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Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
- From: Florian Weimer <fw at deneb dot enyo dot de>
- To: Andrew Pinski <pinskia at physics dot uc dot edu>
- Cc: gdr at integrable-solutions dot net (Gabriel Dos Reis), pinskia at physics dot uc dot edu dot integrable-solutions dot net (Andrew Pinski), iant at google dot com (Ian Lance Taylor), eggert at CS dot UCLA dot EDU (Paul Eggert), autoconf-patches at gnu dot org, bug-gnulib at gnu dot org, gcc at gcc dot gnu dot org, dnovillo at redhat dot com
- Date: Fri, 29 Dec 2006 22:44:02 +0100
- Subject: Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."
- References: <200612291732.kBTHWNkC024013@localhost.localdomain>
* Andrew Pinski:
>> If what you propose is the only way out, and there is no way to make
>> GCC optimizers reasonable, then I believe Paul's proposal is the next
>> option.
>
> But that still does not address the issue is that this is not just about
> GCC any more since autoconf can be used many different compilers and is right
> now. So if you change autoconf to default to -fwrapv and someone comes alongs
> and tries to use it with say ACC (some made up compiler right now). The loop
> goes into an infinite loop because they treat (like GCC did) signed type overflow
> as undefined, autoconf still becomes an issue.
Does autoconf enable higher optimization levels for other compilers by
default?
(BTW, I would be somewhat disappointed if this had to be pampered over
on the autoconf side. If the GNU project needs -fwrapv for its own
software by default, this should be reflected in the compiler's
defaults. I wish more C programs could be moved towards better
conformance, but this could be unrealistic, especially in the short
term.)