[Mesa-dev] llvmpipe broken on Skylake Pentium (LP_NATIVE_VECTOR_WIDTH=128)

[Adam Jackson]

On Mon, 2015-10-12 at 22:55 +0200, Roland Scheidegger wrote:

> I don't know that looks like a generic string you're getting back.
> x86-64 IIRC implies sse2 in llvm, but not the other sseX flags (and if
> we detected sse41 we're going to use intrinsics for these, which then
> may not be available in llvm _potentially_ (I'm really not sure here as
> this code changed, and mesa generally is only adapted to such changes
> once it breaks..., but the string here will be something less generic
> like "ivybridge" usually on real hw).

This was the clue I needed, SSE4.1 intrinsics die because llvm doesn't
think they're legal for the target, because llvm 3.6 doesn't know about
broadwell or skylake so they just appear as generic.  Adding their
model numbers to the Haswell path seems to do the trick (since
apparently Haswell Pentium has the same property re AVX).

- ajax