8 files changed, 243 insertions, 118 deletions

diff --git a/src/compiler/glsl/builtin_variables.cpp b/src/compiler/glsl/builtin_variables.cpp
index ea2d897cc8e..00bc99dd619 100644
--- a/src/compiler/glsl/builtin_variables.cpp
+++ b/src/compiler/glsl/builtin_variables.cpp
@@ -1295,15 +1295,10 @@ builtin_variable_generator::generate_cs_special_vars()
                        uvec3_t, "gl_LocalGroupSizeARB");
    }
 
-   if (state->ctx->Const.LowerCsDerivedVariables) {
-      add_variable("gl_GlobalInvocationID", uvec3_t, ir_var_auto, 0);
-      add_variable("gl_LocalInvocationIndex", uint_t, ir_var_auto, 0);
-   } else {
-      add_system_value(SYSTEM_VALUE_GLOBAL_INVOCATION_ID,
-                       uvec3_t, "gl_GlobalInvocationID");
-      add_system_value(SYSTEM_VALUE_LOCAL_INVOCATION_INDEX,
-                       uint_t, "gl_LocalInvocationIndex");
-   }
+   add_system_value(SYSTEM_VALUE_GLOBAL_INVOCATION_ID,
+                    uvec3_t, "gl_GlobalInvocationID");
+   add_system_value(SYSTEM_VALUE_LOCAL_INVOCATION_INDEX,
+                    uint_t, "gl_LocalInvocationIndex");
 }
 
 
@@ -1474,84 +1469,3 @@ _mesa_glsl_initialize_variables(exec_list *instructions,
       break;
    }
 }
-
-
-/**
- * Initialize compute shader variables with values that are derived from other
- * compute shader variable.
- */
-static void
-initialize_cs_derived_variables(gl_shader *shader,
-                                ir_function_signature *const main_sig)
-{
-   assert(shader->Stage == MESA_SHADER_COMPUTE);
-
-   ir_variable *gl_GlobalInvocationID =
-      shader->symbols->get_variable("gl_GlobalInvocationID");
-   assert(gl_GlobalInvocationID);
-   ir_variable *gl_WorkGroupID =
-      shader->symbols->get_variable("gl_WorkGroupID");
-   assert(gl_WorkGroupID);
-   ir_variable *gl_WorkGroupSize =
-      shader->symbols->get_variable("gl_WorkGroupSize");
-   if (gl_WorkGroupSize == NULL) {
-      void *const mem_ctx = ralloc_parent(shader->ir);
-      gl_WorkGroupSize = new(mem_ctx) ir_variable(glsl_type::uvec3_type,
-                                                  "gl_WorkGroupSize",
-                                                  ir_var_auto);
-      gl_WorkGroupSize->data.how_declared = ir_var_declared_implicitly;
-      gl_WorkGroupSize->data.read_only = true;
-      shader->ir->push_head(gl_WorkGroupSize);
-   }
-   ir_variable *gl_LocalInvocationID =
-      shader->symbols->get_variable("gl_LocalInvocationID");
-   assert(gl_LocalInvocationID);
-
-   /* gl_GlobalInvocationID =
-    *    gl_WorkGroupID * gl_WorkGroupSize + gl_LocalInvocationID
-    */
-   ir_instruction *inst =
-      assign(gl_GlobalInvocationID,
-             add(mul(gl_WorkGroupID, gl_WorkGroupSize),
-                 gl_LocalInvocationID));
-   main_sig->body.push_head(inst);
-
-   /* gl_LocalInvocationIndex =
-    *    gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
-    *    gl_LocalInvocationID.y * gl_WorkGroupSize.x +
-    *    gl_LocalInvocationID.x;
-    */
-   ir_expression *index_z =
-      mul(mul(swizzle_z(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize)),
-          swizzle_y(gl_WorkGroupSize));
-   ir_expression *index_y =
-      mul(swizzle_y(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize));
-   ir_expression *index_y_plus_z = add(index_y, index_z);
-   operand index_x(swizzle_x(gl_LocalInvocationID));
-   ir_expression *index_x_plus_y_plus_z = add(index_y_plus_z, index_x);
-   ir_variable *gl_LocalInvocationIndex =
-      shader->symbols->get_variable("gl_LocalInvocationIndex");
-   assert(gl_LocalInvocationIndex);
-   inst = assign(gl_LocalInvocationIndex, index_x_plus_y_plus_z);
-   main_sig->body.push_head(inst);
-}
-
-
-/**
- * Initialize builtin variables with values based on other builtin variables.
- * These are initialized in the main function.
- */
-void
-_mesa_glsl_initialize_derived_variables(struct gl_context *ctx,
-                                        gl_shader *shader)
-{
-   /* We only need to set CS variables currently. */
-   if (shader->Stage == MESA_SHADER_COMPUTE &&
-       ctx->Const.LowerCsDerivedVariables) {
-      ir_function_signature *const main_sig =
-         _mesa_get_main_function_signature(shader->symbols);
-
-      if (main_sig != NULL)
-         initialize_cs_derived_variables(shader, main_sig);
-   }
-}
diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
index 764c05ad802..51d835bc535 100644
--- a/src/compiler/glsl/glsl_parser_extras.cpp
+++ b/src/compiler/glsl/glsl_parser_extras.cpp
@@ -2009,8 +2009,6 @@ opt_shader_and_create_symbol_table(struct gl_context *ctx,
          break;
       }
    }
-
-   _mesa_glsl_initialize_derived_variables(ctx, shader);
 }
 
