Re: [PATCH/MIPS] Use ins/dins instruction when written manually

[Richard Sandiford <rdsandiford at googlemail dot com>]

Hi Andrew,

Andrew Pinski <andrew.pinski@caviumnetworks.com> writes:
> On Fri, Oct 5, 2012 at 8:43 PM, Andrew Pinski
> <andrew.pinski@caviumnetworks.com> wrote:
>> On Sun, Aug 19, 2012 at 10:13 AM, Richard Sandiford
>> <rdsandiford@googlemail.com> wrote:
>>> Andrew Pinski <andrew.pinski@caviumnetworks.com> writes:
>>>>   Right now we only produce ins when a zero_extract is used on the
>>>> right hand side.  We can do better by adding some patterns which
>>>> combine for the ins instruction.  This patch adds those patterns and a
>>>> testcase which shows a simple example where the code is improved.
>>>
>>> Sorry for the delay in reviewing this.  Had you thought about trying to
>>> teach combine.c about this instead?  It doesn't look like any of the
>>> patterns are really providing more information about the underlying
>>> instruction.
>>
>> combine.c has some code to do this already if one of the src register
>> is the same as the dest register; that is what make_field_assignment
>> does.  Quickly looking at the code, the problem I doing it in
>> make_field_assignment is there is no way to return that you need a
>> copy of the value first unless I am missing something obvious.  Now I
>> agree we should be optimize this in combine rather than these manual
>> patterns.
>
> I now have a patch which implements this in combine which allows the
> backend not need to change.  I generate a SEQUENCE which then
> try_combine splits like we do for PARALLEL but keeping it in the
> correct order and allowing for the case where we are combing two
> instructions into two instructions.
> I hope to be able to post it later on Saturday.

Just wondering, what's the status of this?  Was worried that you might
have posted it and I'd missed it.

Richard