i965/gs: Allow primitive id to be a system value

This allows for gl_PrimitiveId to come in as a system value rather than as
an input.  This is the way it will come in from SPIR-V. We keeps the input
path working for now so we don't break GL.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Cc: "13.0" <mesa-stable@lists.freedesktop.org>

diff --git a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
index 10be41b..2f4306a 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
@@ -626,7 +626,8 @@ brw_compile_gs(const struct brw_compiler *compiler, void *log_data,
    shader = brw_postprocess_nir(shader, compiler->devinfo, is_scalar);
 
    prog_data->include_primitive_id =
-      (shader->info->inputs_read & VARYING_BIT_PRIMITIVE_ID) != 0;
+      (shader->info->inputs_read & VARYING_BIT_PRIMITIVE_ID) ||
+      (shader->info->system_values_read & (1 << SYSTEM_VALUE_PRIMITIVE_ID));
 
    prog_data->invocations = shader->info->gs.invocations;