llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def

//===- AMDGPUGenRegisterBankInfo.def -----------------------------*- 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
/// This file defines all the static objects used by AMDGPURegisterBankInfo.
/// \todo This should be generated by TableGen.
//===----------------------------------------------------------------------===//

namespace llvm {
namespace AMDGPU {

enum PartialMappingIdx {
  None = - 1,
  PM_SGPR1  = 2,
  PM_SGPR16 = 6,
  PM_SGPR32 = 7,
  PM_SGPR64 = 8,
  PM_SGPR128 = 9,
  PM_SGPR256 = 10,
  PM_SGPR512 = 11,
  PM_VGPR1  = 12,
  PM_VGPR16 = 16,
  PM_VGPR32 = 17,
  PM_VGPR64 = 18,
  PM_VGPR128 = 19,
  PM_VGPR256 = 20,
  PM_VGPR512 = 21,
  PM_SGPR96 = 22,
  PM_VGPR96 = 23
};

const RegisterBankInfo::PartialMapping PartMappings[] {
  // StartIdx, Length, RegBank
  {0, 1,  SCCRegBank},
  {0, 1,  VCCRegBank},

  {0, 1,  SGPRRegBank}, // SGPR begin
  {0, 16, SGPRRegBank},
  {0, 32, SGPRRegBank},
  {0, 64, SGPRRegBank},
  {0, 128, SGPRRegBank},
  {0, 256, SGPRRegBank},
  {0, 512, SGPRRegBank},

  {0, 1,  VGPRRegBank}, // VGPR begin
  {0, 16, VGPRRegBank},
  {0, 32, VGPRRegBank},
  {0, 64, VGPRRegBank},
  {0, 128, VGPRRegBank},
  {0, 256, VGPRRegBank},
  {0, 512, VGPRRegBank},
  {0, 96, SGPRRegBank},
  {0, 96, VGPRRegBank},
};

const RegisterBankInfo::ValueMapping ValMappings[] {
  // SCC
  {&PartMappings[0], 1},

  // VCC
  {&PartMappings[1], 1},

  // SGPRs
  {&PartMappings[2], 1},
  {nullptr, 0}, // Illegal power of 2 sizes
  {nullptr, 0},
  {nullptr, 0},
  {&PartMappings[3], 1},
  {&PartMappings[4], 1},
  {&PartMappings[5], 1},
  {&PartMappings[6], 1},
  {&PartMappings[7], 1},
  {&PartMappings[8], 1},

    // VGPRs
  {&PartMappings[9], 1},
  {nullptr, 0},
  {nullptr, 0},
  {nullptr, 0},
  {&PartMappings[10], 1},
  {&PartMappings[11], 1},
  {&PartMappings[12], 1},
  {&PartMappings[13], 1},
  {&PartMappings[14], 1},
  {&PartMappings[15], 1},
  {&PartMappings[16], 1},
  {&PartMappings[17], 1}
};

const RegisterBankInfo::PartialMapping SGPROnly64BreakDown[] {
     /*32-bit op*/ {0, 32, SGPRRegBank},
   /*2x32-bit op*/ {0, 32, SGPRRegBank},
                   {32, 32, SGPRRegBank},
/*<2x32-bit> op*/  {0, 64, SGPRRegBank},

    /*32-bit op*/  {0, 32, VGPRRegBank},
  /*2x32-bit op*/  {0, 32, VGPRRegBank},
                   {32, 32, VGPRRegBank},
};


// For some instructions which can operate 64-bit only for the scalar version.
const RegisterBankInfo::ValueMapping ValMappingsSGPR64OnlyVGPR32[] {
  /*32-bit sgpr*/     {&SGPROnly64BreakDown[0], 1},
  /*2 x 32-bit sgpr*/ {&SGPROnly64BreakDown[1], 2},
  /*64-bit sgpr */    {&SGPROnly64BreakDown[3], 1},

  /*32-bit vgpr*/     {&SGPROnly64BreakDown[4], 1},
  /*2 x 32-bit vgpr*/ {&SGPROnly64BreakDown[5], 2}
};

enum ValueMappingIdx {
  SCCStartIdx = 0,
  SGPRStartIdx = 2,
  VGPRStartIdx = 12
};

const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,
                                                      unsigned Size) {
  unsigned Idx;
  switch (Size) {
  case 1:
    if (BankID == AMDGPU::SCCRegBankID)
      return &ValMappings[0];
    if (BankID == AMDGPU::VCCRegBankID)
      return &ValMappings[1];

    // 1-bit values not from a compare etc.
    Idx = BankID == AMDGPU::SGPRRegBankID ? PM_SGPR1 : PM_VGPR1;
    break;
  case 96:
    assert(BankID != AMDGPU::VCCRegBankID);
    Idx = BankID == AMDGPU::SGPRRegBankID ? PM_SGPR96 : PM_VGPR96;
    break;
  default:
    assert(BankID != AMDGPU::VCCRegBankID);
    Idx = BankID == AMDGPU::VGPRRegBankID ? VGPRStartIdx : SGPRStartIdx;
    Idx += Log2_32_Ceil(Size);
    break;
  }

  assert(Log2_32_Ceil(Size) == Log2_32_Ceil(ValMappings[Idx].BreakDown->Length));
  assert(BankID == ValMappings[Idx].BreakDown->RegBank->getID());

  return &ValMappings[Idx];
}

const RegisterBankInfo::ValueMapping *getValueMappingSGPR64Only(unsigned BankID,
                                                                unsigned Size) {
  if (Size != 64)
    return getValueMapping(BankID, Size);

  if (BankID == AMDGPU::VGPRRegBankID)
    return &ValMappingsSGPR64OnlyVGPR32[4];

  assert(BankID == AMDGPU::SGPRRegBankID);
  return &ValMappingsSGPR64OnlyVGPR32[2];
}

} // End AMDGPU namespace.
} // End llvm namespace.