From 12fe6a6d8fcce42ccfec9e744e3b834aeaf9608b Mon Sep 17 00:00:00 2001
From: Sven Gothel <sgothel@jausoft.com>
Date: Thu, 9 Jan 2014 20:23:35 +0100
Subject: IntBitfield: Fix ctor: min 1 unit; Fix getBitCount(): Use unsigned
right-shift '>>>'
---
src/java/com/jogamp/common/util/IntBitfield.java | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
(limited to 'src/java/com/jogamp/common/util/IntBitfield.java')
diff --git a/src/java/com/jogamp/common/util/IntBitfield.java b/src/java/com/jogamp/common/util/IntBitfield.java
index 07b24dc..2d2f1ef 100644
--- a/src/java/com/jogamp/common/util/IntBitfield.java
+++ b/src/java/com/jogamp/common/util/IntBitfield.java
@@ -51,7 +51,7 @@ public class IntBitfield {
* @param bitCount
*/
public IntBitfield(long bitCount) {
- final int units = (int) ( ( bitCount + 7L ) >> UNIT_SHIFT_L );
+ final int units = (int) Math.max(1L, ( bitCount + 7L ) >>> UNIT_SHIFT_L);
this.storage = new int[units];
this.bitsCountL = (long)units << UNIT_SHIFT_L ;
this.bitsCountI = bitsCountL > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int)bitsCountL;
@@ -61,7 +61,7 @@ public class IntBitfield {
* @param bitCount
*/
public IntBitfield(int bitCount) {
- final int units = ( bitCount + 7 ) >> UNIT_SHIFT_I;
+ final int units = Math.max(1, ( bitCount + 7 ) >>> UNIT_SHIFT_I);
this.storage = new int[units];
this.bitsCountI = units << UNIT_SHIFT_I;
this.bitsCountL = bitsCountI;
@@ -84,7 +84,7 @@ public class IntBitfield {
/** Return <code>true</code> if the bit at position <code>bitnum</code> is set, otherwise <code>false</code>. */
public final boolean get(long bitnum) {
check(bitnum);
- final int u = (int) ( bitnum >> UNIT_SHIFT_L );
+ final int u = (int) ( bitnum >>> UNIT_SHIFT_L );
final int b = (int) ( bitnum - ( (long)u << UNIT_SHIFT_L ) );
return 0 != ( storage[u] & ( 1 << b ) ) ;
}
@@ -92,7 +92,7 @@ public class IntBitfield {
/** Return <code>true</code> if the bit at position <code>bitnum</code> is set, otherwise <code>false</code>. */
public final boolean get(int bitnum) {
check(bitnum);
- final int u = bitnum >> UNIT_SHIFT_I;
+ final int u = bitnum >>> UNIT_SHIFT_I;
final int b = bitnum - ( u << UNIT_SHIFT_I );
return 0 != ( storage[u] & ( 1 << b ) ) ;
}
@@ -103,7 +103,7 @@ public class IntBitfield {
*/
public final boolean put(long bitnum, boolean bit) {
check(bitnum);
- final int u = (int) ( bitnum >> UNIT_SHIFT_L );
+ final int u = (int) ( bitnum >>> UNIT_SHIFT_L );
final int b = (int) ( bitnum - ( (long)u << UNIT_SHIFT_L ) );
final int m = 1 << b;
final boolean prev = 0 != ( storage[u] & m ) ;
@@ -123,7 +123,7 @@ public class IntBitfield {
*/
public final boolean put(int bitnum, boolean bit) {
check(bitnum);
- final int u = bitnum >> UNIT_SHIFT_I;
+ final int u = bitnum >>> UNIT_SHIFT_I;
final int b = bitnum - ( u << UNIT_SHIFT_I );
final int m = 1 << b;
final boolean prev = 0 != ( storage[u] & m ) ;
@@ -146,14 +146,19 @@ public class IntBitfield {
* </pre>
*/
public static final int getBitCount(final int n) {
+ // Note: Original used 'unsigned int',
+ // hence we use the unsigned right-shift '>>>'
int c = n;
- c -= (n >> 1) & 033333333333;
- c -= (n >> 2) & 011111111111;
- return ( (c + ( c >> 3 ) ) & 030707070707 ) % 63;
+ c -= (n >>> 1) & 033333333333;
+ c -= (n >>> 2) & 011111111111;
+ return ( (c + ( c >>> 3 ) ) & 030707070707 ) % 63;
}
/**
* Returns the number of set bits within this bitfield.
+ * <p>
+ * Utilizes {#link {@link #getBitCount(int)}}.
+ * </p>
*/
public long getBitCount() {
long c = 0;
--
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