From patchwork Wed Aug 22 12:29:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wilco Dijkstra X-Patchwork-Id: 960941 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=sourceware.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=libc-alpha-return-95440-incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b="vIHfDF1m"; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=armh.onmicrosoft.com header.i=@armh.onmicrosoft.com header.b="ZKI2M0sM"; dkim-atps=neutral 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 41wRgT5fBsz9s78 for ; Wed, 22 Aug 2018 22:29:25 +1000 (AEST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:cc:subject:date:message-id :content-type:content-transfer-encoding:mime-version; q=dns; s= default; b=YiFXn1F5z583CKmy/YQ0lU2vnXQT+k27vTGEZS/h5/wHkW4QXWYRD 5B/fY+7YpnRQOm+ulMTqG1WExOvu1M7Lhl3ZuZgTro4zPsqyPTiv4k/xTgli+pdj cPH2TnWtADL+7Ie6KGYtfXGxkg3v4MV2qWgfNoMTWsRK7c6UCfCjT4= 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:from:to:cc:subject:date:message-id :content-type:content-transfer-encoding:mime-version; s=default; bh=XykG0dDyob0bZuRL0PuaF2TYEl8=; b=vIHfDF1mDgrhvI5yrUCYLbytPFCc KxfrA6OGQH5QjsNUwE6dp7xtRSQAoCU6wci3ZfC03djsYDis3grw6gPcJ/xm2EdE VSuYEVsyHbLpQS75QLdy6oOmnrYC0XQXOBU/jihJR4Yao+7UjfYuBnLxi+7BLKi3 tmaqz77ciXu6YLk= Received: (qmail 96247 invoked by alias); 22 Aug 2018 12:29:19 -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 95509 invoked by uid 89); 22 Aug 2018 12:29:19 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_HELO_PASS, SPF_PASS autolearn=ham version=3.3.2 spammy=1995, 1.4, quality X-HELO: EUR02-VE1-obe.outbound.protection.outlook.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector1-arm-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=a+JrETItuzKUa+KEYSl1nbcv3LXGyhAHv3gNeU60Ers=; b=ZKI2M0sMuPouYigS45Kao01xH5kox/4RO3lWKOD7JCZLMoTdYWV7TKvxn+u1oyEI0ETz1Igp4b01sdaXg3xy0pkHKETjqzITqsAGrhawrTyUAqhySrZibWOTV2BxJn+7ZRv/ap6i0O72mVjGFgn7WGK+djYTuVVTSZNcpx+AiRg= From: Wilco Dijkstra To: "libc-alpha@sourceware.org" CC: nd Subject: [PATCH] Speedup tanf range reduction Date: Wed, 22 Aug 2018 12:29:12 +0000 Message-ID: authentication-results: spf=none (sender IP is ) smtp.mailfrom=Wilco.Dijkstra@arm.com; received-spf: None (protection.outlook.com: arm.com does not designate permitted sender hosts) MIME-Version: 1.0 Speedup tanf range reduction by using the new sincosf range reduction algorithm. Overall code quality is improved due to inlining, so there is a speedup even if no range reduction is required. Passes GLIBC testsuite on AArch64. Some files are no longer required - they are removed in the next patch. tanf througput gains on Cortex-A72: * |x| < M_PI_4 : 1.1x * |x| < M_PI_2 : 1.2x * |x| < 2 * M_PI: 1.5x * |x| < 120.0 : 1.6x * |x| < Inf : 12.1x ChangeLog: 2018-08-22 Wilco Dijkstra * sysdeps/ieee754/flt-32/s_tanf.c (__tanf): Use fast range reduction. diff --git a/sysdeps/ieee754/flt-32/s_tanf.c b/sysdeps/ieee754/flt-32/s_tanf.c index ba3af54913669e4abdfd864307856ec44138f9b9..a397665c4bab7785049935ef526472afedf82e34 100644 --- a/sysdeps/ieee754/flt-32/s_tanf.c +++ b/sysdeps/ieee754/flt-32/s_tanf.c @@ -21,6 +21,30 @@ static char rcsid[] = "$NetBSD: s_tanf.c,v 1.4 1995/05/10 20:48:20 jtc Exp $"; #include #include #include +#include "s_sincosf.h" + +static inline int32_t +rem_pio2f (float x, float *y) +{ + double dx = x; + int n; + const sincos_t *p = &__sincosf_table[0]; + + if (__glibc_likely (abstop12 (x) < abstop12 (120.0f))) + dx = reduce_fast (dx, p, &n); + else + { + uint32_t xi = asuint (x); + int sign = xi >> 31; + + dx = reduce_large (xi, &n); + dx = sign ? -dx : dx; + } + + y[0] = dx; + y[1] = dx - y[0]; + return n; +} float __tanf(float x) { @@ -42,7 +66,7 @@ float __tanf(float x) /* argument reduction needed */ else { - n = __ieee754_rem_pio2f(x,y); + n = rem_pio2f(x,y); return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even -1 -- n odd */ }