//===---------------- AMDGPUAddrSpace.h -------------------------*- 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
/// AMDGPU address space definition
///
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_AMDGPUADDRSPACE_H
#define LLVM_SUPPORT_AMDGPUADDRSPACE_H

#include <cstdint>

namespace llvm {
/// OpenCL uses address spaces to differentiate between
/// various memory regions on the hardware. On the CPU
/// all of the address spaces point to the same memory,
/// however on the GPU, each address space points to
/// a separate piece of memory that is unique from other
/// memory locations.
namespace AMDGPUAS {
enum : unsigned {
  // The maximum value for flat, generic, local, private, constant and region.
  MAX_AMDGPU_ADDRESS = 9,

  FLAT_ADDRESS = 0,   ///< Address space for flat memory.
  GLOBAL_ADDRESS = 1, ///< Address space for global memory (RAT0, VTX0).
  REGION_ADDRESS = 2, ///< Address space for region memory. (GDS)

  LOCAL_ADDRESS = 3,    ///< Address space for local memory.
  CONSTANT_ADDRESS = 4, ///< Address space for constant memory (VTX2).
  PRIVATE_ADDRESS = 5,  ///< Address space for private memory.

  CONSTANT_ADDRESS_32BIT = 6, ///< Address space for 32-bit constant memory.

  BUFFER_FAT_POINTER = 7, ///< Address space for 160-bit buffer fat pointers.
                          ///< Not used in backend.

  BUFFER_RESOURCE = 8, ///< Address space for 128-bit buffer resources.

  BUFFER_STRIDED_POINTER = 9, ///< Address space for 192-bit fat buffer
                              ///< pointers with an additional index.

  /// Internal address spaces. Can be freely renumbered.
  STREAMOUT_REGISTER = 128, ///< Address space for GS NGG Streamout registers.
  /// end Internal address spaces.

  /// Address space for direct addressable parameter memory (CONST0).
  PARAM_D_ADDRESS = 6,
  /// Address space for indirect addressable parameter memory (VTX1).
  PARAM_I_ADDRESS = 7,

  // Do not re-order the CONSTANT_BUFFER_* enums.  Several places depend on
  // this order to be able to dynamically index a constant buffer, for
  // example:
  //
  // ConstantBufferAS = CONSTANT_BUFFER_0 + CBIdx

  CONSTANT_BUFFER_0 = 8,
  CONSTANT_BUFFER_1 = 9,
  CONSTANT_BUFFER_2 = 10,
  CONSTANT_BUFFER_3 = 11,
  CONSTANT_BUFFER_4 = 12,
  CONSTANT_BUFFER_5 = 13,
  CONSTANT_BUFFER_6 = 14,
  CONSTANT_BUFFER_7 = 15,
  CONSTANT_BUFFER_8 = 16,
  CONSTANT_BUFFER_9 = 17,
  CONSTANT_BUFFER_10 = 18,
  CONSTANT_BUFFER_11 = 19,
  CONSTANT_BUFFER_12 = 20,
  CONSTANT_BUFFER_13 = 21,
  CONSTANT_BUFFER_14 = 22,
  CONSTANT_BUFFER_15 = 23,

  // Some places use this if the address space can't be determined.
  UNKNOWN_ADDRESS_SPACE = ~0u,
};
} // end namespace AMDGPUAS

namespace AMDGPU {
inline bool isFlatGlobalAddrSpace(unsigned AS) {
  return AS == AMDGPUAS::GLOBAL_ADDRESS || AS == AMDGPUAS::FLAT_ADDRESS ||
         AS == AMDGPUAS::CONSTANT_ADDRESS || AS > AMDGPUAS::MAX_AMDGPU_ADDRESS;
}

inline bool isExtendedGlobalAddrSpace(unsigned AS) {
  return AS == AMDGPUAS::GLOBAL_ADDRESS || AS == AMDGPUAS::CONSTANT_ADDRESS ||
         AS == AMDGPUAS::CONSTANT_ADDRESS_32BIT ||
         AS > AMDGPUAS::MAX_AMDGPU_ADDRESS;
}

inline bool isConstantAddressSpace(unsigned AS) {
  switch (AS) {
    using namespace AMDGPUAS;
  case CONSTANT_ADDRESS:
  case CONSTANT_ADDRESS_32BIT:
  case CONSTANT_BUFFER_0:
  case CONSTANT_BUFFER_1:
  case CONSTANT_BUFFER_2:
  case CONSTANT_BUFFER_3:
  case CONSTANT_BUFFER_4:
  case CONSTANT_BUFFER_5:
  case CONSTANT_BUFFER_6:
  case CONSTANT_BUFFER_7:
  case CONSTANT_BUFFER_8:
  case CONSTANT_BUFFER_9:
  case CONSTANT_BUFFER_10:
  case CONSTANT_BUFFER_11:
  case CONSTANT_BUFFER_12:
  case CONSTANT_BUFFER_13:
  case CONSTANT_BUFFER_14:
  case CONSTANT_BUFFER_15:
    return true;
  default:
    return false;
  }
}

namespace DWARFAS {
enum : unsigned {
  GLOBAL = 0,
  GENERIC = 1,
  REGION = 2,
  LOCAL = 3,
  PRIVATE_LANE = 5,
  PRIVATE_WAVE = 6,
  DEFAULT = GLOBAL,
};
} // namespace DWARFAS

namespace impl {
// TODO: Move this into mapToDWARFAddrSpace when we switch to C++23
// (see https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2647r1.html)
static constexpr unsigned LLVMToDWARFAddrSpaceMapping[] = {
    DWARFAS::GENERIC,     //< AMDGPUAS::FLAT_ADDRESS
    DWARFAS::GLOBAL,      //< AMDGPUAS::GLOBAL_ADDRESS
    DWARFAS::REGION,      //< AMDGPUAS::REGION_ADDRESS
    DWARFAS::LOCAL,       //< AMDGPUAS::LOCAL_ADDRESS
    DWARFAS::GLOBAL,      //< AMDGPUAS::CONSTANT_ADDRESS
    DWARFAS::PRIVATE_LANE //< AMDGPUAS::PRIVATE_ADDRESS
};
} // end namespace impl

/// If @p LLVMAddressSpace has a corresponding DWARF encoding,
/// return it; otherwise return the sentinel value -1 to indicate
/// no such mapping exists.
///
/// This maps private/scratch to the focused lane view.
///
/// These mappings must be kept in sync with llvm/docs/AMDGPUUsage.rst
/// table "AMDGPU DWARF Address Space Mapping".
///
/// Note: This could return std::optional<int> but that would require
/// an extra #include.
constexpr int mapToDWARFAddrSpace(unsigned LLVMAddrSpace) {
  constexpr unsigned SizeOfLLVMToDWARFAddrSpaceMapping =
      sizeof(impl::LLVMToDWARFAddrSpaceMapping) /
      sizeof(impl::LLVMToDWARFAddrSpaceMapping[0]);
  if (LLVMAddrSpace < SizeOfLLVMToDWARFAddrSpaceMapping)
    return impl::LLVMToDWARFAddrSpaceMapping[LLVMAddrSpace];
  return -1;
}

/// Get the null pointer value for the given address space.
constexpr int64_t getNullPointerValue(unsigned AS) {
  switch (AS) {
    using namespace AMDGPUAS;
  case PRIVATE_ADDRESS:
  case LOCAL_ADDRESS:
  case REGION_ADDRESS:
    return -1;
  default:
    return 0;
  }
}
} // end namespace AMDGPU

} // end namespace llvm

#endif // LLVM_SUPPORT_AMDGPUADDRSPACE_H