This is the mail archive of the
mailing list for the GCC project.
Re: What is acceptable for -ffast-math? (Was: associative law incombine)
- To: <dewar at gnat dot com>
- Subject: Re: What is acceptable for -ffast-math? (Was: associative law incombine)
- From: Linus Torvalds <torvalds at transmeta dot com>
- Date: Wed, 1 Aug 2001 10:42:08 -0700 (PDT)
- cc: <Theodore dot Papadopoulo at sophia dot inria dot fr>, <amylaar at redhat dot com>, <aoliva at redhat dot com>, <gcc at gcc dot gnu dot org>, <gdr at codesourcery dot com>, <moshier at moshier dot ne dot mediaone dot net>, <tim at hollebeek dot com>, <tprince at computer dot org>
On Wed, 1 Aug 2001 firstname.lastname@example.org wrote:
> <<The above rules, btw, only apply for exact IEEE math, and on a number of
> machines you _will_ see zero for the first one.
> Hello! it was you who restricted the discussion to the x86. If we are allowed
> to go to other machines, we have lots more examples up our sleeves :-)
Fair enough. But note how I didn't claim that you cannot get a difference
in the ULP. I _do_ claim that it is not "wrong" unless you specifically
ask for IEEE math - by virtue of pointing to lots of other machines that
do the same (including, apparently, the most modern architecture on the
planet. I don't have one, I can't test).