}
-ConstantConditionEliminator::ConstantConditionEliminator():
- record_only(false)
+ExpressionInliner::ExpressionInfo::ExpressionInfo():
+ expression(0),
+ assign_scope(0),
+ inline_point(0),
+ inner_oper(0),
+ outer_oper(0),
+ inline_on_rhs(false),
+ trivial(false),
+ available(true)
{ }
-void ConstantConditionEliminator::apply(Stage &stage)
+
+ExpressionInliner::ExpressionInliner():
+ r_ref_info(0),
+ r_any_inlined(false),
+ r_trivial(false),
+ mutating(false),
+ iteration_init(false),
+ iteration_body(0),
+ r_oper(0)
+{ }
+
+bool ExpressionInliner::apply(Stage &s)
{
- stage.content.visit(*this);
- NodeRemover().apply(stage, nodes_to_remove);
+ s.content.visit(*this);
+ return r_any_inlined;
}
-void ConstantConditionEliminator::visit(Block &block)
+void ExpressionInliner::visit_and_record(RefPtr<Expression> &ptr, const Operator *outer_oper, bool on_rhs)
{
- SetForScope<Block *> set_block(current_block, &block);
- for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
+ r_ref_info = 0;
+ ptr->visit(*this);
+ if(r_ref_info && r_ref_info->expression && r_ref_info->available)
{
- insert_point = i;
- (*i)->visit(*this);
+ if(iteration_body && !r_ref_info->trivial)
+ {
+ /* Don't inline non-trivial expressions which were assigned outside
+ an iteration statement. The iteration may run multiple times, which
+ would cause the expression to also be evaluated multiple times. */
+ Block *i = r_ref_info->assign_scope;
+ for(; (i && i!=iteration_body); i=i->parent) ;
+ if(!i)
+ return;
+ }
+
+ r_ref_info->outer_oper = outer_oper;
+ if(r_ref_info->trivial)
+ inline_expression(*r_ref_info->expression, ptr, outer_oper, r_ref_info->inner_oper, on_rhs);
+ else
+ {
+ /* Record the inline point for a non-trivial expression but don't
+ inline it yet. It might turn out it shouldn't be inlined after all. */
+ r_ref_info->inline_point = &ptr;
+ r_ref_info->inline_on_rhs = on_rhs;
+ }
+ }
+}
+
+void ExpressionInliner::inline_expression(Expression &expr, RefPtr<Expression> &ptr, const Operator *outer_oper, const Operator *inner_oper, bool on_rhs)
+{
+ unsigned outer_precedence = (outer_oper ? outer_oper->precedence : 20);
+ unsigned inner_precedence = (inner_oper ? inner_oper->precedence : 0);
+
+ bool needs_parentheses = (inner_precedence>=outer_precedence);
+ if(inner_oper && inner_oper==outer_oper)
+ // Omit parentheses if the operator's natural grouping works out.
+ needs_parentheses = (inner_oper->assoc!=Operator::ASSOCIATIVE && on_rhs!=(inner_oper->assoc==Operator::RIGHT_TO_LEFT));
+
+ if(needs_parentheses)
+ {
+ RefPtr<ParenthesizedExpression> parexpr = new ParenthesizedExpression;
+ parexpr->expression = expr.clone();
+ ptr = parexpr;
+ }
+ else
+ ptr = expr.clone();
+
+ r_any_inlined = true;
+}
+
+void ExpressionInliner::visit(Block &block)
+{
+ TraversingVisitor::visit(block);
+
+ for(map<VariableDeclaration *, ExpressionInfo>::iterator i=expressions.begin(); i!=expressions.end(); )
+ {
+ map<string, VariableDeclaration *>::iterator j = block.variables.find(i->first->name);
+ if(j!=block.variables.end() && j->second==i->first)
+ {
+ if(i->second.expression && i->second.inline_point)
+ inline_expression(*i->second.expression, *i->second.inline_point, i->second.outer_oper, i->second.inner_oper, i->second.inline_on_rhs);
+
+ expressions.erase(i++);
+ }
+ else
+ {
+ /* The expression was assigned in this block and may depend on local
+ variables of the block. If this is a conditionally executed block,
+ the assignment might not always happen. Mark the expression as not
+ available to any outer blocks. */
+ if(i->second.assign_scope==&block)
+ i->second.available = false;
+
+ ++i;
+ }
}
+}
- for(map<string, VariableDeclaration *>::const_iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
- variable_values.erase(i->second);
+void ExpressionInliner::visit(VariableReference &var)
+{
+ if(var.declaration)
+ {
+ map<VariableDeclaration *, ExpressionInfo>::iterator i = expressions.find(var.declaration);
+ if(i!=expressions.end())
+ {
+ /* If a non-trivial expression is referenced multiple times, don't
