mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-27 03:49:03 +08:00
839f820424
* java/lang/VMClassLoader.java (getPrimitiveClass): Now native. Now takes a jchar type-code argument, not a string. * java/lang/natClassLoader.cc (VMClassLoader::getPrimitiveClass): New method. Just call _Jv_FindClassFromSignature. * java/lang/Boolean.java (TYPE): Initialize from VMClassLoader.getPrimitiveClass using type-code. * java/lang/Character.java (TYPE): Likewise. * java/lang/Double.java (TYPE): Likewise. * java/lang/Float.java (TYPE): Likewise. * java/lang/Integer.java (TYPE): Likewise. * java/lang/Long.java (TYPE): Likewise. * java/lang/Short.java (TYPE): Likewise. * java/lang/Void.java (TYPE): Likewise. From-SVN: r46521
516 lines
16 KiB
Java
516 lines
16 KiB
Java
/* java.lang.Float
|
|
Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA.
|
|
|
|
As a special exception, if you link this library with other files to
|
|
produce an executable, this library does not by itself cause the
|
|
resulting executable to be covered by the GNU General Public License.
|
|
This exception does not however invalidate any other reasons why the
|
|
executable file might be covered by the GNU General Public License. */
|
|
|
|
|
|
package java.lang;
|
|
|
|
import gnu.classpath.Configuration;
|
|
|
|
/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
|
|
* "The Java Language Specification", ISBN 0-201-63451-1
|
|
* plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
|
|
* Status: Believed complete and correct.
|
|
*/
|
|
|
|
/**
|
|
* Instances of class <code>Float</code> represent primitive
|
|
* <code>float</code> values.
|
|
*
|
|
* Additionally, this class provides various helper functions and variables
|
|
* related to floats.
|
|
*
|
|
* @author Paul Fisher
|
|
* @author Andrew Haley <aph@cygnus.com>
|
|
* @since JDK 1.0
|
|
*/
|
|
public final class Float extends Number implements Comparable
|
|
{
|
|
/**
|
|
* The maximum positive value a <code>double</code> may represent
|
|
* is 3.4028235e+38f.
|
|
*/
|
|
public static final float MAX_VALUE = 3.4028235e+38f;
|
|
|
|
/**
|
|
* The minimum positive value a <code>float</code> may represent
|
|
* is 1.4e-45.
|
|
*/
|
|
public static final float MIN_VALUE = 1.4e-45f;
|
|
|
|
/**
|
|
* The value of a float representation -1.0/0.0, negative infinity.
|
|
*/
|
|
public static final float NEGATIVE_INFINITY = -1.0f/0.0f;
|
|
|
|
/**
|
|
* The value of a float representation 1.0/0.0, positive infinity.
|
|
*/
|
|
public static final float POSITIVE_INFINITY = 1.0f/0.0f;
|
|
|
|
/**
|
|
* All IEEE 754 values of NaN have the same value in Java.
|
|
*/
|
|
public static final float NaN = 0.0f/0.0f;
|
|
|
|
/**
|
|
* The primitive type <code>float</code> is represented by this
|
|
* <code>Class</code> object.
|
|
*/
|
|
public static final Class TYPE = VMClassLoader.getPrimitiveClass('F');
|
|
|
|
/**
|
|
* The immutable value of this Float.
|
|
*/
|
|
private final float value;
|
|
|
|
private static final long serialVersionUID = -2671257302660747028L;
|
|
|
|
static
|
|
{
|
|
if (Configuration.INIT_LOAD_LIBRARY)
|
|
{
|
|
System.loadLibrary ("javalang");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Create a <code>float</code> from the primitive <code>Float</code>
|
|
* specified.
|
|
*
|
|
* @param value the <code>Float</code> argument
|
|
*/
|
|
public Float (float value)
|
|
{
|
|
this.value = value;
|
|
}
|
|
|
|
/**
|
|
* Create a <code>Float</code> from the primitive <code>double</code>
|
|
* specified.
|
|
*
|
|
* @param value the <code>double</code> argument
|
|
*/
|
|
public Float (double value)
|
|
{
|
|
this.value = (float)value;
|
|
}
|
|
|
|
/**
|
|
* Create a <code>Float</code> from the specified <code>String</code>.
