#include <msp/core/raii.h>
#include <msp/strings/format.h>
#include "optimize.h"
+#include "reflect.h"
using namespace std;
namespace GL {
namespace SL {
+ConstantSpecializer::ConstantSpecializer():
+ values(0)
+{ }
+
+void ConstantSpecializer::apply(Stage &stage, const map<string, int> &v)
+{
+ values = &v;
+ stage.content.visit(*this);
+}
+
+void ConstantSpecializer::visit(VariableDeclaration &var)
+{
+ bool specializable = false;
+ if(var.layout)
+ {
+ vector<Layout::Qualifier> &qualifiers = var.layout->qualifiers;
+ for(vector<Layout::Qualifier>::iterator i=qualifiers.begin(); (!specializable && i!=qualifiers.end()); ++i)
+ if(i->name=="constant_id")
+ {
+ specializable = true;
+ qualifiers.erase(i);
+ }
+
+ if(qualifiers.empty())
+ var.layout = 0;
+ }
+
+ if(specializable)
+ {
+ map<string, int>::const_iterator i = values->find(var.name);
+ if(i!=values->end())
+ {
+ RefPtr<Literal> literal = new Literal;
+ if(var.type=="bool")
+ {
+ literal->token = (i->second ? "true" : "false");
+ literal->value = static_cast<bool>(i->second);
+ }
+ else if(var.type=="int")
+ {
+ literal->token = lexical_cast<string>(i->second);
+ literal->value = i->second;
+ }
+ var.init_expression = literal;
+ }
+ }
+}
+
+
InlineableFunctionLocator::InlineableFunctionLocator():
current_function(0),
return_count(0)
++count;
/* Don't inline functions which are called more than once or are called
recursively. */
- if(count>1 || def==current_function)
+ if((count>1 && def->source!=BUILTIN_SOURCE) || def==current_function)
inlineable.erase(def);
}
void InlineableFunctionLocator::visit(FunctionDeclaration &func)
{
+ bool has_out_params = false;
+ for(NodeArray<VariableDeclaration>::const_iterator i=func.parameters.begin(); (!has_out_params && i!=func.parameters.end()); ++i)
+ has_out_params = ((*i)->interface=="out");
+
unsigned &count = refcounts[func.definition];
- if(count<=1 && func.parameters.empty())
+ if((count<=1 || func.source==BUILTIN_SOURCE) && !has_out_params)
inlineable.insert(func.definition);
SetForScope<FunctionDeclaration *> set(current_function, &func);
InlineContentInjector::InlineContentInjector():
source_func(0),
- remap_names(false),
- deps_only(false)
+ pass(REFERENCED)
{ }
-const string &InlineContentInjector::apply(Stage &stage, FunctionDeclaration &target_func, Block &tgt_blk, const NodeList<Statement>::iterator &ins_pt, FunctionDeclaration &src)
+string InlineContentInjector::apply(Stage &stage, FunctionDeclaration &target_func, Block &tgt_blk, const NodeList<Statement>::iterator &ins_pt, FunctionCall &call)
{
- target_block = &tgt_blk;
- source_func = &src;
- for(NodeList<Statement>::iterator i=src.body.body.begin(); i!=src.body.body.end(); ++i)
+ source_func = call.declaration->definition;
+
+ /* Populate referenced_names from the target function so we can rename
+ variables from the inlined function that would conflict. */
+ pass = REFERENCED;
+ target_func.visit(*this);
+
+ /* Inline and rename passes must be interleaved so used variable names are
+ known when inlining the return statement. */
+ pass = INLINE;
+ staging_block.parent = &tgt_blk;
+ staging_block.variables.clear();
+
+ vector<RefPtr<VariableDeclaration> > params;
+ params.reserve(source_func->parameters.size());
+ for(NodeArray<VariableDeclaration>::iterator i=source_func->parameters.begin(); i!=source_func->parameters.end(); ++i)
+ {
+ RefPtr<VariableDeclaration> var = (*i)->clone();
+ var->interface.clear();
+
+ SetForScope<Pass> set_pass(pass, RENAME);
+ var->visit(*this);
+
+ staging_block.body.push_back_nocopy(var);
+ params.push_back(var);
+ }
+
+ for(NodeList<Statement>::iterator i=source_func->body.body.begin(); i!=source_func->body.body.end(); ++i)
{
r_inlined_statement = 0;
(*i)->visit(*this);
if(!r_inlined_statement)
r_inlined_statement = (*i)->clone();
- SetFlag set_remap(remap_names);
+ SetForScope<Pass> set_pass(pass, RENAME);
r_inlined_statement->visit(*this);