 void
diff --git a/src/compiler/glsl/ir.h b/src/compiler/glsl/ir.h
index 27eafe8e22b..070d7b3ffdd 100644
--- a/src/compiler/glsl/ir.h
+++ b/src/compiler/glsl/ir.h
@@ -2413,10 +2413,6 @@ _mesa_glsl_initialize_variables(exec_list *instructions,
 				struct _mesa_glsl_parse_state *state);
 
 extern void
-_mesa_glsl_initialize_derived_variables(struct gl_context *ctx,
-                                        gl_shader *shader);
-
-extern void
 reparent_ir(exec_list *list, void *mem_ctx);
 
 extern void
diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index eb3ec3b0c7d..f44ddcb05be 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -166,6 +166,7 @@ void optimize_dead_builtin_variables(exec_list *instructions,
 bool lower_tess_level(gl_linked_shader *shader);
 
 bool lower_vertex_id(gl_linked_shader *shader);
+bool lower_cs_derived(gl_linked_shader *shader);
 bool lower_blend_equation_advanced(gl_linked_shader *shader);
 
 bool lower_subroutine(exec_list *instructions, struct _mesa_glsl_parse_state *state);
diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index 37983096784..94bd7fb6592 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -2374,6 +2374,9 @@ link_intrastage_shaders(void *mem_ctx,
    if (ctx->Const.VertexID_is_zero_based)
       lower_vertex_id(linked);
 