|
|
*
|
|
* This method calls <code>Float.parseFloat()</code>.
|
|
*
|
|
* @exception NumberFormatException when the <code>String</code> cannot
|
|
* be parsed into a <code>Float</code>.
|
|
* @param s the <code>String</code> to convert
|
|
* @see #parseFloat(java.lang.String)
|
|
*/
|
|
public Float (String s) throws NumberFormatException
|
|
{
|
|
this.value = parseFloat (s);
|
|
}
|
|
|
|
/**
|
|
* Parse the specified <code>String</code> as a <code>float</code>.
|
|
*
|
|
* The number is really read as <em>n * 10<sup>exponent</sup></em>. The
|
|
* first number is <em>n</em>, and if there is an "<code>E</code>"
|
|
* ("<code>e</code>" is also acceptable), then the integer after that is
|
|
* the exponent.
|
|
* <P>
|
|
* Here are the possible forms the number can take:
|
|
* <BR>
|
|
* <TABLE BORDER=1>
|
|
* <TR><TH>Form</TH><TH>Examples</TH></TR>
|
|
* <TR><TD><CODE>[+-]<number>[.]</CODE></TD><TD>345., -10, 12</TD></TR>
|
|
* <TR><TD><CODE>[+-]<number>.<number></CODE></TD><TD>40.2, 80.00, -12.30</TD></TR>
|
|
* <TR><TD><CODE>[+-]<number>[.]E[+-]<number></CODE></TD><TD>80E12, -12e+7, 4.E-123</TD></TR>
|
|
* <TR><TD><CODE>[+-]<number>.<number>E[+-]<number></CODE></TD><TD>6.02e-22, -40.2E+6, 12.3e9</TD></TR>
|
|
* </TABLE>
|
|
*
|
|
* "<code>[+-]</code>" means either a plus or minus sign may go there, or
|
|
* neither, in which case + is assumed.
|
|
* <BR>
|
|
* "<code>[.]</code>" means a dot may be placed here, but is optional.
|
|
* <BR>
|
|
* "<code><number></code>" means a string of digits (0-9), basically
|
|
* an integer. "<code><number>.<number></code>" is basically
|
|
* a real number, a floating-point value.
|
|
* <P>
|
|
* Remember that a <code>float</code> has a limited range. If the
|
|
* number you specify is greater than <code>Float.MAX_VALUE</code> or less
|
|
* than <code>-Float.MAX_VALUE</code>, it will be set at
|
|
* <code>Float.POSITIVE_INFINITY</code> or
|
|
* <code>Float.NEGATIVE_INFINITY</code>, respectively.
|
|
* <P>
|
|
*
|
|
* Note also that <code>float</code> does not have perfect precision. Many
|
|
* numbers cannot be precisely represented. The number you specify
|
|
* will be rounded to the nearest representable value.
|
|
* <code>Float.MIN_VALUE</code> is the margin of error for <code>float</code>
|
|
* values.
|
|
* <P>
|
|
* If an unexpected character is found in the <code>String</code>, a
|
|
* <code>NumberFormatException</code> will be thrown. Spaces are not
|
|
* allowed and will cause this exception to be thrown.
|
|
*
|
|
* @XXX specify where/how we are not in accord with the spec.
|
|
*
|
|
* @param str the <code>String</code> to convert
|
|
* @return the value of the <code>String</code> as a <code>float</code>.
|
|
* @exception NumberFormatException when the string cannot be parsed to a
|
|
* <code>float</code>.
|
|
* @since JDK 1.2
|
|
* @see #MIN_VALUE
|
|
* @see #MAX_VALUE
|
|
* @see #POSITIVE_INFINITY
|
|
* @see #NEGATIVE_INFINITY
|
|
*/
|
|
public static float parseFloat (String s) throws NumberFormatException
|
|
{
|
|
// The spec says that parseFloat() should work like
|
|
// Double.valueOf(). This is equivalent, in our implementation,
|
|
// but more efficient.
