glsl: remove dead builtins before assigning varying locations

Builtins already have locations assigned so this shouldn't
change anything. We want to call it earlier so we can tranform
GLSL IR to NIR earlier.

Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index 569a8b9f94786541109e36fa30b2985d4bd9903b..7a3d35f925310ca1f7025363c338d74256b7d917 100644 (file)
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4589,8 +4589,12 @@ link_varyings_and_uniforms(unsigned first, unsigned last,
 
       /* If the program is made up of only a single stage */
       if (first == last) {
-
          gl_linked_shader *const sh = prog->_LinkedShaders[last];
+
+         do_dead_builtin_varyings(ctx, NULL, sh, 0, NULL);
+         do_dead_builtin_varyings(ctx, sh, NULL, num_tfeedback_decls,
+                                  tfeedback_decls);
+
          if (prog->SeparateShader) {
             const uint64_t reserved_slots =
                reserved_varying_slot(sh, ir_var_shader_in);
@@ -4606,10 +4610,6 @@ link_varyings_and_uniforms(unsigned first, unsigned last,
                                           reserved_slots))
                return false;
          }
-
-         do_dead_builtin_varyings(ctx, NULL, sh, 0, NULL);
-         do_dead_builtin_varyings(ctx, sh, NULL, num_tfeedback_decls,
-                                  tfeedback_decls);
       } else {
          /* Linking the stages in the opposite order (from fragment to vertex)
           * ensures that inter-shader outputs written to in an earlier stage
@@ -4629,16 +4629,16 @@ link_varyings_and_uniforms(unsigned first, unsigned last,
             const uint64_t reserved_in_slots =
                reserved_varying_slot(sh_next, ir_var_shader_in);
 
+            do_dead_builtin_varyings(ctx, sh_i, sh_next,
+                      next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
+                      tfeedback_decls);
+
             if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next,
                       next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
                       tfeedback_decls,
                       reserved_out_slots | reserved_in_slots))
                return false;
 
-            do_dead_builtin_varyings(ctx, sh_i, sh_next,
-                      next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
-                      tfeedback_decls);
-
             /* This must be done after all dead varyings are eliminated. */
             if (sh_i != NULL) {
                unsigned slots_used = _mesa_bitcount_64(reserved_out_slots);