+   if (ctx->Const.LowerCsDerivedVariables)
+      lower_cs_derived(linked);
+
 #ifdef DEBUG
    /* Compute the source checksum. */
    linked->SourceChecksum = 0;
diff --git a/src/compiler/glsl/lower_cs_derived.cpp b/src/compiler/glsl/lower_cs_derived.cpp
new file mode 100644
index 00000000000..f7ec2a48b47
--- /dev/null
+++ b/src/compiler/glsl/lower_cs_derived.cpp
@@ -0,0 +1,234 @@
+/*
+ * Copyright © 2017 Ilia Mirkin
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file lower_cs_derived.cpp
+ *
+ * For hardware that does not support the gl_GlobalInvocationID and
+ * gl_LocalInvocationIndex system values, replace them with fresh
+ * globals. Note that we can't rely on gl_WorkGroupSize or
+ * gl_LocalGroupSizeARB being available, since they may only have been defined
+ * in a non-main shader.
+ *
+ * [ This can happen if only a secondary shader has the layout(local_size_*)
+ *   declaration. ]
+ *
+ * This is meant to be run post-linking.
+ */
+
+#include "glsl_symbol_table.h"
+#include "ir_hierarchical_visitor.h"
+#include "ir.h"
+#include "ir_builder.h"
+#include "linker.h"
+#include "program/prog_statevars.h"
+#include "builtin_functions.h"
+
+using namespace ir_builder;
+
+namespace {
+
+class lower_cs_derived_visitor : public ir_hierarchical_visitor {
+public:
+   explicit lower_cs_derived_visitor(gl_linked_shader *shader)
+      : progress(false),
+        shader(shader),
+        local_size_variable(shader->Program->info.cs.local_size_variable),
+        gl_WorkGroupSize(NULL),
+        gl_WorkGroupID(NULL),
+        gl_LocalInvocationID(NULL),
+        gl_GlobalInvocationID(NULL),
+        gl_LocalInvocationIndex(NULL)
+   {
+      main_sig = _mesa_get_main_function_signature(shader->symbols);
+      assert(main_sig);
+   }
+
+   virtual ir_visitor_status visit(ir_dereference_variable *);
+
+   ir_variable *add_system_value(
+         int slot, const glsl_type *type, const char *name);
+   void find_sysvals();
+   void make_gl_GlobalInvocationID();
+   void make_gl_LocalInvocationIndex();
+
+   bool progress;
+
+private:
+   gl_linked_shader *shader;
+   bool local_size_variable;
+   ir_function_signature *main_sig;
+
+   ir_rvalue *gl_WorkGroupSize;
+   ir_variable *gl_WorkGroupID;
+   ir_variable *gl_LocalInvocationID;
+
+   ir_variable *gl_GlobalInvocationID;
+   ir_variable *gl_LocalInvocationIndex;
+};
+
+} /* anonymous namespace */
+
+ir_variable *
+lower_cs_derived_visitor::add_system_value(
+      int slot, const glsl_type *type, const char *name)
+{
+   ir_variable *var = new(shader) ir_variable(type, name, ir_var_system_value);
+   var->data.how_declared = ir_var_declared_implicitly;
+   var->data.read_only = true;
+   var->data.location = slot;
+   var->data.explicit_location = true;
+   var->data.explicit_index = 0;
+   shader->ir->push_head(var);
+
+   return var;
+}
+
+void
+lower_cs_derived_visitor::find_sysvals()
+{
+   if (gl_WorkGroupSize != NULL)
+      return;
+
+   ir_variable *WorkGroupSize;
+   if (local_size_variable)
+      WorkGroupSize = shader->symbols->get_variable("gl_LocalGroupSizeARB");
+   else
+      WorkGroupSize = shader->symbols->get_variable("gl_WorkGroupSize");
+   if (WorkGroupSize)
+      gl_WorkGroupSize = new(shader) ir_dereference_variable(WorkGroupSize);
+   gl_WorkGroupID = shader->symbols->get_variable("gl_WorkGroupID");
+   gl_LocalInvocationID = shader->symbols->get_variable("gl_LocalInvocationID");
+
+   /*
+    * These may be missing due to either dead code elimination, or, in the
+    * case of the group size, due to the layout being declared in a non-main
+    * shader. Re-create them.
+    */
+
+   if (!gl_WorkGroupID)
+      gl_WorkGroupID = add_system_value(
+            SYSTEM_VALUE_WORK_GROUP_ID, glsl_type::uvec3_type, "gl_WorkGroupID");
+   if (!gl_LocalInvocationID)
+      gl_LocalInvocationID = add_system_value(
+            SYSTEM_VALUE_LOCAL_INVOCATION_ID, glsl_type::uvec3_type,
+            "gl_LocalInvocationID");
+   if (!WorkGroupSize) {
+      if (local_size_variable) {
+         gl_WorkGroupSize = new(shader) ir_dereference_variable(
+               add_system_value(
+                     SYSTEM_VALUE_LOCAL_GROUP_SIZE, glsl_type::uvec3_type,
+                     "gl_LocalGroupSizeARB"));
+      } else {
+         ir_constant_data data;
+         memset(&data, 0, sizeof(data));
+         for (int i = 0; i < 3; i++)
+            data.u[i] = shader->Program->info.cs.local_size[i];
+         gl_WorkGroupSize = new(shader) ir_constant(glsl_type::uvec3_type, &data);
+      }
+   }
+}
+
+void
+lower_cs_derived_visitor::make_gl_GlobalInvocationID()
+{
+   if (gl_GlobalInvocationID != NULL)
+      return;
+
+   find_sysvals();
+
+   /* gl_GlobalInvocationID =
+    *    gl_WorkGroupID * gl_WorkGroupSize + gl_LocalInvocationID
+    */
+   gl_GlobalInvocationID = new(shader) ir_variable(
