| /* e_fmodl.c -- long double version of e_fmod.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. |
| * ==================================================== |
| */ |
| |
| /* __ieee754_remainderl(x,p) |
| * Return : |
| * returns x REM p = x - [x/p]*p as if in infinite |
| * precise arithmetic, where [x/p] is the (infinite bit) |
| * integer nearest x/p (in half way case choose the even one). |
| * Method : |
| * Based on fmodl() return x-[x/p]chopped*p exactlp. |
| */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| |
| static const long double zero = 0.0L; |
| |
| |
| long double |
| __ieee754_remainderl(long double x, long double p) |
| { |
| int64_t hx,hp; |
| u_int64_t sx,lx,lp; |
| long double p_half; |
| double xhi, xlo, phi, plo; |
| |
| ldbl_unpack (x, &xhi, &xlo); |
| EXTRACT_WORDS64 (hx, xhi); |
| EXTRACT_WORDS64 (lx, xlo); |
| ldbl_unpack (p, &phi, &plo); |
| EXTRACT_WORDS64 (hp, phi); |
| EXTRACT_WORDS64 (lp, plo); |
| sx = hx&0x8000000000000000ULL; |
| hp &= 0x7fffffffffffffffLL; |
| hx &= 0x7fffffffffffffffLL; |
| |
| /* purge off exception values */ |
| if(hp==0) return (x*p)/(x*p); /* p = 0 */ |
| if((hx>=0x7ff0000000000000LL)|| /* x not finite */ |
| (hp>0x7ff0000000000000LL)) /* p is NaN */ |
| return (x*p)/(x*p); |
| |
| |
| if (hp<=0x7fdfffffffffffffLL) x = __ieee754_fmodl(x,p+p); /* now x < 2p */ |
| if (((hx-hp)|(lx-lp))==0) return zero*x; |
| x = fabsl(x); |
| p = fabsl(p); |
| if (hp<0x0020000000000000LL) { |
| if(x+x>p) { |
| x-=p; |
| if(x+x>=p) x -= p; |
| } |
| } else { |
| p_half = 0.5L*p; |
| if(x>p_half) { |
| x-=p; |
| if(x>=p_half) x -= p; |
| } |
| } |
| if (sx) |
| x = -x; |
| return x; |
| } |
| strong_alias (__ieee754_remainderl, __remainderl_finite) |