1 | /* Single precision version of nexttoward.c. |
2 | Conversion to IEEE single float by Jakub Jelinek, jj@ultra.linux.cz. */ |
3 | /* |
4 | * ==================================================== |
5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
6 | * |
7 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
8 | * Permission to use, copy, modify, and distribute this |
9 | * software is freely granted, provided that this notice |
10 | * is preserved. |
11 | * ==================================================== |
12 | */ |
13 | |
14 | /* IEEE functions |
15 | * nexttowardf(x,y) |
16 | * return the next machine floating-point number of x in the |
17 | * direction toward y. |
18 | * This is for machines which use the same binary type for double and |
19 | * long double. |
20 | * Special cases: |
21 | */ |
22 | |
23 | #include <errno.h> |
24 | #include <math.h> |
25 | #include <math-barriers.h> |
26 | #include <math_private.h> |
27 | #include <float.h> |
28 | |
29 | float __nexttowardf(float x, long double y) |
30 | { |
31 | int32_t hx,hy,ix,iy; |
32 | uint32_t ly; |
33 | |
34 | GET_FLOAT_WORD(hx,x); |
35 | EXTRACT_WORDS(hy,ly,y); |
36 | ix = hx&0x7fffffff; /* |x| */ |
37 | iy = hy&0x7fffffff; /* |y| */ |
38 | |
39 | if((ix>0x7f800000) || /* x is nan */ |
40 | ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */ |
41 | return x+y; |
42 | if((long double) x==y) return y; /* x=y, return y */ |
43 | if(ix==0) { /* x == 0 */ |
44 | float u; |
45 | SET_FLOAT_WORD(x,(uint32_t)(hy&0x80000000)|1);/* return +-minsub*/ |
46 | u = math_opt_barrier (x); |
47 | u = u * u; |
48 | math_force_eval (u); /* raise underflow flag */ |
49 | return x; |
50 | } |
51 | if(hx>=0) { /* x > 0 */ |
52 | if(x > y) /* x -= ulp */ |
53 | hx -= 1; |
54 | else /* x < y, x += ulp */ |
55 | hx += 1; |
56 | } else { /* x < 0 */ |
57 | if(x < y) /* x -= ulp */ |
58 | hx -= 1; |
59 | else /* x > y, x += ulp */ |
60 | hx += 1; |
61 | } |
62 | hy = hx&0x7f800000; |
63 | if(hy>=0x7f800000) { |
64 | float u = x+x; /* overflow */ |
65 | math_force_eval (u); |
66 | __set_errno (ERANGE); |
67 | } |
68 | if(hy<0x00800000) { |
69 | float u = x*x; /* underflow */ |
70 | math_force_eval (u); /* raise underflow flag */ |
71 | __set_errno (ERANGE); |
72 | } |
73 | SET_FLOAT_WORD(x,hx); |
74 | return x; |
75 | } |
76 | weak_alias (__nexttowardf, nexttowardf) |
77 | |