1 | /* s_floorf.c -- float version of s_floor.c. |
2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
3 | */ |
4 | |
5 | /* |
6 | * ==================================================== |
7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
8 | * |
9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
10 | * Permission to use, copy, modify, and distribute this |
11 | * software is freely granted, provided that this notice |
12 | * is preserved. |
13 | * ==================================================== |
14 | */ |
15 | |
16 | /* |
17 | * floorf(x) |
18 | * Return x rounded toward -inf to integral value |
19 | * Method: |
20 | * Bit twiddling. |
21 | */ |
22 | |
23 | #include <math.h> |
24 | #include <math_private.h> |
25 | #include <libm-alias-float.h> |
26 | |
27 | float |
28 | __floorf(float x) |
29 | { |
30 | int32_t i0,j0; |
31 | uint32_t i; |
32 | GET_FLOAT_WORD(i0,x); |
33 | j0 = ((i0>>23)&0xff)-0x7f; |
34 | if(j0<23) { |
35 | if(j0<0) { |
36 | /* return 0*sign(x) if |x|<1 */ |
37 | if(i0>=0) {i0=0;} |
38 | else if((i0&0x7fffffff)!=0) |
39 | { i0=0xbf800000;} |
40 | } else { |
41 | i = (0x007fffff)>>j0; |
42 | if((i0&i)==0) return x; /* x is integral */ |
43 | if(i0<0) i0 += (0x00800000)>>j0; |
44 | i0 &= (~i); |
45 | } |
46 | } else { |
47 | if(__builtin_expect(j0==0x80, 0)) return x+x; /* inf or NaN */ |
48 | else return x; /* x is integral */ |
49 | } |
50 | SET_FLOAT_WORD(x,i0); |
51 | return x; |
52 | } |
53 | #ifndef __floorf |
54 | libm_alias_float (__floor, floor) |
55 | #endif |
56 | |