1 files changed, 234 insertions, 0 deletions
diff --git a/src/compiler/glsl/lower_cs_derived.cpp b/src/compiler/glsl/lower_cs_derived.cpp
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+++ b/src/compiler/glsl/lower_cs_derived.cpp
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+/*
+ * 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;
+}