mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-11 19:49:32 +00:00
58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
/* rintq.c -- __float128 version of s_rint.c.
|
|
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*/
|
|
|
|
/*
|
|
* rintq(x)
|
|
* Return x rounded to integral value according to the prevailing
|
|
* rounding mode.
|
|
* Method:
|
|
* Using floating addition.
|
|
* Exception:
|
|
* Inexact flag raised if x not equal to rintq(x).
|
|
*/
|
|
|
|
#include "quadmath-imp.h"
|
|
|
|
static const __float128
|
|
TWO112[2]={
|
|
5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
|
|
-5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
|
|
};
|
|
|
|
__float128
|
|
rintq (__float128 x)
|
|
{
|
|
int64_t i0,j0,sx;
|
|
uint64_t i1 __attribute__ ((unused));
|
|
__float128 w,t;
|
|
GET_FLT128_WORDS64(i0,i1,x);
|
|
sx = (((uint64_t)i0)>>63);
|
|
j0 = ((i0>>48)&0x7fff)-0x3fff;
|
|
if(j0<112) {
|
|
if(j0<0) {
|
|
w = TWO112[sx]+x;
|
|
t = w-TWO112[sx];
|
|
GET_FLT128_MSW64(i0,t);
|
|
SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
|
|
return t;
|
|
}
|
|
} else {
|
|
if(j0==0x4000) return x+x; /* inf or NaN */
|
|
else return x; /* x is integral */
|
|
}
|
|
w = TWO112[sx]+x;
|
|
return w-TWO112[sx];
|
|
}
|