79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
|
/*
|
||
|
|
* Copyright © 2005-2014 Rich Felker, et al.
|
||
|
|
*
|
||
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
||
|
|
* a copy of this software and associated documentation files (the
|
||
|
|
* "Software"), to deal in the Software without restriction, including
|
||
|
|
* without limitation the rights to use, copy, modify, merge, publish,
|
||
|
|
* distribute, sublicense, and/or sell copies of the Software, and to
|
||
|
|
* permit persons to whom the Software is furnished to do so, subject to
|
||
|
|
* the following conditions:
|
||
|
|
*
|
||
|
|
* The above copyright notice and this permission notice shall be
|
||
|
|
* included in all copies or substantial portions of the Software.
|
||
|
|
*
|
||
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
||
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
||
|
|
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
||
|
|
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
||
|
|
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
||
|
|
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <math.h>
|
||
|
|
#include <inttypes.h>
|
||
|
|
#include "local.h"
|
||
|
|
|
||
|
|
union fshape {
|
||
|
|
float value;
|
||
|
|
uint32_t bits;
|
||
|
|
};
|
||
|
|
|
||
|
|
// This is only necessary because the implementation of isnan only works
|
||
|
|
// properly when long double == double.
|
||
|
|
// See: https://sourceware.org/ml/newlib/2014/msg00684.html
|
||
|
|
#ifdef _LDBL_EQ_DOUBLE
|
||
|
|
|
||
|
|
float
|
||
|
|
nexttowardf (float x, long double y)
|
||
|
|
{
|
||
|
|
union fshape ux;
|
||
|
|
uint32_t e;
|
||
|
|
|
||
|
|
if (isnan(x) || isnan(y))
|
||
|
|
return x + y;
|
||
|
|
if (x == y)
|
||
|
|
return y;
|
||
|
|
ux.value = x;
|
||
|
|
if (x == 0) {
|
||
|
|
ux.bits = 1;
|
||
|
|
if (signbit(y))
|
||
|
|
ux.bits |= 0x80000000;
|
||
|
|
} else if (x < y) {
|
||
|
|
if (signbit(x))
|
||
|
|
ux.bits--;
|
||
|
|
else
|
||
|
|
ux.bits++;
|
||
|
|
} else {
|
||
|
|
if (signbit(x))
|
||
|
|
ux.bits++;
|
||
|
|
else
|
||
|
|
ux.bits--;
|
||
|
|
}
|
||
|
|
e = ux.bits & 0x7f800000;
|
||
|
|
/* raise overflow if ux.value is infinite and x is finite */
|
||
|
|
if (e == 0x7f800000) {
|
||
|
|
volatile float force_eval;
|
||
|
|
force_eval = x + x;
|
||
|
|
}
|
||
|
|
/* raise underflow if ux.value is subnormal or zero */
|
||
|
|
if (e == 0) {
|
||
|
|
volatile float force_eval;
|
||
|
|
force_eval = x*x + ux.value*ux.value;
|
||
|
|
}
|
||
|
|
return ux.value;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif // _LDBL_EQ_DOUBLE
|