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1 /*
2  * Copyright (c) 1997, 2005, 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 "jni_util.h"
28 #include "jlong.h"
29 #include "jvm.h"
30 
31 #include "JNIHelp.h"
32 
33 #define NATIVE_METHOD(className, functionName, signature) \
34 { #functionName, signature, (void*)(className ## _ ## functionName) }
35 
36 
37 /*
38  * Find the double float corresponding to a given bit pattern
39  */
40 JNIEXPORT jdouble JNICALL
Double_longBitsToDouble(JNIEnv * env,jclass unused,jlong v)41 Double_longBitsToDouble(JNIEnv *env, jclass unused, jlong v)
42 {
43     union {
44         jlong l;
45         double d;
46     } u;
47     jlong_to_jdouble_bits(&v);
48     u.l = v;
49     return (jdouble)u.d;
50 }
51 
52 /*
53  * Find the bit pattern corresponding to a given double float, NOT collapsing NaNs
54  */
55 JNIEXPORT jlong JNICALL
Double_doubleToRawLongBits(JNIEnv * env,jclass unused,jdouble v)56 Double_doubleToRawLongBits(JNIEnv *env, jclass unused, jdouble v)
57 {
58     union {
59         jlong l;
60         double d;
61     } u;
62     jdouble_to_jlong_bits(&v);
63     u.d = (double)v;
64     return u.l;
65 }
66 static JNINativeMethod gMethods[] = {
67   NATIVE_METHOD(Double, longBitsToDouble, "(J)D"),
68   NATIVE_METHOD(Double, doubleToRawLongBits, "(D)J"),
69 };
70 
register_java_lang_Double(JNIEnv * env)71 void register_java_lang_Double(JNIEnv* env) {
72   jniRegisterNativeMethods(env, "java/lang/Double", gMethods, NELEM(gMethods));
73 }
74