When a TCS is present, the TES input gl_PatchVerticesIn is actually a constant - it's simply the # of output vertices specified by the TCS layout qualifiers. So, we can replace the system value with a constant, which may allow further optimization, and will likely be more efficient.
If the TCS is absent, we can't do this optimization. Cc: Ilia Mirkin <imir...@alum.mit.edu> Cc: Marek Olšák <mar...@gmail.com> Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> --- src/glsl/linker.cpp | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) Works for me on i965, but I haven't set up other drivers to test them (sorry...) diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp index 424b92a..cfd8f81 100644 --- a/src/glsl/linker.cpp +++ b/src/glsl/linker.cpp @@ -2282,6 +2282,22 @@ resize_tes_inputs(struct gl_context *ctx, foreach_in_list(ir_instruction, ir, tes->ir) { ir->accept(&input_resize_visitor); } + + if (tcs) { + /* Convert the gl_PatchVerticesIn system value into a constant, since + * the value is known at this point. + */ + foreach_in_list(ir_instruction, ir, tes->ir) { + ir_variable *var = ir->as_variable(); + if (var && var->data.mode == ir_var_system_value && + var->data.location == SYSTEM_VALUE_VERTICES_IN) { + void *mem_ctx = ralloc_parent(var); + var->data.mode = ir_var_auto; + var->data.location = 0; + var->constant_value = new(mem_ctx) ir_constant(num_vertices); + } + } + } } /** -- 2.6.2 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev