[Mesa-dev] [PATCH 4/5] glsl: include per-patch varyings when generating reserved slot bitfield

[Timothy Arceri]

---
 src/compiler/glsl/link_varyings.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp
index 5a99f0c..0a54559 100644
--- a/src/compiler/glsl/link_varyings.cpp
+++ b/src/compiler/glsl/link_varyings.cpp
@@ -1894,13 +1894,18 @@ canonicalize_shader_io(exec_list *ir, enum ir_variable_mode io_mode)
 /**
  * Generate a bitfield map of the explicit locations for shader varyings.
  *
- * In theory a 32 bits value will be enough but a 64 bits value is future proof.
+ * Note: For Tessellation shaders we are sitting right on the limits of the
+ * 64 bit map. Per-vertex and per-patch both have separate location domains
+ * with a max of MAX_VARYING.
  */
 uint64_t
 reserved_varying_slot(struct gl_shader *stage, ir_variable_mode io_mode)
 {
    assert(io_mode == ir_var_shader_in || io_mode == ir_var_shader_out);
-   assert(MAX_VARYING <= 64); /* avoid an overflow of the returned value */
+   /* Avoid an overflow of the returned value, we multiple by two to handle
+    * handle Tessellation shaders.
+    */
+   assert(MAX_VARYINGS_INCL_PATCH <= 64);
 
    uint64_t slots = 0;
    int var_slot;
@@ -1921,7 +1926,7 @@ reserved_varying_slot(struct gl_shader *stage, ir_variable_mode io_mode)
       unsigned num_elements = get_varying_type(var, stage->Stage)
          ->count_attribute_slots(stage->Stage == MESA_SHADER_VERTEX);
       for (unsigned i = 0; i < num_elements; i++) {
-         if (var_slot >= 0 && var_slot < MAX_VARYING)
+         if (var_slot >= 0 && var_slot < MAX_VARYINGS_INCL_PATCH)
             slots |= UINT64_C(1) << var_slot;
          var_slot += 1;
       }
-- 
2.5.5