# HG changeset patch
# User igerasim
# Date 1522110614 25200
# Node ID 7f3986bad19716a2080aee1a57ae5bb8d88da48f
# Parent  e9cb414f94ebfde99a0da205ad09f50c928ebb17
8199843: Optimize Integer/Long.highestOneBit()
Reviewed-by: redestad, plevart

diff -r e9cb414f94eb -r 7f3986bad197 src/java.base/share/classes/java/lang/Integer.java
--- a/src/java.base/share/classes/java/lang/Integer.java	Mon Mar 26 16:24:16 2018 -0700
+++ b/src/java.base/share/classes/java/lang/Integer.java	Mon Mar 26 17:30:14 2018 -0700
@@ -1574,13 +1574,7 @@
      * @since 1.5
      */
     public static int highestOneBit(int i) {
-        // HD, Figure 3-1
-        i |= (i >>  1);
-        i |= (i >>  2);
-        i |= (i >>  4);
-        i |= (i >>  8);
-        i |= (i >> 16);
-        return i - (i >>> 1);
+        return i & (MIN_VALUE >>> numberOfLeadingZeros(i));
     }
 
     /**
diff -r e9cb414f94eb -r 7f3986bad197 src/java.base/share/classes/java/lang/Long.java
--- a/src/java.base/share/classes/java/lang/Long.java	Mon Mar 26 16:24:16 2018 -0700
+++ b/src/java.base/share/classes/java/lang/Long.java	Mon Mar 26 17:30:14 2018 -0700
@@ -1719,14 +1719,7 @@
      * @since 1.5
      */
     public static long highestOneBit(long i) {
-        // HD, Figure 3-1
-        i |= (i >>  1);
-        i |= (i >>  2);
-        i |= (i >>  4);
-        i |= (i >>  8);
-        i |= (i >> 16);
-        i |= (i >> 32);
-        return i - (i >>> 1);
+        return i & (MIN_VALUE >>> numberOfLeadingZeros(i));
     }
 
     /**