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jeremybenn |
/* VMFloat.java -- VM Specific Float methods
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Copyright (C) 2003 Free Software Foundation
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.lang;
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import gnu.classpath.Configuration;
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/*
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* This class is a reference version, mainly for compiling a class library
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* jar. It is likely that VM implementers replace this with their own
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* version that can communicate effectively with the VM.
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*/
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/**
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* Code relocated from java.lang.Float by
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* @author Dave Grove <groved@us.ibm.com>
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*/
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final class VMFloat
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{
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/**
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* Load native routines necessary for this class.
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*/
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static
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{
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if (Configuration.INIT_LOAD_LIBRARY)
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{
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System.loadLibrary("javalang");
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}
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}
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/**
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* Convert the float to the IEEE 754 floating-point "single format" bit
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* layout. Bit 31 (the most significant) is the sign bit, bits 30-23
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* (masked by 0x7f800000) represent the exponent, and bits 22-0
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* (masked by 0x007fffff) are the mantissa. This function leaves NaN alone,
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* rather than collapsing to a canonical value. The result of this function
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* can be used as the argument to <code>Float.intBitsToFloat(int)</code> to
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* obtain the original <code>float</code> value.
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*
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* @param value the <code>float</code> to convert
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* @return the bits of the <code>float</code>
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* @see #intBitsToFloat(int)
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*/
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static native int floatToRawIntBits(float value);
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/**
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* Convert the argument in IEEE 754 floating-point "single format" bit
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* layout to the corresponding float. Bit 31 (the most significant) is the
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* sign bit, bits 30-23 (masked by 0x7f800000) represent the exponent, and
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* bits 22-0 (masked by 0x007fffff) are the mantissa. This function leaves
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* NaN alone, so that you can recover the bit pattern with
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* <code>Float.floatToRawIntBits(float)</code>.
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*
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* @param bits the bits to convert
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* @return the <code>float</code> represented by the bits
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* @see #floatToIntBits(float)
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* @see #floatToRawIntBits(float)
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*/
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static native float intBitsToFloat(int bits);
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/**
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* @param f the <code>float</code> to convert
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* @return the <code>String</code> representing the <code>float</code>
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*/
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static String toString(float f)
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{
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return VMDouble.toString(f, true);
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}
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/**
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* @param str the <code>String</code> to convert
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* @return the <code>float</code> value of <code>s</code>
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* @throws NumberFormatException if <code>str</code> cannot be parsed as a
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* <code>float</code>
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* @throws NullPointerException if <code>str</code> is null
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*/
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static float parseFloat(String str)
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{
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// XXX Rounding parseDouble() causes some errors greater than 1 ulp from
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// the infinitely precise decimal.
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return (float) Double.parseDouble(str);
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}
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} // class VMFloat
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