From patchwork Fri Apr 1 20:51:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 605016 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qcD7t1p2pz9sCk for ; Sat, 2 Apr 2016 07:51:37 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b=ZWl5dROr; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:subject:message-id:reply-to :mime-version:content-type; q=dns; s=default; b=l0iHFIsMEeC1CHX9 BHnRszcfAAfqQE6dQ2lW54XBAXwXU6chC4xy+mOdG80R1t+0g5feRfQk98tnHwI/ P0OhcNH0KWkG7MSTqvgzq6x/qzZ79goN7M+QbubhU1JrOvcioAzgO5DMHJYRTqzl kclTLYZf9hx2k4ghaO25Zlen0+0= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:subject:message-id:reply-to :mime-version:content-type; s=default; bh=j6ghpiIGHPWFwjhyuZuFll nyjAQ=; b=ZWl5dROrjm9gLwWvmbXewgTWYghAFBHvvl8z3oI1WsvXk5BcSo/YjQ CeExAkRTeeWbNqXJItgXX9mY+vI5j63V/pfV3LnHQp9Mnhf4Ce2TRSMXhHEi7Yq0 YEiqt+aF8SyvPvaBOfX3pH23O/PYKynYljgkAn/roj/ogIEzRNMyg= Received: (qmail 57958 invoked by alias); 1 Apr 2016 20:51:31 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 57938 invoked by uid 89); 1 Apr 2016 20:51:30 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.7 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, NO_DNS_FOR_FROM, RP_MATCHES_RCVD autolearn=no version=3.3.2 spammy=Rep, sk:Fast_Co, sk:fast_co, H*R:D*gmail.com X-HELO: mga11.intel.com X-ExtLoop1: 1 Date: Fri, 1 Apr 2016 13:51:28 -0700 From: "H.J. Lu" To: GNU C Library Subject: [PATCH] Remove Fast_Copy_Backward from Intel Core processors Message-ID: <20160401205128.GA25653@intel.com> Reply-To: "H.J. Lu" MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Intel Core i3, i5 and i7 processors have fast unaligned copy and copy backward is ignored. Remove Fast_Copy_Backward from Intel Core processors to avoid confusion. I will check it in shortly. H.J. --- * sysdeps/x86/cpu-features.c (init_cpu_features): Don't set bit_arch_Fast_Copy_Backward. --- sysdeps/x86/cpu-features.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c index de75c79..963b845 100644 --- a/sysdeps/x86/cpu-features.c +++ b/sysdeps/x86/cpu-features.c @@ -176,11 +176,8 @@ init_cpu_features (struct cpu_features *cpu_features) case 0x2c: case 0x2e: case 0x2f: - /* Rep string instructions, copy backward, unaligned loads + /* Rep string instructions, unaligned load, unaligned copy, and pminub are fast on Intel Core i3, i5 and i7. */ -#if index_arch_Fast_Rep_String != index_arch_Fast_Copy_Backward -# error index_arch_Fast_Rep_String != index_arch_Fast_Copy_Backward -#endif #if index_arch_Fast_Rep_String != index_arch_Fast_Unaligned_Load # error index_arch_Fast_Rep_String != index_arch_Fast_Unaligned_Load #endif @@ -192,7 +189,6 @@ init_cpu_features (struct cpu_features *cpu_features) #endif cpu_features->feature[index_arch_Fast_Rep_String] |= (bit_arch_Fast_Rep_String - | bit_arch_Fast_Copy_Backward | bit_arch_Fast_Unaligned_Load | bit_arch_Fast_Unaligned_Copy | bit_arch_Prefer_PMINUB_for_stringop);