From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id EFA793858C33 for ; Thu, 4 Apr 2024 10:40:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org EFA793858C33 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org EFA793858C33 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712227224; cv=none; b=mGX8RefkcMwNdtEBXcZVTIOyQaO/0/aXSoh4ZK3q+0UNvW229/xPCQqeK59hNVWM3nWbG717kdin19ZYj2N71qK9dXtLVnmtcsTJd02wWsDrr/6VaOAMrs+bhXXWIsgi1WhKO3ZsJmWvxRy8SqS+ftjfWmU15U0cT+YqR6tA0m0= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712227224; c=relaxed/simple; bh=oVnWt3eLd0e4o8dCJ5ETWn2dztYEo8PcqPe9N1yDUEs=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=oEn8MNGDZpEBCOOsaWA/ULArmGur6/4rUJWCVQU7E6pQG9CJSXC/1G0DGsD8TkT5ZxaP64mnMOUDHoVENk/fXuS1J8/EuPBa7GO4ImNVzB2G1dMHls8soGtu7ety3bGjE59Q4rhiNlYVQ9RA7NQPTHcZPFTa/UCAvBTzkyF/jWw= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1712227220; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QGtVD6dVahzR+aElc8vDWe5siTyeqcmbvu4j5hFxW2Y=; b=YnZY7TLtcqEsllHaf/nuG87qZGIbOOH45yKHrynZB7oTi7zU0mo0M6bwnYfoXbdj0VF7NJ t9qeGL8c64NjLXLcF1XAC2j+FulMrb1eNeGrU05Uc6zxWfpg8bNgZWm1XBAa4fXildJfH+ oAfoJQ1o5d1N6BhsXLIuQmlgv8k0NtI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-246-bT_TKzjUOVuiYux8CUWHbQ-1; Thu, 04 Apr 2024 06:40:19 -0400 X-MC-Unique: bT_TKzjUOVuiYux8CUWHbQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E21FD8007A3; Thu, 4 Apr 2024 10:40:18 +0000 (UTC) Received: from x1carbon9g.redhat.com (unknown [10.45.224.102]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4D9291121313; Thu, 4 Apr 2024 10:40:17 +0000 (UTC) From: Arjun Shankar To: libc-stable@sourceware.org Cc: Arjun Shankar , Adhemerval Zanella , "H . J . Lu" Subject: [COMMITTED 2.39 3/3] x86: Expand the comment on when REP STOSB is used on memset Date: Thu, 4 Apr 2024 12:39:58 +0200 Message-ID: <20240404103958.311687-3-arjun@redhat.com> In-Reply-To: <20240404103958.311687-1-arjun@redhat.com> References: <20240404103958.311687-1-arjun@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true X-Spam-Status: No, score=-11.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: From: Adhemerval Zanella Reviewed-by: H.J. Lu (cherry picked from commit 491e55beab7457ed310a4a47496f4a333c5d1032) --- sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S index 9984c3ca0f..97839a2248 100644 --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S @@ -21,7 +21,9 @@ 2. If size is less than VEC, use integer register stores. 3. If size is from VEC_SIZE to 2 * VEC_SIZE, use 2 VEC stores. 4. If size is from 2 * VEC_SIZE to 4 * VEC_SIZE, use 4 VEC stores. - 5. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with + 5. On machines ERMS feature, if size is greater or equal than + __x86_rep_stosb_threshold then REP STOSB will be used. + 6. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with 4 VEC stores and store 4 * VEC at a time until done. */ #include -- 2.43.0