| 1 |
14 |
jlechner |
/* VMFloat.java -- VM Specific Float methods
|
| 2 |
|
|
Copyright (C) 2003 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 |
|
|
/**
|
| 56 |
|
|
* Load native routines necessary for this class.
|
| 57 |
|
|
*/
|
| 58 |
|
|
static
|
| 59 |
|
|
{
|
| 60 |
|
|
if (Configuration.INIT_LOAD_LIBRARY)
|
| 61 |
|
|
{
|
| 62 |
|
|
System.loadLibrary("javalang");
|
| 63 |
|
|
}
|
| 64 |
|
|
}
|
| 65 |
|
|
|
| 66 |
|
|
/**
|
| 67 |
|
|
* Convert the float to the IEEE 754 floating-point "single format" bit
|
| 68 |
|
|
* layout. Bit 31 (the most significant) is the sign bit, bits 30-23
|
| 69 |
|
|
* (masked by 0x7f800000) represent the exponent, and bits 22-0
|
| 70 |
|
|
* (masked by 0x007fffff) are the mantissa. This function collapses all
|
| 71 |
|
|
* versions of NaN to 0x7fc00000. The result of this function can be used
|
| 72 |
|
|
* as the argument to <code>Float.intBitsToFloat(int)</code> to obtain the
|
| 73 |
|
|
* original <code>float</code> value.
|
| 74 |
|
|
*
|
| 75 |
|
|
* @param value the <code>float</code> to convert
|
| 76 |
|
|
* @return the bits of the <code>float</code>
|
| 77 |
|
|
* @see #intBitsToFloat(int)
|
| 78 |
|
|
*/
|
| 79 |
|
|
static native int floatToIntBits(float value);
|
| 80 |
|
|
|
| 81 |
|
|
/**
|
| 82 |
|
|
* Convert the float to the IEEE 754 floating-point "single format" bit
|
| 83 |
|
|
* layout. Bit 31 (the most significant) is the sign bit, bits 30-23
|
| 84 |
|
|
* (masked by 0x7f800000) represent the exponent, and bits 22-0
|
| 85 |
|
|
* (masked by 0x007fffff) are the mantissa. This function leaves NaN alone,
|
| 86 |
|
|
* rather than collapsing to a canonical value. The result of this function
|
| 87 |
|
|
* can be used as the argument to <code>Float.intBitsToFloat(int)</code> to
|
| 88 |
|
|
* obtain the original <code>float</code> value.
|
| 89 |
|
|
*
|
| 90 |
|
|
* @param value the <code>float</code> to convert
|
| 91 |
|
|
* @return the bits of the <code>float</code>
|
| 92 |
|
|
* @see #intBitsToFloat(int)
|
| 93 |
|
|
*/
|
| 94 |
|
|
static native int floatToRawIntBits(float value);
|
| 95 |
|
|
|
| 96 |
|
|
/**
|
| 97 |
|
|
* Convert the argument in IEEE 754 floating-point "single format" bit
|
| 98 |
|
|
* layout to the corresponding float. Bit 31 (the most significant) is the
|
| 99 |
|
|
* sign bit, bits 30-23 (masked by 0x7f800000) represent the exponent, and
|
| 100 |
|
|
* bits 22-0 (masked by 0x007fffff) are the mantissa. This function leaves
|
| 101 |
|
|
* NaN alone, so that you can recover the bit pattern with
|
| 102 |
|
|
* <code>Float.floatToRawIntBits(float)</code>.
|
| 103 |
|
|
*
|
| 104 |
|
|
* @param bits the bits to convert
|
| 105 |
|
|
* @return the <code>float</code> represented by the bits
|
| 106 |
|
|
* @see #floatToIntBits(float)
|
| 107 |
|
|
* @see #floatToRawIntBits(float)
|
| 108 |
|
|
*/
|
| 109 |
|
|
static native float intBitsToFloat(int bits);
|
| 110 |
|
|
|
| 111 |
|
|
} // class VMFloat
|
