glsl: use an enum for AMD_conservative_depth layout qualifiers

The main idea behind this is to free some bits in the flags.q
struct because currently all 64-bits are used and we can't
add more layout qualifiers without reaching a static assert.

In order to do that (mainly for ARB_bindless_texture), use an
enumeration for the AMD_conservative_depth layout qualifiers
because it's forbidden to declare more than one depth qualifier
for gl_FragDepth.

Note that ast_type_qualifier::merge_qualifier() will prevent
using duplicate layout qualifiers by returning a compile-time
error.

No piglit regressions found (including compiler tests) with
RX480 on RadeonSI.

v2: use a switch case

Signed-off-by: Samuel Pitoiset <[email protected]>
Reviewed-by: Andres Gomez <[email protected]> (v1)

1 files changed, 12 insertions, 4 deletions

diff --git a/src/compiler/glsl/ast.h b/src/compiler/glsl/ast.h
index 3dff164232d..11a092e41c2 100644
--- a/src/compiler/glsl/ast.h
+++ b/src/compiler/glsl/ast.h
@@ -463,6 +463,14 @@ enum {
    ast_precision_low
 };
 
+enum {
+   ast_depth_none = 0, /**< Absence of depth qualifier. */
+   ast_depth_any,
+   ast_depth_greater,
+   ast_depth_less,
+   ast_depth_unchanged
+};
+
 struct ast_type_qualifier {
    DECLARE_RALLOC_CXX_OPERATORS(ast_type_qualifier);
 
@@ -528,10 +536,7 @@ struct ast_type_qualifier {
 
          /** \name Layout qualifiers for GL_AMD_conservative_depth */
          /** \{ */
-         unsigned depth_any:1;
-         unsigned depth_greater:1;
-         unsigned depth_less:1;
-         unsigned depth_unchanged:1;
+         unsigned depth_type:1;
          /** \} */
 
 	 /** \name Layout qualifiers for GL_ARB_uniform_buffer_object */
@@ -630,6 +635,9 @@ struct ast_type_qualifier {
    /** Precision of the type (highp/medium/lowp). */
    unsigned precision:2;
 
+   /** Type of layout qualifiers for GL_AMD_conservative_depth. */
+   unsigned depth_type:3;
+
    /**
     * Alignment specified via GL_ARB_enhanced_layouts "align" layout qualifier
     */