- tgt_blk.body.insert(ins_pt, r_inlined_statement);
+
+ staging_block.body.push_back_nocopy(r_inlined_statement);
}
- NodeReorderer().apply(stage, target_func, dependencies);
+ /* Now collect names from the staging block. Local variables that would
+ have conflicted with the target function were renamed earlier. */
+ pass = REFERENCED;
+ referenced_names.clear();
+ staging_block.variables.clear();
+ staging_block.visit(*this);
- return r_result_name;
-}
+ /* Rename variables in the target function so they don't interfere with
+ global identifiers used by the source function. */
+ pass = RENAME;
+ staging_block.parent = source_func->body.parent;
+ target_func.visit(*this);
-string InlineContentInjector::create_unused_name(const string &base, bool always_prefix)
-{
- string result = base;
- if(always_prefix || target_block->variables.count(result))
- result = format("_%s_%s", source_func->name, base);
- unsigned initial_size = result.size();
- for(unsigned i=1; target_block->variables.count(result); ++i)
- {
- result.erase(initial_size);
- result += format("_%d", i);
- }
- return result;
+ // Put the argument expressions in place after all renaming has been done.
+ for(unsigned i=0; i<source_func->parameters.size(); ++i)
+ params[i]->init_expression = call.arguments[i]->clone();
+
+ tgt_blk.body.splice(ins_pt, staging_block.body);
+
+ NodeReorderer().apply(stage, target_func, DependencyCollector().apply(*source_func));
+
+ return r_result_name;
}
void InlineContentInjector::visit(VariableReference &var)
{
- if(remap_names)
+ if(pass==RENAME)
{
- map<string, VariableDeclaration *>::const_iterator i = variable_map.find(var.name);
- if(i!=variable_map.end())
+ map<string, VariableDeclaration *>::const_iterator i = staging_block.variables.find(var.name);
+ if(i!=staging_block.variables.end())
var.name = i->second->name;
}
- else if(var.declaration)
- {
- SetFlag set_deps(deps_only);
- dependencies.insert(var.declaration);
- var.declaration->visit(*this);
- }
+ else if(pass==REFERENCED)
+ referenced_names.insert(var.name);
}
void InlineContentInjector::visit(InterfaceBlockReference &iface)
{
- if(!remap_names && iface.declaration)
- {
- SetFlag set_deps(deps_only);
- dependencies.insert(iface.declaration);
- iface.declaration->visit(*this);
- }
+ if(pass==REFERENCED)
+ referenced_names.insert(iface.name);
}
void InlineContentInjector::visit(FunctionCall &call)
{
- if(!remap_names && call.declaration)
- dependencies.insert(call.declaration);
+ if(pass==REFERENCED)
+ referenced_names.insert(call.name);
TraversingVisitor::visit(call);
}
{
TraversingVisitor::visit(var);
- if(var.type_declaration)
+ if(pass==RENAME)
{
- SetFlag set_deps(deps_only);
- dependencies.insert(var.type_declaration);
- var.type_declaration->visit(*this);
- }
-
- if(!remap_names && !deps_only)
- {
- RefPtr<VariableDeclaration> inlined_var = var.clone();
- inlined_var->name = create_unused_name(var.name, false);
- r_inlined_statement = inlined_var;
-
- variable_map[var.name] = inlined_var.get();
+ /* Check against conflicts with the other context as well as variables
+ already renamed here. */
+ bool conflict = (staging_block.variables.count(var.name) || referenced_names.count(var.name));
+ staging_block.variables[var.name] = &var;
+ if(conflict)
+ {
+ string mapped_name = get_unused_variable_name(staging_block, var.name);
+ if(mapped_name!=var.name)
+ {
+ staging_block.variables[mapped_name] = &var;
+ var.name = mapped_name;
+ }
+ }
}
+ else if(pass==REFERENCED)
+ referenced_names.insert(var.type);
}
void InlineContentInjector::visit(Return &ret)
{
TraversingVisitor::visit(ret);
- if(ret.expression)
+ if(pass==INLINE && ret.expression)
{
- /* Create a new variable to hold the return value of the inlined
- function. */
- r_result_name = create_unused_name("return", true);
+ // Create a new variable to hold the return value of the inlined function.
