[PATCH 1/2, x86] Add palignr support for AVX2.

[Evgeny Stupachenko]

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On Mon, Sep 8, 2014 at 2:03 PM, Evgeny Stupachenko <evstupac@gmail.com> wrote:
> PING
>
> On Wed, Aug 27, 2014 at 7:50 PM, Evgeny Stupachenko <evstupac@gmail.com> wrote:
>> The rotate insn appeared right after expand.
>> I've done it similar to define_insn_and_split "*avx_vperm_broadcast_<mode>".
>> I don't see any potential losses on splitting that after reload.
>>
>> On Tue, Aug 26, 2014 at 8:29 PM, Richard Henderson <rth@redhat.com> wrote:
>>> On 08/26/2014 05:59 AM, Evgeny Stupachenko wrote:
>>>> +(define_insn_and_split "avx2_rotate<mode>_perm"
>>>> +  [(set (match_operand:V_256 0 "register_operand" "=&x")
>>>> +      (vec_select:V_256
>>>> +       (match_operand:V_256 1 "register_operand" "x")
>>>> +       (match_parallel 2 "palignr_operand"
>>>> +         [(match_operand 3 "const_int_operand" "n")])))]
>>>> +  "TARGET_AVX2"
>>>> +  "#"
>>>> +  "&& reload_completed"
>>>> +  [(const_int 0)]
>>>
>>> Why are you waiting until after reload to expand this?  It's only the
>>> vec_select parallel that determines which direction the palignr should be done.
>>>
>>> This seems like something you could do during permutation expansion.
>>>
>>>
>>> r~
>>>
>>>