[Mlir-commits] [mlir] [mlir][vector] Create `VectorToLLVMDialectInterface` (PR #121440)

[Ivan Butygin]

https://github.com/Hardcode84 updated https://github.com/llvm/llvm-project/pull/121440

>From 1ced298bb014d04038226345acd01a7b506f87bc Mon Sep 17 00:00:00 2001
From: Ivan Butygin <ivan.butygin at gmail.com>
Date: Wed, 1 Jan 2025 17:40:07 +0100
Subject: [PATCH] [mlir][vector] Create `VectorToLLVMDialectInterface`

Create `VectorToLLVMDialectInterface` which allows automatic conversion discovery by generic `--convert-to-llvm` pass.
This only covers final dialect conversion step and not any previous preparation steps.
Also, currently there is no way to pass any additional parameters through this conversion interface, but most users using default parameters anyway.
---
 .../VectorToLLVM/ConvertVectorToLLVM.h        |  3 +++
 mlir/include/mlir/InitAllExtensions.h         |  2 ++
 .../VectorToLLVM/ConvertVectorToLLVM.cpp      | 25 +++++++++++++++++++
 mlir/lib/Dialect/Vector/IR/VectorOps.cpp      |  2 ++
 .../vector-to-llvm-interface.mlir             | 14 +++++++++++
 5 files changed, 46 insertions(+)
 create mode 100644 mlir/test/Conversion/VectorToLLVM/vector-to-llvm-interface.mlir

diff --git a/mlir/include/mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h b/mlir/include/mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h
index 5fda62e3584c79..1e29bfeb9c3921 100644
--- a/mlir/include/mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h
+++ b/mlir/include/mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h
@@ -24,6 +24,9 @@ void populateVectorToLLVMConversionPatterns(
     const LLVMTypeConverter &converter, RewritePatternSet &patterns,
     bool reassociateFPReductions = false, bool force32BitVectorIndices = false);
 
+namespace vector {
+void registerConvertVectorToLLVMInterface(DialectRegistry &registry);
+}
 } // namespace mlir
 
 #endif // MLIR_CONVERSION_VECTORTOLLVM_CONVERTVECTORTOLLVM_H_
diff --git a/mlir/include/mlir/InitAllExtensions.h b/mlir/include/mlir/InitAllExtensions.h
index 14a6a2787b3a5d..887db344ed88b6 100644
--- a/mlir/include/mlir/InitAllExtensions.h
+++ b/mlir/include/mlir/InitAllExtensions.h
@@ -26,6 +26,7 @@
 #include "mlir/Conversion/NVVMToLLVM/NVVMToLLVM.h"
 #include "mlir/Conversion/OpenMPToLLVM/ConvertOpenMPToLLVM.h"
 #include "mlir/Conversion/UBToLLVM/UBToLLVM.h"
+#include "mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h"
 #include "mlir/Dialect/AMX/Transforms.h"
 #include "mlir/Dialect/Affine/TransformOps/AffineTransformOps.h"
 #include "mlir/Dialect/Bufferization/TransformOps/BufferizationTransformOps.h"
@@ -76,6 +77,7 @@ inline void registerAllExtensions(DialectRegistry &registry) {
   registerConvertAMXToLLVMInterface(registry);
   gpu::registerConvertGpuToLLVMInterface(registry);
   NVVM::registerConvertGpuToNVVMInterface(registry);
+  vector::registerConvertVectorToLLVMInterface(registry);
 
   // Register all transform dialect extensions.
   affine::registerTransformDialectExtension(registry);
diff --git a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
index d688d8e2ab6588..30eed1c849a7c6 100644
--- a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
+++ b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
@@ -9,6 +9,7 @@
 #include "mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h"
 