+ r_result_name = get_unused_variable_name(staging_block, "_return");
RefPtr<VariableDeclaration> var = new VariableDeclaration;
var->source = ret.source;
var->line = ret.line;
FunctionInliner::FunctionInliner():
current_function(0),
- r_any_inlined(false)
+ r_any_inlined(false),
+ r_inlined_here(false)
{ }
bool FunctionInliner::apply(Stage &s)
return r_any_inlined;
}
-void FunctionInliner::visit_and_inline(RefPtr<Expression> &ptr)
+void FunctionInliner::visit(RefPtr<Expression> &ptr)
{
r_inline_result = 0;
ptr->visit(*this);
ptr = r_inline_result;
r_any_inlined = true;
}
+ r_inline_result = 0;
}
void FunctionInliner::visit(Block &block)
{
SetForScope<Block *> set_block(current_block, &block);
SetForScope<NodeList<Statement>::iterator> save_insert_point(insert_point, block.body.begin());
- for(NodeList<Statement>::iterator i=block.body.begin(); i!=block.body.end(); ++i)
+ for(NodeList<Statement>::iterator i=block.body.begin(); (!r_inlined_here && i!=block.body.end()); ++i)
{
insert_point = i;
(*i)->visit(*this);
}
}
-void FunctionInliner::visit(UnaryExpression &unary)
-{
- visit_and_inline(unary.expression);
- r_inline_result = 0;
-}
-
-void FunctionInliner::visit(BinaryExpression &binary)
-{
- visit_and_inline(binary.left);
- visit_and_inline(binary.right);
- r_inline_result = 0;
-}
-
-void FunctionInliner::visit(MemberAccess &memacc)
-{
- visit_and_inline(memacc.left);
- r_inline_result = 0;
-}
-
void FunctionInliner::visit(FunctionCall &call)
{
- for(NodeArray<Expression>::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++i)
- visit_and_inline(*i);
+ for(NodeArray<Expression>::iterator i=call.arguments.begin(); (!r_inlined_here && i!=call.arguments.end()); ++i)
+ visit(*i);
+
+ if(r_inlined_here)
+ return;
FunctionDeclaration *def = call.declaration;
if(def)
if(def && inlineable.count(def))
{
- string result_name = InlineContentInjector().apply(*stage, *current_function, *current_block, insert_point, *def);
+ string result_name = InlineContentInjector().apply(*stage, *current_function, *current_block, insert_point, call);
// This will later get removed by UnusedVariableRemover.
