Skip to content

Commit

Permalink
Refactor mapIdx and mapIdxPitchBytes
Browse files Browse the repository at this point in the history
  • Loading branch information
@bernhardmgruber
bernhardmgruber committed Sep 8, 2023
1 parent eb8f532 commit 6f989d9
Showing 1 changed file with 63 additions and 218 deletions.
281 changes: 63 additions & 218 deletions include/alpaka/idx/MapIdx.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,237 +12,82 @@

namespace alpaka
{
namespace detail
{
//! Maps a linear index to a N dimensional index.
template<std::size_t TidxDimOut, std::size_t TidxDimIn, typename TSfinae = void>
struct MapIdx;
//! Maps a N dimensional index to the same N dimensional index.
template<std::size_t TidxDim>
struct MapIdx<TidxDim, TidxDim>
{
// \tparam TElem Type of the index values.
// \param idx Idx to be mapped.
// \param extent Spatial size to map the index to.
// \return A N dimensional vector.
ALPAKA_NO_HOST_ACC_WARNING
template<typename TElem>
ALPAKA_FN_HOST_ACC static auto mapIdx(
Vec<DimInt<TidxDim>, TElem> const& idx,
[[maybe_unused]] Vec<DimInt<TidxDim>, TElem> const& extent) -> Vec<DimInt<TidxDim>, TElem>
{
return idx;
}
};
//! Maps a 1 dimensional index to a N dimensional index.
template<std::size_t TidxDimOut>
struct MapIdx<TidxDimOut, 1u, std::enable_if_t<(TidxDimOut > 1u)>>
{
// \tparam TElem Type of the index values.
// \param idx Idx to be mapped.
// \param extent Spatial size to map the index to
// \return A N dimensional vector.
ALPAKA_NO_HOST_ACC_WARNING
template<typename TElem>
ALPAKA_FN_HOST_ACC static auto mapIdx(
Vec<DimInt<1u>, TElem> const& idx,
Vec<DimInt<TidxDimOut>, TElem> const& extent) -> Vec<DimInt<TidxDimOut>, TElem>
{
auto idxNd = Vec<DimInt<TidxDimOut>, TElem>::all(0u);

constexpr std::size_t lastIdx(TidxDimOut - 1u);

// fast-dim
idxNd[lastIdx] = static_cast<TElem>(idx[0u] % extent[lastIdx]);

// in-between
TElem hyperPlanesBefore = extent[lastIdx];
for(std::size_t r(1u); r < lastIdx; ++r)
{
std::size_t const d = lastIdx - r;
idxNd[d] = static_cast<TElem>(idx[0u] / hyperPlanesBefore % extent[d]);
hyperPlanesBefore *= extent[d];
}

// slow-dim
idxNd[0u] = static_cast<TElem>(idx[0u] / hyperPlanesBefore);

return idxNd;
}
};
//! Maps a 1 dimensional index to a N dimensional index.
template<std::size_t TidxDimIn>
struct MapIdx<1u, TidxDimIn, std::enable_if_t<(TidxDimIn > 1u)>>
{
// \tparam TElem Type of the index values.
// \param idx Idx to be mapped.
// \param extent Spatial size to map the index to.
// \return A 1 dimensional vector.
ALPAKA_NO_HOST_ACC_WARNING
template<typename TElem>
ALPAKA_FN_HOST_ACC static auto mapIdx(
Vec<DimInt<TidxDimIn>, TElem> const& idx,
Vec<DimInt<TidxDimIn>, TElem> const& extent) -> Vec<DimInt<1u>, TElem>
{
TElem idx1d(idx[0u]);
for(std::size_t d(1u); d < TidxDimIn; ++d)
{
idx1d = static_cast<TElem>(idx1d * extent[d] + idx[d]);
}
return {idx1d};
}
};

template<std::size_t TidxDimOut>
struct MapIdx<TidxDimOut, 0u>
{
template<typename TElem, std::size_t TidxDimExtents>
ALPAKA_FN_HOST_ACC static auto mapIdx(
Vec<DimInt<0u>, TElem> const&,
Vec<DimInt<TidxDimExtents>, TElem> const&) -> Vec<DimInt<TidxDimOut>, TElem>
{
return Vec<DimInt<TidxDimOut>, TElem>::zeros();
}
};

template<std::size_t TidxDimIn>
struct MapIdx<0u, TidxDimIn>
{
template<typename TElem, std::size_t TidxDimExtents>
ALPAKA_FN_HOST_ACC static auto mapIdx(
Vec<DimInt<TidxDimIn>, TElem> const&,
Vec<DimInt<TidxDimExtents>, TElem> const&) -> Vec<DimInt<0u>, TElem>
{
return {};
}
};
} // namespace detail

