From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) by sourceware.org (Postfix) with ESMTPS id 5AE993858D1E for ; Tue, 25 Apr 2023 16:01:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 5AE993858D1E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-lf1-x12f.google.com with SMTP id 2adb3069b0e04-4eff1f7f34bso2610836e87.0 for ; Tue, 25 Apr 2023 09:01:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1682438494; x=1685030494; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=tgS+Ag242nKVMGTf67Rt6SqSQMtvp7zxO7bHnQWkerE=; b=G0wkXt4X8uQRONE6iOdL+j6FmFC3/By/GdX4W+AkuS6c8udbskzycd93FNUfZfzJhs PkPa/zBy4nL4FDcpl2C4XYKjTiiKkwvS8Mq9vZP+Rb+7Km7xa8TXEd2XEQWymGQqXpR3 1MAdYzc24hf58u3HT44zYDZ27fxmr+2yimQ6MPv1qOu0Jns78pzsy8cnyWwZCEtF6UsJ LyJI193snTDma7s4GbKCL2UgEp7TCIGBwCQnAp9V5ybo4HXOdDn32tuqUfr5qGatxo3t HiyaU8PtbLg1BeX68K/Ou/Eti0iKViYTASHavH4AuxG8sJaO0Sa8V30nNhAMPeQ/KEov dRcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682438494; x=1685030494; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tgS+Ag242nKVMGTf67Rt6SqSQMtvp7zxO7bHnQWkerE=; b=Fv0/zcshRFkGKFjbxms8BYS0tx2v3kfiSuW3AtbyGQhQVoYt+FdjBwPljKUSIU+9KK RHfNG4DBNYhgWbORFdSw6h6QPDu9dBB5jqEfSKLsLpyreGu8q5nZWpV2Zp7of/EoOkfR Ob3Ou9VqULreigxK7OFubss4K82CFXnbiOEFbM5CDVxDBk8bBebmXJ9zts77ebRYW8or ZeLRZUVdMoIS0qncuN5iKT6ZZFXdbM/X4+Hs6qyUBtKzYL4DfdUvW5TC1G8fDq+KfP7n W42IN3CEs14i8eZv7vBhQJSdEqQA9vt1mOXcf8yI3WMn2s8+7ItSKAvhzuEyDy4AS83Z 6zAQ== X-Gm-Message-State: AAQBX9eMnu/3lnB31I5eQBCNAq9pd+1+vmWcJc5vJYoE5cA2/49MIB64 pGubvUGo3+DB+Yt+MvaR1vFf864DRI35NYW8IA+KG8KiMFU= X-Google-Smtp-Source: AKy350YAE0vTarTvmfzAGpwFCbsuiIy15B5wxfed4ao0GY9LQQHDpyTfLZlhVZzNLxg0cGLGu7QlBj8HrzXcA21T/nc= X-Received: by 2002:ac2:55a4:0:b0:4ed:bf01:3ff3 with SMTP id y4-20020ac255a4000000b004edbf013ff3mr4206611lfg.43.1682438493610; Tue, 25 Apr 2023 09:01:33 -0700 (PDT) MIME-Version: 1.0 References: <279ab746-8a75-6396-2907-0c893ea1be1b@starynkevitch.net> In-Reply-To: <279ab746-8a75-6396-2907-0c893ea1be1b@starynkevitch.net> From: Andy Date: Tue, 25 Apr 2023 18:01:22 +0200 Message-ID: Subject: Re: a small C (naive) program faster with clang than with gcc To: Basile Starynkevitch Cc: gcc@gcc.gnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=0.5 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE 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: I see it in godbolt GCC compiles to: movsx eax, BYTE PTR [rdi+2] cmp al, 9 ja .L42 Clang: movzx edx, byte ptr [rdi + 2] cmp edx, 9 ja .LBB0_40 GCC extend with sign, Clang with zero. cmp with 32 bit register is apparently faster than 8bit pon., 24 kwi 2023 o 17:34 Basile Starynkevitch napisa=C5=82(a): > > Hello all, > > > Consider the naive program (GPLv3+) to solve the cryptaddition > > `NEUF` + `DEUX` =3D `ONZE` > > onhttps://github.com/bstarynk/misc-basile/blob/master/CryptArithm/neuf%2B= deux%3Donze/naive0.c (commit0d1bd0e > ) > > > On Linux/x86-64 that source code compiled with gcc-12 -O3 is twice as > slower as with clang -O3 > > (Debian/Sid or Ubuntu/22/10) > > Feel free to add it to some testsuite! > > > Thanks > > > -- > Basile Starynkevitch > (only mine opinions / les opinions sont miennes uniquement) > 92340 Bourg-la-Reine, France > web page: starynkevitch.net/Basile/ & refpersys.org