Initial revision

From-SVN: r102075

libjava/classpath/vm/reference/java/lang/VMFloat.java

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+/* VMFloat.java -- VM Specific Float methods
+   Copyright (C) 2003 Free Software Foundation
+
+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., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package java.lang;
+
+import gnu.classpath.Configuration;
+
+/*
+ * This class is a reference version, mainly for compiling a class library
+ * jar.  It is likely that VM implementers replace this with their own
+ * version that can communicate effectively with the VM.
+ */
+
+/**
+ * Code relocated from java.lang.Float by 
+ * @author Dave Grove <groved@us.ibm.com>
+ */
+final class VMFloat
+{
+
+  /**
+   * Load native routines necessary for this class.
+   */
+  static
+  {
+    if (Configuration.INIT_LOAD_LIBRARY)
+      {
+        System.loadLibrary("javalang");
+      }
+  }
+
+  /**
+   * Convert the float to the IEEE 754 floating-point "single format" bit
+   * layout. Bit 31 (the most significant) is the sign bit, bits 30-23
+   * (masked by 0x7f800000) represent the exponent, and bits 22-0
+   * (masked by 0x007fffff) are the mantissa. This function collapses all
+   * versions of NaN to 0x7fc00000. The result of this function can be used
+   * as the argument to <code>Float.intBitsToFloat(int)</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>
+   * @see #intBitsToFloat(int)
+   */
+  static native int floatToIntBits(float value);
+
+  /**
+   * Convert the float to the IEEE 754 floating-point "single format" bit
+   * layout. Bit 31 (the most significant) is the sign bit, bits 30-23
+   * (masked by 0x7f800000) represent the exponent, and bits 22-0
+   * (masked by 0x007fffff) are the mantissa. This function leaves NaN alone,
+   * rather than collapsing to a canonical value. The result of this function
+   * can be used as the argument to <code>Float.intBitsToFloat(int)</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>
+   * @see #intBitsToFloat(int)
+   */
+  static native int floatToRawIntBits(float value);
+
+  /**
+   * Convert the argument in IEEE 754 floating-point "single format" bit
+   * layout to the corresponding float. Bit 31 (the most significant) is the
+   * sign bit, bits 30-23 (masked by 0x7f800000) represent the exponent, and
+   * bits 22-0 (masked by 0x007fffff) are the mantissa. This function leaves
+   * NaN alone, so that you can recover the bit pattern with
+   * <code>Float.floatToRawIntBits(float)</code>.
+   *
+   * @param bits the bits to convert
+   * @return the <code>float</code> represented by the bits
+   * @see #floatToIntBits(float)
+   * @see #floatToRawIntBits(float)
+   */
+  static native float intBitsToFloat(int bits);
+
+} // class VMFloat