Comment # 8 on bug 79575 from Henri Verbeet

(In reply to comment #7)
> Looks like this is happening purely for testing if a fpu control word would
> be preserved, the actual value used by d3d does disable them just fine
> (though, of course, this could also happen on any app, not just wine, if it
> unmasks exceptions before calling into mesa code).
It's perhaps important to point out that Wine isn't a single application as
such, and we don't have a lot of control over how individual applications setup
the FPU. The test in question exists because some applications expect us to
setup the FPU in a specific way, while others expect us to leave it alone.
Without having looked much into the llvm source for the backtrace, it's perhaps
also a bit odd that compiling a pass-through shader is doing anything involving
denormals in the first place.

> Though IIRC you aren't actually expected to leave the fpu control word in a
> non-standard state when you're calling into library code, so I'm not really
> sure if this qualifies as a mesa bug. In any way since this happens in llvm
> code finally here it might even be a bug there. I guess the only way to fix
Mostly just for reference, regressions every now and then aside, the Wine D3D
tests pretty much just pass with r600g / sb; that's currently my main
development setup. (And somewhat off-topic, but not entirely unrelated to this
bug, the reason that that's not a radeonsi system is because I think the llvm
dependency is just painful to work with.)