//! Maps a N dimensional index to a N dimensional position.
//! Maps an N-dimensional index to an N-dimensional position. At least one dimension must always be 1 or zero.
//!
//! \tparam TidxDimOut Dimension of the index vector to map to.
//! \tparam TidxDimIn Dimension of the index vector to map from.
//! \tparam TElem Type of the elements of the index vector to map from.
//! \tparam TDimOut Dimension of the index vector to map to.
//! \param in The index vector to map from.
//! \param extent The extents of the input or output space, whichever has more than 1 dimensions.
ALPAKA_NO_HOST_ACC_WARNING template<
std::size_t TidxDimOut,
std::size_t TidxDimIn,
std::size_t TidxDimExtents,
std::size_t TDimOut,
std::size_t TDimIn,
std::size_t TDimExtents,
typename TElem>
ALPAKA_FN_HOST_ACC auto mapIdx(
Vec<DimInt<TidxDimIn>, TElem> const& idx,
Vec<DimInt<TidxDimExtents>, TElem> const& extent) -> Vec<DimInt<TidxDimOut>, TElem>
ALPAKA_FN_HOST_ACC auto mapIdx(Vec<DimInt<TDimIn>, TElem> const& in, Vec<DimInt<TDimExtents>, TElem> const& extent)
-> Vec<DimInt<TDimOut>, TElem>
{
return detail::MapIdx<TidxDimOut, TidxDimIn>::mapIdx(idx, extent);
}

namespace detail
{
//! Maps a linear index to a N dimensional index assuming a buffer without padding.
template<std::size_t TidxDimOut, std::size_t TidxDimIn, typename TSfinae = void>
struct MapIdxPitchBytes;

//! Maps a N dimensional index to the same N dimensional index assuming a buffer without padding.
template<std::size_t TidxDim>
struct MapIdxPitchBytes<TidxDim, TidxDim>
{
// \tparam TElem Type of the index values.
// \param idx Idx to be mapped.
// \param pitch Spatial pitch (in elems) to map the index to
// \return N dimensional vector.
ALPAKA_NO_HOST_ACC_WARNING
template<typename TElem>
ALPAKA_FN_HOST_ACC static auto mapIdxPitchBytes(
Vec<DimInt<TidxDim>, TElem> const& idx,
[[maybe_unused]] Vec<DimInt<TidxDim>, TElem> const& pitch) -> Vec<DimInt<TidxDim>, TElem>
{
return idx;
}
};
//! Maps a 1 dimensional index to a N dimensional index assuming a buffer without padding.
template<std::size_t TidxDimOut>
struct MapIdxPitchBytes<TidxDimOut, 1u, std::enable_if_t<(TidxDimOut > 1u)>>
if constexpr(TDimOut == 0 || TDimIn == 0)
return Vec<DimInt<TDimOut>, TElem>::zeros();
else if constexpr(TDimOut == TDimIn)
return in;
else if constexpr(TDimOut == 1)
{
// \tparam TElem Type of the index values.
// \param idx Idx to be mapped.
// \param pitch Spatial pitch (in elems) to map the index to
// \return N dimensional vector.
ALPAKA_NO_HOST_ACC_WARNING
template<typename TElem>
ALPAKA_FN_HOST_ACC static auto mapIdxPitchBytes(
Vec<DimInt<1u>, TElem> const& idx,
Vec<DimInt<TidxDimOut>, TElem> const& pitch) -> Vec<DimInt<TidxDimOut>, TElem>
{
auto idxNd = Vec<DimInt<TidxDimOut>, TElem>::zeros();

constexpr std::size_t lastIdx = TidxDimOut - 1u;

TElem tmp = idx[0u];
for(std::size_t d(0u); d < lastIdx; ++d)
{
idxNd[d] = static_cast<TElem>(tmp / pitch[d]);
tmp %= pitch[d];
}
idxNd[lastIdx] = tmp;

