From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by sourceware.org (Postfix) with ESMTPS id 8EF0C3858D39 for ; Wed, 3 Apr 2024 01:57:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 8EF0C3858D39 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 8EF0C3858D39 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::102f ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712109479; cv=none; b=FboF2R1ZnLsekw7+rWtwtfAUbW8TvYNcgZvZne/Fl4+xaGu3TY2QKymFMH73x3TgI8xlEeZjVR0A5jv2+lEI4rfwW7aF0v+z3YXERpNA71pOxsF/IaMI5Rt/Z6q1bbsv2A+6WYHHYC/Pc3wMC6ZOTuChSx++Oe1791TENz2fIXk= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712109479; c=relaxed/simple; bh=GBknkrP+AloMVverUXb4zjIZ4d2uZQmT4NcqVnj/LUE=; h=DKIM-Signature:MIME-Version:From:Date:Message-ID:Subject:To; b=BmahIsW1MKLMvJTy9BNpVzNSXuo0PhIYDQFojB911Fwax7A5xjfbHtfzQiHnpQG5++gqfmdrYGRs8h/6996fnLBpks1Hv0yBeZCwwxr6lxwA7Eua5KcrnPSDKS+oedeJntBO62QQG5HJ4JSF7322WVFFX3piDlvVC+cevDCBTdQ= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-pj1-x102f.google.com with SMTP id 98e67ed59e1d1-2a2601f0562so1006139a91.0 for ; Tue, 02 Apr 2024 18:57:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1712109476; x=1712714276; darn=sourceware.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=tJVKc3+xGGW0PwxtXofVc/WhKQ+lsAr/hWkiK18PKIU=; b=aPmrUyAtrVK0626yjXe9rKIF1OQVLitW/DN8Tvh7xB7psDJEo1DsshxFAB8pLu3AH2 E1c4AWvH8zoA5LO++9suCJYTs+bux/QaKUupDtoW5QjXd9xff6cvvEMC+uTuTnjdKKUW 77vDrqUW/Z/NDo+bwHmNABTHpzTabZPgl1ZcjSvoDg3w+j1ElCVBgUPeNAeYQ5Lzj1IE t0RK/GArdCyjXD3CDo+unsX00Z7kqxLWWx56ztPyfLKlTLYDybEMeaFkkd3tGTE2qg/0 luQC52T70JuyWUYgn6zEqtgrwia1RxJ9v6RzaSrmvvQ9OKQ7V+5BjfS5R3//TRKLOnsG eWVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712109476; x=1712714276; h=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=tJVKc3+xGGW0PwxtXofVc/WhKQ+lsAr/hWkiK18PKIU=; b=eDZTefQA02pPrm27HYYy/29YHmygKXuCjncNjlaHXP92Df0B74MqgpQ997cZZzZeVJ D+T6edevhpBb+BKIFUc0W7BOX6m7DMyjxn5fj+cksMcCO1ho8er6/u3MRcVLO/WuZkxc HGr8bKcrRSsBgBeHCZGEqWv8YJeVlY5lkFSgGl2nmed4/CIDfnnOjjdhe7n8KOSZjUOj FHw56gd51Z/2K2BCrjiNr7dbaF7ntMg6q0F9fzgOiF22SKvCSJg6iIDQ2cwP46CSZtQc ap6PBspACEfW9m6B4BWmLOZwr7QO4v3zmQkYeAtUYPUfaKJR09ZPQtX+4yQOZ/t0WJI8 oHmQ== X-Gm-Message-State: AOJu0YxBEXzxLNuWAjqUYNOxLiTBFCl5ie7F1c6RbOhyWXJKwhxvFkbS wJNquK4mWB2zrFkBE98uzPn2vNqPFHj6BuUQ3e0+Tmt48/uZyOeEKGjuFyQEqg1tctOqtMgK576 2eff/HgxRtIF5kpeziznT0Clta58= X-Google-Smtp-Source: AGHT+IHv0nCWIs5Lgdt+37VyADPObwc575UTSka1+8cj4/Roo0ixUVsYd5mOsBZhU3vTJMT+20uZMD3r16M1WUaAp8M= X-Received: by 2002:a17:90b:3842:b0:2a2:c16:d673 with SMTP id nl2-20020a17090b384200b002a20c16d673mr13449898pjb.36.1712109476097; Tue, 02 Apr 2024 18:57:56 -0700 (PDT) MIME-Version: 1.0 References: <2b5dde8f-2d72-4c76-bb93-347eade87a8f@linaro.org> In-Reply-To: <2b5dde8f-2d72-4c76-bb93-347eade87a8f@linaro.org> From: abush wang Date: Wed, 3 Apr 2024 09:57:44 +0800 Message-ID: Subject: Re: [PATCH] stdlib: reorganize stdlib Makefile routines by functionality To: Adhemerval Zanella Netto Cc: abushwang via Libc-alpha , "H.J. Lu" , Florian Weimer Content-Type: multipart/alternative; boundary="00000000000023b7960615278dc2" X-Spam-Status: No, score=-2.0 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=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: --00000000000023b7960615278dc2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I have try to add iteration like this const int num_iterations =3D 100; and I get: Average time for lrand48: 37 cycles there is a huge gap about the order of magnitude of cycles. It seems like the first call for lrand48 do more thing than subsequent calls On Tue, Apr 2, 2024 at 10:16=E2=80=AFPM Adhemerval Zanella Netto < adhemerval.zanella@linaro.org> wrote: > > > On 01/04/24 08:47, abush wang wrote: > > This is test: > > ``` > > uint64_t getnsecs() { > > uint32_t lo, hi; > > __asm__ __volatile__ ( > > "rdtsc" : "=3Da"(lo), "=3Dd"(hi) > > ); > > return ((uint64_t)hi << 32) | lo; > > } > > > > int main() { > > const int num_iterations =3D 1; > > This low number of iteration makes the benchmark pretty much useless > on modern hardware with frequency scaling. By raising to something > like 1000000000 I see no variation on my workstation (Ryzen 5900). > > > uint64_t start, end, total_time =3D 0; > > > > start =3D getnsecs(); > > for (int i =3D 0; i < num_iterations; i++) { > > (void) lrand48(); > > } > > end =3D getnsecs(); > > total_time +=3D (end - start); > > > > printf("Average time for lrand48: %lu cycles\n", total_time / > num_iterations); > > return 0; > > } > > ``` > > before: > > Average time for lrand48: 21418 cycles > > > > after: > > Average time for lrand48: 9892 cycles > --00000000000023b7960615278dc2--