| /* s_nexttowardf.c -- float version of s_nextafter.c. |
| * Special i387 version. |
| * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| */ |
| |
| /* |
| * ==================================================== |
| * 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> |
| #include <float.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,iy; |
| u_int32_t hy,ly,esy; |
| |
| GET_FLOAT_WORD(hx,x); |
| GET_LDOUBLE_WORDS(esy,hy,ly,y); |
| ix = hx&0x7fffffff; /* |x| */ |
| iy = esy&0x7fff; /* |y| */ |
| |
| /* Intel's extended format has the normally implicit 1 explicit |
| present. Sigh! */ |
| if((ix>0x7f800000) || /* x is nan */ |
| (iy>=0x7fff&&(((hy&0x7fffffff)|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,((esy&0x8000)<<16)|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(esy>=0x8000||((ix>>23)&0xff)>iy-0x3f80 |
| || (((ix>>23)&0xff)==iy-0x3f80 |
| && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x > y, x -= ulp */ |
| hx -= 1; |
| } else { /* x < y, x += ulp */ |
| hx += 1; |
| } |
| } else { /* x < 0 */ |
| if(esy<0x8000||((ix>>23)&0xff)>iy-0x3f80 |
| || (((ix>>23)&0xff)==iy-0x3f80 |
| && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x < y, x -= ulp */ |
| hx -= 1; |
| } else { /* x > y, x += ulp */ |
| hx += 1; |
| } |
| } |
| hy = hx&0x7f800000; |
| if(hy>=0x7f800000) { |
| x = x+x; /* overflow */ |
| if (FLT_EVAL_METHOD != 0) |
| /* Force conversion to float. */ |
| asm ("" : "+m"(x)); |
| return x; |
| } |
| 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) |
