Re: [PATCH] [RFC]Support vectorization for Complex type.

[Jeff Law <jeffreyalaw@gmail.com>]

On 7/10/2022 9:43 PM, liuhongt via Gcc-patches wrote:
> The patch only handles load/store(including ctor/permutation, except
> gather/scatter) for complex type, other operations don't needs to be
> handled since they will be lowered by pass cplxlower.(MASK_LOAD is not
> supported for complex type, so no need to handle either).
>
> Instead of support vector(2) _Complex double, this patch takes vector(4)
> double as vector type of _Complex double. Since vectorizer originally
> takes TYPE_VECTOR_SUBPARTS as nunits which is not true for complex
> type, the patch handles nunits/ncopies/vf specially for complex type.
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
> Also test the patch for SPEC2017 and find there's complex type vectorization
> in 510/549(but no performance impact).
No comment on the implementation.  From a benchmarking standpoint you 
might want to look at cam4 in speed, not rate mode.     I'd bet you'd 
want -ffast-math or -fcx-limited-range to avoid divdc3 and have those 
calls expanded inline which may give you a better crack at exposing 
vectorization opportunities in there.

jeff