From owner-freebsd-bugs@freebsd.org Wed May 8 16:53:48 2019 Return-Path: <owner-freebsd-bugs@freebsd.org> Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B165E158D61B for <freebsd-bugs@mailman.ysv.freebsd.org>; Wed, 8 May 2019 16:53:48 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 487EA8524C for <freebsd-bugs@freebsd.org>; Wed, 8 May 2019 16:53:48 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 0C31B158D61A; Wed, 8 May 2019 16:53:48 +0000 (UTC) Delivered-To: bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C44CE158D619 for <bugs@mailman.ysv.freebsd.org>; Wed, 8 May 2019 16:53:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 63A048524A for <bugs@FreeBSD.org>; Wed, 8 May 2019 16:53:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id BB4AA980D for <bugs@FreeBSD.org>; Wed, 8 May 2019 16:53:46 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x48GrkYZ047329 for <bugs@FreeBSD.org>; Wed, 8 May 2019 16:53:46 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x48GrkXK047328 for bugs@FreeBSD.org; Wed, 8 May 2019 16:53:46 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 237800] pow(3) returns inaccurate results Date: Wed, 08 May 2019 16:53:46 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: misc X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: khw@cpan.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.mimetype attachments.created Message-ID: <bug-237800-227@https.bugs.freebsd.org/bugzilla/> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports <freebsd-bugs.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-bugs>, <mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs/> List-Post: <mailto:freebsd-bugs@freebsd.org> List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-bugs>, <mailto:freebsd-bugs-request@freebsd.org?subject=subscribe> X-List-Received-Date: Wed, 08 May 2019 16:53:48 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D237800 Bug ID: 237800 Summary: pow(3) returns inaccurate results Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: misc Assignee: bugs@FreeBSD.org Reporter: khw@cpan.org Attachment #204271 text/plain mime type: Created attachment 204271 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D204271&action= =3Dedit Reproducer .c The attached essentially one-liner, program prints 0x1.431e0fae6d722p+96 on FreeBSD 13 clang version 8.0.0 (tags/RELEASE_800/final 356365) (based on LLVM 8.0.0) On Linux, it prints 0x1.431e0fae6d721p+96 a difference of 1 in the final hex digit of the mantissa. The Linux versio= n is the correct value. We are getting identical failures on 11.2, 12.0, and Open BSD 6.4 http://www.cpantesters.org/distro/M/Math-Clipper.html?grade=3D3&perlmat=3D1= &patches=3D2&oncpan=3D2&distmat=3D2&perlver=3DALL&osname=3DALL&version=3D1.= 27 I work on maintaining and extending the Perl 5 programming language. We ma= de a change earlier in our current development cycle that improved the accuracy = of converting a string representing a floating point number into an equivalent double precision C value. We now use strtod() instead of atof(). That bro= ke the module Math::Clipper. It turns out it was relying on the imprecision of atof() to work around this pow() bug. That work around was added in May 20= 18. The above smoke reports rely on a volunteer network of people to do the testing. That means the coverage of a module such as Math::Clipper is spot= ty.=20 Probably it's failing Open BSD in other versions of Perl, but those just di= dn't get tested. --=20 You are receiving this mail because: You are the assignee for the bug.=