return idxNd;
}
};
//! Maps a N dimensional index to a 1 dimensional index assuming a buffer without padding.
template<std::size_t TidxDimIn>
struct MapIdxPitchBytes<1u, TidxDimIn, std::enable_if_t<(TidxDimIn > 1u)>>
TElem out = in[0];
for(std::size_t d = 1; d < TDimIn; ++d)
out = static_cast<TElem>(out * extent[d] + in[d]);
return {out};
}
else if constexpr(TDimIn == 1)
{
// \tparam TElem Type of the index values.
// \param idx Idx to be mapped.
// \param pitch Spatial pitch (in elems) to map the index to
// \return A 1 dimensional vector.
ALPAKA_NO_HOST_ACC_WARNING
template<typename TElem>
ALPAKA_FN_HOST_ACC static auto mapIdxPitchBytes(
Vec<DimInt<TidxDimIn>, TElem> const& idx,
Vec<DimInt<TidxDimIn>, TElem> const& pitch) -> Vec<DimInt<1u>, TElem>
auto flat = in.front();
Vec<DimInt<TDimOut>, TElem> out;
for(std::size_t d = TDimOut - 1u; d > 0; d--)
{
using DimMinusOne = DimInt<TidxDimIn - 1>;
return {idx.back() + (subVecBegin<DimMinusOne>(pitch) * subVecBegin<DimMinusOne>(idx)).sum()};
out[d] = static_cast<TElem>(flat % extent[d]);
flat /= extent[d];
}
};
out.front() = static_cast<TElem>(flat);
return out;
}
else
static_assert(!sizeof(TElem), "Not implemented");
}

template<std::size_t TidxDimOut>
struct MapIdxPitchBytes<TidxDimOut, 0u>
//! Maps an N dimensional index to a N dimensional position based on the pitches of a view without padding or a
//! byte view. At least one dimension must always be 1 or zero.
//!
//! \tparam TDimOut Dimension of the index vector to map to.
//! \param in The index vector to map from.
//! \param pitches The pitches of the input or output space, whichever has more than 1 dimensions.
ALPAKA_NO_HOST_ACC_WARNING
template<std::size_t TDimOut, std::size_t TDimIn, std::size_t TidxDimPitch, typename TElem>
ALPAKA_FN_HOST_ACC auto mapIdxPitchBytes(
Vec<DimInt<TDimIn>, TElem> const& in,
Vec<DimInt<TidxDimPitch>, TElem> const& pitches) -> Vec<DimInt<TDimOut>, TElem>
{
if constexpr(TDimOut == 0 || TDimIn == 0)
return Vec<DimInt<TDimOut>, TElem>::zeros();
else if constexpr(TDimOut == TDimIn)
return in;
else if constexpr(TDimOut == 1)
{
template<typename TElem, std::size_t TidxDimExtents>
ALPAKA_FN_HOST_ACC static auto mapIdxPitchBytes(
Vec<DimInt<0u>, TElem> const&,
Vec<DimInt<TidxDimExtents>, TElem> const&) -> Vec<DimInt<TidxDimOut>, TElem>
{
return Vec<DimInt<TidxDimOut>, TElem>::zeros();
}
};

template<std::size_t TidxDimIn>
struct MapIdxPitchBytes<0u, TidxDimIn>
using DimMinusOne = DimInt<TDimIn - 1>;
return {in.back() + (subVecBegin<DimMinusOne>(pitches) * subVecBegin<DimMinusOne>(in)).sum()};
}
else if constexpr(TDimIn == 1)
{
template<typename TElem, std::size_t TidxDimExtents>
ALPAKA_FN_HOST_ACC static auto mapIdxPitchBytes(
Vec<DimInt<TidxDimIn>, TElem> const&,
Vec<DimInt<TidxDimExtents>, TElem> const&) -> Vec<DimInt<0u>, TElem>
auto result = Vec<DimInt<TDimOut>, TElem>::zeros();

TElem out = in.front();
for(std::size_t d = 0; d < TDimOut - 1u; ++d)
{
return {};
result[d] = static_cast<TElem>(out / pitches[d]);
out %= pitches[d];
}
};
} // namespace detail
result.back() = out;

//! Maps an N dimensional index to a N dimensional position based on
//! pitch in a buffer without padding or a byte buffer.
//!
//! \tparam TidxDimOut Dimension of the index vector to map to.
//! \tparam TidxDimIn Dimension of the index vector to map from.
//! \tparam TElem Type of the elements of the index vector to map from.
ALPAKA_NO_HOST_ACC_WARNING
template<std::size_t TidxDimOut, std::size_t TidxDimIn, std::size_t TidxDimPitch, typename TElem>
ALPAKA_FN_HOST_ACC auto mapIdxPitchBytes(
Vec<DimInt<TidxDimIn>, TElem> const& idx,
Vec<DimInt<TidxDimPitch>, TElem> const& pitch) -> Vec<DimInt<TidxDimOut>, TElem>
{
return detail::MapIdxPitchBytes<TidxDimOut, TidxDimIn>::mapIdxPitchBytes(idx, pitch);
return result;
}
else
static_assert(!sizeof(TElem), "Not implemented");
}
} // namespace alpaka

0 comments on commit 6f989d9

Please sign in to comment.