|
|
return (float) Double.parseDouble (s);
|
|
}
|
|
|
|
/**
|
|
* Convert the <code>float</code> value of this <code>Float</code>
|
|
* to a <code>String</code>. This method calls
|
|
* <code>Float.toString(float)</code> to do its dirty work.
|
|
*
|
|
* @return the <code>String</code> representation of this <code>Float</code>.
|
|
* @see #toString(float)
|
|
*/
|
|
public String toString ()
|
|
{
|
|
return toString (value);
|
|
}
|
|
|
|
/**
|
|
* If the <code>Object</code> is not <code>null</code>, is an
|
|
* <code>instanceof</code> <code>Float</code>, and represents
|
|
* the same primitive <code>float</code> value return
|
|
* <code>true</code>. Otherwise <code>false</code> is returned.
|
|
* <p>
|
|
* Note that there are two differences between <code>==</code> and
|
|
* <code>equals()</code>. <code>0.0f == -0.0f</code> returns <code>true</code>
|
|
* but <code>new Float(0.0f).equals(new Float(-0.0f))</code> returns
|
|
* <code>false</code>. And <code>Float.NaN == Float.NaN</code> returns
|
|
* <code>false</code>, but
|
|
* <code>new Float(Float.NaN).equals(new Float(Float.NaN))</code> returns
|
|
* <code>true</code>.
|
|
*
|
|
* @param obj the object to compare to
|
|
* @return whether the objects are semantically equal.
|
|
*/
|
|
public boolean equals (Object obj)
|
|
{
|
|
if (!(obj instanceof Float))
|
|
return false;
|
|
|
|
Float f = (Float) obj;
|
|
|
|
return floatToIntBits (value) == floatToIntBits (f.floatValue ());
|
|
}
|
|
|
|
/**
|
|
* Return a hashcode representing this Object.
|
|
* <code>Float</code>'s hash code is calculated by calling the
|
|
* <code>floatToIntBits()</code> function.
|
|
* @return this Object's hash code.
|
|
* @see java.lang.Float.floatToIntBits(float)
|
|
*/
|
|
public int hashCode ()
|
|
{
|
|
return floatToIntBits (value);
|
|
}
|
|
|
|
/**
|
|
* Return the value of this <code>Double</code> when cast to an
|
|
* <code>int</code>.
|
|
*/
|
|
public int intValue ()
|
|
{
|
|
return (int) value;
|
|
}
|
|
|
|
/**
|
|
* Return the value of this <code>Double</code> when cast to a
|
|
* <code>long</code>.
|
|
*/
|
|
public long longValue ()
|
|
{
|
|
return (long) value;
|
|
}
|
|
|
|
/**
|
|
* Return the value of this <code>Double</code> when cast to a
|
|
* <code>float</code>.
|
|
*/
|
|
public float floatValue ()
|
|
{
|
|
return (float) value;
|
|
}
|
|
|
|
/**
|
|
* Return the primitive <code>double</code> value represented by this
|
|
* <code>Double</code>.
|
|
*/
|
|
public double doubleValue ()
|
|
{
|
|
return (double) value;
|
|
}
|
|
|
|
/**
|
|
* Convert the <code>float</code> to a <code>String</code>.
|
|
* <P>
|
|
*
|
|
* Floating-point string representation is fairly complex: here is a
|
|
* rundown of the possible values. "<CODE>[-]</CODE>" indicates that a
|
|
* negative sign will be printed if the value (or exponent) is negative.
|
|
* "<CODE><number></CODE>" means a string of digits (0-9).
|
|
* "<CODE><digit></CODE>" means a single digit (0-9).
