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Re: Where does the time go?
On Thu, May 20, 2010 at 11:21 PM, Xinliang David Li <davidxl@google.com> wrote:
> On Thu, May 20, 2010 at 2:18 PM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
>> On Thu, May 20, 2010 at 11:14 PM, Xinliang David Li <davidxl@google.com> wrote:
>>> stack variable overlay and stack slot assignments is here too.
>>
>> Yes, and for these I would like to add a separate timevar. Agree?
>
> Yes. ?(By the way, we are rewriting this pass to eliminate the code
> motion/aliasing problem -- but that is a different topic).
Btw, we want to address the same problem by representing the
points where (big) variables go out-of scope in the IL, also to
help DSE. The original idea was to simply drop in an aggregate
assignment from an undefined value at the end of the scope
during lowering, like
var = {undefined};
which we'd expand to nothing. Of course shifting the problem to
the RTL optimizers, so better expand to a similar RTL construct.
But then are you addressing the similar problem on the RTL side?
Richard.