A case that PRE optimization hurts performance

[Václav Zeman]

 On Tue, 2 Aug 2011 10:37:03 +0800, Jiangning Liu wrote:
> Hi,
>
> For the following simple test case, PRE optimization hoists 
> computation
> (s!=1) into the default branch of the switch statement, and finally 
> causes
> very poor code generation. This problem occurs in both X86 and ARM, 
> and I
> believe it is also a problem for other targets.
>
>[...]
>
> Do you have any idea about this?
 Fill a bug report to GCC Bugzilla <http://gcc.gnu.org/bugzilla/>

-- 
 VZ