mirror of
https://github.com/urbit/shrub.git
synced 2024-12-23 10:52:12 +03:00
97 lines
3.8 KiB
C
97 lines
3.8 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, 2016, 2017 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_fast64_t f32_to_i64( float32_t a, uint_fast8_t roundingMode, bool exact )
|
|
{
|
|
union ui32_f32 uA;
|
|
uint_fast32_t uiA;
|
|
bool sign;
|
|
int_fast16_t exp;
|
|
uint_fast32_t sig;
|
|
int_fast16_t shiftDist;
|
|
#ifdef SOFTFLOAT_FAST_INT64
|
|
uint_fast64_t sig64, extra;
|
|
struct uint64_extra sig64Extra;
|
|
#else
|
|
uint32_t extSig[3];
|
|
#endif
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uA.f = a;
|
|
uiA = uA.ui;
|
|
sign = signF32UI( uiA );
|
|
exp = expF32UI( uiA );
|
|
sig = fracF32UI( uiA );
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
shiftDist = 0xBE - exp;
|
|
if ( shiftDist < 0 ) {
|
|
softfloat_raiseFlags( softfloat_flag_invalid );
|
|
return
|
|
(exp == 0xFF) && sig ? i64_fromNaN
|
|
: sign ? i64_fromNegOverflow : i64_fromPosOverflow;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
if ( exp ) sig |= 0x00800000;
|
|
#ifdef SOFTFLOAT_FAST_INT64
|
|
sig64 = (uint_fast64_t) sig<<40;
|
|
extra = 0;
|
|
if ( shiftDist ) {
|
|
sig64Extra = softfloat_shiftRightJam64Extra( sig64, 0, shiftDist );
|
|
sig64 = sig64Extra.v;
|
|
extra = sig64Extra.extra;
|
|
}
|
|
return softfloat_roundToI64( sign, sig64, extra, roundingMode, exact );
|
|
#else
|
|
extSig[indexWord( 3, 2 )] = sig<<8;
|
|
extSig[indexWord( 3, 1 )] = 0;
|
|
extSig[indexWord( 3, 0 )] = 0;
|
|
if ( shiftDist ) softfloat_shiftRightJam96M( extSig, shiftDist, extSig );
|
|
return softfloat_roundMToI64( sign, extSig, roundingMode, exact );
|
|
#endif
|
|
|
|
}
|
|
|