faiss/gpu/utils/nvidia/fp16_emu.cuh

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/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
// from Nvidia cuDNN library samples; modified to compile within faiss
#pragma once
namespace faiss { namespace gpu {
/*
* Copyright 1993-2014 NVIDIA Corporation. All rights reserved.
*
* NOTICE TO LICENSEE:
*
* This source code and/or documentation ("Licensed Deliverables") are
* subject to NVIDIA intellectual property rights under U.S. and
* international Copyright laws.
*
* These Licensed Deliverables contained herein is PROPRIETARY and
* CONFIDENTIAL to NVIDIA and is being provided under the terms and
* conditions of a form of NVIDIA software license agreement by and
* between NVIDIA and Licensee ("License Agreement") or electronically
* accepted by Licensee. Notwithstanding any terms or conditions to
* the contrary in the License Agreement, reproduction or disclosure
* of the Licensed Deliverables to any third party without the express
* written consent of NVIDIA is prohibited.
*
* NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE
* LICENSE AGREEMENT, NVIDIA MAKES NO REPRESENTATION ABOUT THE
* SUITABILITY OF THESE LICENSED DELIVERABLES FOR ANY PURPOSE. IT IS
* PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED WARRANTY OF ANY KIND.
* NVIDIA DISCLAIMS ALL WARRANTIES WITH REGARD TO THESE LICENSED
* DELIVERABLES, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
* NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE.
* NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE
* LICENSE AGREEMENT, IN NO EVENT SHALL NVIDIA BE LIABLE FOR ANY
* SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OR ANY
* DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
* WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THESE LICENSED DELIVERABLES.
*
* U.S. Government End Users. These Licensed Deliverables are a
* "commercial item" as that term is defined at 48 C.F.R. 2.101 (OCT
* 1995), consisting of "commercial computer software" and "commercial
* computer software documentation" as such terms are used in 48
* C.F.R. 12.212 (SEPT 1995) and is provided to the U.S. Government
* only as a commercial end item. Consistent with 48 C.F.R.12.212 and
* 48 C.F.R. 227.7202-1 through 227.7202-4 (JUNE 1995), all
* U.S. Government End Users acquire the Licensed Deliverables with
* only those rights set forth herein.
*
* Any use of the Licensed Deliverables in individual and commercial
* software must include, in the user documentation and internal
* comments to the code, the above Disclaimer and U.S. Government End
* Users Notice.
*/
// Conversion from/to 16-bit floating point (half-precision).
#define HLF_EPSILON 4.887581E-04
typedef struct __align__(2) {
unsigned short x;
} half1;
half1 cpu_float2half_rn(float f);
float cpu_half2float(half1 h);
static __inline__ __device__ __host__ half1 habs(half1 h)
{
h.x &= 0x7fffU;
return h;
}
static __inline__ __device__ __host__ half1 hneg(half1 h)
{
h.x ^= 0x8000U;
return h;
}
static __inline__ __device__ __host__ int ishnan(half1 h)
{
// When input is NaN, exponent is all ones and mantissa is non-zero.
return (h.x & 0x7c00U) == 0x7c00U && (h.x & 0x03ffU) != 0;
}
static __inline__ __device__ __host__ int ishinf(half1 h)
{
// When input is +/- inf, exponent is all ones and mantissa is zero.
return (h.x & 0x7c00U) == 0x7c00U && (h.x & 0x03ffU) == 0;
}
static __inline__ __device__ __host__ int ishequ(half1 x, half1 y)
{
return ishnan(x) == 0 && ishnan(y) == 0 && x.x == y.x;
}
static __inline__ __device__ __host__ half1 hzero()
{
half1 ret;
ret.x = 0x0000U;
return ret;
}
static __inline__ __device__ __host__ half1 hone()
{
half1 ret;
ret.x = 0x3c00U;
return ret;
}
} } // namespace