Remove conditionals and loops that can be determined to never run

[libs/gl.git] / source / programcompiler.h

diff --git a/source/programcompiler.h b/source/programcompiler.h
index 2ef4aa7d9b77c5f853968da6e4e9dbc310c9abec..f585ba92347ae52e580eec7c5d42ce993fc8c483 100644 (file)
--- a/source/programcompiler.h
+++ b/source/programcompiler.h
@@ -9,6 +9,7 @@ namespace Msp {
 namespace GL {
 
 class Program;
+class Resources;
 
 class ProgramCompiler
 {
@@ -48,6 +49,7 @@ private:
                virtual void visit(ProgramSyntax::Assignment &);
                virtual void visit(ProgramSyntax::FunctionCall &);
                virtual void visit(ProgramSyntax::ExpressionStatement &);
+               virtual void visit(ProgramSyntax::Import &);
                virtual void visit(ProgramSyntax::Layout &);
                virtual void visit(ProgramSyntax::StructDeclaration &);
                virtual void visit(ProgramSyntax::VariableDeclaration &);
@@ -58,6 +60,31 @@ private:
                virtual void visit(ProgramSyntax::Return &);
        };
 
+       template<typename T>
+       struct NodeGatherer: Visitor
+       {
+               typedef std::list<T *> ResultType;
+
+               std::list<T *> nodes;
+
+               const ResultType &get_result() const { return nodes; }
+               virtual void visit(T &n) { nodes.push_back(&n); }
+       };
+
+       struct DeclarationCombiner: Visitor
+       {
+               bool toplevel;
+               std::map<std::string, std::vector<ProgramSyntax::FunctionDeclaration *> > functions;
+               std::map<std::string, ProgramSyntax::VariableDeclaration *> variables;
+               bool remove_node;
+
+               DeclarationCombiner();
+
+               virtual void visit(ProgramSyntax::Block &);
+               virtual void visit(ProgramSyntax::FunctionDeclaration &);
+               virtual void visit(ProgramSyntax::VariableDeclaration &);
+       };
+
        struct VariableResolver: Visitor
        {
                std::vector<ProgramSyntax::Block *> blocks;
@@ -109,6 +136,39 @@ private:
                virtual void visit(ProgramSyntax::VariableDeclaration &);
        };
 
+       struct ExpressionEvaluator: ProgramSyntax::NodeVisitor
+       {
+               typedef std::map<ProgramSyntax::VariableDeclaration *, ProgramSyntax::Expression *> ValueMap;
+
+               const ValueMap *variable_values;
+               float result;
+               bool result_valid;
+
+               ExpressionEvaluator();
+               ExpressionEvaluator(const ValueMap &);
+
+               virtual void visit(ProgramSyntax::Literal &);
+               virtual void visit(ProgramSyntax::VariableReference &);
+               virtual void visit(ProgramSyntax::UnaryExpression &);
+               virtual void visit(ProgramSyntax::BinaryExpression &);
+       };
+
+       struct ConstantConditionEliminator: Visitor
+       {
+               unsigned scope_level;
+               ExpressionEvaluator::ValueMap variable_values;
+               bool remove_node;
+               ProgramSyntax::Block *replacement_block;
+
+               ConstantConditionEliminator();
+
+               virtual void visit(ProgramSyntax::Block &);
+               virtual void visit(ProgramSyntax::Assignment &);
+               virtual void visit(ProgramSyntax::VariableDeclaration &);
+               virtual void visit(ProgramSyntax::Conditional &);
+               virtual void visit(ProgramSyntax::Iteration &);
+       };
+
        struct UnusedVariableLocator: Visitor
        {
                struct AssignmentList
@@ -158,6 +218,7 @@ private:
                virtual void visit(ProgramSyntax::VariableDeclaration &);
        };
 
+       Resources *resources;
        ProgramParser parser;
        ProgramSyntax::Module *module;
 
@@ -165,7 +226,7 @@ public:
        ProgramCompiler();
 
        void compile(const std::string &);
-       void compile(IO::Base &);
+       void compile(IO::Base &, Resources * = 0);
        void add_shaders(Program &);
 
 private:
@@ -173,6 +234,7 @@ private:
        static ProgramSyntax::Module &get_builtins_module();
        static ProgramSyntax::Stage *get_builtins(ProgramSyntax::StageType);
        void process();
+       void import(const std::string &);
        void generate(ProgramSyntax::Stage &);
        bool optimize(ProgramSyntax::Stage &);
        static void inject_block(ProgramSyntax::Block &, const ProgramSyntax::Block &);