/*
 * The contents of this file are subject to the Netscape 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/NPL/
 *
 * 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 Netscape are
 * Copyright (C) 1997-1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s):
 * Norris Boyd
 * Roger Lawrence
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU Public License (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 NPL, indicate your decision by
 * deleting the provisions above and replace 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 NPL or the GPL.
 */



package org.mozilla.javascript.optimizer;

class DataFlowBitSet {

    private int itsBits[];
    int itsSize;

    DataFlowBitSet(int size)
    {
        itsSize = size;
        itsBits = new int[(size >> 5) + 1];
    }

    int size()
    {
        return itsSize;
    }

    void set(int n)
    {
        if ((n < 0) || (n >= itsSize))
                  throw new RuntimeException("DataFlowBitSet bad index " + n);
        itsBits[n >> 5] |= 1 << (n & 31);
    }

    boolean test(int n)
    {
        if ((n < 0) || (n >= itsSize))
                  throw new RuntimeException("DataFlowBitSet bad index " + 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 ((n < 0) || (n >= itsSize))
                  throw new RuntimeException("DataFlowBitSet bad index " + 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];
    }

    public String toString()
    {
        StringBuffer result = new StringBuffer();
        result.append("DataFlowBitSet, size = " + itsSize + "\n");
        for (int i = 0; i < itsBits.length; i++)
            result.append(Integer.toHexString(itsBits[i]) + " ");
        return result.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;
    }
}

@@ -1546,24 +1546,32 @@
 Bits%5B%5D;%0A    
+private 
 int itsSize;
@@ -1667,17 +1667,18 @@
 ize 
-%3E%3E 5) + 1
++ 31) %3E%3E 5
 %5D;%0A 
@@ -1777,110 +1777,43 @@
 if (
-(n %3C 0) %7C%7C (n %3E= itsSize))%0A                  throw new RuntimeException(%22DataFlowBitSet
+!(0 %3C= n && n %3C itsSize))
  bad
- i
+I
 ndex
- %22 + 
+(
 n);%0A
@@ -1907,110 +1907,43 @@
 if (
-(n %3C 0) %7C%7C (n %3E= itsSize))%0A                  throw new RuntimeException(%22DataFlowBitSet
+!(0 %3C= n && n %3C itsSize))
  bad
- i
+I
 ndex
- %22 + 
+(
 n);%0A
@@ -2204,110 +2204,43 @@
 if (
-(n %3C 0) %7C%7C (n %3E= itsSize))%0A                  throw new RuntimeException(%22DataFlowBitSet
+!(0 %3C= n && n %3C itsSize))
  bad
- i
+I
 ndex
- %22 + 
+(
 n);%0A
@@ -2660,22 +2660,18 @@
 gBuffer 
-result
+sb
  = new S
@@ -2685,38 +2685,34 @@
 ffer();%0A        
-result
+sb
 .append(%22DataFlo
@@ -2732,28 +2732,105 @@
  = %22
- + itsSize + %22%5Cn%22
+);%0A        sb.append(itsSize);%0A        sb.append('%5Cn'
 );%0A
+        int bitsLength = itsBits.length;%0A
     
@@ -2853,25 +2853,21 @@
  0; i %3C 
+b
 its
-Bits.l
+L
 ength; i
@@ -2861,32 +2861,34 @@
 bitsLength; i++)
+ %7B
 %0A            res
@@ -2884,22 +2884,18 @@
         
-result
+sb
 .append(
@@ -2929,16 +2929,48 @@
 %5Bi%5D)
- + %22 %22);
+);%0A            sb.append(' ');%0A        %7D
 %0A   
@@ -2985,14 +2985,10 @@
 urn 
-result
+sb
 .toS
@@ -3826,11 +3826,126 @@
 d;%0A    %7D
+%0A%0A    private void badIndex(int n)%0A    %7B%0A        throw new RuntimeException(%22DataFlowBitSet bad index %22 + n);%0A    %7D
 %0A%7D%0A

Use (size + 31) >> 5, not (size >> 5) + 1 as a size for int array buffer so in the case when size % 32 == 0 array would not hold a never used tail element.