+         glsl_type::uvec3_type, "__GlobalInvocationID", ir_var_temporary);
+   shader->ir->push_head(gl_GlobalInvocationID);
+
+   ir_instruction *inst =
+      assign(gl_GlobalInvocationID,
+             add(mul(gl_WorkGroupID, gl_WorkGroupSize->clone(shader, NULL)),
+                 gl_LocalInvocationID));
+   main_sig->body.push_head(inst);
+}
+
+void
+lower_cs_derived_visitor::make_gl_LocalInvocationIndex()
+{
+   if (gl_LocalInvocationIndex != NULL)
+      return;
+
+   find_sysvals();
+
+   /* gl_LocalInvocationIndex =
+    *    gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
+    *    gl_LocalInvocationID.y * gl_WorkGroupSize.x +
+    *    gl_LocalInvocationID.x;
+    */
+   gl_LocalInvocationIndex = new(shader)
+      ir_variable(glsl_type::uint_type, "__LocalInvocationIndex", ir_var_temporary);
+   shader->ir->push_head(gl_LocalInvocationIndex);
+
+   ir_expression *index_z =
+      mul(mul(swizzle_z(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize->clone(shader, NULL))),
+          swizzle_y(gl_WorkGroupSize->clone(shader, NULL)));
+   ir_expression *index_y =
+      mul(swizzle_y(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize->clone(shader, NULL)));
+   ir_expression *index_y_plus_z = add(index_y, index_z);
+   operand index_x(swizzle_x(gl_LocalInvocationID));
+   ir_expression *index_x_plus_y_plus_z = add(index_y_plus_z, index_x);
+   ir_instruction *inst =
+      assign(gl_LocalInvocationIndex, index_x_plus_y_plus_z);
+   main_sig->body.push_head(inst);
+}
+
+ir_visitor_status
+lower_cs_derived_visitor::visit(ir_dereference_variable *ir)
+{
+   if (ir->var->data.mode == ir_var_system_value &&
+       ir->var->data.location == SYSTEM_VALUE_GLOBAL_INVOCATION_ID) {
+      make_gl_GlobalInvocationID();
+      ir->var = gl_GlobalInvocationID;
+      progress = true;
+   }
+
+   if (ir->var->data.mode == ir_var_system_value &&
+       ir->var->data.location == SYSTEM_VALUE_LOCAL_INVOCATION_INDEX) {
+      make_gl_LocalInvocationIndex();
+      ir->var = gl_LocalInvocationIndex;
+      progress = true;
+   }
+
+   return visit_continue;
+}
+
+bool
+lower_cs_derived(gl_linked_shader *shader)
+{
+   if (shader->Stage != MESA_SHADER_COMPUTE)
+      return false;
+
+   lower_cs_derived_visitor v(shader);
+   v.run(shader->ir);
+
+   return v.progress;
+}
diff --git a/src/compiler/glsl/meson.build b/src/compiler/glsl/meson.build
index d1a75eb8c36..76fcafb9910 100644
--- a/src/compiler/glsl/meson.build
+++ b/src/compiler/glsl/meson.build
@@ -124,6 +124,7 @@ files_libglsl = files(
   'lower_buffer_access.cpp',
   'lower_buffer_access.h',
   'lower_const_arrays_to_uniforms.cpp',
+  'lower_cs_derived.cpp',
   'lower_discard.cpp',
   'lower_discard_flow.cpp',
   'lower_distance.cpp',
diff --git a/src/compiler/glsl/opt_dead_builtin_variables.cpp b/src/compiler/glsl/opt_dead_builtin_variables.cpp
index 03e578982b9..0d4e3a8f00a 100644
--- a/src/compiler/glsl/opt_dead_builtin_variables.cpp
+++ b/src/compiler/glsl/opt_dead_builtin_variables.cpp
@@ -62,23 +62,6 @@ optimize_dead_builtin_variables(exec_list *instructions,
        * information, so removing these variables from the user shader will
        * cause problems later.
        *
-       * For compute shaders, gl_GlobalInvocationID has some dependencies, so
-       * we avoid removing these dependencies.
-       *
-       * We also avoid removing gl_GlobalInvocationID at this stage because it
-       * might be used by a linked shader. In this case it still needs to be
-       * initialized by the main function.
-       *
-       *    gl_GlobalInvocationID =
-       *       gl_WorkGroupID * gl_WorkGroupSize + gl_LocalInvocationID
-       *
-       * Similarly, we initialize gl_LocalInvocationIndex in the main function:
-       *
-       *    gl_LocalInvocationIndex =
-       *       gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
-       *       gl_LocalInvocationID.y * gl_WorkGroupSize.x +
-       *       gl_LocalInvocationID.x;
-       *
        * Matrix uniforms with "Transpose" are not eliminated because there's
        * an optimization pass that can turn references to the regular matrix
        * into references to the transpose matrix.  Eliminating the transpose
@@ -90,11 +73,6 @@ optimize_dead_builtin_variables(exec_list *instructions,
        */
       if (strcmp(var->name, "gl_ModelViewProjectionMatrix") == 0
           || strcmp(var->name, "gl_Vertex") == 0
-          || strcmp(var->name, "gl_WorkGroupID") == 0
-          || strcmp(var->name, "gl_WorkGroupSize") == 0
-          || strcmp(var->name, "gl_LocalInvocationID") == 0
-          || strcmp(var->name, "gl_GlobalInvocationID") == 0
-          || strcmp(var->name, "gl_LocalInvocationIndex") == 0
           || strstr(var->name, "Transpose") != NULL)
          continue;