===- SLPTree.h - SLP vectorization graph (BoUpSLP) ----------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Internal header for the SLP vectorization graph. The BoUpSLP class and its
+// nested types are added here in a follow-up change; this change seeds the
+// header with the small helpers BoUpSLP depends on.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TRANSFORMS_VECTORIZE_SLPVECTORIZER_SLPTREE_H
+#define LLVM_LIB_TRANSFORMS_VECTORIZE_SLPVECTORIZER_SLPTREE_H
+
+#include "llvm/IR/ValueHandle.h"
+
+namespace llvm::slpvectorizer {
+
+/// If the ScheduleRegionSizeBudget is exhausted, we allow small scheduling
+/// regions to be handled.
+static const int MinScheduleRegionSize = 16;
+
+/// A vectorized part of a split reduction, combined into the final reduction
+/// result by the horizontal reduction emitter.
+struct ReductionVectorPart {
+  /// The vectorized value, tracked in case it is replaced while other parts
+  /// are vectorized.
+  WeakTrackingVH Vec;
+  /// The number of times each lane is repeated in the reduction (emitted as a
+  /// multiplication by the scale for add/fadd reductions).
+  unsigned Scale = 1;
+  /// Signedness of \p Vec for reductions, operating on truncated types.
+  bool IsSigned = false;
+  /// True if the value was already reduced in-tree.
+  bool ReducedInTree = false;
+  /// True if the part contribution is subtracted from (rather than added to)
+  /// the final reduction result. Used for reassociated fadd reductions,
+  /// flattened through fsub/fneg operations.
+  bool Negated = false;
+};
+
+} // namespace llvm::slpvectorizer
+
+#endif // LLVM_LIB_TRANSFORMS_VECTORIZE_SLPVECTORIZER_SLPTREE_H