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Re: [patch, committed] PR48602 Fix optimization issue
- From: Janne Blomqvist <blomqvist dot janne at gmail dot com>
- To: Jerry DeLisle <jvdelisle at frontier dot com>
- Cc: gfortran <fortran at gcc dot gnu dot org>, gcc patches <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 20 Apr 2011 14:09:30 +0300
- Subject: Re: [patch, committed] PR48602 Fix optimization issue
- References: <4DAE6188.80807@frontier.com>
On Wed, Apr 20, 2011 at 07:31, Jerry DeLisle <jvdelisle@frontier.com> wrote:
> Â ÂUse asm volatile to mark temp variable, avoiding optimization errors.
I wonder, would it make sense to compile the entire IO library with
-fexcess-precision=standard in order to avoid further similar issues?
This would keep the code free from tricks like this patch, and not
reduce performance on targets with sane floating point (e.g. x86_64).
That being said, we do so little floating point calculations in the IO
library that I don't think the performance hit either from forcing
this var to memory or from -fexcess-precision=standard would be
noticeable.
I say IO library because for other things like some intrinsic
functions (matmul, ...) we probably don't want to reduce performance
in the name of avoiding excess precision.
--
Janne Blomqvist