Re: [RFC] gcc feature request: Moving blocks into sections

Xinliang David Li
2013-08-05T19:30:53Z

On Mon, Aug 5, 2013 at 12:16 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 2013-08-05 at 12:04 -0700, Andi Kleen wrote:
>> Steven Rostedt <rostedt@goodmis.org> writes:
>>
>> Can't you just use -freorder-blocks-and-partition?
>
> Yeah, I'm familiar with this option.
>

This option works best with FDO. FDOed linux kernel rocks :)

>>
>> This should already partition unlikely blocks into a
>> different section. Just a single one of course.
>>
>> FWIW the disadvantage is that multiple code sections tends
>> to break various older dwarf unwinders, as it needs
>> dwarf3 latest'n'greatest.
>
> If the option was so good, I would expect everyone would be using it ;-)
>

There were lots of problems with this option -- recently cleaned
up/fixed by Teresa in GCC trunk.

thanks,

David

>
> I'm mainly only concerned with the tracepoints. I'm asking to be able to
> do this with just the tracepoint code, and affect nobody else.
>
> -- Steve
>
>