|
|
* <P>
|
|
*
|
|
* <TABLE BORDER=1>
|
|
* <TR><TH>Value of Float</TH><TH>String Representation</TH></TR>
|
|
* <TR>
|
|
* <TD>[+-] 0</TD>
|
|
* <TD>[<CODE>-</CODE>]<CODE>0.0</CODE></TD>
|
|
* </TR>
|
|
* <TR>
|
|
* <TD>Between [+-] 10<SUP>-3</SUP> and 10<SUP>7</SUP></TD>
|
|
* <TD><CODE>[-]number.number</CODE></TD>
|
|
* </TR>
|
|
* <TR>
|
|
* <TD>Other numeric value</TD>
|
|
* <TD><CODE>[-]<digit>.<number>E[-]<number></CODE></TD>
|
|
* </TR>
|
|
* <TR>
|
|
* <TD>[+-] infinity</TD>
|
|
* <TD><CODE>[-]Infinity</CODE></TD>
|
|
* </TR>
|
|
* <TR>
|
|
* <TD>NaN</TD>
|
|
* <TD><CODE>NaN</CODE></TD>
|
|
* </TR>
|
|
* </TABLE>
|
|
*
|
|
* Yes, negative zero <EM>is</EM> a possible value. Note that there is
|
|
* <EM>always</EM> a <CODE>.</CODE> and at least one digit printed after
|
|
* it: even if the number is 3, it will be printed as <CODE>3.0</CODE>.
|
|
* After the ".", all digits will be printed except trailing zeros. No
|
|
* truncation or rounding is done by this function.
|
|
*
|
|
* @XXX specify where we are not in accord with the spec.
|
|
*
|
|
* @param f the <code>float</code> to convert
|
|
* @return the <code>String</code> representing the <code>float</code>.
|
|
*/
|
|
public static String toString (float f)
|
|
{
|
|
return Double.toString ((double) f, true);
|
|
}
|
|
|
|
/**
|
|
* Return the result of calling <code>new Float(java.lang.String)</code>.
|
|
*
|
|
* @param s the <code>String</code> to convert to a <code>Float</code>.
|
|
* @return a new <code>Float</code> representing the <code>String</code>'s
|
|
* numeric value.
|
|
*
|
|
* @exception NumberFormatException thrown if <code>String</code> cannot
|
|
* be parsed as a <code>double</code>.
|
|
* @see #Float(java.lang.String)
|
|
* @see #parseFloat(java.lang.String)
|
|
*/
|
|
public static Float valueOf (String s) throws NumberFormatException
|
|
{
|
|
return new Float (s);
|
|
}
|
|
|
|
/**
|
|
* Return <code>true</code> if the value of this <code>Float</code>
|
|
* is the same as <code>NaN</code>, otherwise return <code>false</code>.
|
|
* @return whether this <code>Float</code> is <code>NaN</code>.
|
|
*/
|
|
public boolean isNaN ()
|
|
{
|
|
return isNaN (value);
|
|
}
|
|
|
|
/**
|
|
* Return <code>true</code> if the <code>float</code> has the same
|
|
* value as <code>NaN</code>, otherwise return <code>false</code>.
|
|
*
|
|
* @param v the <code>float</code> to compare
|
|
* @return whether the argument is <code>NaN</code>.
|
|
*/
|
|
public static boolean isNaN (float v)
|
|
{
|
|
// This works since NaN != NaN is the only reflexive inequality
|
|
// comparison which returns true.
|
|
return v != v;
|
|
}
|
|
|
|
/**
|
|
* Return <code>true</code> if the value of this <code>Float</code>
|
|
* is the same as <code>NEGATIVE_INFINITY</code> or
|
|
* <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>.
|
|
*
|
|
* @return whether this <code>Float</code> is (-/+) infinity.
|
|
*/
|
|
public boolean isInfinite ()
|
|
{
|
|
return isInfinite (value);
|
|
}
|
|
|
|
/**
|
|
* Return <code>true</code> if the <code>float</code> has a value
|
|
* equal to either <code>NEGATIVE_INFINITY</code> or
|
|
* <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>.
|
|
*
|
|
* @param v the <code>float</code> to compare
|
|
* @return whether the argument is (-/+) infinity.
|
|
*/
|
|
public static boolean isInfinite (float v)
|
|
{
|
|
return (v == POSITIVE_INFINITY || v == NEGATIVE_INFINITY);
|
|
}
|
|
|
|
/**
|
|
* Return the int bits of the specified <code>float</code>.
|
|
* The result of this function can be used as the argument to
|
|
* <code>Float.intBitsToFloat(long)</code> to obtain the
|
|
* original <code>float</code> value.
|
|
*
|
|
* @param value the <code>float</code> to convert
|
|
* @return the bits of the <code>float</code>.
