Date: Tue, 11 Sep 2012 08:12:30 -0700 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Tijl Coosemans <tijl@coosemans.org> Cc: toolchain@FreeBSD.org, Dimitry Andric <dim@FreeBSD.org>, current@FreeBSD.org Subject: Re: Clang as default compiler November 4th Message-ID: <20120911151230.GB87526@troutmask.apl.washington.edu> In-Reply-To: <504F4A6B.4010001@coosemans.org> References: <20120910211207.GC64920@lor.one-eyed-alien.net> <20120911104518.GF37286@deviant.kiev.zoral.com.ua> <20120911120649.GA52235@freebsd.org> <20120911132410.GA87126@troutmask.apl.washington.edu> <504F4645.4070900@FreeBSD.org> <504F4A6B.4010001@coosemans.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Sep 11, 2012 at 04:27:55PM +0200, Tijl Coosemans wrote: > On 11-09-2012 16:10, Dimitry Andric wrote: > > On 2012-09-11 15:24, Steve Kargl wrote: > >> What is important is whether software built with clang functions > >> correctly. See for example, > >> > >> http://math-atlas.sourceforge.net/errata.html#WhatComp > > > > Yes, maths support, specifically precision, is admittedly still one of > > clang's (really llvm's) weaker points. It is currently not really a > > high priority item for upstream. > > > > This is obviously something that a certain part of our userbase will > > care a lot about, while most of the time they won't care so much about > > licensing or politics. So those people are probably better off using > > gcc for the time being. > > Does it affect the accuracy of libm functions? > I'm not sure if anyone has done any extensive testing. I've started to run some of my test codes to compare certain functions in a clang-compiled libm, gcc-compiled libm, and reference solutions generated from math/mpfr. For a locally patched j0f, I found that clang gave much worse accuracy. If I revert the local patch, clang and gcc are to give the same results. Unfortnately, an unpatched j0f gives 500000 ULP errors. -- Steve
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120911151230.GB87526>