diff options
Diffstat (limited to 'third_party/eigen3/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h')
-rw-r--r-- | third_party/eigen3/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/third_party/eigen3/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h b/third_party/eigen3/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h new file mode 100644 index 0000000000..44aff63702 --- /dev/null +++ b/third_party/eigen3/unsupported/Eigen/CXX11/src/Tensor/TensorUInt128.h @@ -0,0 +1,232 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2015 Benoit Steiner <benoit.steiner.goog@gmail.com> +// +// This Source Code Form is subject to the terms of the Mozilla +// Public License v. 2.0. If a copy of the MPL was not distributed +// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#ifndef EIGEN_CXX11_TENSOR_TENSOR_UINT128_H +#define EIGEN_CXX11_TENSOR_TENSOR_UINT128_H + +namespace Eigen { +namespace internal { + +template <uint64_t n> +struct static_val { + static const uint64_t value = n; + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE operator uint64_t() const { return n; } + + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE static_val() { } + template <typename T> + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE static_val(const T& v) { + eigen_assert(v == n); + } +}; + + +template <typename HIGH = uint64_t, typename LOW = uint64_t> +struct TensorUInt128 +{ + HIGH high; + LOW low; + + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE + TensorUInt128(int x) : high(0), low(x) { + eigen_assert(x >= 0); + } + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE + TensorUInt128(int64_t x) : high(0), low(x) { + eigen_assert(x >= 0); + } + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE + TensorUInt128(uint64_t x) : high(0), low(x) { } + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE + TensorUInt128(uint64_t y, uint64_t x) : high(y), low(x) { } + + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE operator LOW() const { + return low; + } + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE LOW lower() const { + return low; + } + EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE HIGH upper() const { + return high; + } +}; + + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE +static bool operator == (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + return (lhs.high == rhs.high) & (lhs.low == rhs.low); +} + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE +static bool operator != (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + return (lhs.high != rhs.high) | (lhs.low != rhs.low); +} + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE +static bool operator >= (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + if (lhs.high != rhs.high) { + return lhs.high > rhs.high; + } + return lhs.low >= rhs.low; +} + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE +static bool operator < (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + if (lhs.high != rhs.high) { + return lhs.high < rhs.high; + } + return lhs.low < rhs.low; +} + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE +static TensorUInt128<uint64_t, uint64_t> operator + (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + TensorUInt128<uint64_t, uint64_t> result(lhs.high + rhs.high, lhs.low + rhs.low); + if (result.low < rhs.low) { + result.high += 1; + } + return result; +} + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE +static TensorUInt128<uint64_t, uint64_t> operator - (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + TensorUInt128<uint64_t, uint64_t> result(lhs.high - rhs.high, lhs.low - rhs.low); + if (result.low > lhs.low) { + result.high -= 1; + } + return result; +} + + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE +static TensorUInt128<uint64_t, uint64_t> operator * (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + // Split each 128-bit integer into 4 32-bit integers, and then do the + // multiplications by hand as follow: + // lhs a b c d + // rhs e f g h + // ----------- + // ah bh ch dh + // bg cg dg + // cf df + // de + // The result is stored in 2 64bit integers, high and low. + + const uint64_t LOW = 0x00000000FFFFFFFFLL; + const uint64_t HIGH = 0xFFFFFFFF00000000LL; + + uint64_t d = lhs.low & LOW; + uint64_t c = (lhs.low & HIGH) >> 32LL; + uint64_t b = lhs.high & LOW; + uint64_t a = (lhs.high & HIGH) >> 32LL; + + uint64_t h = rhs.low & LOW; + uint64_t g = (rhs.low & HIGH) >> 32LL; + uint64_t f = rhs.high & LOW; + uint64_t e = (rhs.high & HIGH) >> 32LL; + + // Compute the low 32 bits of low + uint64_t acc = d * h; + uint64_t low = acc & LOW; + // Compute the high 32 bits of low. Add a carry every time we wrap around + acc >>= 32LL; + uint64_t carry = 0; + uint64_t acc2 = acc + c * h; + if (acc2 < acc) { + carry++; + } + acc = acc2 + d * g; + if (acc < acc2) { + carry++; + } + low |= (acc << 32LL); + + // Carry forward the high bits of acc to initiate the computation of the + // low 32 bits of high + acc2 = (acc >> 32LL) | (carry << 32LL); + carry = 0; + + acc = acc2 + b * h; + if (acc < acc2) { + carry++; + } + acc2 = acc + c * g; + if (acc2 < acc) { + carry++; + } + acc = acc2 + d * f; + if (acc < acc2) { + carry++; + } + uint64_t high = acc & LOW; + + // Start to compute the high 32 bits of high. + acc2 = (acc >> 32LL) | (carry << 32LL); + + acc = acc2 + a * h; + acc2 = acc + b * g; + acc = acc2 + c * f; + acc2 = acc + d * e; + high |= (acc2 << 32LL); + + return TensorUInt128<uint64_t, uint64_t>(high, low); +} + +template <typename HL, typename LL, typename HR, typename LR> +EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE +static TensorUInt128<uint64_t, uint64_t> operator / (const TensorUInt128<HL, LL>& lhs, const TensorUInt128<HR, LR>& rhs) +{ + if (rhs == TensorUInt128<static_val<0>, static_val<1> >(1)) { + return TensorUInt128<uint64_t, uint64_t>(lhs.high, lhs.low); + } else if (lhs < rhs) { + return TensorUInt128<uint64_t, uint64_t>(0); + } else { + // calculate the biggest power of 2 times rhs that's less than or equal to lhs + TensorUInt128<uint64_t, uint64_t> power2(1); + TensorUInt128<uint64_t, uint64_t> d(rhs); + TensorUInt128<uint64_t, uint64_t> tmp(lhs - d); + while (lhs >= d) { + tmp = tmp - d; + d = d + d; + power2 = power2 + power2; + } + + tmp = TensorUInt128<uint64_t, uint64_t>(lhs.high, lhs.low); + TensorUInt128<uint64_t, uint64_t> result(0); + while (power2 != TensorUInt128<static_val<0>, static_val<0> >(0)) { + if (tmp >= d) { + tmp = tmp - d; + result = result + power2; + } + // Shift right + power2 = TensorUInt128<uint64_t, uint64_t>(power2.high >> 1, (power2.low >> 1) | (power2.high << 63)); + d = TensorUInt128<uint64_t, uint64_t>(d.high >> 1, (d.low >> 1) | (d.high << 63)); + } + + return result; + } +} + + +} // namespace internal +} // namespace Eigen + + +#endif // EIGEN_CXX11_TENSOR_TENSOR_UINT128_H |