mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-11 19:49:32 +00:00
65 lines
1.7 KiB
C
65 lines
1.7 KiB
C
/* modfq.c -- __float128 version of s_modf.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.
|
|
* ====================================================
|
|
*/
|
|
|
|
#include "quadmath-imp.h"
|
|
|
|
static const __float128 one = 1.0;
|
|
|
|
__float128
|
|
modfq (__float128 x, __float128 *iptr)
|
|
{
|
|
int64_t i0,i1,j0;
|
|
uint64_t i;
|
|
GET_FLT128_WORDS64(i0,i1,x);
|
|
j0 = ((i0>>48)&0x7fff)-0x3fff; /* exponent of x */
|
|
if(j0<48) { /* integer part in high x */
|
|
if(j0<0) { /* |x|<1 */
|
|
/* *iptr = +-0 */
|
|
SET_FLT128_WORDS64(*iptr,i0&0x8000000000000000ULL,0);
|
|
return x;
|
|
} else {
|
|
i = (0x0000ffffffffffffLL)>>j0;
|
|
if(((i0&i)|i1)==0) { /* x is integral */
|
|
*iptr = x;
|
|
/* return +-0 */
|
|
SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
|
|
return x;
|
|
} else {
|
|
SET_FLT128_WORDS64(*iptr,i0&(~i),0);
|
|
return x - *iptr;
|
|
}
|
|
}
|
|
} else if (j0>111) { /* no fraction part */
|
|
*iptr = x*one;
|
|
/* We must handle NaNs separately. */
|
|
if (j0 == 0x4000 && ((i0 & 0x0000ffffffffffffLL) | i1))
|
|
return x*one;
|
|
/* return +-0 */
|
|
SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
|
|
return x;
|
|
} else { /* fraction part in low x */
|
|
i = -1ULL>>(j0-48);
|
|
if((i1&i)==0) { /* x is integral */
|
|
*iptr = x;
|
|
/* return +-0 */
|
|
SET_FLT128_WORDS64(x,i0&0x8000000000000000ULL,0);
|
|
return x;
|
|
} else {
|
|
SET_FLT128_WORDS64(*iptr,i0,i1&(~i));
|
|
return x - *iptr;
|
|
}
|
|
}
|
|
}
|