diff options
Diffstat (limited to 'math/s_nexttowardf.c')
-rw-r--r-- | math/s_nexttowardf.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/math/s_nexttowardf.c b/math/s_nexttowardf.c new file mode 100644 index 0000000..1a10266 --- /dev/null +++ b/math/s_nexttowardf.c @@ -0,0 +1,86 @@ +/* Single precision version of nexttoward.c. + Conversion to IEEE single float 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. + * ==================================================== + */ + +/* IEEE functions + * nexttowardf(x,y) + * return the next machine floating-point number of x in the + * direction toward y. + * This is for machines which use the same binary type for double and + * long double. + * Special cases: + */ + +#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,hy,ix,iy; + u_int32_t ly; + + GET_FLOAT_WORD(hx,x); + EXTRACT_WORDS(hy,ly,y); + ix = hx&0x7fffffff; /* |x| */ + iy = hy&0x7fffffff; /* |y| */ + + if((ix>0x7f800000) || /* x is nan */ + ((iy>=0x7ff00000)&&((iy-0x7ff00000)|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 x2; + SET_FLOAT_WORD(x,(u_int32_t)(hy&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>>23)>(iy>>20)-0x380 + || ((ix>>23)==(iy>>20)-0x380 + && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff))) /* x > y, x -= ulp */ + hx -= 1; + else /* x < y, x += ulp */ + hx += 1; + } else { /* x < 0 */ + if(hy>=0||(ix>>23)>(iy>>20)-0x380 + || ((ix>>23)==(iy>>20)-0x380 + && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff))) /* 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) : "m"(x)); + return x; + } + if(hy<0x00800000) { /* underflow */ + float x2 = x*x; + if(x2!=x) { /* raise underflow flag */ + SET_FLOAT_WORD(x2,hx); + return x2; + } + } + SET_FLOAT_WORD(x,hx); + return x; +} +weak_alias (__nexttowardf, nexttowardf) |