This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] PR 38201: -mfma/-mavx and -msse5/-msse4a don't work together
- From: "Richard Guenther" <richard dot guenther at gmail dot com>
- To: "Ross Ridge" <rridge at csclub dot uwaterloo dot ca>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Wed, 10 Dec 2008 10:53:51 +0100
- Subject: Re: [PATCH] PR 38201: -mfma/-mavx and -msse5/-msse4a don't work together
- References: <20081210023954.32EF273F1D@caffeine.csclub.uwaterloo.ca>
On Wed, Dec 10, 2008 at 3:39 AM, Ross Ridge <rridge@csclub.uwaterloo.ca> wrote:
> H.J. Lu writes:
>>Andrew recommended SSE5 FMA :-). The issue is the one you choose
>>today may not be the one you want tomorrow in which case such a gcc
>>is useless.
>
> I agree with H.J. Lu here, this isn't a choice that should be made
> arbitrarily. The choice should be made by the user. The last thing
> GCC needs is more undocumented behaviour that users unknowingly end up
> depending on.
But in this case the user chooses to let the compile choose. HJs change results
in less choice for the user.
Richard.