mirror of
https://github.com/urbit/shrub.git
synced 2024-12-23 19:05:48 +03:00
83 lines
3.2 KiB
C
83 lines
3.2 KiB
C
|
|
/*============================================================================
|
|
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
|
Package, Release 3, by John R. Hauser.
|
|
|
|
Copyright 2011, 2012, 2013, 2014 The Regents of the University of California
|
|
(Regents). All Rights Reserved. Redistribution and use in source and binary
|
|
forms, with or without modification, are permitted provided that the following
|
|
conditions are met:
|
|
|
|
Redistributions of source code must retain the above copyright notice,
|
|
this list of conditions, and the following two paragraphs of disclaimer.
|
|
Redistributions in binary form must reproduce the above copyright notice,
|
|
this list of conditions, and the following two paragraphs of disclaimer in the
|
|
documentation and/or other materials provided with the distribution. Neither
|
|
the name of the Regents nor the names of its contributors may be used to
|
|
endorse or promote products derived from this software without specific prior
|
|
written permission.
|
|
|
|
IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
|
|
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
|
|
OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
|
|
BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
|
|
HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE
|
|
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
|
|
|
=============================================================================*/
|
|
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
#include "platform.h"
|
|
#include "internals.h"
|
|
#include "softfloat.h"
|
|
|
|
int_fast64_t f128_to_i64( float128_t a, uint_fast8_t roundingMode, bool exact )
|
|
{
|
|
union ui128_f128 uA;
|
|
uint_fast64_t uiA64, uiA0;
|
|
bool sign;
|
|
int_fast32_t exp;
|
|
uint_fast64_t sig64, sig0;
|
|
int_fast32_t shiftCount;
|
|
struct uint128 sig128;
|
|
struct uint64_extra sigExtra;
|
|
|
|
uA.f = a;
|
|
uiA64 = uA.ui.v64;
|
|
uiA0 = uA.ui.v0;
|
|
sign = signF128UI64( uiA64 );
|
|
exp = expF128UI64( uiA64 );
|
|
sig64 = fracF128UI64( uiA64 );
|
|
sig0 = uiA0;
|
|
shiftCount = 0x402F - exp;
|
|
if ( shiftCount <= 0 ) {
|
|
if ( shiftCount < -15 ) {
|
|
softfloat_raiseFlags( softfloat_flag_invalid );
|
|
return
|
|
! sign || ((exp == 0x7FFF) && (sig64 | sig0))
|
|
? INT64_C( 0x7FFFFFFFFFFFFFFF )
|
|
: -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1;
|
|
}
|
|
sig64 |= UINT64_C( 0x0001000000000000 );
|
|
if ( shiftCount ) {
|
|
sig128 = softfloat_shortShiftLeft128( sig64, sig0, -shiftCount );
|
|
sig64 = sig128.v64;
|
|
sig0 = sig128.v0;
|
|
}
|
|
} else {
|
|
if ( exp ) sig64 |= UINT64_C( 0x0001000000000000 );
|
|
sigExtra = softfloat_shiftRightJam64Extra( sig64, sig0, shiftCount );
|
|
sig64 = sigExtra.v;
|
|
sig0 = sigExtra.extra;
|
|
}
|
|
return softfloat_roundPackToI64( sign, sig64, sig0, roundingMode, exact );
|
|
|
|
}
|
|
|