Re: [PATCH v3] Re: OpenMP: Generate SIMD clones for functions with "declare target"

[Sandra Loosemore <sandra@codesourcery.com>]

On 10/20/22 08:07, Jakub Jelinek wrote:
> Thus, IMHO it is exactly the pass_omp_simd_clone pass where you want to
> implement this auto-simdization discovery, guarded with
> #ifdef ACCEL_COMPILER and the new option (which means it will be done
> only for gcn and not on the host right now).

I'm running into a practical difficulty with making this controlled by a 
static #ifdef: namely, testing.

One of my test cases examines the .s output to make sure that the clones 
are emitted as local symbols and not global.  I have not been able to 
find the symbol linkage information in any of the dump files, and I have 
also not been able to figure out how to get a .s file from the offload 
compiler even outside of the DejaGnu test harness.  (It's possible I am 
just an extreme dummy about the latter problem, but so far none of my 
colleagues here has been able to give me a recipe either.)

On top of that, I worry that this should be tested more broadly than for 
the one target we're presently focusing on (AMD GCN), and we'll get much 
more regular test coverage if it's also enabled for x86_64 target which 
has the necessary compute_vecsize_and_simdlen target hook.

I remember Carlos O'Donnell used to have a favorite mantra, "design for 
test".  So, maybe generalize the new -fopenmp-target-simd-clone option 
to take a parameter to force clones to be generated on the OpenMP host 
for test purposes?  The "declare target" directive already has a clause

device_type(host|nohost|any)

that defaults to "any"; maybe we could use that syntax like
-fopenmp-target-simd-clone=any
and use the intersection of the two sets to determine what to 
auto-generate clones for?

-Sandra