if(result_name.empty())
- result_name = "msp_unused_from_inline";
+ result_name = "_msp_unused_from_inline";
RefPtr<VariableReference> ref = new VariableReference;
ref->name = result_name;
/* Inlined variables need to be resolved before this function can be
inlined further. */
inlineable.erase(current_function);
+ r_inlined_here = true;
}
- else
- r_inline_result = 0;
-}
-
-void FunctionInliner::visit(ExpressionStatement &expr)
-{
- visit_and_inline(expr.expression);
-}
-
-void FunctionInliner::visit(VariableDeclaration &var)
-{
- if(var.init_expression)
- visit_and_inline(var.init_expression);
- r_inline_result = 0;
}
void FunctionInliner::visit(FunctionDeclaration &func)
{
SetForScope<FunctionDeclaration *> set_func(current_function, &func);
TraversingVisitor::visit(func);
-}
-
-void FunctionInliner::visit(Conditional &cond)
-{
- visit_and_inline(cond.condition);
- cond.body.visit(*this);
+ r_inlined_here = false;
}
void FunctionInliner::visit(Iteration &iter)
iter.body.visit(*this);
}
-void FunctionInliner::visit(Return &ret)
-{
- if(ret.expression)
- visit_and_inline(ret.expression);
-}
-
-
-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)
-{ }
-
ExpressionInliner::ExpressionInliner():
r_ref_info(0),
return r_any_inlined;
}
-void ExpressionInliner::visit_and_record(RefPtr<Expression> &ptr, const Operator *outer_oper, bool on_rhs)
+void ExpressionInliner::inline_expression(Expression &expr, RefPtr<Expression> &ptr)
+{
+ ptr = expr.clone();
+ r_any_inlined = true;
+}
+
+void ExpressionInliner::visit(Block &block)
+{
+ TraversingVisitor::visit(block);
+
+ for(map<string, VariableDeclaration *>::iterator i=block.variables.begin(); i!=block.variables.end(); ++i)
+ {
+ map<Assignment::Target, ExpressionInfo>::iterator j = expressions.lower_bound(i->second);
+ for(; (j!=expressions.end() && j->first.declaration==i->second); )
+ {
+ if(j->second.expression && j->second.inline_point)
+ inline_expression(*j->second.expression, *j->second.inline_point);
+
+ expressions.erase(j++);
+ }
+ }
+
+ /* Expressions assigned in this block may depend on local variables of the
+ block. If this is a conditionally executed block, the assignments might not
+ always happen. Mark the expressions as not available to any outer blocks. */
+ for(map<Assignment::Target, ExpressionInfo>::iterator i=expressions.begin(); i!=expressions.end(); ++i)
+ if(i->second.assign_scope==&block)
+ i->second.available = false;
+}
+
+void ExpressionInliner::visit(RefPtr<Expression> &expr)
{
r_ref_info = 0;
- ptr->visit(*this);
+ expr->visit(*this);
if(r_ref_info && r_ref_info->expression && r_ref_info->available)
{
if(iteration_body && !r_ref_info->trivial)
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);
+ inline_expression(*r_ref_info->expression, expr);
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;
- }
+ r_ref_info->inline_point = &expr;
}
+ r_oper = expr->oper;
+ r_ref_info = 0;
}
void ExpressionInliner::visit(VariableReference &var)
{
if(var.declaration)
{
- map<VariableDeclaration *, ExpressionInfo>::iterator i = expressions.find(var.declaration);
+ map<Assignment::Target, ExpressionInfo>::iterator i = expressions.find(var.declaration);
if(i!=expressions.end())
{
/* If a non-trivial expression is referenced multiple times, don't
void ExpressionInliner::visit(MemberAccess &memacc)
{
- visit_and_record(memacc.left, memacc.oper, false);
- r_ref_info = 0;
- r_oper = memacc.oper;
+ visit(memacc.left);
+ r_trivial = false;
+}
+
+void ExpressionInliner::visit(Swizzle &swizzle)
+{
+ visit(swizzle.left);
r_trivial = false;
}
void ExpressionInliner::visit(UnaryExpression &unary)
{
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;
+ visit(unary.expression);
r_trivial = false;
}
void ExpressionInliner::visit(BinaryExpression &binary)
{
- visit_and_record(binary.left, binary.oper, false);
+ visit(binary.left);
{
SetFlag clear_target(mutating, false);
- visit_and_record(binary.right, binary.oper, true);
+ visit(binary.right);
}
- r_ref_info = 0;
- r_oper = binary.oper;
r_trivial = false;
}
{
{
SetFlag set_target(mutating);
- visit_and_record(assign.left, assign.oper, false);
+ visit(assign.left);
}
r_oper = 0;
- visit_and_record(assign.right, assign.oper, true);
+ visit(assign.right);
- if(assign.target_declaration)
+ map<Assignment::Target, ExpressionInfo>::iterator i = expressions.find(assign.target);
