glsl: Add ir_demote

To represent the new `demote` keyword when using
EXT_demote_to_helper_invocation extension.  Most of the changes are to
include it in the visitors.

Demote is not considered a control flow, so also include an empty
visit member function in ir_control_flow_visitor.

Only NIR actually supports `demote`, so assert the translations for
TGSI and Mesa's gl_program -- since the demote is not expected to
appear for those.

Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/compiler/glsl/ir.h b/src/compiler/glsl/ir.h
index ba831f2c1ed..e3c28bbb2b8 100644
--- a/src/compiler/glsl/ir.h
+++ b/src/compiler/glsl/ir.h
@@ -74,6 +74,7 @@ enum ir_node_type {
    ir_type_loop_jump,
    ir_type_return,
    ir_type_discard,
+   ir_type_demote,
    ir_type_emit_vertex,
    ir_type_end_primitive,
    ir_type_barrier,
@@ -1805,6 +1806,28 @@ public:
 
 
 /**
+ * IR instruction representing demote statements from
+ * GL_EXT_demote_to_helper_invocation.
+ */
+class ir_demote : public ir_instruction {
+public:
+   ir_demote()
+      : ir_instruction(ir_type_demote)
+   {
+   }
+
+   virtual ir_demote *clone(void *mem_ctx, struct hash_table *ht) const;
+
+   virtual void accept(ir_visitor *v)
+   {
+      v->visit(this);
+   }
+
+   virtual ir_visitor_status accept(ir_hierarchical_visitor *);
+};
+
+
+/**
  * Texture sampling opcodes used in ir_texture
  */
 enum ir_texture_opcode {