diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/s_nexttoward.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128/s_nexttoward.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/s_nexttoward.c b/sysdeps/ieee754/ldbl-128/s_nexttoward.c new file mode 100644 index 0000000000..f121be2fac --- /dev/null +++ b/sysdeps/ieee754/ldbl-128/s_nexttoward.c @@ -0,0 +1,97 @@ +/* s_nexttoward.c + * Conversion from s_nextafter.c by Ulrich Drepper, Cygnus Support, + * drepper@cygnus.com and 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. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: $"; +#endif + +/* IEEE functions + * nexttoward(x,y) + * return the next machine floating-point number of x in the + * direction toward y. + * Special cases: + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ + double __nexttoward(double x, long double y) +#else + double __nexttoward(x,y) + double x; + long double y; +#endif +{ + int32_t hx,ix; + int64_t hy,iy; + u_int32_t lx; + u_int64_t ly; + + EXTRACT_WORDS(hx,lx,x); + GET_LDOUBLE_WORDS64(hy,ly,y); + ix = hx&0x7fffffff; /* |x| */ + iy = hy&0x7fffffffffffffffLL; /* |y| */ + + if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */ + ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) + /* y is nan */ + return x+y; + if((long double) x==y) return x; /* x=y, return x */ + if((ix|lx)==0) { /* x == 0 */ + double x2; + INSERT_WORDS(x,(u_int32_t)((hy>>32)&0x80000000),1);/* return +-minsub */ + x2 = x*x; + if(x2==x) return x2; else return x; /* raise underflow flag */ + } + if(hx>=0) { /* x > 0 */ + if (hy<0||(ix>>20)>(iy>>48)-0x3c00 + || ((ix>>20)==(iy>>48)-0x3c00 + && (((((int64_t)hx)<<28)|(lx>>4))>(hy&0x0000ffffffffffffLL) + || (((((int64_t)hx)<<28)|(lx>>4))==(hy&0x0000ffffffffffffLL) + && (lx&0xf)>(ly>>60))))) { /* x > y, x -= ulp */ + if(lx==0) hx -= 1; + lx -= 1; + } else { /* x < y, x += ulp */ + lx += 1; + if(lx==0) hx += 1; + } + } else { /* x < 0 */ + if (hy>=0||(ix>>20)>(iy>>48)-0x3c00 + || ((ix>>20)==(iy>>48)-0x3c00 + && (((((int64_t)hx)<<28)|(lx>>4))>(hy&0x0000ffffffffffffLL) + || (((((int64_t)hx)<<28)|(lx>>4))==(hy&0x0000ffffffffffffLL) + && (lx&0xf)>(ly>>60))))) { /* x < y, x -= ulp */ + if(lx==0) hx -= 1; + lx -= 1; + } else { /* x > y, x += ulp */ + lx += 1; + if(lx==0) hx += 1; + } + } + hy = hx&0x7ff00000; + if(hy>=0x7ff00000) return x+x; /* overflow */ + if(hy<0x00100000) { /* underflow */ + double x2 = x*x; + if(x2!=x) { /* raise underflow flag */ + INSERT_WORDS(x2,hx,lx); + return x2; + } + } + INSERT_WORDS(x,hx,lx); + return x; +} +weak_alias (__nexttoward, nexttoward) |