+ if(i!=expressions.end())
{
- 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;
- }
+ /* 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.available = true;
}
- r_ref_info = 0;
- r_oper = assign.oper;
+ r_trivial = false;
+}
+
+void ExpressionInliner::visit(TernaryExpression &ternary)
+{
+ visit(ternary.condition);
+ visit(ternary.true_expr);
+ visit(ternary.false_expr);
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;
+ TraversingVisitor::visit(call);
r_trivial = false;
}
{
r_oper = 0;
r_trivial = true;
- if(var.init_expression)
- visit_and_record(var.init_expression, 0, false);
+ TraversingVisitor::visit(var);
bool constant = var.constant;
if(constant && var.layout)
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);
SetForScope<Block *> set_body(iteration_body, &iter.body);
if(iter.condition)
- iter.condition->visit(*this);
+ visit(iter.condition);
iter.body.visit(*this);
if(iter.loop_expression)
- iter.loop_expression->visit(*this);
+ visit(iter.loop_expression);
+}
+
+
+BasicTypeDeclaration::Kind ConstantFolder::get_value_kind(const Variant &value)
+{
+ if(value.check_type<bool>())
+ return BasicTypeDeclaration::BOOL;
+ else if(value.check_type<int>())
+ return BasicTypeDeclaration::INT;
+ else if(value.check_type<float>())
+ return BasicTypeDeclaration::FLOAT;
+ else
+ return BasicTypeDeclaration::VOID;
+}
+
+template<typename T>
+T ConstantFolder::evaluate_logical(char oper, T left, T right)
+{
+ switch(oper)
+ {
+ case '&': return left&right;
+ case '|': return left|right;
+ case '^': return left^right;
+ default: return T();
+ }
+}
+
+template<typename T>
+bool ConstantFolder::evaluate_relation(const char *oper, T left, T right)
+{
+ switch(oper[0]|oper[1])
+ {
+ case '<': return left<right;
+ case '<'|'=': return left<=right;
+ case '>': return left>right;
+ case '>'|'=': return left>=right;
+ default: return false;
+ }
+}
+
+template<typename T>
+T ConstantFolder::evaluate_arithmetic(char oper, T left, T right)
+{
+ switch(oper)
+ {
+ case '+': return left+right;
+ case '-': return left-right;
+ case '*': return left*right;
+ case '/': return left/right;
+ default: return T();
+ }
+}
+
+void ConstantFolder::set_result(const Variant &value, bool literal)
+{
+ r_constant_value = value;
+ r_constant = true;
+ r_literal = literal;
+}
+
+void ConstantFolder::visit(RefPtr<Expression> &expr)
+{
+ r_constant_value = Variant();
+ r_constant = false;
+ r_literal = false;
+ r_uses_iter_var = false;
+ expr->visit(*this);
+ /* Don't replace literals since they'd only be replaced with an identical
+ literal. Also skip anything that uses an iteration variable, but pass on
+ the result so the Iteration visiting function can handle it. */
+ if(!r_constant || r_literal || r_uses_iter_var)
+ return;
+
+ BasicTypeDeclaration::Kind kind = get_value_kind(r_constant_value);
+ if(kind==BasicTypeDeclaration::VOID)
+ {
+ r_constant = false;
+ return;
+ }
+
+ RefPtr<Literal> literal = new Literal;
+ if(kind==BasicTypeDeclaration::BOOL)
+ literal->token = (r_constant_value.value<bool>() ? "true" : "false");
+ else if(kind==BasicTypeDeclaration::INT)
+ literal->token = lexical_cast<string>(r_constant_value.value<int>());
+ else if(kind==BasicTypeDeclaration::FLOAT)
+ literal->token = lexical_cast<string>(r_constant_value.value<float>());
+ literal->value = r_constant_value;
+ expr = literal;
+}
+
+void ConstantFolder::visit(Literal &literal)
+{
+ set_result(literal.value, true);
+}
+
+void ConstantFolder::visit(VariableReference &var)
+{
+ /* If an iteration variable is initialized with a constant value, return
+ that value here for the purpose of evaluating the loop condition for the
+ first iteration. */
+ if(var.declaration==iteration_var)
+ {
+ set_result(iter_init_value);
+ r_uses_iter_var = true;
+ }
+}
+
+void ConstantFolder::visit(MemberAccess &memacc)
+{
+ TraversingVisitor::visit(memacc);
+ r_constant = false;
+}
+
+void ConstantFolder::visit(Swizzle &swizzle)
+{
+ TraversingVisitor::visit(swizzle);
+ r_constant = false;
+}
+
+void ConstantFolder::visit(UnaryExpression &unary)
+{
+ TraversingVisitor::visit(unary);
+ bool can_fold = r_constant;
+ r_constant = false;
+ if(!can_fold)
+ return;
+
+ BasicTypeDeclaration::Kind kind = get_value_kind(r_constant_value);
+
+ char oper = unary.oper->token[0];
+ char oper2 = unary.oper->token[1];
+ if(oper=='!')
