mirror of
https://github.com/urbit/shrub.git
synced 2024-12-23 10:52:12 +03:00
97 lines
3.9 KiB
C
97 lines
3.9 KiB
C
|
|
/*============================================================================
|
|
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
|
Package, Release 3c, by John R. Hauser.
|
|
|
|
Copyright 2011, 2012, 2013, 2014, 2015 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"
|
|
|
|
float16_t extF80_to_f16( extFloat80_t a )
|
|
{
|
|
union { struct extFloat80M s; extFloat80_t f; } uA;
|
|
uint_fast16_t uiA64;
|
|
uint_fast64_t uiA0;
|
|
bool sign;
|
|
int_fast32_t exp;
|
|
uint_fast64_t sig;
|
|
struct commonNaN commonNaN;
|
|
uint_fast16_t uiZ, sig16;
|
|
union ui16_f16 uZ;
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uA.f = a;
|
|
uiA64 = uA.s.signExp;
|
|
uiA0 = uA.s.signif;
|
|
sign = signExtF80UI64( uiA64 );
|
|
exp = expExtF80UI64( uiA64 );
|
|
sig = uiA0;
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
if ( exp == 0x7FFF ) {
|
|
if ( sig & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) {
|
|
softfloat_extF80UIToCommonNaN( uiA64, uiA0, &commonNaN );
|
|
uiZ = softfloat_commonNaNToF16UI( &commonNaN );
|
|
} else {
|
|
uiZ = packToF16UI( sign, 0x1F, 0 );
|
|
}
|
|
goto uiZ;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
sig16 = softfloat_shortShiftRightJam64( sig, 49 );
|
|
if ( ! (exp | sig16) ) {
|
|
uiZ = packToF16UI( sign, 0, 0 );
|
|
goto uiZ;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
exp -= 0x3FF1;
|
|
if ( sizeof (int_fast16_t) < sizeof (int_fast32_t) ) {
|
|
if ( exp < -0x40 ) exp = -0x40;
|
|
}
|
|
return softfloat_roundPackToF16( sign, exp, sig16 );
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uiZ:
|
|
uZ.ui = uiZ;
|
|
return uZ.f;
|
|
|
|
}
|
|
|