1 /*
2 * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26
27 #include "mlib_image.h"
28
29 #include <jni.h>
30 #include "jni_util.h"
31
32 /*
33 * Declare library specific JNI_Onload entry if static build
34 */
35 DEF_STATIC_JNI_OnLoad
36
37 /***************************************************************/
38 typedef union {
39 mlib_d64 db;
40 struct {
41 #ifdef _LITTLE_ENDIAN
42 mlib_s32 int1, int0;
43 #else
44 mlib_s32 int0, int1;
45 #endif
46 } two_int;
47 } type_union_mlib_d64;
48
49 #define DVAIN52 4.503599627370496e15
50
51 /***************************************************************/
mlib_ilogb(mlib_d64 X)52 mlib_s32 mlib_ilogb(mlib_d64 X)
53 {
54 type_union_mlib_d64 arg;
55 mlib_s32 n;
56
57 if (X == 0.0)
58 return -MLIB_S32_MAX;
59 arg.db = X;
60 n = arg.two_int.int0 & 0x7ff00000;
61 if (n)
62 n = (n < 0x7ff00000) ? (n >> 20) - 1023 : MLIB_S32_MAX;
63 else {
64 arg.db = X * DVAIN52;
65 n = ((arg.two_int.int0 & 0x7ff00000) >> 20) - 1075;
66 }
67 return n;
68 }
69
70 /***************************************************************/
71