| 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 | /***************************************************************/ |
| 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 | |