X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Fprogramcompiler.cpp;h=a3691b112fd4fc22d8121f04c4d37024037f8470;hp=a1be91ca4f575228fe2f48ccb374fb0097c6dccb;hb=20af6dd2f04caa224d8cae00befc97d010a1ed08;hpb=e37d3b91500994df3de4fe47bd3d3e75d3104b46

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index a1be91ca..a3691b11 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -35,8 +35,6 @@ namespace GL {
 
 using namespace ProgramSyntax;
 
-// XXX For some reason global declarations are emitted for otherwise undeclared local variables
-
 ProgramCompiler::ProgramCompiler():
 	resources(0),
 	module(0)
@@ -1210,14 +1208,12 @@ void ProgramCompiler::FunctionInliner::visit(Return &ret)
 
 ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator():
 	variable_values(0),
-	const_only(false),
 	result(0.0f),
 	result_valid(false)
 { }
 
-ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator(const ValueMap *v, bool c):
-	variable_values(v),
-	const_only(c),
+ProgramCompiler::ExpressionEvaluator::ExpressionEvaluator(const ValueMap &v):
+	variable_values(&v),
 	result(0.0f),
 	result_valid(false)
 { }
@@ -1242,8 +1238,6 @@ void ProgramCompiler::ExpressionEvaluator::visit(VariableReference &var)
 {
 	if(!var.declaration)
 		return;
-	if(const_only && !var.declaration->constant)
-		return;
 
 	if(variable_values)
 	{
@@ -1304,7 +1298,7 @@ void ProgramCompiler::ExpressionEvaluator::visit(BinaryExpression &binary)
 
 ProgramCompiler::ConstantConditionEliminator::ConstantConditionEliminator():
 	scope_level(0),
-	in_loop(false)
+	record_only(false)
 { }
 
 void ProgramCompiler::ConstantConditionEliminator::visit(Block &block)
@@ -1316,6 +1310,13 @@ void ProgramCompiler::ConstantConditionEliminator::visit(Block &block)
 		variable_values.erase(i->second);
 }
 
+void ProgramCompiler::ConstantConditionEliminator::visit(UnaryExpression &unary)
+{
+	if(VariableReference *var = dynamic_cast<VariableReference *>(unary.expression.get()))
+		if(unary.oper=="++" || unary.oper=="--")
+			variable_values.erase(var->declaration);
+}
+
 void ProgramCompiler::ConstantConditionEliminator::visit(Assignment &assign)
 {
 	variable_values.erase(assign.target_declaration);
@@ -1329,30 +1330,49 @@ void ProgramCompiler::ConstantConditionEliminator::visit(VariableDeclaration &va
 
 void ProgramCompiler::ConstantConditionEliminator::visit(Conditional &cond)
 {
-	ExpressionEvaluator eval(&variable_values, in_loop);
-	cond.condition->visit(eval);
-	if(eval.result_valid)
-		flatten_block(eval.result ? cond.body : cond.else_body);
-	else
-		TraversingVisitor::visit(cond);
+	if(!record_only)
+	{
+		ExpressionEvaluator eval(variable_values);
+		cond.condition->visit(eval);
+		if(eval.result_valid)
+		{
+			flatten_block(eval.result ? cond.body : cond.else_body);
+			return;
+		}
+	}
+
+	TraversingVisitor::visit(cond);
 }
 
 void ProgramCompiler::ConstantConditionEliminator::visit(Iteration &iter)
 {
-	// XXX Should this not visit init_statement first?
-	if(iter.condition)
+	if(!record_only)
 	{
-		ExpressionEvaluator eval(0, in_loop);
-		iter.condition->visit(eval);
-		if(eval.result_valid && !eval.result)
+		if(iter.condition)
 		{
-			remove_node = true;
-			return;
+			/* If the loop condition is always false on the first iteration, the
+			entire loop can be removed */
+			if(iter.init_statement)
+				iter.init_statement->visit(*this);
+			ExpressionEvaluator eval(variable_values);
+			iter.condition->visit(eval);
+			if(eval.result_valid && !eval.result)
+			{
+				remove_node = true;
+				return;
+			}
 		}
+
+		/* Record all assignments that occur inside the loop body so those
+		variables won't be considered as constant */
+		SetFlag set_record(record_only);
+		TraversingVisitor::visit(iter);
 	}
 
-	SetFlag set_loop(in_loop);
 	TraversingVisitor::visit(iter);
+
+	if(VariableDeclaration *init_decl = dynamic_cast<VariableDeclaration *>(iter.init_statement.get()))
+		variable_values.erase(init_decl);
 }