568506ecbe
This implementation is copied from mesa. It uses x86_64 assembler on CPUs where it's supported, otherwise falls back on a software implementation (cogl-soft-float.c). It's intended to be used for packing and unpacking f16 format bitmaps. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3441>
122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
/*
|
|
* Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
|
|
* Copyright (C) 2018-2019 Intel Corporation
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included
|
|
* in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
|
|
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
|
|
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
* OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
/* This source file is originally from Mesa (src/util/half_float.h). */
|
|
|
|
#ifndef COGL_HALF_FLOAT_H
|
|
#define COGL_HALF_FLOAT_H
|
|
|
|
#include "cogl/cogl-types.h"
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include "cogl/cogl-cpu-caps.h"
|
|
#include "cogl/cogl-soft-float.h"
|
|
|
|
#ifdef __x86_64
|
|
#include <immintrin.h>
|
|
#endif
|
|
|
|
#define FP16_ONE ((uint16_t) 0x3c00)
|
|
#define FP16_ZERO ((uint16_t) 0)
|
|
|
|
COGL_EXPORT
|
|
uint16_t cogl_float_to_half_slow (float val);
|
|
|
|
COGL_EXPORT
|
|
float cogl_half_to_float_slow (uint16_t val);
|
|
|
|
COGL_EXPORT
|
|
uint8_t cogl_half_to_unorm8 (uint16_t v);
|
|
|
|
COGL_EXPORT
|
|
uint16_t cogl_uint16_div_64k_to_half (uint16_t v);
|
|
|
|
COGL_EXPORT
|
|
uint16_t cogl_float_to_float16_rtz_slow (float val);
|
|
|
|
static inline uint16_t
|
|
cogl_float_to_half (float val)
|
|
{
|
|
#ifdef __x86_64
|
|
if (cogl_cpu_has_cap (COGL_CPU_CAP_F16C))
|
|
{
|
|
__m128 in = {val};
|
|
__m128i out;
|
|
|
|
/* $0 = round to nearest */
|
|
__asm volatile ("vcvtps2ph $0, %1, %0" : "=v" (out) : "v" (in));
|
|
return out[0];
|
|
}
|
|
#endif
|
|
return cogl_float_to_half_slow (val);
|
|
}
|
|
|
|
static inline float
|
|
cogl_half_to_float (uint16_t val)
|
|
{
|
|
#ifdef __x86_64
|
|
if (cogl_cpu_has_cap (COGL_CPU_CAP_F16C))
|
|
{
|
|
__m128i in = {val};
|
|
__m128 out;
|
|
|
|
__asm volatile ("vcvtph2ps %1, %0" : "=v" (out) : "v" (in));
|
|
return out[0];
|
|
}
|
|
#endif
|
|
return cogl_half_to_float_slow (val);
|
|
}
|
|
|
|
static inline uint16_t
|
|
cogl_float_to_float16_rtz (float val)
|
|
{
|
|
#ifdef __x86_64
|
|
if (cogl_cpu_has_cap (COGL_CPU_CAP_F16C))
|
|
{
|
|
__m128 in = {val};
|
|
__m128i out;
|
|
|
|
/* $3 = round towards zero (truncate) */
|
|
__asm volatile ("vcvtps2ph $3, %1, %0" : "=v" (out) : "v" (in));
|
|
return out[0];
|
|
}
|
|
#endif
|
|
return cogl_float_to_float16_rtz_slow (val);
|
|
}
|
|
|
|
static inline uint16_t
|
|
cogl_float_to_float16_rtne (float val)
|
|
{
|
|
return cogl_float_to_half (val);
|
|
}
|
|
|
|
static inline gboolean
|
|
cogl_half_is_negative (uint16_t h)
|
|
{
|
|
return !!(h & 0x8000);
|
|
}
|
|
|
|
#endif /* COGL_HALF_FLOAT_H */
|