PPC64 libmvec implementation of sincos

GT tnggil@protonmail.com
Thu Jan 16 11:40:00 GMT 2020

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Thursday, January 9, 2020 8:42 AM, Richard Biener <richard.guenther@gmail.com> wrote:

> As for the other question for testing you probably want to provide a
> OMP simd declaration
> of a function like
> _Complex double mycexpi (double);
> and make a testcase like
> void foo (_Complex double * __restrict out, double *in)
> {
> for (int i = 0; i < 1024; ++i)
> {
> out[i] = mycexpi (in[i]);
> }
> }
> or eventually with two output arrays and explicit __real/__imag
> processing. The real
> and main question is how is the OMP SIMD declaration of mycexpi looking like?
> So I'd completely side-step sincos() and GCCs sincos() ->
> __builtin_cepxi transform
> and concentrate on OMP SIMD of a function with the signature we need to handle.
> Richard.

I think what is required here is to attach either #pragma omp declare simd or __attribute__ ((simd))
to the declaration of builtin cexpi. In gcc/builtins.def, some attributes are provided during
creation of cexpi (line 656, call containing BUILT_IN_CEXPI). Attaching the simd attributes to
function declarations is how sin, cos, and the other math functions were handled in math-vector.h
glibc header file.

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