Re: Compiler performance tests on FreeBSD 10.0-CURRENT

On Tue, Sep 4, 2012 at 3:14 PM, Steve Kargl
<sgk_at_troutmask.apl.washington.edu> wrote:
> On Tue, Sep 04, 2012 at 11:59:39PM +0200, Dimitry Andric wrote:
>> On 2012-09-04 23:43, Steve Kargl wrote:
>> >On Tue, Sep 04, 2012 at 10:39:40PM +0200, Dimitry Andric wrote:
>> >>I recently performed a series of compiler performance tests on FreeBSD
>> >>10.0-CURRENT, particularly comparing gcc 4.2.1 and gcc 4.7.1 against
>> >>clang 3.1 and clang 3.2.
>> ...
>> >The benchmark is somewhat meaningless if one does not
>> >know the options that were used during the testing.
>>
>> If you meant the compilation options, those were simply the FreeBSD
>> defaults for all tested programs, e.g. "-O2 -pipe", except for boost,
>> which uses "-ftemplate-depth-128 -O3 -finline-functions".  I will add
>> some explicit notes about them.
>
> Yes, I meant the options specified on the compiler command line.
> 'gcc -O0 -pipe' compiles code faster than 'gcc -O3 -save-temps',
> and the former uses much less memory.

    Steve does have a point. Posting the results of
CFLAGS/CPPFLAGS/LDFLAGS/etc for config.log (and maybe poking through
the code to figure out what *FLAGS were used elsewhere) is more
valuable than the data is in its current state (unfortunately..
autoconf makes things more complicated).
    Maybe we need some micro benchmarks for this (no, I'm not volunteering :P).
Thanks!
-Garrett