From nobody Thu Aug 29 19:46:45 2024 X-Original-To: numerics@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4WvsH91Jxpz52VvW for ; Thu, 29 Aug 2024 19:46:45 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4WvsH90Bx4z4CbJ for ; Thu, 29 Aug 2024 19:46:45 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1724960805; a=rsa-sha256; cv=none; b=epq7BWYn1GE6lC7Rj9YGFsKkPjym7AWLitT00YVvT3RfxWXeZ8QgETEvE+Cilg7AUvFION eenuq9NxMkex5Wr3rHnCvDwzXeWMDEwVtGgXA9L544sKTceCG34wPdzujTj4nvrBz+FUH7 3AM4Vux0rCCFe7jBTCBYTzD3XMiSzEfBJldE713JgH21EXVoNQlJCiHBnqUllKgW32/wN5 RySDof8G5C54sJoQoxoDz/nwEomLTbtWY2nReH1jUUJO4wvxadQUHZcMnArIGeU0VYEpWu waBO1khPyY0mKaesLJJ1VH1C5AwDN2wEIoEzWgCjCmdqtomv8FsExtGoxUWAlA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1724960805; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JPOUJHr1NTbW6RcqydEbUq2Qz/R04hkHY8KQJbrJuao=; b=kgMwT1yH5R1R1GMgT1R/+L24mrTkXQ9wj0lAt7eGwsrKH/CIlZw7saVj97tc44KqBI0CUv OCaeAXiR5UPiN3k3K7WPl1Ll0RXJ5hZiYGQZ4yDFd4riCtox+nZHFTGz6zF45VaOQBMhUf 67FH8vTgFtmLngKVlPy7UcEbsk592Jpci+WHqMnZxRLXHOYTH4c1YsS07ByngylTw19iDp FRtz3EKH6VZMOpXqldb4oj9mTIQKBtVNEY5k0Vybt11orVS1lwDYwlLFPhIkR0ayTtzWFR vZYbGqYr+p/pMgU+W0KXa24nIR0BZ9JB/RxfYwGY68pKIM2LAMMhtIkNLrK2vQ== Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4WvsH86pHSzWct for ; Thu, 29 Aug 2024 19:46:44 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 47TJkiMD080617 for ; Thu, 29 Aug 2024 19:46:44 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from bugzilla@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 47TJkilg080616 for numerics@FreeBSD.org; Thu, 29 Aug 2024 19:46:44 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: bugzilla set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: numerics@FreeBSD.org Subject: [Bug 281001] Improve accuracy of asinf(x) and acosf(x) Date: Thu, 29 Aug 2024 19:46:45 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: commit-hook@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: numerics@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Discussions of high quality implementation of libm functions List-Archive: https://lists.freebsd.org/archives/freebsd-numerics List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-numerics@FreeBSD.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D281001 --- Comment #3 from commit-hook@FreeBSD.org --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=3D41e016289f77deb88b0ef1ec3f7b2ab35= 15ac7c8 commit 41e016289f77deb88b0ef1ec3f7b2ab3515ac7c8 Author: Steve Kargl AuthorDate: 2024-08-29 19:44:48 +0000 Commit: Dimitry Andric CommitDate: 2024-08-29 19:44:48 +0000 Improve accuracy of asinf(3) and acosf(3) This uses a better rational approximation to improve the accuracy of both functions. For exhaustive testing of asinf(3) in the interval, the current libm gives: % ./tlibm asin -fPED -x 0x1p-12f -X 1 Interval tested for asinf: [0.000244141,1] ulp <=3D 0.5: 97.916% 98564994 | 97.916% 98564994 0.5 < ulp < 0.6: 2.038% 2051023 | 99.953% 100616017 0.6 < ulp < 0.7: 0.047% 47254 | 100.000% 100663271 0.7 < ulp < 0.8: 0.000% 25 | 100.000% 100663296 Max ulp: 0.729891 at 5.00732839e-01 which isn't too bad given that much of the computation is actually done in double floating point. With the new rational approximation, exhaustive testing yields: % ./tlibm asin -fPED -x 0x1p-12f -X 1 Interval tested for asinf: [0.000244141,1] ulp <=3D 0.5: 99.711% 100372643 | 99.711% 100372643 0.5 < ulp < 0.6: 0.288% 290357 | 100.000% 100663000 0.6 < ulp < 0.7: 0.000% 296 | 100.000% 100663296 Max ulp: 0.636344 at 5.09706438e-01 Similarly, for exhaustive testing of asinf(3) in the interval, the current libm gives: % ./tlibm acos -fPED -x -1 -X -0x1p-12f Interval tested for acosf: [-1,-0.000244141] ulp <=3D 0.5: 97.008% 97651921 | 97.008% 97651921 0.5 < ulp < 0.6: 2.441% 2457242 | 99.450% 100109163 0.6 < ulp < 0.7: 0.472% 475503 | 99.922% 100584666 0.7 < ulp < 0.8: 0.071% 71309 | 99.993% 100655975 0.8 < ulp < 0.9: 0.007% 7319 | 100.000% 100663294 0.9 < ulp < 1.0: 0.000% 2 | 100.000% 100663296 Max ulp: 0.914007 at -5.01484931e-01 % ./tlibm acos -fPED -x 0x1p-12f -X 1 Interval tested for acosf: [0.000244141,1] ulp <=3D 0.5: 97.317% 97962530 | 97.317% 97962530 0.5 < ulp < 0.6: 2.340% 2355182 | 99.657% 100317712 0.6 < ulp < 0.7: 0.314% 316134 | 99.971% 100633846 0.7 < ulp < 0.8: 0.029% 29450 | 100.000% 100663296 Max ulp: 0.796035 at 4.99814630e-01 With the new rational approximation, exhaustive testing yields: % ./tlibm acos -fPED -x -1 -X -0x1p-12f Interval tested for acosf: [-1,-0.000244141] ulp <=3D 0.5: 97.010% 97653245 | 97.010% 97653245 0.5 < ulp < 0.6: 2.442% 2458373 | 99.452% 100111618 0.6 < ulp < 0.7: 0.473% 476012 | 99.925% 100587630 0.7 < ulp < 0.8: 0.068% 68603 | 99.993% 100656233 0.8 < ulp < 0.9: 0.007% 7063 | 100.000% 100663296 Max ulp: 0.896189 at -5.04511118e-01 % ./tlibm acos -fPED -x 0x1p-12f -X 1 Interval tested for acosf: [0.000244141,1] ulp <=3D 0.5: 97.650% 98298175 | 97.650% 98298175 0.5 < ulp < 0.6: 2.028% 2041709 | 99.679% 100339884 0.6 < ulp < 0.7: 0.292% 293555 | 99.970% 100633439 0.7 < ulp < 0.8: 0.030% 29857 | 100.000% 100663296 Max ulp: 0.775875 at 4.91849005e-01 PR: 281001 MFC after: 1 week lib/msun/src/e_acosf.c | 20 +++++++++++++------- lib/msun/src/e_asinf.c | 22 ++++++++++++++-------- 2 files changed, 27 insertions(+), 15 deletions(-) --=20 You are receiving this mail because: You are the assignee for the bug.=