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1da177e4 LT |
1 | /* IEEE754 floating point arithmetic |
2 | * double precision: common utilities | |
3 | */ | |
4 | /* | |
5 | * MIPS floating point support | |
6 | * Copyright (C) 1994-2000 Algorithmics Ltd. | |
1da177e4 LT |
7 | * |
8 | * ######################################################################## | |
9 | * | |
10 | * This program is free software; you can distribute it and/or modify it | |
11 | * under the terms of the GNU General Public License (Version 2) as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | * This program is distributed in the hope it will be useful, but WITHOUT | |
15 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | * for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with this program; if not, write to the Free Software Foundation, Inc., | |
21 | * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. | |
22 | * | |
23 | * ######################################################################## | |
24 | */ | |
25 | ||
26 | ||
27 | #include "ieee754dp.h" | |
28 | ||
29 | ieee754dp ieee754dp_fint(int x) | |
30 | { | |
ecf52d3c AN |
31 | u64 xm; |
32 | int xe; | |
33 | int xs; | |
1da177e4 LT |
34 | |
35 | CLEARCX; | |
36 | ||
1da177e4 LT |
37 | if (x == 0) |
38 | return ieee754dp_zero(0); | |
39 | if (x == 1 || x == -1) | |
40 | return ieee754dp_one(x < 0); | |
41 | if (x == 10 || x == -10) | |
42 | return ieee754dp_ten(x < 0); | |
43 | ||
44 | xs = (x < 0); | |
45 | if (xs) { | |
46 | if (x == (1 << 31)) | |
47 | xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */ | |
48 | else | |
49 | xm = -x; | |
50 | } else { | |
51 | xm = x; | |
52 | } | |
53 | ||
54 | #if 1 | |
55 | /* normalize - result can never be inexact or overflow */ | |
56 | xe = DP_MBITS; | |
57 | while ((xm >> DP_MBITS) == 0) { | |
58 | xm <<= 1; | |
59 | xe--; | |
60 | } | |
61 | return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT); | |
62 | #else | |
63 | /* normalize */ | |
64 | xe = DP_MBITS + 3; | |
65 | while ((xm >> (DP_MBITS + 3)) == 0) { | |
66 | xm <<= 1; | |
67 | xe--; | |
68 | } | |
69 | DPNORMRET1(xs, xe, xm, "fint", x); | |
70 | #endif | |
71 | } | |
72 | ||
73 | ieee754dp ieee754dp_funs(unsigned int u) | |
74 | { | |
75 | if ((int) u < 0) | |
76 | return ieee754dp_add(ieee754dp_1e31(), | |
77 | ieee754dp_fint(u & ~(1 << 31))); | |
78 | return ieee754dp_fint(u); | |
79 | } |