+ inline it. */
+ if(i->second.inline_point && !i->second.trivial)
+ i->second.expression = 0;
+ /* Mutating expressions are analogous to self-referencing assignments
+ and prevent inlining. */
+ if(mutating)
+ i->second.expression = 0;
+ r_ref_info = &i->second;
+ }
+ }
+}
+
+void ExpressionInliner::visit(MemberAccess &memacc)
+{
+ visit_and_record(memacc.left, memacc.oper, false);
+ r_ref_info = 0;
+ r_oper = memacc.oper;
+ r_trivial = false;
}
-void ConstantConditionEliminator::visit(UnaryExpression &unary)
+void ExpressionInliner::visit(UnaryExpression &unary)
{
- if(VariableReference *var = dynamic_cast<VariableReference *>(unary.expression.get()))
- if(unary.oper->token[1]=='+' || unary.oper->token[1]=='-')
- variable_values.erase(var->declaration);
+ SetFlag set_target(mutating, mutating || unary.oper->token[1]=='+' || unary.oper->token[1]=='-');
+ visit_and_record(unary.expression, unary.oper, false);
+ r_ref_info = 0;
+ r_oper = unary.oper;
+ r_trivial = false;
}
-void ConstantConditionEliminator::visit(Assignment &assign)
+void ExpressionInliner::visit(BinaryExpression &binary)
{
- variable_values.erase(assign.target_declaration);
+ visit_and_record(binary.left, binary.oper, false);
+ {
+ SetFlag clear_target(mutating, false);
+ visit_and_record(binary.right, binary.oper, true);
+ }
+ r_ref_info = 0;
+ r_oper = binary.oper;
+ r_trivial = false;
}
-void ConstantConditionEliminator::visit(VariableDeclaration &var)
+void ExpressionInliner::visit(Assignment &assign)
{
+ {
+ SetFlag set_target(mutating);
+ visit_and_record(assign.left, assign.oper, false);
+ }
+ r_oper = 0;
+ visit_and_record(assign.right, assign.oper, true);
+
+ if(assign.target_declaration)
+ {
+ map<VariableDeclaration *, ExpressionInfo>::iterator i = expressions.find(assign.target_declaration);
+ if(i!=expressions.end())
+ {
+ /* Self-referencing assignments can't be inlined without additional
+ work. Just clear any previous expression. */
+ i->second.expression = (assign.self_referencing ? 0 : assign.right.get());
+ i->second.assign_scope = current_block;
+ i->second.inline_point = 0;
+ i->second.inner_oper = r_oper;
+ i->second.available = true;
+ }
+ }
+
+ r_ref_info = 0;
+ r_oper = assign.oper;
+ r_trivial = false;
+}
+
+void ExpressionInliner::visit(FunctionCall &call)
+{
+ for(NodeArray<Expression>::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++i)
+ visit_and_record(*i, 0, false);
+ r_ref_info = 0;
+ r_oper = 0;
+ r_trivial = false;
+}
+
+void ExpressionInliner::visit(VariableDeclaration &var)
+{
+ r_oper = 0;
+ r_trivial = true;
+ if(var.init_expression)
+ visit_and_record(var.init_expression, 0, false);
+
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();
+
+ /* Only inline global variables if they're constant and have trivial
+ initializers. Non-constant variables could change in ways which are hard to
+ analyze and non-trivial expressions could be expensive to inline. */
+ if((current_block->parent || (constant && r_trivial)) && var.interface.empty())
+ {
+ ExpressionInfo &info = expressions[&var];
+ /* Assume variables declared in an iteration initialization statement
+ will have their values change throughout the iteration. */
+ info.expression = (iteration_init ? 0 : var.init_expression.get());
+ info.assign_scope = current_block;
+ info.inner_oper = r_oper;
+ info.trivial = r_trivial;
+ }
+}
+
+void ExpressionInliner::visit(Conditional &cond)
+{
+ visit_and_record(cond.condition, 0, false);
+ cond.body.visit(*this);
+}
+
+void ExpressionInliner::visit(Iteration &iter)
+{
+ SetForScope<Block *> set_block(current_block, &iter.body);
+ if(iter.init_statement)
+ {
+ SetFlag set_init(iteration_init);
+ iter.init_statement->visit(*this);
+ }
+
+ SetForScope<Block *> set_body(iteration_body, &iter.body);
+ if(iter.condition)
+ iter.condition->visit(*this);
+ iter.body.visit(*this);
+ if(iter.loop_expression)
+ iter.loop_expression->visit(*this);
+}
+
+void ExpressionInliner::visit(Return &ret)
+{
+ if(ret.expression)
