glsl: Add uniform_locations_assigned parameter to do_dead_code opt pass

Setting this flag prevents declarations of uniforms from being removed
from the IR.  Since the IR is directly used by several API functions
that query uniforms in shaders, uniform declarations cannot be removed
after the locations have been set.  However, it should still be safe
to reorder the declarations (this is not tested).

Signed-off-by: Ian Romanick <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41980
Tested-by: Brian Paul <[email protected]>
Reviewed-by: Bryan Cain <[email protected]>
Cc: Vinson Lee <[email protected]>
Cc: José Fonseca <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Yuanhan Liu <[email protected]>

1 files changed, 21 insertions, 2 deletions

diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
index a9075b2b1be..e2112fe6dd0 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -883,8 +883,27 @@ ast_struct_specifier::ast_struct_specifier(char *identifier,
    this->declarations.push_degenerate_list_at_head(&declarator_list->link);
 }
 
+/**
+ * Do the set of common optimizations passes
+ *
+ * \param ir                          List of instructions to be optimized
+ * \param linked                      Is the shader linked?  This enables
+ *                                    optimizations passes that remove code at
+ *                                    global scope and could cause linking to
+ *                                    fail.
+ * \param uniform_locations_assigned  Have locations already been assigned for
+ *                                    uniforms?  This prevents the declarations
+ *                                    of unused uniforms from being removed.
+ *                                    The setting of this flag only matters if
+ *                                    \c linked is \c true.
+ * \param max_unroll_iterations       Maximum number of loop iterations to be
+ *                                    unrolled.  Setting to 0 forces all loops
+ *                                    to be unrolled.
+ */
 bool
-do_common_optimization(exec_list *ir, bool linked, unsigned max_unroll_iterations)
+do_common_optimization(exec_list *ir, bool linked,
+		       bool uniform_locations_assigned,
+		       unsigned max_unroll_iterations)
 {
    GLboolean progress = GL_FALSE;
 
@@ -900,7 +919,7 @@ do_common_optimization(exec_list *ir, bool linked, unsigned max_unroll_iteration
    progress = do_copy_propagation(ir) || progress;
    progress = do_copy_propagation_elements(ir) || progress;
    if (linked)
-      progress = do_dead_code(ir) || progress;
+      progress = do_dead_code(ir, uniform_locations_assigned) || progress;
    else
       progress = do_dead_code_unlinked(ir) || progress;
    progress = do_dead_code_local(ir) || progress;