From patchwork Thu Mar 16 15:12:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juan Quintela X-Patchwork-Id: 13177777 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 88302C7618E for ; Thu, 16 Mar 2023 15:14:24 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pcpHh-0001bn-7J; Thu, 16 Mar 2023 11:12:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pcpHa-0001XX-Dx for qemu-devel@nongnu.org; Thu, 16 Mar 2023 11:12:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pcpHY-0003KB-CW for qemu-devel@nongnu.org; Thu, 16 Mar 2023 11:12:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678979563; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=j2ZKMZ8E9Z75S0HKJJkGW1ixZ1CA1Gl+IXoT6JvRfxQ=; b=Tpof6Ffrq2cmqpbpdUAwuwrBFVI9lYoO3RgdPX/nqcuGSNZMVxnSV12PkQP5FhRWO9FQXs 83CWJZr83oVPM0kggc05YDjc2PBBzAD/7yYSFxhlOtaqEZqIqWTGL2JCpW8XefsCnYZDP4 5TkrQBoRtYSLOaeYq1FS+52wJuRaKpQ= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-673-c30GZD26MTyec8Rg5CNr2w-1; Thu, 16 Mar 2023 11:12:33 -0400 X-MC-Unique: c30GZD26MTyec8Rg5CNr2w-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A924C3815F7A; Thu, 16 Mar 2023 15:12:30 +0000 (UTC) Received: from secure.mitica (unknown [10.39.195.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id EACF1492B02; Thu, 16 Mar 2023 15:12:29 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: Juan Quintela , "Dr. David Alan Gilbert" , Matheus Tavares Bernardino Subject: [PULL 3/7] migration/xbzrle: use ctz64 to avoid undefined result Date: Thu, 16 Mar 2023 16:12:21 +0100 Message-Id: <20230316151225.11362-4-quintela@redhat.com> In-Reply-To: <20230316151225.11362-1-quintela@redhat.com> References: <20230316151225.11362-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Matheus Tavares Bernardino __builtin_ctzll() produces undefined results when the argument is 0. This can be seen through test-xbzrle, which produces the following warning: ../migration/xbzrle.c:265: runtime error: passing zero to ctz(), which is not a valid argument Replace __builtin_ctzll() with our ctz64() wrapper which properly handles 0. Signed-off-by: Matheus Tavares Bernardino Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- migration/xbzrle.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/migration/xbzrle.c b/migration/xbzrle.c index 05366e86c0..21b92d4eae 100644 --- a/migration/xbzrle.c +++ b/migration/xbzrle.c @@ -12,6 +12,7 @@ */ #include "qemu/osdep.h" #include "qemu/cutils.h" +#include "qemu/host-utils.h" #include "xbzrle.h" /* @@ -233,7 +234,7 @@ int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen, break; } never_same = false; - num = __builtin_ctzll(~comp); + num = ctz64(~comp); num = (num < bytes_to_check) ? num : bytes_to_check; zrun_len += num; bytes_to_check -= num; @@ -262,7 +263,7 @@ int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen, nzrun_len += 64; break; } - num = __builtin_ctzll(comp); + num = ctz64(comp); num = (num < bytes_to_check) ? num : bytes_to_check; nzrun_len += num; bytes_to_check -= num;