1 files changed, 123 insertions, 0 deletions
diff --git a/src/compiler/glsl/lower_subroutine.cpp b/src/compiler/glsl/lower_subroutine.cpp
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+++ b/src/compiler/glsl/lower_subroutine.cpp
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+/*
+ * Copyright © 2015 Red Hat
+ *
+ * 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_subroutine.cpp
+ *
+ * lowers subroutines to an if ladder.
+ */
+
+#include "compiler/glsl_types.h"
+#include "glsl_parser_extras.h"
+#include "ir.h"
+#include "ir_builder.h"
+
+using namespace ir_builder;
+namespace {
+
+class lower_subroutine_visitor : public ir_hierarchical_visitor {
+public:
+   lower_subroutine_visitor(struct _mesa_glsl_parse_state *state)
+      : state(state)
+   {
+      this->progress = false;
+   }
+
+   ir_visitor_status visit_leave(ir_call *);
+   ir_call *call_clone(ir_call *call, ir_function_signature *callee);
+   bool progress;
+   struct _mesa_glsl_parse_state *state;
+};
+
+}
+
+bool
+lower_subroutine(exec_list *instructions, struct _mesa_glsl_parse_state *state)
+{
+   lower_subroutine_visitor v(state);
+   visit_list_elements(&v, instructions);
+   return v.progress;
+}
+
+ir_call *
+lower_subroutine_visitor::call_clone(ir_call *call, ir_function_signature *callee)
+{
+   void *mem_ctx = ralloc_parent(call);
+   ir_dereference_variable *new_return_ref = NULL;
+   if (call->return_deref != NULL)
+      new_return_ref = call->return_deref->clone(mem_ctx, NULL);
+
+   exec_list new_parameters;
+
+   foreach_in_list(ir_instruction, ir, &call->actual_parameters) {
+      new_parameters.push_tail(ir->clone(mem_ctx, NULL));
+   }
+
+   return new(mem_ctx) ir_call(callee, new_return_ref, &new_parameters);
+}
+
+ir_visitor_status
+lower_subroutine_visitor::visit_leave(ir_call *ir)
+{
+   if (!ir->sub_var)
+      return visit_continue;
+
+   void *mem_ctx = ralloc_parent(ir);
+   ir_if *last_branch = NULL;
+
+   for (int s = this->state->num_subroutines - 1; s >= 0; s--) {
+      ir_rvalue *var;
+      ir_constant *lc = new(mem_ctx)ir_constant(s);
+      ir_function *fn = this->state->subroutines[s];
+      bool is_compat = false;
+
+      for (int i = 0; i < fn->num_subroutine_types; i++) {
+         if (ir->sub_var->type->without_array() == fn->subroutine_types[i]) {
+            is_compat = true;
+            break;
+         }
+      }
+      if (is_compat == false)
+         continue;
+
+      if (ir->array_idx != NULL)
+         var = ir->array_idx->clone(mem_ctx, NULL);
+      else
+         var = new(mem_ctx) ir_dereference_variable(ir->sub_var);
+
+      ir_function_signature *sub_sig =
+         fn->exact_matching_signature(this->state,
+                                      &ir->actual_parameters);
+
+      ir_call *new_call = call_clone(ir, sub_sig);
+      if (!last_branch)
+         last_branch = if_tree(equal(subr_to_int(var), lc), new_call);
+      else
+         last_branch = if_tree(equal(subr_to_int(var), lc), new_call, last_branch);
+   }
+   if (last_branch)
+      ir->insert_before(last_branch);
+   ir->remove();
+
+   return visit_continue;
+}