[Mlir-commits] [mlir] [mlir] Add strided metadata range dataflow analysis (PR #161280)

[Fabian Mora]

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@@ -0,0 +1,145 @@
+//===- InferStridedMetadataInterface.h - Strided Metadata Inference -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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains definitions of the strided metadata inference interface
+// defined in `InferStridedMetadataInterface.td`
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_INTERFACES_INFERSTRIDEDMETADATAINTERFACE_H
+#define MLIR_INTERFACES_INFERSTRIDEDMETADATAINTERFACE_H
+
+#include "mlir/Interfaces/InferIntRangeInterface.h"
+
+namespace mlir {
+/// A class that represents the strided metadata range information, including
+/// offsets, sizes, and strides as integer ranges.
+class StridedMetadataRange {
+public:
+  /// Default constructor creates uninitialized ranges.
+  StridedMetadataRange() = default;
+
+  /// Returns a ranked strided metadata range.
+  static StridedMetadataRange
+  getRanked(SmallVectorImpl<ConstantIntRanges> &&offsets,
+            SmallVectorImpl<ConstantIntRanges> &&sizes,
+            SmallVectorImpl<ConstantIntRanges> &&strides) {
+    return StridedMetadataRange(std::move(offsets), std::move(sizes),
+                                std::move(strides));
+  }
+
+  /// Returns a strided metadata range with maximum ranges.
+  static StridedMetadataRange getMaxRanges(int32_t indexBitwidth,
+                                           int32_t offsetsRank,
+                                           int32_t sizeRank,
+                                           int32_t stridedRank) {
+    return StridedMetadataRange(
+        SmallVector<ConstantIntRanges>(
+            offsetsRank, ConstantIntRanges::maxRange(indexBitwidth)),
----------------
fabianmcg wrote:

Could you expand the comment a bit? Rely on them to be nonnegative to do what?

Also, while I don't think it's possible to have negative sizes with memrefs, in general it's possible to have a size range with negative values.

Think of a ptr that gets advanced and we are tracking the full size of the ptr range, in that case the range of the advanced ptr can be negative.

https://github.com/llvm/llvm-project/pull/161280