--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jaxp/src/com/sun/org/apache/bcel/internal/generic/SWITCH.java Thu Apr 12 08:38:26 2012 -0700
@@ -0,0 +1,186 @@
+/*
+ * reserved comment block
+ * DO NOT REMOVE OR ALTER!
+ */
+package com.sun.org.apache.bcel.internal.generic;
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation. All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ * if any, must include the following acknowledgment:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowledgment may appear in the software itself,
+ * if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ * "Apache BCEL" must not be used to endorse or promote products
+ * derived from this software without prior written permission. For
+ * written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ * "Apache BCEL", nor may "Apache" appear in their name, without
+ * prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+/**
+ * SWITCH - Branch depending on int value, generates either LOOKUPSWITCH or
+ * TABLESWITCH instruction, depending on whether the match values (int[]) can be
+ * sorted with no gaps between the numbers.
+ *
+ * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
+ */
+public final class SWITCH implements CompoundInstruction {
+ private int[] match;
+ private InstructionHandle[] targets;
+ private Select instruction;
+ private int match_length;
+
+ /**
+ * Template for switch() constructs. If the match array can be
+ * sorted in ascending order with gaps no larger than max_gap
+ * between the numbers, a TABLESWITCH instruction is generated, and
+ * a LOOKUPSWITCH otherwise. The former may be more efficient, but
+ * needs more space.
+ *
+ * Note, that the key array always will be sorted, though we leave
+ * the original arrays unaltered.
+ *
+ * @param match array of match values (case 2: ... case 7: ..., etc.)
+ * @param targets the instructions to be branched to for each case
+ * @param target the default target
+ * @param max_gap maximum gap that may between case branches
+ */
+ public SWITCH(int[] match, InstructionHandle[] targets,
+ InstructionHandle target, int max_gap) {
+ this.match = (int[])match.clone();
+ this.targets = (InstructionHandle[])targets.clone();
+
+ if((match_length = match.length) < 2) // (almost) empty switch, or just default
+ instruction = new TABLESWITCH(match, targets, target);
+ else {
+ sort(0, match_length - 1);
+
+ if(matchIsOrdered(max_gap)) {
+ fillup(max_gap, target);
+
+ instruction = new TABLESWITCH(this.match, this.targets, target);
+ }
+ else
+ instruction = new LOOKUPSWITCH(this.match, this.targets, target);
+ }
+ }
+
+ public SWITCH(int[] match, InstructionHandle[] targets,
+ InstructionHandle target) {
+ this(match, targets, target, 1);
+ }
+
+ private final void fillup(int max_gap, InstructionHandle target) {
+ int max_size = match_length + match_length * max_gap;
+ int[] m_vec = new int[max_size];
+ InstructionHandle[] t_vec = new InstructionHandle[max_size];
+ int count = 1;
+
+ m_vec[0] = match[0];
+ t_vec[0] = targets[0];
+
+ for(int i=1; i < match_length; i++) {
+ int prev = match[i-1];
+ int gap = match[i] - prev;
+
+ for(int j=1; j < gap; j++) {
+ m_vec[count] = prev + j;
+ t_vec[count] = target;
+ count++;
+ }
+
+ m_vec[count] = match[i];
+ t_vec[count] = targets[i];
+ count++;
+ }
+
+ match = new int[count];
+ targets = new InstructionHandle[count];
+
+ System.arraycopy(m_vec, 0, match, 0, count);
+ System.arraycopy(t_vec, 0, targets, 0, count);
+ }
+
+ /**
+ * Sort match and targets array with QuickSort.
+ */
+ private final void sort(int l, int r) {
+ int i = l, j = r;
+ int h, m = match[(l + r) / 2];
+ InstructionHandle h2;
+
+ do {
+ while(match[i] < m) i++;
+ while(m < match[j]) j--;
+
+ if(i <= j) {
+ h=match[i]; match[i]=match[j]; match[j]=h; // Swap elements
+ h2=targets[i]; targets[i]=targets[j]; targets[j]=h2; // Swap instructions, too
+ i++; j--;
+ }
+ } while(i <= j);
+
+ if(l < j) sort(l, j);
+ if(i < r) sort(i, r);
+ }
+
+ /**
+ * @return match is sorted in ascending order with no gap bigger than max_gap?
+ */
+ private final boolean matchIsOrdered(int max_gap) {
+ for(int i=1; i < match_length; i++)
+ if(match[i] - match[i-1] > max_gap)
+ return false;
+
+ return true;
+ }
+
+ public final InstructionList getInstructionList() {
+ return new InstructionList(instruction);
+ }
+
+ public final Instruction getInstruction() {
+ return instruction;
+ }
+}