Implement constant folding in the GLSL compiler

[libs/gl.git] / source / glsl / optimize.h

diff --git a/source/glsl/optimize.h b/source/glsl/optimize.h
index 8a888e15bec7c11e019b172570e758a06f46963b..1262823f53ead86c058734fc0d62841b70f7dea3 100644 (file)
--- a/source/glsl/optimize.h
+++ b/source/glsl/optimize.h
@@ -3,7 +3,6 @@
 
 #include <map>
 #include <set>
-#include "evaluate.h"
 #include "visitor.h"
 
 namespace Msp {
@@ -137,11 +136,59 @@ private:
        virtual void visit(Iteration &);
 };
 
+/** Replaces expressions consisting entirely of literals with the results of
+evaluating the expression.*/
+class ConstantFolder: private TraversingVisitor
+{
+private:
+       VariableDeclaration *iteration_var;
+       Variant iter_init_value;
+       Variant r_constant_value;
+       bool iteration_init;
+       bool r_constant;
+       bool r_literal;
+       bool r_uses_iter_var;
+       bool r_any_folded;
+
+public:
+       bool apply(Stage &s) { s.content.visit(*this); return r_any_folded; }
+
+private:
+       static BasicTypeDeclaration::Kind get_value_kind(const Variant &);
+       template<typename T>
+       static T evaluate_logical(char, T, T);
+       template<typename T>
+       static bool evaluate_relation(const char *, T, T);
+       template<typename T>
+       static T evaluate_arithmetic(char, T, T);
+       void set_result(const Variant &, bool = false);
+
+       virtual void visit(RefPtr<Expression> &);
+       virtual void visit(Literal &);
+       virtual void visit(VariableReference &);
+       virtual void visit(MemberAccess &);
+       virtual void visit(Swizzle &);
+       virtual void visit(UnaryExpression &);
+       virtual void visit(BinaryExpression &);
+       virtual void visit(Assignment &);
+       virtual void visit(TernaryExpression &);
+       virtual void visit(FunctionCall &);
+       virtual void visit(VariableDeclaration &);
+       virtual void visit(Iteration &);
+};
+
 /** Removes conditional statements and loops where the condition can be
 determined as constant at compile time. */
 class ConstantConditionEliminator: private TraversingVisitor
 {
 private:
+       enum ConstantStatus
+       {
+               CONSTANT_FALSE,
+               CONSTANT_TRUE,
+               NOT_CONSTANT
+       };
+
        NodeList<Statement>::iterator insert_point;
        std::set<Node *> nodes_to_remove;
 
@@ -149,6 +196,8 @@ public:
        void apply(Stage &);
 
 private:
+       ConstantStatus check_constant_condition(const Expression &);
+
        virtual void visit(Block &);
        virtual void visit(Conditional &);
        virtual void visit(Iteration &);