[Mlir-commits] [mlir] [MLIR][LLVM] DI Expression Rewrite & Legalization (PR #77541)

[Tobias Gysi]

================
@@ -0,0 +1,66 @@
+//===- DIExpressionRewriter.h - Rewriter for DIExpression operators -------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// A driver for running rewrite patterns on DIExpression operators.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_DIALECT_LLVMIR_TRANSFORMS_DIEXPRESSIONREWRITER_H
+#define MLIR_DIALECT_LLVMIR_TRANSFORMS_DIEXPRESSIONREWRITER_H
+
+#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
+#include <deque>
+
+namespace mlir {
+namespace LLVM {
+
+/// Rewriter for DIExpressionAttr.
+///
+/// Users of this rewriter register their own rewrite patterns. Each pattern
+/// matches on a contiguous range of LLVM DIExpressionElemAttrs, and can be
+/// used to rewrite it into a new range of DIExpressionElemAttrs of any length.
+class DIExpressionRewriter {
+public:
+  using OperatorT = LLVM::DIExpressionElemAttr;
+
+  class ExprRewritePattern {
+  public:
+    using OperatorT = DIExpressionRewriter::OperatorT;
+    using OpIterT = std::deque<OperatorT>::const_iterator;
+    using OpIterRange = llvm::iterator_range<OpIterT>;
+
+    virtual ~ExprRewritePattern() = default;
+    /// Check whether a particular prefix of operators matches this pattern.
----------------
gysit wrote:

```suggestion
    /// Checks whether a particular prefix of operators matches this pattern.
```
ultra nit: usually we use third person plural for the first verb of a comment (here and below)

https://github.com/llvm/llvm-project/pull/77541