1 // 2 // java_lang_Double.c 3 // Android 4 // 5 // Copyright 2005 The Android Open Source Project 6 // 7 #include "JNIHelp.h" 8 9 #include <math.h> 10 #include <stdlib.h> 11 #include <stdio.h> 12 #include <stdint.h> 13 14 typedef union { 15 uint64_t bits; 16 double d; 17 } Double; 18 19 #define NaN (0x7ff8000000000000ULL) 20 21 /* 22 * public static native long doubleToLongBits(double value) 23 */ 24 static jlong doubleToLongBits(JNIEnv* env, jclass clazz, jdouble val) 25 { 26 Double d; 27 28 d.d = val; 29 30 // For this method all values in the NaN range are 31 // normalized to the canonical NaN value. 32 33 if (isnan(d.d)) 34 d.bits = NaN; 35 36 return d.bits; 37 } 38 39 /* 40 * public static native long doubleToRawLongBits(double value) 41 */ 42 static jlong doubleToRawLongBits(JNIEnv* env, jclass clazz, jdouble val) 43 { 44 Double d; 45 46 d.d = val; 47 48 return d.bits; 49 } 50 51 /* 52 * public static native double longBitsToDouble(long bits) 53 */ 54 static jdouble longBitsToDouble(JNIEnv* env, jclass clazz, jlong val) 55 { 56 Double d; 57 58 d.bits = val; 59 60 return d.d; 61 } 62 63 /* 64 * JNI registration 65 */ 66 static JNINativeMethod gMethods[] = { 67 /* name, signature, funcPtr */ 68 { "doubleToLongBits", "(D)J", doubleToLongBits }, 69 { "doubleToRawLongBits", "(D)J", doubleToRawLongBits }, 70 { "longBitsToDouble", "(J)D", longBitsToDouble }, 71 }; 72 int register_java_lang_Double(JNIEnv* env) 73 { 74 return jniRegisterNativeMethods(env, "java/lang/Double", 75 gMethods, NELEM(gMethods)); 76 } 77 78
