Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
4349 | Serge | 1 | /* lround adapted to be llround for Newlib, 2009 by Craig Howland. */ |
2 | /* |
||
3 | * ==================================================== |
||
4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
||
5 | * |
||
6 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
||
7 | * Permission to use, copy, modify, and distribute this |
||
8 | * software is freely granted, provided that this notice |
||
9 | * is preserved. |
||
10 | * ==================================================== |
||
11 | */ |
||
12 | |||
13 | #include "fdlibm.h" |
||
14 | |||
15 | #ifndef _DOUBLE_IS_32BITS |
||
16 | |||
17 | long long int |
||
18 | llround(double x) |
||
19 | { |
||
20 | __int32_t sign, exponent_less_1023; |
||
21 | /* Most significant word, least significant word. */ |
||
22 | __uint32_t msw, lsw; |
||
23 | long long int result; |
||
24 | |||
25 | EXTRACT_WORDS(msw, lsw, x); |
||
26 | |||
27 | /* Extract sign. */ |
||
28 | sign = ((msw & 0x80000000) ? -1 : 1); |
||
29 | /* Extract exponent field. */ |
||
30 | exponent_less_1023 = ((msw & 0x7ff00000) >> 20) - 1023; |
||
31 | msw &= 0x000fffff; |
||
32 | msw |= 0x00100000; |
||
33 | |||
34 | /* exponent_less_1023 in [-1023,1024] */ |
||
35 | if (exponent_less_1023 < 20) |
||
36 | { |
||
37 | /* exponent_less_1023 in [-1023,19] */ |
||
38 | if (exponent_less_1023 < 0) |
||
39 | { |
||
40 | if (exponent_less_1023 < -1) |
||
41 | return 0; |
||
42 | else |
||
43 | return sign; |
||
44 | } |
||
45 | else |
||
46 | { |
||
47 | /* exponent_less_1023 in [0,19] */ |
||
48 | /* shift amt in [0,19] */ |
||
49 | msw += 0x80000 >> exponent_less_1023; |
||
50 | /* shift amt in [20,1] */ |
||
51 | result = msw >> (20 - exponent_less_1023); |
||
52 | } |
||
53 | } |
||
54 | else if (exponent_less_1023 < (8 * sizeof (long long int)) - 1) |
||
55 | { |
||
56 | /* 64bit longlong: exponent_less_1023 in [20,62] */ |
||
57 | if (exponent_less_1023 >= 52) |
||
58 | /* 64bit longlong: exponent_less_1023 in [52,62] */ |
||
59 | /* 64bit longlong: shift amt in [32,42] */ |
||
60 | result = ((long long int) msw << (exponent_less_1023 - 20)) |
||
61 | /* 64bit longlong: shift amt in [0,10] */ |
||
62 | | (lsw << (exponent_less_1023 - 52)); |
||
63 | else |
||
64 | { |
||
65 | /* 64bit longlong: exponent_less_1023 in [20,51] */ |
||
66 | unsigned int tmp = lsw |
||
67 | /* 64bit longlong: shift amt in [0,31] */ |
||
68 | + (0x80000000 >> (exponent_less_1023 - 20)); |
||
69 | if (tmp < lsw) |
||
70 | ++msw; |
||
71 | /* 64bit longlong: shift amt in [0,31] */ |
||
72 | result = ((long long int) msw << (exponent_less_1023 - 20)) |
||
73 | /* ***64bit longlong: shift amt in [32,1] */ |
||
74 | | SAFE_RIGHT_SHIFT (tmp, (52 - exponent_less_1023)); |
||
75 | } |
||
76 | } |
||
77 | else |
||
78 | /* Result is too large to be represented by a long long int. */ |
||
79 | return (long long int)x; |
||
80 | |||
81 | return sign * result; |
||
82 | } |
||
83 | |||
84 | #endif /* _DOUBLE_IS_32BITS */><>>><>><>>>>> |