On Wed, Oct 18, 2023 at 07:14:36AM +0000, Richard Biener wrote:
> It's interesting that when the target has AVX512 enabled we get
> AVX512 style masks used also for SSE and AVX vector sizes but the
> OMP SIMD clones for SSE and AVX vector sizes use SSE/AVX style
> masks and only the AVX512 size clone uses the AVX512 integer mode
> mask. That necessarily requires an extra setup instruction for
> the mask argument.
It is an ABI matter, the ABI of the clones shouldn't change just because
of a supposedly non ABI changing option (ISA flags like -mavx512f etc.).
Under the hood, if the callers are -mavx512f the expectation is that the
AVX512 simd clone will be used, but of course that doesn't have to be the
case either because of options requesting only 256 or 128-bit vector width
or loops with small safelen or number of iterations or other reasons.
Jakub
