| /* s_nexttowardf.c -- float version of s_nextafter.c. |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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 |
| |
| #include "math.h" |
| #include "math_private.h" |
| |
| #ifdef __STDC__ |
| float __nexttowardf(float x, long double y) |
| #else |
| float __nexttowardf(x,y) |
| float x; |
| long double y; |
| #endif |
| { |
| int32_t hx,ix; |
| int64_t hy,iy; |
| u_int64_t ly; |
| |
| GET_FLOAT_WORD(hx,x); |
| GET_LDOUBLE_WORDS64(hy,ly,y); |
| ix = hx&0x7fffffff; /* |x| */ |
| iy = hy&0x7fffffffffffffffLL; /* |y| */ |
| |
| if((ix>0x7f800000) || /* x is nan */ |
| ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0)) |
| /* y is nan */ |
| return x+y; |
| if((long double) x==y) return y; /* x=y, return y */ |
| if(ix==0) { /* x == 0 */ |
| float u; |
| SET_FLOAT_WORD(x,(u_int32_t)((hy>>32)&0x80000000)|1);/* return +-minsub*/ |
| u = math_opt_barrier (x); |
| u = u * u; |
| math_force_eval (u); /* raise underflow flag */ |
| return x; |
| } |
| if(hx>=0) { /* x > 0 */ |
| if(hy<0||(ix>>23)>(iy>>48)-0x3f80 |
| || ((ix>>23)==(iy>>48)-0x3f80 |
| && (ix&0x7fffff)>((hy>>25)&0x7fffff))) {/* x > y, x -= ulp */ |
| hx -= 1; |
| } else { /* x < y, x += ulp */ |
| hx += 1; |
| } |
| } else { /* x < 0 */ |
| if(hy>=0||(ix>>23)>(iy>>48)-0x3f80 |
| || ((ix>>23)==(iy>>48)-0x3f80 |
| && (ix&0x7fffff)>((hy>>25)&0x7fffff))) {/* x < y, x -= ulp */ |
| hx -= 1; |
| } else { /* x > y, x += ulp */ |
| hx += 1; |
| } |
| } |
| hy = hx&0x7f800000; |
| if(hy>=0x7f800000) return x+x; /* overflow */ |
| if(hy<0x00800000) { |
| float u = x*x; /* underflow */ |
| math_force_eval (u); /* raise underflow flag */ |
| } |
| SET_FLOAT_WORD(x,hx); |
| return x; |
| } |
| weak_alias (__nexttowardf, nexttowardf) |
