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Re: flag_complex_method = 2 in C++?
- From: Mark Mitchell <mark at codesourcery dot com>
- To: Richard Guenther <rguenther at suse dot de>
- Cc: Paolo Carlini <pcarlini at suse dot de>, gcc at gcc dot gnu dot org, Jakub Jelinek <jakub at redhat dot com>, Doug Gregor <dgregor at cs dot indiana dot edu>
- Date: Thu, 05 Jul 2007 10:28:49 -0700
- Subject: Re: flag_complex_method = 2 in C++?
- References: <468D08DF.4050103@suse.de> <Pine.LNX.4.64.0707051712200.24708@zhemvz.fhfr.qr>
Richard Guenther wrote:
>> I'm having a look to libstdc++/30482, which basically is C++ issue: Jakub
>> basically raises the issue of whether we want to use by default the
>> C99-conforming division in C++ too. Personally, I would be in favor of
>> enabling it unconditionally, modulo maybe a performance check (Richard...).
>> Otherwise, we should at least enable it for C++0x, which refers to C99 as C
>> language, of course.
>>
>> What do people think?
>
> Well, I agree to enable this by default.
I'd prefer not to introduce a situation in which compiling the same code
with "gcc" and with "g++" behaves differently and which performs worse
in one case than the other. Users expect the C subset of C++ to perform
like C.
If we want the C99 rules, let's just turn them on everywhere, and then
let users who want "quick and dirty" complex arithmetic to use the flag
that turns that on. And, turn that on by default for -ffast-math?
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713