 #include "mlir/Conversion/ArithCommon/AttrToLLVMConverter.h"
+#include "mlir/Conversion/ConvertToLLVM/ToLLVMInterface.h"
 #include "mlir/Conversion/LLVMCommon/PrintCallHelper.h"
 #include "mlir/Conversion/LLVMCommon/TypeConverter.h"
 #include "mlir/Conversion/LLVMCommon/VectorPattern.h"
@@ -1933,3 +1934,27 @@ void mlir::populateVectorToLLVMMatrixConversionPatterns(
   patterns.add<VectorMatmulOpConversion>(converter);
   patterns.add<VectorFlatTransposeOpConversion>(converter);
 }
+
+namespace {
+struct VectorToLLVMDialectInterface : public ConvertToLLVMPatternInterface {
+  using ConvertToLLVMPatternInterface::ConvertToLLVMPatternInterface;
+  void loadDependentDialects(MLIRContext *context) const final {
+    context->loadDialect<LLVM::LLVMDialect>();
+  }
+
+  /// Hook for derived dialect interface to provide conversion patterns
+  /// and mark dialect legal for the conversion target.
+  void populateConvertToLLVMConversionPatterns(
+      ConversionTarget &target, LLVMTypeConverter &typeConverter,
+      RewritePatternSet &patterns) const final {
+    populateVectorToLLVMConversionPatterns(typeConverter, patterns);
+  }
+};
+} // namespace
+
+void mlir::vector::registerConvertVectorToLLVMInterface(
+    DialectRegistry &registry) {
+  registry.addExtension(+[](MLIRContext *ctx, vector::VectorDialect *dialect) {
+    dialect->addInterfaces<VectorToLLVMDialectInterface>();
+  });
+}
diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
index ae1cf95732336a..b57d89f0a96c01 100644
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -13,6 +13,7 @@
 
 #include "mlir/Dialect/Vector/IR/VectorOps.h"
 
+#include "mlir/Conversion/ConvertToLLVM/ToLLVMInterface.h"
 #include "mlir/Dialect/Affine/IR/ValueBoundsOpInterfaceImpl.h"
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Dialect/Arith/Utils/Utils.h"
@@ -429,6 +430,7 @@ void VectorDialect::initialize() {
                             TransferWriteOp>();
   declarePromisedInterface<SubsetExtractionOpInterface, TransferReadOp>();
   declarePromisedInterface<SubsetInsertionOpInterface, TransferWriteOp>();
+  declarePromisedInterface<ConvertToLLVMPatternInterface, VectorDialect>();
 }
 
 /// Materialize a single constant operation from a given attribute value with
diff --git a/mlir/test/Conversion/VectorToLLVM/vector-to-llvm-interface.mlir b/mlir/test/Conversion/VectorToLLVM/vector-to-llvm-interface.mlir
new file mode 100644
index 00000000000000..5252bb25ecab54
--- /dev/null
+++ b/mlir/test/Conversion/VectorToLLVM/vector-to-llvm-interface.mlir
@@ -0,0 +1,14 @@
+// Most of the vector lowering is tested in vector-to-llvm.mlir, this file only for the interface smoke test
+// RUN: mlir-opt --convert-to-llvm="filter-dialects=vector" --split-input-file %s | FileCheck %s
+
+func.func @bitcast_f32_to_i32_vector_0d(%arg0: vector<f32>) -> vector<i32> {
+  %0 = vector.bitcast %arg0 : vector<f32> to vector<i32>
+  return %0 : vector<i32>
+}
+
+// CHECK-LABEL: @bitcast_f32_to_i32_vector_0d
+// CHECK-SAME:  %[[ARG_0:.*]]: vector<f32>
+// CHECK:       %[[VEC_F32_1D:.*]] = builtin.unrealized_conversion_cast %[[ARG_0]] : vector<f32> to vector<1xf32>
+// CHECK:       %[[VEC_I32_1D:.*]] = llvm.bitcast %[[VEC_F32_1D]] : vector<1xf32> to vector<1xi32>
+// CHECK:       %[[VEC_I32_0D:.*]] = builtin.unrealized_conversion_cast %[[VEC_I32_1D]] : vector<1xi32> to vector<i32>
+// CHECK:       return %[[VEC_I32_0D]] : vector<i32>