llvm/llvm/include/llvm/Frontend/OpenMP/OMPGridValues.h

//====--- OMPGridValues.h - Language-specific address spaces --*- C++ -*-====//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Provides definitions for Target specific Grid Values
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_FRONTEND_OPENMP_OMPGRIDVALUES_H
#define LLVM_FRONTEND_OPENMP_OMPGRIDVALUES_H

namespace llvm {

namespace omp {

/// \brief Defines various target-specific GPU grid values that must be
///        consistent between host RTL (plugin), device RTL, and clang.
///        We can change grid values for a "fat" binary so that different
///        passes get the correct values when generating code for a
///        multi-target binary. Both amdgcn and nvptx values are stored in
///        this file. In the future, should there be differences between GPUs
///        of the same architecture, then simply make a different array and
///        use the new array name.
///
/// Example usage in clang:
///   const unsigned slot_size =
///   ctx.GetTargetInfo().getGridValue().GV_Warp_Size;
///
/// Example usage in libomptarget/deviceRTLs:
///   #include "llvm/Frontend/OpenMP/OMPGridValues.h"
///   #ifdef __AMDGPU__
///     #define GRIDVAL AMDGPUGridValues
///   #else
///     #define GRIDVAL NVPTXGridValues
///   #endif
///   ... Then use this reference for GV_Warp_Size in the deviceRTL source.
///   llvm::omp::GRIDVAL().GV_Warp_Size
///
/// Example usage in libomptarget hsa plugin:
///   #include "llvm/Frontend/OpenMP/OMPGridValues.h"
///   #define GRIDVAL AMDGPUGridValues
///   ... Then use this reference to access GV_Warp_Size in the hsa plugin.
///   llvm::omp::GRIDVAL().GV_Warp_Size
///
/// Example usage in libomptarget cuda plugin:
///    #include "llvm/Frontend/OpenMP/OMPGridValues.h"
///    #define GRIDVAL NVPTXGridValues
///   ... Then use this reference to access GV_Warp_Size in the cuda plugin.
///    llvm::omp::GRIDVAL().GV_Warp_Size
///

struct GV { … };

/// For AMDGPU GPUs
static constexpr GV AMDGPUGridValues64 = …;

static constexpr GV AMDGPUGridValues32 = …;

template <unsigned wavesize> constexpr const GV &getAMDGPUGridValues() { … }

/// For Nvidia GPUs
static constexpr GV NVPTXGridValues = …;

} // namespace omp
} // namespace llvm

#endif // LLVM_FRONTEND_OPENMP_OMPGRIDVALUES_H