NVVMToLLVMIRTranslation.cpp

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//===- NVVMToLLVMIRTranslation.cpp - Translate NVVM to LLVM IR ------------===//
//
// 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 implements a translation between the MLIR NVVM dialect and
// LLVM IR.
//
//===----------------------------------------------------------------------===//

#include "mlir/Target/LLVMIR/Dialect/NVVM/NVVMToLLVMIRTranslation.h"
#include "mlir/Dialect/LLVMIR/NVVMDialect.h"
#include "mlir/IR/Operation.h"
#include "mlir/Target/LLVMIR/ModuleTranslation.h"

#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/IntrinsicsNVPTX.h"

using namespace mlir;
using namespace mlir::LLVM;
using mlir::LLVM::detail::createIntrinsicCall;

static llvm::Intrinsic::ID getShflIntrinsicId(llvm::Type *resultType,
                                              NVVM::ShflKind kind,
                                              bool withPredicate) {

  if (withPredicate) {
    resultType = cast<llvm::StructType>(resultType)->getElementType(0);
    switch (kind) {
    case NVVM::ShflKind::bfly:
      return resultType->isFloatTy()
                 ? llvm::Intrinsic::nvvm_shfl_sync_bfly_f32p
                 : llvm::Intrinsic::nvvm_shfl_sync_bfly_i32p;
    case NVVM::ShflKind::up:
      return resultType->isFloatTy() ? llvm::Intrinsic::nvvm_shfl_sync_up_f32p
                                     : llvm::Intrinsic::nvvm_shfl_sync_up_i32p;
    case NVVM::ShflKind::down:
      return resultType->isFloatTy()
                 ? llvm::Intrinsic::nvvm_shfl_sync_down_f32p
                 : llvm::Intrinsic::nvvm_shfl_sync_down_i32p;
    case NVVM::ShflKind::idx:
      return resultType->isFloatTy() ? llvm::Intrinsic::nvvm_shfl_sync_idx_f32p
                                     : llvm::Intrinsic::nvvm_shfl_sync_idx_i32p;
    }
  } else {
    switch (kind) {
    case NVVM::ShflKind::bfly:
      return resultType->isFloatTy() ? llvm::Intrinsic::nvvm_shfl_sync_bfly_f32
                                     : llvm::Intrinsic::nvvm_shfl_sync_bfly_i32;
    case NVVM::ShflKind::up:
      return resultType->isFloatTy() ? llvm::Intrinsic::nvvm_shfl_sync_up_f32
                                     : llvm::Intrinsic::nvvm_shfl_sync_up_i32;
    case NVVM::ShflKind::down:
      return resultType->isFloatTy() ? llvm::Intrinsic::nvvm_shfl_sync_down_f32
                                     : llvm::Intrinsic::nvvm_shfl_sync_down_i32;
    case NVVM::ShflKind::idx:
      return resultType->isFloatTy() ? llvm::Intrinsic::nvvm_shfl_sync_idx_f32
                                     : llvm::Intrinsic::nvvm_shfl_sync_idx_i32;
    }
  }
  llvm_unreachable("unknown shuffle kind");
}

namespace {
/// Implementation of the dialect interface that converts operations belonging
/// to the NVVM dialect to LLVM IR.
class NVVMDialectLLVMIRTranslationInterface
    : public LLVMTranslationDialectInterface {
public:
  using LLVMTranslationDialectInterface::LLVMTranslationDialectInterface;

  /// Translates the given operation to LLVM IR using the provided IR builder
  /// and saving the state in `moduleTranslation`.
  LogicalResult
  convertOperation(Operation *op, llvm::IRBuilderBase &builder,
                   LLVM::ModuleTranslation &moduleTranslation) const final {
    Operation &opInst = *op;
#include "mlir/Dialect/LLVMIR/NVVMConversions.inc"

    return failure();
  }

  /// Attaches module-level metadata for functions marked as kernels.
  LogicalResult
  amendOperation(Operation *op, NamedAttribute attribute,
                 LLVM::ModuleTranslation &moduleTranslation) const final {
    if (attribute.getName() == NVVM::NVVMDialect::getKernelFuncAttrName()) {
      auto func = dyn_cast<LLVM::LLVMFuncOp>(op);
      if (!func)
        return failure();

      llvm::LLVMContext &llvmContext = moduleTranslation.getLLVMContext();
      llvm::Function *llvmFunc =
          moduleTranslation.lookupFunction(func.getName());
      llvm::Metadata *llvmMetadata[] = {
          llvm::ValueAsMetadata::get(llvmFunc),
          llvm::MDString::get(llvmContext, "kernel"),
          llvm::ValueAsMetadata::get(
              llvm::ConstantInt::get(llvm::Type::getInt32Ty(llvmContext), 1))};
      llvm::MDNode *llvmMetadataNode =
          llvm::MDNode::get(llvmContext, llvmMetadata);
      moduleTranslation.getOrInsertNamedModuleMetadata("nvvm.annotations")
          ->addOperand(llvmMetadataNode);
    }
    return success();
  }
};
} // end namespace

void mlir::registerNVVMDialectTranslation(DialectRegistry &registry) {
  registry.insert<NVVM::NVVMDialect>();
  registry.addDialectInterface<NVVM::NVVMDialect,
                               NVVMDialectLLVMIRTranslationInterface>();
}

void mlir::registerNVVMDialectTranslation(MLIRContext &context) {
  DialectRegistry registry;
  registerNVVMDialectTranslation(registry);
  context.appendDialectRegistry(registry);
}