[llvm-commits] [PATCH] Restructure a part of SimplifyCFG

[Chris Lattner]

On May 22, 2008, at 9:07 AM, Matthijs Kooijman wrote:

> Hi All,
>
>> The patch looks great to me, if it passes tests, please apply.
> I've pulled the patch through the (nightly) test bench a few times  
> and there were no
> extra failed tests. I also couldn't find any reproducible performance
> degradations in the llc and jit runs.
>
> It does seem that some of the cbe tests suffer some degradation, but  
> I'm not
> sure how important that is. In the particular case I looked at, the  
> code was
> only restructured a little bit, but the removal of a loop preheader  
> resulted
> in a single do { } while(1) structure in the output where there used  
> to be
> two. I guess this throws off gcc's optimizer when recompiling the C  
> code.
>
> I'll do a last full test run tonight (to do one thorough check of llc
> performance) and commit tomorrow morning.

Sounds great.  Don't worry too much about CBE performance.  It can  
depend on all sorts of random things in your host C compiler.  The CBE  
needs to be mostly correct because we use it for bugpoint, but perf  
isn't so important.

Thanks Matthijs!

-Chris