On Thu, 2015-01-08 at 01:49 -0800, Kenneth Graunke wrote: > On Thursday, January 08, 2015 10:21:45 AM Iago Toral wrote: > > Hi, > > > > In GLSL ES when the same uniform is declared in multiple shaders it must > > have the same precision qualifier. There are a few dEQP tests that fail > > because this is not checked in Mesa. > > > > I think the right place to add this check would be in > > cross_validate_globals(), but to do this we would need to access > > precision qualifiers from an ir_variable (specifically, I think we need > > this to be in glsl_type so we can do this check with uniform structs > > too, which is what the tests actually check). > > > > I see precision qualifiers being parsed and stored in the AST, but I > > don't see where this information is passed to the IR: ir_variable or > > glsl_type don't have this info, in fact, > > apply_type_qualifier_to_variable() in ast_to_hir.cpp seems to ignore the > > ast precision qualifier data completely. > > > > So I am guessing that we should add precision information to the > > glsl_type, but I wonder if there is a reason why this hasn't been done > > yet, considering that there seems to be some kind of support for > > precision qualifiers already, at least in the parser... am I missing > > something? > > > > Iago > > When we implemented the compiler, nobody really cared about lower precision. > Desktop GLSL is actually spec'd to parse and ignore the qualifiers - they > literally are mandated to mean nothing - so they're only useful for ES, and > we've seen very few ES apps. > > Making lowp, mediump, and highp the same precision is valid, and at the time, > we were mostly targeting desktop hardware that didn't have a lower precision > option anyway. These days, we could potentially use it for half float. > > Hooking it up isn't a bad plan - we just haven't gotten around to it. > It does seem like we need to at least be tracking it so we can properly > enforce the rules, and adding that would be a good step towards actually > doing something with it. > > --Ken
I see, I'll try to add them together with the necessary checks then. Thanks for the quick reply! Iago _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
