[Mesa-dev] radeonsi: LLVM r187139 broke some piglit tests

[Michel Dänzer]

On Mit, 2013-07-31 at 08:42 -0700, Tom Stellard wrote:
> On Wed, Jul 31, 2013 at 01:04:01PM +0200, Michel Dänzer wrote:
> > 
> > LLVM revision 187139 ('Allocate local registers in order for optimal
> > coloring.') broke some derivative related piglit tests with the radeonsi
> > driver. 
> > 
> > I'm attaching a diff between the bad and good generated code (as printed
> > with RADEON_DUMP_SHADERS=1) for the glsl-derivs test. The only
> > difference I can see is in which registers are used in which order.
> > 
> > I wonder if we might be missing S_WAITCNT after DS_READ/WRITE
> > instructions in some cases, but I haven't spotted any candidates for
> > that in the bad code which aren't there in the good code as well. Can
> > anyone else spot something I've missed?
> 
> Shouldn't we be using the S_BARRIER instruction to keep the threads in sync?

Doesn't seem to help unfortunately, but thanks for the good suggestion.


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer