Eyck Jentzsch
dcaf5467e8
(http://www.jhauser.us/arithmetic/SoftFloat.html) with RISCV specialization and cmake build
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 3e, by John R. Hauser.
|
|
|
|
Copyright 2011, 2012, 2013, 2014, 2015, 2016 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"
|
|
|
|
int_fast32_t f64_to_i32_r_minMag( float64_t a, bool exact )
|
|
{
|
|
union ui64_f64 uA;
|
|
uint_fast64_t uiA;
|
|
int_fast16_t exp;
|
|
uint_fast64_t sig;
|
|
int_fast16_t shiftDist;
|
|
bool sign;
|
|
int_fast32_t absZ;
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uA.f = a;
|
|
uiA = uA.ui;
|
|
exp = expF64UI( uiA );
|
|
sig = fracF64UI( uiA );
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
shiftDist = 0x433 - exp;
|
|
if ( 53 <= shiftDist ) {
|
|
if ( exact && (exp | sig) ) {
|
|
softfloat_exceptionFlags |= softfloat_flag_inexact;
|
|
}
|
|
return 0;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
sign = signF64UI( uiA );
|
|
if ( shiftDist < 22 ) {
|
|
if (
|
|
sign && (exp == 0x41E) && (sig < UINT64_C( 0x0000000000200000 ))
|
|
) {
|
|
if ( exact && sig ) {
|
|
softfloat_exceptionFlags |= softfloat_flag_inexact;
|
|
}
|
|
return -0x7FFFFFFF - 1;
|
|
}
|
|
softfloat_raiseFlags( softfloat_flag_invalid );
|
|
return
|
|
(exp == 0x7FF) && sig ? i32_fromNaN
|
|
: sign ? i32_fromNegOverflow : i32_fromPosOverflow;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
sig |= UINT64_C( 0x0010000000000000 );
|
|
absZ = sig>>shiftDist;
|
|
if ( exact && ((uint_fast64_t) (uint_fast32_t) absZ<<shiftDist != sig) ) {
|
|
softfloat_exceptionFlags |= softfloat_flag_inexact;
|
|
}
|
|
return sign ? -absZ : absZ;
|
|
|
|
}
|
|
|