Use UNSAFE.getLong() to speed up BitSetMethods#anySet()

Author: tedyu

unsafe/src/main/java/org/apache/spark/unsafe/bitset/BitSetMethods.java

@@ -29,6 +29,7 @@
 public final class BitSetMethods {
 
   private static final long WORD_SIZE = 8;
+  private static final int SIZE_OF_LONG = Long.SIZE;
 
   private BitSetMethods() {
     // Make the default constructor private, since this only holds static methods.
@@ -71,7 +72,13 @@ public static boolean isSet(Object baseObject, long baseOffset, int index) {
    * Returns {@code true} if any bit is set.
    */
   public static boolean anySet(Object baseObject, long baseOffset, long bitSetWidthInBytes) {
-    for (int i = 0; i <= bitSetWidthInBytes; i++) {
+    long widthInLong = bitSetWidthInBytes / SIZE_OF_LONG;
+    for (long i = 0; i <= widthInLong; i++) {
+      if (PlatformDependent.UNSAFE.getLong(baseObject, baseOffset + i) != 0) {
+        return true;
+      }
+    }
+    for (long i = SIZE_OF_LONG * widthInLong; i <= bitSetWidthInBytes; i++) {
       if (PlatformDependent.UNSAFE.getByte(baseObject, baseOffset + i) != 0) {
         return true;
       }