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/**************************************************************************
*
* Copyright 2010 Luca Barbieri
*
* 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 (including the
* next paragraph) 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 COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS 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.
*
**************************************************************************/
#ifndef U_HALF_H
#define U_HALF_H
#include "pipe/p_compiler.h"
#include "util/u_math.h"
#ifdef __cplusplus
extern "C" {
#endif
extern const uint32_t util_half_to_float_mantissa_table[2048];
extern const uint32_t util_half_to_float_exponent_table[64];
extern const uint32_t util_half_to_float_offset_table[64];
extern const uint16_t util_float_to_half_base_table[512];
extern const uint8_t util_float_to_half_shift_table[512];
/*
* Note that if the half float is a signaling NaN, the x87 FPU will turn
* it into a quiet NaN immediately upon loading into a float.
*
* Additionally, denormals may be flushed to zero.
*
* To avoid this, use the floatui functions instead of the float ones
* when just doing conversion rather than computation on the resulting
* floats.
*/
static INLINE uint32_t
util_half_to_floatui(uint16_t h)
{
unsigned exp = h >> 10;
return util_half_to_float_mantissa_table[util_half_to_float_offset_table[exp] + (h & 0x3ff)] + util_half_to_float_exponent_table[exp];
}
static INLINE float
util_half_to_float(uint16_t h)
{
union fi r;
r.ui = util_half_to_floatui(h);
return r.f;
}
static INLINE uint16_t
util_floatui_to_half(uint32_t v)
{
unsigned signexp = v >> 23;
return util_float_to_half_base_table[signexp] + ((v & 0x007fffff) >> util_float_to_half_shift_table[signexp]);
}
static INLINE uint16_t
util_float_to_half(float f)
{
union fi i;
i.f = f;
return util_floatui_to_half(i.ui);
}
#ifdef __cplusplus
}
#endif
#endif /* U_HALF_H */
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