[Mlir-commits] [mlir] [mlir] Add optional PatternBenefit to function / SCF conversion patterns (PR #159752)

[Matthias Springer]

https://github.com/matthias-springer created https://github.com/llvm/llvm-project/pull/159752

Pattern benefit allows users to give priority to a pattern.


>From ade7071aa0138d9991f698c701ce7cad0dcfb084 Mon Sep 17 00:00:00 2001
From: Matthias Springer <me at m-sp.org>
Date: Fri, 19 Sep 2025 10:39:14 +0000
Subject: [PATCH] [mlir] Add optional PatternBenefit to function / SCF
 conversion patterns

---
 .../include/mlir/Dialect/SCF/Transforms/Patterns.h |  5 +++--
 mlir/include/mlir/Transforms/DialectConversion.h   | 12 +++++++-----
 .../SCF/Transforms/StructuralTypeConversions.cpp   |  9 +++++----
 mlir/lib/Transforms/Utils/DialectConversion.cpp    | 14 ++++++++------
 4 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/mlir/include/mlir/Dialect/SCF/Transforms/Patterns.h b/mlir/include/mlir/Dialect/SCF/Transforms/Patterns.h
index 00c8a5c0c517b..cfe68f61a7a42 100644
--- a/mlir/include/mlir/Dialect/SCF/Transforms/Patterns.h
+++ b/mlir/include/mlir/Dialect/SCF/Transforms/Patterns.h
@@ -51,12 +51,13 @@ class ForLoopPipeliningPattern : public OpRewritePattern<ForOp> {
 /// TypeConverter, but otherwise don't care what type conversions are happening.
 void populateSCFStructuralTypeConversionsAndLegality(
     const TypeConverter &typeConverter, RewritePatternSet &patterns,
-    ConversionTarget &target);
+    ConversionTarget &target, PatternBenefit benefit = 1);
 
 /// Similar to `populateSCFStructuralTypeConversionsAndLegality` but does not
 /// populate the conversion target.
 void populateSCFStructuralTypeConversions(const TypeConverter &typeConverter,
-                                          RewritePatternSet &patterns);
+                                          RewritePatternSet &patterns,
+                                          PatternBenefit benefit = 1);
 
 /// Updates the ConversionTarget with dynamic legality of SCF operations based
 /// on the provided type converter.
diff --git a/mlir/include/mlir/Transforms/DialectConversion.h b/mlir/include/mlir/Transforms/DialectConversion.h
index 6ef649e8fc13a..ed7e2a08ebfd9 100644
--- a/mlir/include/mlir/Transforms/DialectConversion.h
+++ b/mlir/include/mlir/Transforms/DialectConversion.h
@@ -811,17 +811,19 @@ convertOpResultTypes(Operation *op, ValueRange operands,
 /// ops which use FunctionType to represent their type.
 void populateFunctionOpInterfaceTypeConversionPattern(
     StringRef functionLikeOpName, RewritePatternSet &patterns,
-    const TypeConverter &converter);
+    const TypeConverter &converter, PatternBenefit benefit = 1);
 
 template <typename FuncOpT>
 void populateFunctionOpInterfaceTypeConversionPattern(
-    RewritePatternSet &patterns, const TypeConverter &converter) {
-  populateFunctionOpInterfaceTypeConversionPattern(FuncOpT::getOperationName(),
-                                                   patterns, converter);
+    RewritePatternSet &patterns, const TypeConverter &converter,
+    PatternBenefit benefit = 1) {
+  populateFunctionOpInterfaceTypeConversionPattern(
+      FuncOpT::getOperationName(), patterns, converter, benefit);
 }
 
 void populateAnyFunctionOpInterfaceTypeConversionPattern(
-    RewritePatternSet &patterns, const TypeConverter &converter);
+    RewritePatternSet &patterns, const TypeConverter &converter,
+    PatternBenefit benefit = 1);
 
