(Resend with description) Re: Request for review (XS): 6837146 Should perform unswitch before maximally unroll in loop transformation

[Tom Rodriguez]

This seems ok.  Was there an example that motivated this change?

tom

On May 4, 2009, at 3:49 PM, Changpeng Fang wrote:

> http://cr.openjdk.java.net/~cfang/6837146/webrev.00/
>
> Problem Summary:
> The concern is the ordering of maximally unroll and unswitch of a  
> loop in loop transformation.
> Current implementation is that maximally unroll is performed before  
> loop unswitch. The problem
> is if a loop is maximally unrolled (fully unrolled), it will never  
> be unswitched. This will leave
> many conditional statements (blocks) in the code which should not  
> appear if the loop can be
> unswitched.
>
> Proposed Solution:
> Change the ordering of unswitch and maximally_unroll in loop  
> transformation. After unswitch,
> the loop should still be able to be maximally unrolled.
>
> Thanks,
>
> Changpeng
>
>
>
> On 05/04/09 15:05, Changpeng Fang wrote:
>> http://cr.openjdk.java.net/~cfang/6837146/webrev.00/
>>
>> Summary: Change the ordering of do_unswitch and do_maximally_unroll  
>> in loop transformation.
>>
>> Thanks,
>>
>> Changpeng
>>
>