84 lines
3.5 KiB
C
84 lines
3.5 KiB
C
/*============================================================================
|
|
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
|
Package, Release 3e, 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 "internals.h"
|
|
#include "primitives.h"
|
|
#include "specialize.h"
|
|
#include "softfloat.h"
|
|
|
|
float32_t f128_to_f32(float128_t a, struct softfloat_status_t *status)
|
|
{
|
|
uint64_t uiA64, uiA0;
|
|
bool sign;
|
|
int32_t exp;
|
|
uint64_t frac64;
|
|
struct commonNaN commonNaN;
|
|
uint32_t uiZ, frac32;
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uiA64 = a.v64;
|
|
uiA0 = a.v0;
|
|
sign = signF128UI64(uiA64);
|
|
exp = expF128UI64(uiA64);
|
|
frac64 = fracF128UI64(uiA64) | (uiA0 != 0);
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
if (exp == 0x7FFF) {
|
|
if (frac64) {
|
|
softfloat_f128UIToCommonNaN(uiA64, uiA0, &commonNaN, status);
|
|
uiZ = softfloat_commonNaNToF32UI(&commonNaN);
|
|
} else {
|
|
uiZ = packToF32UI(sign, 0xFF, 0);
|
|
}
|
|
return uiZ;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
frac32 = softfloat_shortShiftRightJam64(frac64, 18);
|
|
if (! (exp | frac32)) {
|
|
return packToF32UI(sign, 0, 0);
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
exp -= 0x3F81;
|
|
if (sizeof (int16_t) < sizeof (int32_t)) {
|
|
if (exp < -0x1000) exp = -0x1000;
|
|
}
|
|
return softfloat_roundPackToF32(sign, exp, frac32 | 0x40000000, status);
|
|
}
|