Re: [PATCH 6/8] Handle SCRATCH in decompose_address

[Jeff Law <law@redhat.com>]

On 10/22/14 17:01, Maxim Kuvyrkov wrote:
> On Oct 23, 2014, at 9:02 AM, Jeff Law <law@redhat.com> wrote:
>
>> On 10/20/14 21:35, Maxim Kuvyrkov wrote:
>>> Hi,
>>>
>>> This patch is a simple fix to allow decompose_address to handle
>>> SCRATCH'es during 2nd scheduler pass. This patch is a
>>> prerequisite for a scheduler improvement that relies on
>>> decompose_address to parse insns.
>>>
>>> Bootstrapped and regtested on x86_64-linux-gnu and regtested on
>>> arm-linux-gnueabihf and aarch64-linux-gnu.
>> I'd like to see some further discussion here.
>>
>> get_base_term is supposed to look at its argument as a base
>> address. I'm curious under what circumstances you want to have a
>> SCRATCH as a base address?
>>
>> I didn't see anything in patch #8 which obviously dependended on
>> this, but maybe it's in there, but more subtle than expected.
>>
>> If you can justify why it's useful to handle scratch in here, then
>> the patch will be fine.
>
> Without this patch decompose_address() ICEs during second scheduler
> pass on prologue instructions that usually have "(clobber (mem:BLK
> (scratch))".  The only reason for this patch is to prevent that fault
> and enable use of decompose_address during 2nd scheduler pass.
>
> Does this answer your question, or are you looking for a more
> in-depth reason?
Yea, that's everything I needed to know.  Patch approved.

Thanks,
Jeff