cutlass/include/cute/numeric/integer_subbyte.hpp

234 lines
7.0 KiB
C++

/***************************************************************************************************
* Copyright (c) 2023 - 2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: BSD-3-Clause
*
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*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
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*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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#pragma once
#if defined(__CUDACC_RTC__)
#include <cuda/std/cstdint>
#else
#include <cstdint>
#endif
#include <cute/config.hpp>
#include <cute/util/type_traits.hpp>
namespace cute {
///////////////////////////////////////////////////////////////////////////////////////////////////
template <int Bits, bool Signed = true>
struct integer_subbyte
{
/// Storage type
using Storage = uint8_t;
/// Number of bits
static_assert(Bits <= 8*sizeof(Storage), "Require a subbyte of bits in integer_subbyte");
/// External type
using xint_t = typename conditional<Signed, int, unsigned>::type;
/// Bitmask for truncation from larger integers
static constexpr Storage bits_mask_ = Storage((1 << Bits) - 1);
/// Bitmask for the sign bit
static constexpr Storage sign_mask_ = Storage((Signed ? 1 : 0) << (Bits - 1));
//
// Data members
//
Storage storage;
//
// Methods
//
/// No operation
CUTE_HOST_DEVICE constexpr
integer_subbyte() {}
/// Conversion from integer type
CUTE_HOST_DEVICE constexpr
integer_subbyte(int value) // NOTE: Sign extension?
: storage(reinterpret_cast<Storage const&>(value) & bits_mask_) {}
CUTE_HOST_DEVICE constexpr
integer_subbyte(unsigned value)
: storage(reinterpret_cast<Storage const&>(value) & bits_mask_) {}
/// Convert to int or unsigned
CUTE_HOST_DEVICE constexpr
operator xint_t() const {
if (sign_mask_ & storage) { // Sign extend
return xint_t(storage) | ~xint_t(bits_mask_);
} else {
return xint_t(storage);
}
}
/// Equality
CUTE_HOST_DEVICE constexpr
bool operator==(integer_subbyte const& rhs) const {
return storage == rhs.storage;
}
/// Inequality
CUTE_HOST_DEVICE constexpr
bool operator!=(integer_subbyte const& rhs) const {
return storage != rhs.storage;
}
/// Less than or equal
CUTE_HOST_DEVICE constexpr
bool operator<=(integer_subbyte const& rhs) const {
if (sign_mask_ & storage) {
return !(rhs.storage < storage);
} else {
return storage <= rhs.storage;
}
}
/// Less than
CUTE_HOST_DEVICE constexpr
bool operator<(integer_subbyte const& rhs) const {
if (sign_mask_ & storage) {
return !(rhs.storage <= storage);
} else {
return storage < rhs.storage;
}
}
/// Greater than or equal
CUTE_HOST_DEVICE constexpr
bool operator>=(integer_subbyte const& rhs) const {
return !(*this < rhs);
}
/// Greater than
CUTE_HOST_DEVICE constexpr
bool operator>(integer_subbyte const& rhs) const {
return !(*this <= rhs);
}
};
///////////////////////////////////////////////////////////////////////////////////////////////////
/// 1-bit unsigned integer type
using uint1b_t = integer_subbyte<1, false>;
/// 2-bit integer type
using int2b_t = integer_subbyte<2, true>;
/// 2-bit unsigned integer type
using uint2b_t = integer_subbyte<2, false>;
/// 4-bit integer type
using int4b_t = integer_subbyte<4, true>;
/// 4-bit unsigned integer type
using uint4b_t = integer_subbyte<4, false>;
/// 1-bit binary type
using bin1_t = bool;
} // namespace cute
///////////////////////////////////////////////////////////////////////////////////////////////////
#if !defined(__CUDACC_RTC__)
#include <limits>
namespace CUTE_STL_NAMESPACE {
template <>
struct numeric_limits<cute::uint1b_t> {
CUTE_HOST_DEVICE static constexpr
cute::uint1b_t const lowest() noexcept { return 0; }
CUTE_HOST_DEVICE static constexpr
cute::uint1b_t const min() noexcept { return 0; }
CUTE_HOST_DEVICE static constexpr
cute::uint1b_t const max() noexcept { return 1; }
static constexpr bool is_integer = true;
static constexpr bool is_signed = false;
};
template <>
struct numeric_limits<cute::int2b_t> {
CUTE_HOST_DEVICE static constexpr
cute::int2b_t lowest() noexcept { return -2; }
CUTE_HOST_DEVICE static constexpr
cute::int2b_t min() noexcept { return -2; }
CUTE_HOST_DEVICE static constexpr
cute::int2b_t max() noexcept { return 1; }
static constexpr bool is_integer = true;
static constexpr bool is_signed = true;
};
template <>
struct numeric_limits<cute::uint2b_t> {
CUTE_HOST_DEVICE static constexpr
cute::uint2b_t const lowest() noexcept { return 0; }
CUTE_HOST_DEVICE static constexpr
cute::uint2b_t const min() noexcept { return 0; }
CUTE_HOST_DEVICE static constexpr
cute::uint2b_t const max() noexcept { return 3; }
static constexpr bool is_integer = true;
static constexpr bool is_signed = false;
};
template <>
struct numeric_limits<cute::int4b_t> {
CUTE_HOST_DEVICE static constexpr
cute::int4b_t lowest() noexcept { return -8; }
CUTE_HOST_DEVICE static constexpr
cute::int4b_t min() noexcept { return -8; }
CUTE_HOST_DEVICE static constexpr
cute::int4b_t max() noexcept { return 7; }
static constexpr bool is_integer = true;
static constexpr bool is_signed = true;
};
template <>
struct numeric_limits<cute::uint4b_t> {
CUTE_HOST_DEVICE static constexpr
cute::uint4b_t const lowest() noexcept { return 0; }
CUTE_HOST_DEVICE static constexpr
cute::uint4b_t const min() noexcept { return 0; }
CUTE_HOST_DEVICE static constexpr
cute::uint4b_t const max() noexcept { return 15; }
static constexpr bool is_integer = true;
static constexpr bool is_signed = false;
};
} // namespace std
#endif // !defined(__CUDACC_RTC__)