CaRMtl/org/mozilla/javascript/optimizer/DataFlowBitSet.java

136 lines
3.9 KiB
Java

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Norris Boyd
* Roger Lawrence
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.javascript.optimizer;
class DataFlowBitSet {
private int itsBits[];
private int itsSize;
DataFlowBitSet(int size)
{
itsSize = size;
itsBits = new int[(size + 31) >> 5];
}
void set(int n)
{
if (!(0 <= n && n < itsSize)) badIndex(n);
itsBits[n >> 5] |= 1 << (n & 31);
}
boolean test(int n)
{
if (!(0 <= n && n < itsSize)) badIndex(n);
return ((itsBits[n >> 5] & (1 << (n & 31))) != 0);
}
void not()
{
int bitsLength = itsBits.length;
for (int i = 0; i < bitsLength; i++)
itsBits[i] = ~itsBits[i];
}
void clear(int n)
{
if (!(0 <= n && n < itsSize)) badIndex(n);
itsBits[n >> 5] &= ~(1 << (n & 31));
}
void clear()
{
int bitsLength = itsBits.length;
for (int i = 0; i < bitsLength; i++)
itsBits[i] = 0;
}
void or(DataFlowBitSet b)
{
int bitsLength = itsBits.length;
for (int i = 0; i < bitsLength; i++)
itsBits[i] |= b.itsBits[i];
}
@Override
public String toString()
{
StringBuffer sb = new StringBuffer();
sb.append("DataFlowBitSet, size = ");
sb.append(itsSize);
sb.append('\n');
int bitsLength = itsBits.length;
for (int i = 0; i < bitsLength; i++) {
sb.append(Integer.toHexString(itsBits[i]));
sb.append(' ');
}
return sb.toString();
}
boolean df(DataFlowBitSet in, DataFlowBitSet gen, DataFlowBitSet notKill)
{
int bitsLength = itsBits.length;
boolean changed = false;
for (int i = 0; i < bitsLength; i++) {
int oldBits = itsBits[i];
itsBits[i] = (in.itsBits[i] | gen.itsBits[i]) & notKill.itsBits[i];
changed |= (oldBits != itsBits[i]);
}
return changed;
}
boolean df2(DataFlowBitSet in, DataFlowBitSet gen, DataFlowBitSet notKill)
{
int bitsLength = itsBits.length;
boolean changed = false;
for (int i = 0; i < bitsLength; i++) {
int oldBits = itsBits[i];
itsBits[i] = (in.itsBits[i] & notKill.itsBits[i]) | gen.itsBits[i];
changed |= (oldBits != itsBits[i]);
}
return changed;
}
private void badIndex(int n)
{
throw new RuntimeException("DataFlowBitSet bad index " + n);
}
}