From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by sourceware.org (Postfix) with ESMTPS id 573453858436 for ; Thu, 2 Sep 2021 15:01:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 573453858436 Received: by mail-pf1-x431.google.com with SMTP id s29so1856855pfw.5 for ; Thu, 02 Sep 2021 08:01:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:from:to:cc:references:in-reply-to :subject:date:mime-version:importance; bh=0CrbgG5E5m5AX97uHUAhSVhCvoxFyD17TrEx6EuuZ3w=; b=Y9zlFFvkeYCLVj1q3/T3Hx1xcBdEcweZearez4+JRFjgtuKOnfVsLaUVeqOnoIeZp4 VcetM1IahxMgQ89cUZT4bKgNPkVYc/TjaUmnDxbJIeaWrPikrOAChkPA0RjW26Odq1ZQ r/JT4FfTVnnTACsJxpXq/bAyrwCc/9P6UWSJL6DfDE2850cG9sJ4wMGLcxKB5lEnyJ+t b03QJQRA8zkSrKUklPQzfaU/AHwsUDNJvvtPpHYCuhzV90KndJKmO/AJjgMq6FAAXqCV b0M9WdRglU7ZRTLMBpf73vyM35vzLNUVklb+tn2QY36Tvrk6vcRS8TJ1uHqPXu4Y+j+3 h2tA== X-Gm-Message-State: AOAM532J/UpVAwcRZZxXHiJ7eFJh8gBy3UTLt7VUJPbxqdffswPLgzdo +HfrudX82++tgJjQqcQ35qbwpXEbFHY= X-Google-Smtp-Source: ABdhPJxgp5hB97RDihI8z6DPvDQ+zds4+WWNqZUVZ7jsaj5+N3foITE4oQeuYN7ievUCRG29x+Ydnw== X-Received: by 2002:a63:5f08:: with SMTP id t8mr3608126pgb.353.1630594901478; Thu, 02 Sep 2021 08:01:41 -0700 (PDT) Received: from DESKTOP0OKG1VA ([202.169.113.201]) by smtp.gmail.com with ESMTPSA id z131sm2663347pfc.159.2021.09.02.08.01.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 Sep 2021 08:01:40 -0700 (PDT) Message-ID: <18CA5177BA304CEAB8464FD24D0DF307@DESKTOP0OKG1VA> From: "Paul Edwards" To: "Ulrich Weigand" Cc: , "Ulrich Weigand" References: <200906051520.n55FKg7T016481@d12av02.megacenter.de.ibm.com> In-Reply-To: Subject: Re: s390 port Date: Fri, 3 Sep 2021 01:01:36 +1000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 16.4.3528.331 X-MimeOLE: Produced By Microsoft MimeOLE V16.4.3528.331 X-Spam-Status: No, score=-1.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, HTML_MESSAGE, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Sep 2021 15:01:52 -0000 Hi Ulrich. I just checked my copy of s390.md and I don=E2=80=99t see LA being used for arithmetic. If your copy of s390.md is using LA for arithmetic then would it be possible to have an option to use a normal mathematics instruction instead of LA? Do you have any more examples besides LA being used for maths instead of a proper maths instruction? Also, I just realized =E2=80=93 if GCC is using LA for maths for 32-bit registers, then values will be limited to 2 GiB instead of 4 GiB for unsigned, but that is not the case. BFN. Paul. From: Ulrich Weigand=20 Sent: Friday, September 3, 2021 12:53 AM To: Paul Edwards=20 Cc: gcc@gcc.gnu.org ; Ulrich Weigand=20 Subject: Re: s390 port "Paul Edwards" wrote on 02.09.2021 16:50:35: > Could you give me an example of an instruction > generated by =E2=80=93m31 that is not expected to work > on an AM64 system? Well, everything related to address computation, of course. For example, GCC may use LA on -m31 to implement a 31-bit addition, while it may use LA on -m64 to implement a 64-bit addition. Bye, Ulrich