https://bugs.freedesktop.org/show_bug.cgi?id=32271 --- Comment #3 from Ian Romanick <idr@xxxxxxxxxxxxxxx> 2010-12-10 13:42:47 PST --- (In reply to comment #2) > I wonder if lowering DDX/DDY to SFL makes any difference compared to using a > shader that outputs (0,0,0,1). The lowering pass I was referring to would happen long before the Mesa IR level. At that point there is no SFL instruction. We'd just replace the ir_unop_dFdx and ir_unop_dFdy expressions with constants of 0 in the appropriate type. Backends (e.g., ir_to_mesa) can convert these constants to whatever is appropriate. This way backends for GPUs that can't handle these operations will never even see them. That is, after all, the whole point of the various lowering passes in the GLSL compiler. :) -- Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
