You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
91 lines
3.4 KiB
91 lines
3.4 KiB
|
|
/*============================================================================
|
|
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
|
Package, Release 3d, by John R. Hauser.
|
|
|
|
Copyright 2025 The Regents of the University of California. All rights
|
|
reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
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,
|
|
this list of conditions, and the following disclaimer in the documentation
|
|
and/or other materials provided with the distribution.
|
|
|
|
3. Neither the name of the University 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 REGENTS AND CONTRIBUTORS "AS IS", AND ANY
|
|
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
|
|
DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
|
|
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
=============================================================================*/
|
|
|
|
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
#include "platform.h"
|
|
#include "internals.h"
|
|
#include "specialize.h"
|
|
#include "softfloat.h"
|
|
|
|
float8_t f32_to_e5m2( float32_t a, bool saturationMode )
|
|
{
|
|
union ui32_f32 uA;
|
|
uint_fast32_t uiA;
|
|
bool sign;
|
|
int_fast16_t exp;
|
|
uint_fast32_t frac;
|
|
uint_fast16_t frac8;
|
|
struct commonNaN commonNaN;
|
|
uint_fast8_t uiZ;
|
|
union ui8_f8 uZ;
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uA.f = a;
|
|
uiA = uA.ui;
|
|
sign = signF32UI( uiA );
|
|
exp = expF32UI( uiA );
|
|
frac = fracF32UI( uiA );
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
if ( exp == 0xFF ) {
|
|
if ( frac ) { // nan
|
|
softfloat_f32UIToCommonNaN( uiA, &commonNaN );
|
|
uiZ = softfloat_commonNaNToE5M2UI( &commonNaN );
|
|
} else {
|
|
/* If saturation mode is enabled, convert Inf to the max value of E5M2, otherwise Inf */
|
|
uiZ = saturationMode
|
|
? packToE5M2UI( sign, 0x1E, 0x3 )
|
|
: packToE5M2UI( sign, 0x1F, 0x0 );
|
|
}
|
|
goto uiZ;
|
|
}
|
|
/* Use additional 4 bits for rounding. We will have 2+4 bits including the sticky bit*/
|
|
frac8 = frac>>17 | ((frac & 0x1FFFF) != 0);
|
|
if ( !(exp | frac8) ) {
|
|
uiZ = packToE5M2UI( sign, 0, 0 );
|
|
goto uiZ;
|
|
}
|
|
|
|
/* Add the implicit leading 1 to the fraction and shift exp by (127-15)+1 */
|
|
return softfloat_roundPackToE5M2( sign, exp - 113, frac8 | 0x40, saturationMode);
|
|
uiZ:
|
|
uZ.ui = uiZ;
|
|
return uZ.f;
|
|
}
|
|
|
|
|