#11084: Singular 3-1-1-4.p6 fails to build with gcc 4.6.0.
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Reporter: drkirkby
| Owner: GeorgSWeber
Type: defect
| Status: needs_review
Priority: blocker
| Milestone: sage-4.7.1
Component: build
| Keywords:
Author: David Kirkby
| Upstream: None of the above - read trac for reasoning.
Reviewer: AlexanderDreyer
| Merged:
Work_issues: Testing on Linux, OS X, Solaris 10 (both x86 and SPARC) with gcc
4.6.0 |
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Comment(by jdemeyer):
Replying to [comment:34 drkirkby]:
> Replying to [comment:23 jdemeyer]:
> > David, would you agree with the compromise to weaken your wording
about the `-O3` issue? I.e. replace "Please do not push the optimisation
to -O3. This has caused too many problems." by something along the lines
of "Currently, building Singular with -O3 fails using gcc 4.6.0.
Therefore, we compile using -O2."
>
> I will make it less strong, but I feel it needs to be a bit stronger
than just mention gcc 4.6.0.
>
> How about
>
> ''The original Singular source code builds part of Singular with -O2 and
part with -O3. On several occasions Sage has forced the optimisation of
the complete package to -O3, but this has caused various problems (tickets
x, y, and x) either with specific compilers or on specific platforms. If
you feel tempted to increase the optimiation to -O3, ask on the Singular
mailing ([email protected]) list for advice and discuss in on sage-
devel first. Also note that -O3 can be slower than -O2 in some
instances.''
>
> Does that seem reasonable?
It's not unreasonable, but a lot of fuzz about nothing. What do you think
of the following comment from my spkg:
{{{
# By default, parts of Singular are compiled with -O2 and parts
# with -O3. If we do set any CFLAGS, this always overrides the
# default CFLAGS set by upstream. In order to be compatible, we
# set the optimization to -O2.
}}}
I think it's most important to explain '''why''' we use `-O2`. Since
there is a good reason to use `-O2`, of course one should not randomly
increase the `-O` level.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11084#comment:37>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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