[PATCH, rtl-optimization]: Fix post-reload compare elimination pre-pass

Richard Henderson rth@redhat.com
Sat Feb 11 22:51:00 GMT 2012


On 02/11/2012 07:09 AM, Uros Bizjak wrote:
> On Sat, Feb 11, 2012 at 1:26 AM, Richard Henderson <rth@redhat.com> wrote:
>> On 02/09/2012 03:47 PM, Uros Bizjak wrote:
>>> 2012-02-10  Uros Bizjak  <ubizjak@gmail.com>
>>>
>>>       * compare-elim.c (find_comparisons_in_bb): Eliminate only compares
>>>       having mode compatible with the mode of previous compare.  Substitute
>>>       compare mode of previous compare with the mode, compatible
>>>       with eliminated and previous compare.
>>
>> This patch is ok for 4.8.
> 
> Unfortunately, we need to update all uses of flag register with a new,
> compatible mode, as well, similar to how compatible mode is handled in
> CSE2 pass with cse_condition_code_reg in cse.c

We do?  What subsequent pass really cares?
What goes wrong leaving things as they are?


r~



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