X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Fprogramcompiler.cpp;h=9b3266755b0b4f36c7bdc1ebe3471ebba48e8d40;hp=82a324dec52d8e7c9e92b8d8c56cb15264e423f3;hb=ba97b71564cadd322fe1bf3d8afe556b38ef0647;hpb=a0caabaed3aeb8947133d78986bfb4ae5ae3c893

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index 82a324de..9b326675 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -167,6 +167,9 @@ void ProgramCompiler::generate(Stage &stage)
 
 bool ProgramCompiler::optimize(Stage &stage)
 {
+	apply<ConstantConditionEliminator>(stage);
+	apply<VariableResolver>(stage);
+
 	set<Node *> unused = apply<UnusedVariableLocator>(stage);
 	apply<NodeRemover>(stage, unused);
 
@@ -839,6 +842,162 @@ void ProgramCompiler::VariableRenamer::visit(VariableDeclaration &var)
 }
 
 
+ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator():
+	variable_values(0),
+	result(0.0f),
+	result_valid(false)
+{ }
+
+ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator(const ValueMap &v):
+	variable_values(&v),
+	result(0.0f),
+	result_valid(false)
+{ }
+
+void ProgramCompiler::ExpressionEvaluator::visit(Literal &literal)
+{
+	if(literal.token=="true")
+		result = 1.0f;
+	else if(literal.token=="false")
+		result = 0.0f;
+	else
+		result = lexical_cast<float>(literal.token);
+	result_valid = true;
+}
+
+void ProgramCompiler::ExpressionEvaluator::visit(VariableReference &var)
+{
+	if(!var.declaration)
+		return;
+
+	if(variable_values)
+	{
+		ValueMap::const_iterator i = variable_values->find(var.declaration);
+		if(i!=variable_values->end())
+			i->second->visit(*this);
+	}
+	else if(var.declaration->init_expression)
+		var.declaration->init_expression->visit(*this);
+}
+
+void ProgramCompiler::ExpressionEvaluator::visit(UnaryExpression &unary)
+{
+	result_valid = false;
+	unary.expression->visit(*this);
+	if(!result_valid)
+		return;
+
+	if(unary.oper=="!")
+		result = !result;
+	else
+		result_valid = false;
+}
+
+void ProgramCompiler::ExpressionEvaluator::visit(BinaryExpression &binary)
+{
+	result_valid = false;
+	binary.left->visit(*this);
+	if(!result_valid)
+		return;
+
+	float left_result = result;
+	result_valid = false;
+	binary.right->visit(*this);
+	if(!result_valid)
+		return;
+
+	if(binary.oper=="<")
+		result = (left_result<result);
+	else if(binary.oper=="<=")
+		result = (left_result<=result);
+	else if(binary.oper==">")
+		result = (left_result>result);
+	else if(binary.oper==">=")
+		result = (left_result>=result);
+	else if(binary.oper=="==")
+		result = (left_result==result);
+	else if(binary.oper=="!=")
+		result = (left_result!=result);
+	else if(binary.oper=="&&")
+		result = (left_result && result);
+	else if(binary.oper=="||")
+		result = (left_result || result);
+	else
+		result_valid = false;
+}
+
+
+ProgramCompiler::ConstantConditionEliminator::ConstantConditionEliminator():
+	scope_level(0),
+	remove_node(false),
+	replacement_block(0)
+{ }
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Block &block)
+{
+	SetForScope<unsigned> set(scope_level, scope_level+1);
+	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
+	{
+		(*i)->visit(*this);
+		if(replacement_block)
+		{
+			for(list<NodePtr<Node> >::iterator j=replacement_block->body.begin(); j!=replacement_block->body.end(); ++j)
+				block.body.insert(i, *j);
+			replacement_block = 0;
+		}
+
+		if(remove_node)
+			block.body.erase(i++);
+		else
+			++i;
+		remove_node = false;
+	}
+
+	for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
+		variable_values.erase(i->second);
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Assignment &assign)
+{
+	variable_values.erase(assign.target_declaration);
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(VariableDeclaration &var)
+{
+	if(var.constant || scope_level>1)
+		variable_values[&var] = &*var.init_expression;
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Conditional &cond)
+{
+	ExpressionEvaluator eval(variable_values);
+	cond.condition->visit(eval);
+	if(eval.result_valid)
+	{
+		remove_node = true;
+		replacement_block = (eval.result ? &cond.body : &cond.else_body);
+	}
+	else
+		TraversingVisitor::visit(cond);
+}
+
+void ProgramCompiler::ConstantConditionEliminator::visit(Iteration &iter)
+{
+	if(iter.condition)
+	{
+		ExpressionEvaluator eval;
+		iter.condition->visit(eval);
+		if(eval.result_valid && !eval.result)
+		{
+			remove_node = true;
+			return;
+		}
+	}
+
+	TraversingVisitor::visit(iter);
+}
+
+
 ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
 	aggregate(0),
 	assignment(0),