| /* sf_nextafter.c -- float version of s_nextafter.c. |
| * 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. |
| * ==================================================== |
| */ |
| |
| #include "fdlibm.h" |
| |
| #ifdef __STDC__ |
| float nextafterf(float x, float y) |
| #else |
| float nextafterf(x,y) |
| float x,y; |
| #endif |
| { |
| __int32_t hx,hy,ix,iy; |
| |
| GET_FLOAT_WORD(hx,x); |
| GET_FLOAT_WORD(hy,y); |
| ix = hx&0x7fffffff; /* |x| */ |
| iy = hy&0x7fffffff; /* |y| */ |
| |
| if(FLT_UWORD_IS_NAN(ix) || |
| FLT_UWORD_IS_NAN(iy)) |
| return x+y; |
| if(x==y) return x; /* x=y, return x */ |
| if(FLT_UWORD_IS_ZERO(ix)) { /* x == 0 */ |
| SET_FLOAT_WORD(x,(hy&0x80000000)|FLT_UWORD_MIN); |
| y = x*x; |
| if(y==x) return y; else return x; /* raise underflow flag */ |
| } |
| if(hx>=0) { /* x > 0 */ |
| if(hx>hy) { /* x > y, x -= ulp */ |
| hx -= 1; |
| } else { /* x < y, x += ulp */ |
| hx += 1; |
| } |
| } else { /* x < 0 */ |
| if(hy>=0||hx>hy){ /* x < y, x -= ulp */ |
| hx -= 1; |
| } else { /* x > y, x += ulp */ |
| hx += 1; |
| } |
| } |
| hy = hx&0x7f800000; |
| if(hy>FLT_UWORD_MAX) return x+x; /* overflow */ |
| if(hy<0x00800000) { /* underflow */ |
| y = x*x; |
| if(y!=x) { /* raise underflow flag */ |
| SET_FLOAT_WORD(y,hx); |
| return y; |
| } |
| } |
| SET_FLOAT_WORD(x,hx); |
| return x; |
| } |
| |
| #ifdef _DOUBLE_IS_32BITS |
| |
| #ifdef __STDC__ |
| double nextafter(double x, double y) |
| #else |
| double nextafter(x,y) |
| double x,y; |
| #endif |
| { |
| return (double) nextafterf((float) x, (float) x); |
| } |
| |
| #endif /* defined(_DOUBLE_IS_32BITS) */ |