[MLIR][Conversion] Add convert-xevm-to-llvm pass. [Re-attempt] (#148103)

Although XeVM is an LLVM extension dialect,
SPIR-V backend relies on [function
calls](https://llvm.org/docs/SPIRVUsage.html#instructions-as-function-calls)
instead of defining LLVM intrinsics to represent SPIR-V instructions.
convert-xevm-to-llvm pass lowers xevm ops to function declarations and
calls using the above naming convention.
In the future, most part of the pass should be replaced with llvmBuilder
and handled as part of translation to LLVM instead.

---------
Co-authored-by: Artem Kroviakov <[email protected]>

Author: silee2

mlir/include/mlir/Conversion/Passes.h

@@ -80,6 +80,7 @@
 #include "mlir/Conversion/VectorToSCF/VectorToSCF.h"
 #include "mlir/Conversion/VectorToSPIRV/VectorToSPIRVPass.h"
 #include "mlir/Conversion/VectorToXeGPU/VectorToXeGPU.h"
+#include "mlir/Conversion/XeVMToLLVM/XeVMToLLVM.h"
 
 namespace mlir {
 

mlir/include/mlir/Conversion/Passes.td

@@ -1495,4 +1495,13 @@ def ConvertVectorToXeGPU : Pass<"convert-vector-to-xegpu"> {
   ];
 }
 
+//===----------------------------------------------------------------------===//
+// XeVMToLLVM
+//===----------------------------------------------------------------------===//
+
+def ConvertXeVMToLLVMPass : Pass<"convert-xevm-to-llvm"> {
+  let summary = "Convert XeVM to LLVM dialect";
+  let dependentDialects = ["LLVM::LLVMDialect"];
+}
+
 #endif // MLIR_CONVERSION_PASSES

mlir/include/mlir/Conversion/XeVMToLLVM/XeVMToLLVM.h

@@ -0,0 +1,27 @@
+//===-- XeVMToLLVM.h - Convert XeVM to LLVM dialect -------------*- C++ -*-===//
+//
+// This file is licensed 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
+//
+//===----------------------------------------------------------------------===//
+#ifndef MLIR_CONVERSION_XEVMTOLLVM_XEVMTOLLVMPASS_H_
+#define MLIR_CONVERSION_XEVMTOLLVM_XEVMTOLLVMPASS_H_
+
+#include <memory>
+
+namespace mlir {
+class DialectRegistry;
+class LLVMTypeConverter;
+class RewritePatternSet;
+class Pass;
+
+#define GEN_PASS_DECL_CONVERTXEVMTOLLVMPASS
+#include "mlir/Conversion/Passes.h.inc"
+
+void populateXeVMToLLVMConversionPatterns(RewritePatternSet &patterns);
+
+void registerConvertXeVMToLLVMInterface(DialectRegistry &registry);
+} // namespace mlir
+
+#endif // MLIR_CONVERSION_XEVMTOLLVM_XEVMTOLLVMPASS_H_

mlir/include/mlir/InitAllExtensions.h

@@ -32,6 +32,7 @@
 #include "mlir/Conversion/SCFToEmitC/SCFToEmitC.h"
 #include "mlir/Conversion/UBToLLVM/UBToLLVM.h"
 #include "mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h"
+#include "mlir/Conversion/XeVMToLLVM/XeVMToLLVM.h"
 #include "mlir/Dialect/AMX/Transforms.h"
 #include "mlir/Dialect/Affine/TransformOps/AffineTransformOps.h"
 #include "mlir/Dialect/ArmNeon/TransformOps/ArmNeonVectorTransformOps.h"
@@ -91,6 +92,7 @@ inline void registerAllExtensions(DialectRegistry &registry) {
   gpu::registerConvertGpuToLLVMInterface(registry);
   NVVM::registerConvertGpuToNVVMInterface(registry);
   vector::registerConvertVectorToLLVMInterface(registry);
+  registerConvertXeVMToLLVMInterface(registry);
 
   // Register all transform dialect extensions.
   affine::registerTransformDialectExtension(registry);

mlir/lib/Conversion/CMakeLists.txt

@@ -73,3 +73,4 @@ add_subdirectory(VectorToLLVM)
 add_subdirectory(VectorToSCF)
 add_subdirectory(VectorToSPIRV)
 add_subdirectory(VectorToXeGPU)
+add_subdirectory(XeVMToLLVM)

mlir/lib/Conversion/XeVMToLLVM/CMakeLists.txt

@@ -0,0 +1,21 @@
+add_mlir_conversion_library(MLIRXeVMToLLVM
+  XeVMToLLVM.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${MLIR_MAIN_INCLUDE_DIR}/mlir/Conversion/XeVMToLLVM
+
+  DEPENDS
+  MLIRConversionPassIncGen
+
+  LINK_COMPONENTS
+  Core
+
+  LINK_LIBS PUBLIC
+  MLIRFuncDialect
+  MLIRGPUDialect
+  MLIRLLVMCommonConversion
+  MLIRLLVMDialect
+  MLIRXeVMDialect
+  MLIRPass
+  MLIRTransforms
+)