copy_traits_sm90_tma_swizzle.hpp

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#pragma once

/// @file copy_traits_sm90_tma_swizzle.hpp
/// @brief Functions for converting swizzle layout to TMA descriptor

#if !defined(__CUDACC_RTC__)
#include <cuda.h>
#endif

#include <cute/arch/copy_sm90_desc.hpp>
#include <cute/swizzle_layout.hpp>

namespace cute::detail {

template <int B, int M, int S>
CUTE_HOST_DEVICE constexpr
TMA::SmemSwizzleBits
get_tma_swizzle_bits(Swizzle<B,M,S>)
{
  if constexpr (M == 4) {
    switch (B) {
      default:  static_assert(0 <= B && B <= 3, "Expected B = 0,1,2, or 3 when M == 4. Unsupported layout swizzle.");
      case 3:   return TMA::SmemSwizzleBits::B128;
      case 2:   return TMA::SmemSwizzleBits::B64;
      case 1:   return TMA::SmemSwizzleBits::B32;
      case 0:   return TMA::SmemSwizzleBits::DISABLE;
    }
  } else
  {
    static_assert(M < 0, "Unsupported layout swizzle.");
  }
}

template <class Layout>
TMA::SmemSwizzleBits
get_tma_swizzle_bits(Layout const& layout)
{
  return get_tma_swizzle_bits(get_swizzle_portion(layout));
}

template <int B, int M, int S>
CUTE_HOST_DEVICE constexpr
TMA::SmemSwizzleBase
get_tma_swizzle_base(Swizzle<B,M,S>)
{
  if constexpr (M == 4) {
    static_assert(0 <= B && B <= 3, "Expected B = 0,1,2, or 3 when M == 4. Unsupported layout swizzle.");
    static_assert(S == 3, "Expected S = 3 when M == 4. Unsupported layout swizzle.");
    return TMA::SmemSwizzleBase::SWIZZLE_BASE_16B;
  } 
  else {
    static_assert(M == 4, "Expected 128b=16B=(2^4)B base swizzle.");
  }
}

template <class Layout>
TMA::SmemSwizzleBase
get_tma_swizzle_base(Layout const& layout)
{
  return get_tma_swizzle_base(get_swizzle_portion(layout));
}

} // namespace cute::detail