 //===----------------------------------------------------------------------===//
 // Conversion PatternRewriter
diff --git a/mlir/lib/Dialect/SCF/Transforms/StructuralTypeConversions.cpp b/mlir/lib/Dialect/SCF/Transforms/StructuralTypeConversions.cpp
index 072bc501aa5c6..b0c781c7aff11 100644
--- a/mlir/lib/Dialect/SCF/Transforms/StructuralTypeConversions.cpp
+++ b/mlir/lib/Dialect/SCF/Transforms/StructuralTypeConversions.cpp
@@ -217,10 +217,11 @@ class ConvertConditionOpTypes : public OpConversionPattern<ConditionOp> {
 } // namespace
 
 void mlir::scf::populateSCFStructuralTypeConversions(
-    const TypeConverter &typeConverter, RewritePatternSet &patterns) {
+    const TypeConverter &typeConverter, RewritePatternSet &patterns,
+    PatternBenefit benefit) {
   patterns.add<ConvertForOpTypes, ConvertIfOpTypes, ConvertYieldOpTypes,
                ConvertWhileOpTypes, ConvertConditionOpTypes>(
-      typeConverter, patterns.getContext());
+      typeConverter, patterns.getContext(), benefit);
 }
 
 void mlir::scf::populateSCFStructuralTypeConversionTarget(
@@ -240,7 +241,7 @@ void mlir::scf::populateSCFStructuralTypeConversionTarget(
 
 void mlir::scf::populateSCFStructuralTypeConversionsAndLegality(
     const TypeConverter &typeConverter, RewritePatternSet &patterns,
-    ConversionTarget &target) {
-  populateSCFStructuralTypeConversions(typeConverter, patterns);
+    ConversionTarget &target, PatternBenefit benefit) {
+  populateSCFStructuralTypeConversions(typeConverter, patterns, benefit);
   populateSCFStructuralTypeConversionTarget(typeConverter, target);
 }
diff --git a/mlir/lib/Transforms/Utils/DialectConversion.cpp b/mlir/lib/Transforms/Utils/DialectConversion.cpp
index f7565cfb0e45e..ff1e31536cea7 100644
--- a/mlir/lib/Transforms/Utils/DialectConversion.cpp
+++ b/mlir/lib/Transforms/Utils/DialectConversion.cpp
@@ -3802,8 +3802,9 @@ namespace {
 struct FunctionOpInterfaceSignatureConversion : public ConversionPattern {
   FunctionOpInterfaceSignatureConversion(StringRef functionLikeOpName,
                                          MLIRContext *ctx,
-                                         const TypeConverter &converter)
-      : ConversionPattern(converter, functionLikeOpName, /*benefit=*/1, ctx) {}
+                                         const TypeConverter &converter,
+                                         PatternBenefit benefit)
+      : ConversionPattern(converter, functionLikeOpName, benefit, ctx) {}
 
   LogicalResult
   matchAndRewrite(Operation *op, ArrayRef<Value> /*operands*/,
@@ -3848,15 +3849,16 @@ mlir::convertOpResultTypes(Operation *op, ValueRange operands,
 
 void mlir::populateFunctionOpInterfaceTypeConversionPattern(
     StringRef functionLikeOpName, RewritePatternSet &patterns,
-    const TypeConverter &converter) {
+    const TypeConverter &converter, PatternBenefit benefit) {
   patterns.add<FunctionOpInterfaceSignatureConversion>(
-      functionLikeOpName, patterns.getContext(), converter);
+      functionLikeOpName, patterns.getContext(), converter, benefit);
 }
 
 void mlir::populateAnyFunctionOpInterfaceTypeConversionPattern(
-    RewritePatternSet &patterns, const TypeConverter &converter) {
+    RewritePatternSet &patterns, const TypeConverter &converter,
+    PatternBenefit benefit) {
   patterns.add<AnyFunctionOpInterfaceSignatureConversion>(
-      converter, patterns.getContext());
+      converter, patterns.getContext(), benefit);
 }
 
 //===----------------------------------------------------------------------===//