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Re: [RFC] cortex-a{53,57}-simd.md missing?


;; Crude Advanced SIMD approximation.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define_insn_reservation "cortex_53_advsimd" 4
    (and (eq_attr "tune" "cortexa53")
         (eq_attr:q "is_neon_type" "yes"))
    "cortex_a53_simd0")

Does it mean that all AdvSIMD instructions for cortex-a53 are supposed
to be of latency = 4?

Yes.


In cortex-a57.md the description for "neon" instructions is more full,
it contains a lot of statements for different SIMD instructions.
It appeared in trunk just a month ago.

Yes.


Are there any plans to release detailed pipeline descriptions for SIMD
instructions for cortex-a53?
> How can it influence the performance of the generated code?

No, we have no immediate plans. Obviously if we find a reason and workloads where such changes are merited it will be picked up.

That being said I believe the current description isn't too bad on the Cortex-A53 - it's definitely better than having none at all.


regards
Ramana



--
Best regards,
Ilya Palachev




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