From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.10]) by sourceware.org (Postfix) with ESMTPS id 672A8385043E for ; Wed, 11 Nov 2020 00:00:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 672A8385043E Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=whitebox@nefkom.net Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4CW4ct719Dz1rtN6; Wed, 11 Nov 2020 01:00:46 +0100 (CET) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4CW4ct5hQLz1r578; Wed, 11 Nov 2020 01:00:46 +0100 (CET) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id 0kHLTYY220HX; Wed, 11 Nov 2020 01:00:45 +0100 (CET) X-Auth-Info: tVuNb+HxeHAyC2v4CDiHDyo3gtjTxBuzkoBJxdT++PfMkZvKLausckj+tJqY4Vot Received: from igel.home (ppp-46-244-173-48.dynamic.mnet-online.de [46.244.173.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Wed, 11 Nov 2020 01:00:45 +0100 (CET) Received: by igel.home (Postfix, from userid 1000) id 796972C35D5; Wed, 11 Nov 2020 01:00:45 +0100 (CET) From: Andreas Schwab To: "Stefan Kanthak" Cc: "Eric Botcazou" , gcc-patches@gcc.gnu.org Subject: Re: [PATCH] Better __ashlDI3, __ashrDI3 and __lshrDI3 functions, plus fixed __bswapsi2 function References: <116F1589A8244FB494091BCD4E6398AB@H270> <7786108.h9Zq5u0u6d@fomalhaut> <003190C0741B4AF0B73E189026EADC84@H270> X-Yow: The PINK SOCKS were ORIGINALLY from 1952!! But they went to MARS around 1953!! Date: Wed, 11 Nov 2020 01:00:45 +0100 In-Reply-To: <003190C0741B4AF0B73E189026EADC84@H270> (Stefan Kanthak's message of "Tue, 10 Nov 2020 20:44:32 +0100") Message-ID: <87zh3oiwya.fsf@igel.home> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Nov 2020 00:00:50 -0000 On Nov 10 2020, Stefan Kanthak wrote: > Eric Botcazou wrote: > >>> The implementation of the __ashlDI3(), __ashrDI3() and __lshrDI3() functions >>> is rather bad, it yields bad machine code at least on i386 and AMD64. Since >>> GCC knows how to shift integers twice the register size these functions can >>> be written as one-liners. >> >> These functions are precisely meant to be used when GCC cannot do that. > > On which processor(s) is GCC unable to generate code for DWtype shifts? On most 32-bit targets with -Os. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."