[Mesa-dev] [PATCH v2 1/3] glsl: add glsl_external_mode() helper

[Timothy Arceri]

This allows us to get the variable mode as specified by the GLSL
spec. We will use this in the following patch.
---
 src/compiler/glsl/ast_to_hir.cpp | 73 ++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index 3bf581571e2..a7a9ac80769 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -4175,6 +4175,79 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
    apply_image_qualifier_to_variable(qual, var, state, loc);
 }
 
+/**
+ * Get the GLSL mode specified in for system values (if any).
+ */
+static enum ir_variable_mode
+glsl_external_mode(enum ir_variable_mode internal_mode, gl_shader_stage stage,
+                   unsigned slot) {
+   if (internal_mode == ir_var_system_value) {
+      switch (slot) {
+      case SYSTEM_VALUE_SUBGROUP_SIZE:
+         return ir_var_uniform;
+      case SYSTEM_VALUE_PRIMITIVE_ID:
+         if (stage == MESA_SHADER_GEOMETRY) {
+            return ir_var_shader_out;
+         } else {
+            return ir_var_shader_in;
+         }
+      case SYSTEM_VALUE_TESS_LEVEL_OUTER:
+      case SYSTEM_VALUE_TESS_LEVEL_INNER:
+         if (stage == MESA_SHADER_TESS_CTRL) {
+            return ir_var_shader_out;
+         } else {
+            assert(stage == MESA_SHADER_TESS_EVAL);
+            return ir_var_shader_in;
+         }
+      case SYSTEM_VALUE_SUBGROUP_INVOCATION:
+      case SYSTEM_VALUE_SUBGROUP_EQ_MASK:
+      case SYSTEM_VALUE_SUBGROUP_GE_MASK:
+      case SYSTEM_VALUE_SUBGROUP_GT_MASK:
+      case SYSTEM_VALUE_SUBGROUP_LE_MASK:
+      case SYSTEM_VALUE_SUBGROUP_LT_MASK:
+      case SYSTEM_VALUE_INSTANCE_ID:
+      case SYSTEM_VALUE_VERTEX_ID:
+      case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
+      case SYSTEM_VALUE_BASE_VERTEX:
+      case SYSTEM_VALUE_BASE_INSTANCE:
+      case SYSTEM_VALUE_DRAW_ID:
+      case SYSTEM_VALUE_INVOCATION_ID:
+      case SYSTEM_VALUE_FRAG_COORD:
+      case SYSTEM_VALUE_FRONT_FACE:
+      case SYSTEM_VALUE_SAMPLE_ID:
+      case SYSTEM_VALUE_SAMPLE_POS:
+      case SYSTEM_VALUE_SAMPLE_MASK_IN:
+      case SYSTEM_VALUE_HELPER_INVOCATION:
+      case SYSTEM_VALUE_TESS_COORD:
+      case SYSTEM_VALUE_VERTICES_IN:
+      case SYSTEM_VALUE_LOCAL_INVOCATION_ID:
+      case SYSTEM_VALUE_LOCAL_INVOCATION_INDEX:
+      case SYSTEM_VALUE_GLOBAL_INVOCATION_ID:
+      case SYSTEM_VALUE_WORK_GROUP_ID:
+      case SYSTEM_VALUE_NUM_WORK_GROUPS:
+      case SYSTEM_VALUE_LOCAL_GROUP_SIZE:
+         return ir_var_shader_in;
+      case SYSTEM_VALUE_NUM_SUBGROUPS:
+      case SYSTEM_VALUE_SUBGROUP_ID:
+      case SYSTEM_VALUE_INSTANCE_INDEX:
+      case SYSTEM_VALUE_FIRST_VERTEX:
+      case SYSTEM_VALUE_IS_INDEXED_DRAW:
+      case SYSTEM_VALUE_DEVICE_INDEX:
+      case SYSTEM_VALUE_VIEW_INDEX:
+      case SYSTEM_VALUE_VERTEX_CNT:
+         /* These system values have no GLSL facing equal */
+         return internal_mode;
+      case SYSTEM_VALUE_MAX:
+         unreachable("Invalid system value slot SYSTEM_VALUE_MAX");
+         break;
+      default:
+         unreachable("Unhandled system value in glsl_external_mode()");
+      }
+   }
+
+   return internal_mode;
+}
+
 /**
  * Get the variable that is being redeclared by this declaration or if it
  * does not exist, the current declared variable.
-- 
2.17.0