i965/vs: Add virtual function make_reg_for_system_value().

The system values handled by vec4_visitor::visit(ir_variable *) are
VS-specific (vertex ID and instance ID).  This patch moves the
handling of those values into a new virtual function,
make_reg_for_system_value(), so that this VS-specific code won't be
inherited by geomtry shaders.

Reviewed-by: Jordan Justen <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index cd3b6e70305..6bc0d304f12 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -482,6 +482,7 @@ public:
    void dump_instructions();
 
 protected:
+   virtual dst_reg *make_reg_for_system_value(ir_variable *ir) = 0;
    virtual int setup_attributes(int payload_reg) = 0;
    virtual void emit_prolog() = 0;
    virtual void emit_program_code() = 0;
@@ -499,6 +500,7 @@ public:
                    void *mem_ctx);
 
 protected:
+   virtual dst_reg *make_reg_for_system_value(ir_variable *ir);
    virtual int setup_attributes(int payload_reg);
    virtual void emit_prolog();
    virtual void emit_program_code();