|
|
*/
|
|
public static native int floatToIntBits (float value);
|
|
|
|
/**
|
|
* Return the int bits of the specified <code>float</code>.
|
|
* The result of this function can be used as the argument to
|
|
* <code>Float.intBitsToFloat(long)</code> to obtain the
|
|
* original <code>float</code> value. The difference between
|
|
* this function and <code>floatToIntBits</code> is that this
|
|
* function does not collapse NaN values.
|
|
*
|
|
* @param value the <code>float</code> to convert
|
|
* @return the bits of the <code>float</code>.
|
|
*/
|
|
public static native int floatToRawIntBits (float value);
|
|
|
|
/**
|
|
* Return the <code>float</code> represented by the long
|
|
* bits specified.
|
|
*
|
|
* @param bits the long bits representing a <code>double</code>
|
|
* @return the <code>float</code> represented by the bits.
|
|
*/
|
|
public static native float intBitsToFloat (int bits);
|
|
|
|
/**
|
|
* Returns 0 if the <code>float</code> value of the argument is
|
|
* equal to the value of this <code>Float</code>. Returns a number
|
|
* less than zero if the value of this <code>Float</code> is less
|
|
* than the <code>Float</code> value of the argument, and returns a
|
|
* number greater than zero if the value of this <code>Float</code>
|
|
* is greater than the <code>float</code> value of the argument.
|
|
* <br>
|
|
* <code>Float.NaN</code> is greater than any number other than itself,
|
|
* even <code>Float.POSITIVE_INFINITY</code>.
|
|
* <br>
|
|
* <code>0.0</code> is greater than <code>-0.0</code>.
|
|
*
|
|
* @param f the Float to compare to.
|
|
* @return 0 if the <code>Float</code>s are the same, < 0 if this
|
|
* <code>Float</code> is less than the <code>Float</code> in
|
|
* in question, or > 0 if it is greater.
|
|
*
|
|
* @since 1.2
|
|
*/
|
|
public int compareTo (Float f)
|
|
{
|
|
return compare (value, f.value);
|
|
}
|
|
|
|
/**
|
|
* Returns 0 if the first argument is equal to the second argument.
|
|
* Returns a number less than zero if the first argument is less than the
|
|
* second argument, and returns a number greater than zero if the first
|
|
* argument is greater than the second argument.
|
|
* <br>
|
|
* <code>Float.NaN</code> is greater than any number other than itself,
|
|
* even <code>Float.POSITIVE_INFINITY</code>.
|
|
* <br>
|
|
* <code>0.0</code> is greater than <code>-0.0</code>.
|
|
*
|
|
* @param x the first float to compare.
|
|
* @param y the second float to compare.
|
|
* @return 0 if the arguments are the same, < 0 if the
|
|
* first argument is less than the second argument in
|
|
* in question, or > 0 if it is greater.
|
|
* @since 1.4
|
|
*/
|
|
public static int compare (float x, float y)
|
|
{
|
|
if (isNaN (x))
|
|
return isNaN (y) ? 0 : 1;
|
|
if (isNaN (y))
|
|
return -1;
|
|
if (x == 0.0 && y == -0.0)
|
|
return 1;
|
|
if (x == -0.0 && y == 0.0)
|
|
return -1;
|
|
if (x == y)
|
|
return 0;
|
|
|
|
return x > y ? 1 : -1;
|
|
}
|
|
|
|
/**
|
|
* Compares the specified <code>Object</code> to this <code>Float</code>
|
|
* if and only if the <code>Object</code> is an instanceof
|
|
* <code>Float</code>.
|
|
* Otherwise it throws a <code>ClassCastException</code>
|
|
*
|
|
* @param o the Object to compare to.
|
|
* @return 0 if the <code>Float</code>s are the same, < 0 if this
|
|
* <code>Float</code> is less than the <code>Float</code> in
|
|
* in question, or > 0 if it is greater.
|
|
* @throws ClassCastException if the argument is not a <code>Float</code>
|
|
*
|
|
* @since 1.2
|
|
*/
|
|
public int compareTo (Object o)
|
|
{
|
|
return compareTo ((Float) o);
|
|
}
|
|
}
|