Add some documentation to the GLSL compiler

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

diff --git a/source/glsl/optimize.cpp b/source/glsl/optimize.cpp
index 7bbe14da382b6dbd54fb23ce113187f7e8616de3..2215f8335cd06a23ea71e2c381cb1776362b81cd 100644 (file)
--- a/source/glsl/optimize.cpp
+++ b/source/glsl/optimize.cpp
@@ -14,7 +14,7 @@ InlineableFunctionLocator::InlineableFunctionLocator():
 void InlineableFunctionLocator::visit(FunctionCall &call)
 {
        FunctionDeclaration *def = call.declaration;
-       if(def && def->definition!=def)
+       if(def)
                def = def->definition;
 
        if(def)
@@ -46,7 +46,7 @@ FunctionInliner::FunctionInliner():
 void FunctionInliner::apply(Stage &stage)
 {
        inlineable = InlineableFunctionLocator().apply(stage);
-       visit(stage.content);
+       stage.content.visit(*this);
 }
 
 void FunctionInliner::visit_and_inline(RefPtr<Expression> &ptr)
@@ -95,7 +95,7 @@ void FunctionInliner::visit(FunctionCall &call)
                visit_and_inline(*i);
 
        FunctionDeclaration *def = call.declaration;
-       if(def && def->definition!=def)
+       if(def)
                def = def->definition;
 
        if(def && inlineable.count(def))
@@ -124,14 +124,23 @@ void FunctionInliner::visit(Return &ret)
 
 
 ConstantConditionEliminator::ConstantConditionEliminator():
-       scope_level(0),
        record_only(false)
 { }
 
+void ConstantConditionEliminator::apply(Stage &stage)
+{
+       stage.content.visit(*this);
+       NodeRemover().apply(stage, nodes_to_remove);
+}
+
 void ConstantConditionEliminator::visit(Block &block)
 {
-       SetForScope<unsigned> set(scope_level, scope_level+1);
-       BlockModifier::visit(block);
+       SetForScope<Block *> set_block(current_block, &block);
+       for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
+       {
+               insert_point = i;
+               (*i)->visit(*this);
+       }
 
        for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
                variable_values.erase(i->second);
@@ -151,7 +160,13 @@ void ConstantConditionEliminator::visit(Assignment &assign)
 
 void ConstantConditionEliminator::visit(VariableDeclaration &var)
 {
-       if(var.constant || scope_level>1)
+       bool constant = var.constant;
+       if(constant && var.layout)
+       {
+               for(vector<Layout::Qualifier>::const_iterator i=var.layout->qualifiers.begin(); (constant && i!=var.layout->qualifiers.end()); ++i)
+                       constant = (i->name!="constant_id");
+       }
+       if((constant || current_block->parent) && var.init_expression)
                variable_values[&var] = var.init_expression.get();
 }
 
@@ -163,7 +178,9 @@ void ConstantConditionEliminator::visit(Conditional &cond)
                cond.condition->visit(eval);
                if(eval.is_result_valid())
                {
-                       flatten_block(eval.get_result() ? cond.body : cond.else_body);
+                       Block &block = (eval.get_result() ? cond.body : cond.else_body);
+                       current_block->body.splice(insert_point, block.body);
+                       nodes_to_remove.insert(&cond);
                        return;
                }
        }
@@ -185,7 +202,7 @@ void ConstantConditionEliminator::visit(Iteration &iter)
                        iter.condition->visit(eval);
                        if(eval.is_result_valid() && !eval.get_result())
                        {
-                               remove_node = true;
+                               nodes_to_remove.insert(&iter);
                                return;
                        }
                }
@@ -214,14 +231,13 @@ UnusedVariableRemover::UnusedVariableRemover():
        aggregate(0),
        assignment(0),
        assignment_target(false),
-       assign_to_subscript(false),
-       global_scope(true)
+       assign_to_subscript(false)
 { }
 
 bool UnusedVariableRemover::apply(Stage &stage)
 {
        variables.push_back(BlockVariableMap());
-       visit(stage.content);
+       stage.content.visit(*this);
        BlockVariableMap &global_variables = variables.back();
        for(BlockVariableMap::iterator i=global_variables.begin(); i!=global_variables.end(); ++i)
        {
@@ -249,11 +265,16 @@ void UnusedVariableRemover::visit(VariableReference &var)
        if(var.declaration && !assignment_target)
        {
                VariableInfo &var_info = variables.back()[var.declaration];
-               var_info.assignments.clear();
+               clear_assignments(var_info, false);
                var_info.referenced = true;
        }
 }
 
+void UnusedVariableRemover::visit(InterfaceBlockReference &iface)
+{
+       unused_nodes.erase(iface.declaration);
+}
+
 void UnusedVariableRemover::visit(MemberAccess &memacc)
 {
        TraversingVisitor::visit(memacc);
@@ -344,12 +365,9 @@ void UnusedVariableRemover::visit(FunctionDeclaration &func)
 {
        variables.push_back(BlockVariableMap());
 
-       {
-               SetForScope<bool> set(global_scope, false);
-               for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
-                       (*i)->visit(*this);
-               func.body.visit(*this);
-       }
+       for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
+               (*i)->visit(*this);
+       func.body.visit(*this);
 
        BlockVariableMap &block_variables = variables.back();
        for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
@@ -429,7 +447,7 @@ void UnusedVariableRemover::visit(Iteration &iter)
        BlockVariableMap &block_variables = variables.back();
        for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
                if(!i->second.local && i->second.referenced)
-                       i->second.assignments.clear();
+                       clear_assignments(i->second, false);
 
        merge_down_variables();
 }
@@ -437,7 +455,7 @@ void UnusedVariableRemover::visit(Iteration &iter)
 
 bool UnusedFunctionRemover::apply(Stage &stage)
 {
-       visit(stage.content);
+       stage.content.visit(*this);
        NodeRemover().apply(stage, unused_nodes);
        return !unused_nodes.empty();
 }