1 | /* |
2 | * Copyright (c) 2000, 2018, 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 | #include "jni.h" |
27 | #include "AlphaMath.h" |
28 | |
29 | JNIEXPORT unsigned char mul8table[256][256]; |
30 | JNIEXPORT unsigned char div8table[256][256]; |
31 | |
32 | void initAlphaTables() |
33 | { |
34 | unsigned int i; |
35 | unsigned int j; |
36 | |
37 | for (i = 1; i < 256; i++) { /* SCALE == (1 << 24) */ |
38 | unsigned int inc = (i << 16) + (i<<8) + i; /* approx. SCALE * (i/255.0) */ |
39 | unsigned int val = inc + (1 << 23); /* inc + SCALE*0.5 */ |
40 | for (j = 1; j < 256; j++) { |
41 | mul8table[i][j] = (val >> 24); /* val / SCALE */ |
42 | val += inc; |
43 | } |
44 | } |
45 | |
46 | for (i = 1; i < 256; i++) { |
47 | unsigned int inc; |
48 | unsigned int val; |
49 | inc = 0xff; |
50 | inc = ((inc << 24) + i/2) / i; |
51 | val = (1 << 23); |
52 | for (j = 0; j < i; j++) { |
53 | div8table[i][j] = (val >> 24); |
54 | val += inc; |
55 | } |
56 | for (j = i; j < 256; j++) { |
57 | div8table[i][j] = 255; |
58 | } |
59 | } |
60 | } |
61 | |