Hi All I have updated the webrev with all the suggestions, which passes ArraysEqCmpTest.java. Earlier webrev failed the same test. This webrev also modifies the BufferMismatch.java in similar way. Please take a look and let me know what you think. Updated webrev is here: http://cr.openjdk.java.net/~vdeshpande/vectorizedMismatch_jdk/webrev.01/ I have also modified the bug with updated webrev. Regards, Vivek From: Deshpande, Vivek R Sent: Tuesday, June 19, 2018 10:57 AM To: Paul Sandoz <paul.sandoz@oracle.com>; Roger.Riggs@oracle.com Cc: David Holmes <david.holmes@oracle.com>; core-libs-dev@openjdk.java.net; Viswanathan, Sandhya <sandhya.viswanathan@intel.com> Subject: RE: RFR(S): 8205194: Improve the Array Comparison when there is a mismatch at first element. Hi Roger I will also test with zero length arrays and let you know. Thanks for the input. Regards, Vivek From: Deshpande, Vivek R Sent: Tuesday, June 19, 2018 10:17 AM To: 'Paul Sandoz' <paul.sandoz@oracle.com<mailto:paul.sandoz@oracle.com>> Cc: David Holmes <david.holmes@oracle.com<mailto:david.holmes@oracle.com>>; core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>; Viswanathan, Sandhya <sandhya.viswanathan@intel.com<mailto:sandhya.viswanathan@intel.com>> Subject: RE: RFR(S): 8205194: Improve the Array Comparison when there is a mismatch at first element. Thanks Paul for quick review. I will work on the things you have mentioned and get back soon. I will also test this with test/jdk/java/util/Arrays/ArraysEqCmpTest.java. Regards, Vivek From: Paul Sandoz [mailto:paul.sandoz@oracle.com] Sent: Tuesday, June 19, 2018 9:55 AM To: Deshpande, Vivek R <vivek.r.deshpande@intel.com<mailto:vivek.r.deshpande@intel.com>> Cc: David Holmes <david.holmes@oracle.com<mailto:david.holmes@oracle.com>>; core-libs-dev@openjdk.java.net<mailto:core-libs-dev@openjdk.java.net>; Viswanathan, Sandhya <sandhya.viswanathan@intel.com<mailto:sandhya.viswanathan@intel.com>> Subject: Re: RFR(S): 8205194: Improve the Array Comparison when there is a mismatch at first element. Hi Vivek, Thanks for investigating this. 164 public static int mismatch(boolean[] a, 165 boolean[] b, 166 int length) { 167 int i = 0; 168 if (a[i] != b[i]) 169 return i; You might as well replace the use if i with 0 and i think you can move this to be performed when the length is greater than the threshold, that way you don’t impact small arrays below the threshold. 186 public static int mismatch(boolean[] a, int aFromIndex, 187 boolean[] b, int bFromIndex, 188 int length) { 189 int i = 0; 190 if (a[i] != b[i]) 191 return i; This is incorrect. You need to use aFromIndex and bFromIndex. Do you run the test test/jdk/java/util/Arrays/ArraysEqCmpTest.java? If that passed then we need to strengthen for the case of a mismatch on the first relative element in each array. Paul. On Jun 19, 2018, at 9:36 AM, Deshpande, Vivek R <vivek.r.deshpande@intel.com<mailto:vivek.r.deshpande@intel.com>> wrote: Thanks David. Sending it to core-libs-dev. I would like to contribute a patch which improves the array comparison when there is a mismatch for the first element. This avoids call to vectorizedMismatch method and gives ~80x speed up. Could you please review and sponsor the patch. Link to bug: https://bugs.openjdk.java.net/browse/JDK-8205194 webrev: http://cr.openjdk.java.net/~vdeshpande/vectorizedMismatch_jdk/webrev.00/ Regards, Vivek -----Original Message----- From: David Holmes [mailto:david.holmes@oracle.com] Sent: Monday, June 18, 2018 10:32 PM To: Deshpande, Vivek R <vivek.r.deshpande@intel.com<mailto:vivek.r.deshpande@intel.com>>; jdk-dev@openjdk.java.net<mailto:jdk-dev@openjdk.java.net> Subject: Re: RFR(S): 8205194: Improve the Array Comparison when there is a mismatch at first element. Hi Vivek, Reviews should take place on the appropriate mailing list for the code being changed, not on the jdk-dev list. Please takes this to core-libs-dev. Thanks, David On 19/06/2018 9:52 AM, Deshpande, Vivek R wrote: Hi All Forgot to add the links: https://bugs.openjdk.java.net/browse/JDK-8205194 webrev: http://cr.openjdk.java.net/~vdeshpande/vectorizedMismatch_jdk/webrev.0 0/ Regards. Vivek From: Deshpande, Vivek R Sent: Monday, June 18, 2018 4:50 PM To: 'jdk-dev@openjdk.java.net' <jdk-dev@openjdk.java.net<mailto:jdk-dev@openjdk.java.net>> Cc: 'Paul Sandoz' <paul.sandoz@oracle.com<mailto:paul.sandoz@oracle.com>>; Viswanathan, Sandhya <sandhya.viswanathan@intel.com<mailto:sandhya.viswanathan@intel.com>> Subject: RFR(S): 8205194: Improve the Array Comparison when there is a mismatch at first element. Hi All I would like to contribute a patch which improves the array comparison when there is a mismatch for the first element. This avoids call to vectorizedMismatch method and gives ~80x speed up. Please review and sponsor the patch. Regards, Vivek