This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: PowerPC suboptimal "add with carry" optimization
On 26 April 2010 14:21, Joakim Tjernlund <joakim.tjernlund@transmode.se> wrote:
> Manuel López-Ibáñez <lopezibanez@gmail.com> wrote on 2010/04/26 13:59:04:
>> On 26 April 2010 09:13, Joakim Tjernlund <joakim.tjernlund@transmode.se> wrote:
>> > Ian Lance Taylor <iant@google.com> wrote on 2010/04/25 20:07:03:
>> >> Joakim Tjernlund <joakim.tjernlund@transmode.se> writes:
>> >>
>> >> > Noticed that gcc 4.3.4 doesn't optimize "add with carry" properly:
>> >>
>> >> Please file a missed-optimization report according to
>> >> http://gcc.gnu.org/bugs/ . ?Thanks.
>> >
>> > I rather not, going through all that just for one odd report. I was hoping
>> > an interested part would pick it up from my email.
>>
>> What is to be done besides what you have done here but in a more
>> useful, structured manner? I am asking because we want to make things
>> simple but not simpler than they become more complex for us.
>
> Lots of stuff to read on that page, lots of info to supply,
> registering an account, specify all that system info and so on.
>
I don't think it will take you much more than 15 minutes.
>> Aren't you interested in someone fixing the bug?
>
> Sure or better yet, show me some way to restructure the C code so proper
> asm code is generated.
This would perhaps help you now but not a future you, not anyone else
in the world. (On the other hand, I don't have a workaround, sorry).
Cheers,
Manuel.