amd64/115581: [patch] -mfancy-math-387 has no effect
numisemis at yahoo.com
Tue Aug 21 08:10:08 PDT 2007
The following reply was made to PR amd64/115581; it has been noted by GNATS.
From: Simun Mikecin <numisemis at yahoo.com>
To: Bruce Evans <brde at optusnet.com.au>
Cc: bug-followup at freebsd.org
Subject: Re: amd64/115581: [patch] -mfancy-math-387 has no effect
Date: Tue, 21 Aug 2007 07:37:41 -0700 (PDT)
--- Bruce Evans <brde at optusnet.com.au> wrote:
> > This PR is about -mfancy-math-387 usage when compiling 32-bit compatibility
> > libraries that are gone be used on FreeBSD/amd64.
> > As far as I can see FreeBSD's libm on i386 uses those fancy instructions (for
> > example /usr/src.current/lib/msun/i387/s_sin.S), so the same libm will be
> > used for running 32-bit apps on FreeBSD/amd64.
> Well, that's in asm so it is not affected by compiler flags. Compiler
> flags can cause the library to be not used at all in some cases where
> the library is better.
I'm just wondering will it have a positive impact on performance if FreeBSD/i386 libm is changed
not to use that asm code with fancy instructions (just like FreeBSD/amd64 does).
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more.
More information about the freebsd-amd64