+ visit_and_record(ret.expression, 0, false);
+}
+
+
+void ConstantConditionEliminator::apply(Stage &stage)
+{
+ stage.content.visit(*this);
+ NodeRemover().apply(stage, nodes_to_remove);
+}
+
+void ConstantConditionEliminator::visit(Block &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);
+ }
}
void ConstantConditionEliminator::visit(Conditional &cond)
{
- if(!record_only)
+ ExpressionEvaluator eval;
+ cond.condition->visit(eval);
+ if(eval.is_result_valid())
{
- ExpressionEvaluator eval(variable_values);
- cond.condition->visit(eval);
- if(eval.is_result_valid())
- {
- Block &block = (eval.get_result() ? cond.body : cond.else_body);
- current_block->body.splice(insert_point, block.body);
- nodes_to_remove.insert(&cond);
- return;
- }
+ Block &block = (eval.get_result() ? cond.body : cond.else_body);
+ current_block->body.splice(insert_point, block.body);
+ nodes_to_remove.insert(&cond);
+ return;
}
TraversingVisitor::visit(cond);
void ConstantConditionEliminator::visit(Iteration &iter)
{
- if(!record_only)
+ if(iter.condition)
{
- if(iter.condition)
+ /* If the loop condition is always false on the first iteration, the
+ entire loop can be removed */
+ ExpressionEvaluator::ValueMap values;
+ if(VariableDeclaration *var = dynamic_cast<VariableDeclaration *>(iter.init_statement.get()))
+ values[var] = var->init_expression.get();
+ ExpressionEvaluator eval(values);
+ iter.condition->visit(eval);
+ if(eval.is_result_valid() && !eval.get_result())
{
- /* 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.is_result_valid() && !eval.get_result())
- {
- nodes_to_remove.insert(&iter);
- return;
- }
+ nodes_to_remove.insert(&iter);
+ 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);
}
TraversingVisitor::visit(iter);
-
- if(VariableDeclaration *init_decl = dynamic_cast<VariableDeclaration *>(iter.init_statement.get()))
- variable_values.erase(init_decl);
}
virtual void visit(Return &);
};
+/** Inlines variables into expressions. Variables with trivial values (those
+consisting of a single literal or variable reference) are always inlined.
+Variables which are only referenced once are also inlined. */
+class ExpressionInliner: private TraversingVisitor
+{
+private:
+ struct ExpressionInfo
+ {
+ Expression *expression;
+ Block *assign_scope;
+ RefPtr<Expression> *inline_point;
+ const Operator *inner_oper;
+ const Operator *outer_oper;
+ bool inline_on_rhs;
+ bool trivial;
+ bool available;
+
+ ExpressionInfo();
+ };
+
+ std::map<VariableDeclaration *, ExpressionInfo> expressions;
+ ExpressionInfo *r_ref_info;
+ bool r_any_inlined;
+ bool r_trivial;
+ bool mutating;
+ bool iteration_init;
+ Block *iteration_body;
+ const Operator *r_oper;
+
+public:
+ ExpressionInliner();
+
+ bool apply(Stage &);
+
+private:
+ void visit_and_record(RefPtr<Expression> &, const Operator *, bool);
+ void inline_expression(Expression &, RefPtr<Expression> &, const Operator *, const Operator *, bool);
+ virtual void visit(Block &);
+ virtual void visit(VariableReference &);
+ virtual void visit(MemberAccess &);
+ virtual void visit(UnaryExpression &);
+ virtual void visit(BinaryExpression &);
+ virtual void visit(Assignment &);
+ virtual void visit(FunctionCall &);
+ virtual void visit(VariableDeclaration &);
+ virtual void visit(Conditional &);
+ virtual void visit(Iteration &);
+ virtual void visit(Return &);
+};
+
/** Removes conditional statements and loops where the condition can be
determined as constant at compile time. */
class ConstantConditionEliminator: private TraversingVisitor
{
private:
- bool record_only;
- ExpressionEvaluator::ValueMap variable_values;
NodeList<Statement>::iterator insert_point;
std::set<Node *> nodes_to_remove;
public:
- ConstantConditionEliminator();
-
void apply(Stage &);
private:
virtual void visit(Block &);
- virtual void visit(UnaryExpression &);
- virtual void visit(Assignment &);
- virtual void visit(VariableDeclaration &);
virtual void visit(Conditional &);
virtual void visit(Iteration &);
};
projects / libs / gl.git / commitdiff