[PATCH, combine] Try REG_EQUAL for nonzero_bits

[Jeff Law]

On 04/27/2015 04:26 AM, Thomas Preud'homme wrote:
>> From: Jeff Law [mailto:law@redhat.com]
>> Sent: Saturday, April 25, 2015 3:00 AM
>> Do you have a testcase where this change can result in better generated
>> code.  If so please add that testcase.  It's OK if it's ARM specific.
>
> Hi Jeff,
>
> Last time I tried I couldn't reduce the code to a small testcase but if I remember
> well it was mostly due to the problem of finding a good test for creduce
> (zero extension is not unique enough). I'll try again with a more manual approach
> and get back to you.
OK.  No need for heroics -- give it a shot, but don't burn an insane 
amount of time on it.  If we can't get to a reasonable testcase, then so 
be it.

jeff