1 files changed, 74 insertions, 0 deletions
diff --git a/mesalib/src/glsl/ir_function_can_inline.cpp b/mesalib/src/glsl/ir_function_can_inline.cpp
new file mode 100644
index 000000000..f29f277ef
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+++ b/mesalib/src/glsl/ir_function_can_inline.cpp
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+/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * 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 ir_function_can_inline.cpp
+ *
+ * Determines if we can inline a function call using ir_function_inlining.cpp.
+ *
+ * The primary restriction is that we can't return from the function
+ * other than as the last instruction.  We could potentially work
+ * around this for some constructs by flattening control flow and
+ * moving the return to the end, or by using breaks from a do {} while
+ * (0) loop surrounding the function body.
+ */
+
+#include "ir.h"
+
+class ir_function_can_inline_visitor : public ir_hierarchical_visitor {
+public:
+   ir_function_can_inline_visitor()
+   {
+      this->num_returns = 0;
+   }
+
+   virtual ir_visitor_status visit_enter(ir_return *);
+
+   int num_returns;
+};
+
+ir_visitor_status
+ir_function_can_inline_visitor::visit_enter(ir_return *ir)
+{
+   (void) ir;
+   this->num_returns++;
+   return visit_continue;
+}
+
+bool
+can_inline(ir_call *call)
+{
+   ir_function_can_inline_visitor v;
+   const ir_function_signature *callee = call->get_callee();
+
+   v.run((exec_list *) &callee->body);
+
+   /* If the function is empty (no last instruction) or does not end with a
+    * return statement, we need to count the implicit return.
+    */
+   ir_instruction *last = (ir_instruction *)callee->body.get_tail();
+   if (last == NULL || !last->as_return())
+      v.num_returns++;
+
+   return v.num_returns == 1;
+}