//=- VectorComputeUtil.cpp - vector compute utilities implemetation * C++ -*-=//
//
//                     The LLVM/SPIR-V Translator
//
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//===----------------------------------------------------------------------===//
//
// This file implements translation of VC float control bits
//
//===----------------------------------------------------------------------===//

#include "VectorComputeUtil.h"
#include "SPIRVInternal.h"
#include "llvm/IR/Metadata.h"
using namespace VectorComputeUtil;
using namespace SPIRV;

enum VCFloatControl {
  VC_RTE = 0,      // Round to nearest or even
  VC_RTP = 1 << 4, // Round towards +ve inf
  VC_RTN = 2 << 4, // Round towards -ve inf
  VC_RTZ = 3 << 4, // Round towards zero

  VC_DENORM_FTZ = 0,            // Denorm mode flush to zero
  VC_DENORM_D_ALLOW = 1 << 6,   // Denorm mode double allow
  VC_DENORM_F_ALLOW = 1 << 7,   // Denorm mode float allow
  VC_DENORM_HF_ALLOW = 1 << 10, // Denorm mode half allow

  VC_FLOAT_MODE_IEEE = 0, // Single precision float IEEE mode
  VC_FLOAT_MODE_ALT = 1   // Single precision float ALT mode
};

enum VCFloatControlMask {
  VC_ROUND_MASK = (VC_RTE | VC_RTP | VC_RTN | VC_RTZ),
  VC_FLOAT_MASK = (VC_FLOAT_MODE_IEEE | VC_FLOAT_MODE_ALT)
};

typedef SPIRVMap<FPRoundingMode, VCFloatControl> FPRoundingModeControlBitMap;
typedef SPIRVMap<FPOperationMode, VCFloatControl> FPOperationModeControlBitMap;
typedef SPIRVMap<VCFloatType, VCFloatControl> VCFloatTypeDenormMaskMap;
template <> inline void SPIRVMap<FPRoundingMode, VCFloatControl>::init() {
  add(spv::FPRoundingModeRTE, VC_RTE);
  add(spv::FPRoundingModeRTP, VC_RTP);
  add(spv::FPRoundingModeRTN, VC_RTN);
  add(spv::FPRoundingModeRTZ, VC_RTZ);
}
template <> inline void SPIRVMap<FPOperationMode, VCFloatControl>::init() {
  add(spv::FPOperationModeIEEE, VC_FLOAT_MODE_IEEE);
  add(spv::FPOperationModeALT, VC_FLOAT_MODE_ALT);
}
template <> inline void SPIRVMap<VCFloatType, VCFloatControl>::init() {
  add(Double, VC_DENORM_D_ALLOW);
  add(Float, VC_DENORM_F_ALLOW);
  add(Half, VC_DENORM_HF_ALLOW);
}

namespace VectorComputeUtil {

FPRoundingMode getFPRoundingMode(unsigned FloatControl) noexcept {
  return FPRoundingModeControlBitMap::rmap(
      VCFloatControl(VC_ROUND_MASK & FloatControl));
}

FPDenormMode getFPDenormMode(unsigned FloatControl,
                             VCFloatType FloatType) noexcept {
  VCFloatControl DenormMask =
      VCFloatTypeDenormMaskMap::map(FloatType); // 1 Bit mask
  return (DenormMask == (DenormMask & FloatControl))
             ? spv::FPDenormModePreserve
             : spv::FPDenormModeFlushToZero;
}

FPOperationMode getFPOperationMode(unsigned FloatControl) noexcept {
  return FPOperationModeControlBitMap::rmap(
      VCFloatControl(VC_FLOAT_MASK & FloatControl));
}

unsigned getVCFloatControl(FPRoundingMode RoundMode) noexcept {
  return FPRoundingModeControlBitMap::map(RoundMode);
}
unsigned getVCFloatControl(FPOperationMode FloatMode) noexcept {
  return FPOperationModeControlBitMap::map(FloatMode);
}
unsigned getVCFloatControl(FPDenormMode DenormMode,
                           VCFloatType FloatType) noexcept {
  if (DenormMode == spv::FPDenormModePreserve)
    return VCFloatTypeDenormMaskMap::map(FloatType);
  return VC_DENORM_FTZ;
}

SPIRVStorageClassKind
getVCGlobalVarStorageClass(SPIRAddressSpace AddressSpace) noexcept {
  switch (AddressSpace) {
  case SPIRAS_Private:
    return StorageClassPrivate;
  case SPIRAS_Local:
    return StorageClassWorkgroup;
  case SPIRAS_Global:
    return StorageClassCrossWorkgroup;
  case SPIRAS_Constant:
    return StorageClassUniformConstant;
  default:
    assert(false && "Unexpected address space");
    return StorageClassPrivate;
  }
}

SPIRAddressSpace
getVCGlobalVarAddressSpace(SPIRVStorageClassKind StorageClass) noexcept {
  switch (StorageClass) {
  case StorageClassPrivate:
    return SPIRAS_Private;
  case StorageClassWorkgroup:
    return SPIRAS_Local;
  case StorageClassCrossWorkgroup:
    return SPIRAS_Global;
  case StorageClassUniformConstant:
    return SPIRAS_Constant;
  default:
    assert(false && "Unexpected storage class");
    return SPIRAS_Private;
  }
}

std::string getVCBufferSurfaceName() {
  return std::string(kVCType::VCBufferSurface) + kAccessQualPostfix::Type;
}

std::string getVCBufferSurfaceName(SPIRVAccessQualifierKind Access) {
  return std::string(kVCType::VCBufferSurface) +
         getAccessQualifierPostfix(Access).str() + kAccessQualPostfix::Type;
}

} // namespace VectorComputeUtil