On Oct 12, 2009, at 2:27 AM, Chris Lattner wrote:
> On Oct 10, 2009, at 7:48 AM, Jakub Staszak wrote:
>
>> This patch fixes pr3707.
>
> Can you explain a little more what this does? What is the intuition
> behind disabling this optimization?
Oh, this patch is crap :( Sorry for this.
The problem is that we lack of optimization for case like:
loopto:
%timeout.0 = phi i32 [ 2000, %loopto ], [ %timeout.0.ph,
%loopto.outer ]
Then something like "%reg<def> = MOV 2000" is inserted into
loopto
block and executed every time. I haven't found any optimization which
can handle this and move instruction into some outer block.
--
Jakub Staszak