I reviewed 8143355 today and my main question is where are range checks?
Thanks,
Vladimir
On 11/25/15 1:53 AM, Paul Sandoz wrote:
Hi,
And this is the review for the Java part:
http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8136924-arrays-mismatch-vectorized-unsafe/webrev/
Which will be updated to add @HotSpotIntrinsicCandidate when JDK-8143355 is
pushed. [1]
The plan is all reviewed changes will be pushed to hs-comp and then we follow
up:
1) adding the intrinsic to other platforms
2) improving C1 (perhaps even the interpreter?) since the intrinsic is a
stub which IIUC makes it easier to plug in.
3) take a swing at consolidating other equal/compare intrinsics, such as
those for char[]/String-based equal/compare
4) adding methods to String such as mismatch method.
I can help by pushing all reviewed patches. I will kick off a JPRT run with all
patches applied.
I did evaluate/test the HotSpot patch (stared at the patch and generated code for
UseAVX < 2, and measured) and reviewed with my limited knowledge of HotSpot.
Paul.
[1]
diff -r 01b49c2960fd src/java.base/share/classes/java/util/ArraysSupport.java
--- a/src/java.base/share/classes/java/util/ArraysSupport.java Tue Nov 17
15:42:53 2015 +0100
+++ b/src/java.base/share/classes/java/util/ArraysSupport.java Tue Nov 17
17:05:09 2015 +0100
@@ -24,7 +24,7 @@
*/
package java.util;
-//import jdk.internal.HotSpotIntrinsicCandidate;
+import jdk.internal.HotSpotIntrinsicCandidate;
import jdk.internal.misc.Unsafe;
class ArraysSupport {
@@ -72,7 +72,7 @@
* If a mismatch is not found the negation of one plus the number of
* remaining pairs of elements to be checked in the tail of the two arrays.
*/
-// @HotSpotIntrinsicCandidate
+ @HotSpotIntrinsicCandidate
static int vectorizedMismatch(Object a, long aOffset,
Object b, long bOffset,
int length,
On 25 Nov 2015, at 01:00, Deshpande, Vivek R <vivek.r.deshpa...@intel.com>
wrote:
Hi all
We would like to contribute a patch from Intel which optimizes
vectorizedMismatch() method in java.util.ArraysSupport.java for X86
architecture using AVX instructions.
The improvement gives more than 2x gain over Unsafe implementation for long
arrays.
The bug is blocked by bug: vectorized support for array equals/compare/mismatch
using Unsafe (https://bugs.openjdk.java.net/browse/JDK-8136924.)
Could you please review and sponsor this patch.
Bug-id:
https://bugs.openjdk.java.net/browse/JDK-8143355
webrev:
http://cr.openjdk.java.net/~mcberg/8143355/webrev.01/
Thanks and regards,
Vivek
