1 /* VMFloat.java -- VM Specific Float methods 2 Copyright (C) 2003, 2006 Free Software Foundation 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 package java.lang; 39 40 import gnu.classpath.Configuration; 41 42 /* 43 * This class is a reference version, mainly for compiling a class library 44 * jar. It is likely that VM implementers replace this with their own 45 * version that can communicate effectively with the VM. 46 */ 47 48 /** 49 * Code relocated from java.lang.Float by 50 * @author Dave Grove <groved@us.ibm.com> 51 */ 52 final class VMFloat 53 { 54 /** 55 * Convert the float to the IEEE 754 floating-point "single format" bit 56 * layout. Bit 31 (the most significant) is the sign bit, bits 30-23 57 * (masked by 0x7f800000) represent the exponent, and bits 22-0 58 * (masked by 0x007fffff) are the mantissa. This function collapses all 59 * versions of NaN to 0x7fc00000. The result of this function can be used 60 * as the argument to <code>Float.intBitsToFloat(int)</code> to obtain the 61 * original <code>float</code> value. 62 * 63 * @param value the <code>float</code> to convert 64 * @return the bits of the <code>float</code> 65 * @see #intBitsToFloat(int) 66 */ floatToIntBits(float value)67 static native int floatToIntBits(float value); 68 69 /** 70 * Convert the float to the IEEE 754 floating-point "single format" bit 71 * layout. Bit 31 (the most significant) is the sign bit, bits 30-23 72 * (masked by 0x7f800000) represent the exponent, and bits 22-0 73 * (masked by 0x007fffff) are the mantissa. This function leaves NaN alone, 74 * rather than collapsing to a canonical value. The result of this function 75 * can be used as the argument to <code>Float.intBitsToFloat(int)</code> to 76 * obtain the original <code>float</code> value. 77 * 78 * @param value the <code>float</code> to convert 79 * @return the bits of the <code>float</code> 80 * @see #intBitsToFloat(int) 81 */ floatToRawIntBits(float value)82 static native int floatToRawIntBits(float value); 83 84 /** 85 * Convert the argument in IEEE 754 floating-point "single format" bit 86 * layout to the corresponding float. Bit 31 (the most significant) is the 87 * sign bit, bits 30-23 (masked by 0x7f800000) represent the exponent, and 88 * bits 22-0 (masked by 0x007fffff) are the mantissa. This function leaves 89 * NaN alone, so that you can recover the bit pattern with 90 * <code>Float.floatToRawIntBits(float)</code>. 91 * 92 * @param bits the bits to convert 93 * @return the <code>float</code> represented by the bits 94 * @see #floatToIntBits(float) 95 * @see #floatToRawIntBits(float) 96 */ intBitsToFloat(int bits)97 static native float intBitsToFloat(int bits); 98 99 /** 100 * @param f the <code>float</code> to convert 101 * @return the <code>String</code> representing the <code>float</code> 102 */ toString(float f)103 static String toString(float f) 104 { 105 return VMDouble.toString(f, true); 106 } 107 108 /** 109 * @param str the <code>String</code> to convert 110 * @return the <code>float</code> value of <code>s</code> 111 * @throws NumberFormatException if <code>str</code> cannot be parsed as a 112 * <code>float</code> 113 * @throws NullPointerException if <code>str</code> is null 114 */ parseFloat(String str)115 static float parseFloat(String str) 116 { 117 // XXX Rounding parseDouble() causes some errors greater than 1 ulp from 118 // the infinitely precise decimal. 119 return (float) Double.parseDouble(str); 120 } 121 } // class VMFloat 122