+ {
+ if(kind==BasicTypeDeclaration::BOOL)
+ set_result(!r_constant_value.value<bool>());
+ }
+ else if(oper=='~')
+ {
+ if(kind==BasicTypeDeclaration::INT)
+ set_result(~r_constant_value.value<int>());
+ }
+ else if(oper=='-' && !oper2)
+ {
+ if(kind==BasicTypeDeclaration::INT)
+ set_result(-r_constant_value.value<int>());
+ else if(kind==BasicTypeDeclaration::FLOAT)
+ set_result(-r_constant_value.value<float>());
+ }
+}
+
+void ConstantFolder::visit(BinaryExpression &binary)
+{
+ visit(binary.left);
+ bool left_constant = r_constant;
+ bool left_iter_var = r_uses_iter_var;
+ Variant left_value = r_constant_value;
+ visit(binary.right);
+ if(left_iter_var)
+ r_uses_iter_var = true;
+
+ bool can_fold = (left_constant && r_constant);
+ r_constant = false;
+ if(!can_fold)
+ return;
+
+ BasicTypeDeclaration::Kind left_kind = get_value_kind(left_value);
+ BasicTypeDeclaration::Kind right_kind = get_value_kind(r_constant_value);
+ // Currently only expressions with both sides of equal types are handled.
+ if(left_kind!=right_kind)
+ return;
+
+ char oper = binary.oper->token[0];
+ char oper2 = binary.oper->token[1];
+ if(oper=='&' || oper=='|' || oper=='^')
+ {
+ if(oper2==oper && left_kind==BasicTypeDeclaration::BOOL)
+ set_result(evaluate_logical(oper, left_value.value<bool>(), r_constant_value.value<bool>()));
+ else if(!oper2 && left_kind==BasicTypeDeclaration::INT)
+ set_result(evaluate_logical(oper, left_value.value<int>(), r_constant_value.value<int>()));
+ }
+ else if((oper=='<' || oper=='>') && oper2!=oper)
+ {
+ if(left_kind==BasicTypeDeclaration::INT)
+ set_result(evaluate_relation(binary.oper->token, left_value.value<int>(), r_constant_value.value<int>()));
+ else if(left_kind==BasicTypeDeclaration::FLOAT)
+ set_result(evaluate_relation(binary.oper->token, left_value.value<float>(), r_constant_value.value<float>()));
+ }
+ else if((oper=='=' || oper=='!') && oper2=='=')
+ {
+ if(left_kind==BasicTypeDeclaration::INT)
+ set_result((left_value.value<int>()==r_constant_value.value<int>()) == (oper=='='));
+ if(left_kind==BasicTypeDeclaration::FLOAT)
+ set_result((left_value.value<float>()==r_constant_value.value<float>()) == (oper=='='));
+ }
+ else if(oper=='+' || oper=='-' || oper=='*' || oper=='/')
+ {
+ if(left_kind==BasicTypeDeclaration::INT)
+ set_result(evaluate_arithmetic(oper, left_value.value<int>(), r_constant_value.value<int>()));
+ else if(left_kind==BasicTypeDeclaration::FLOAT)
+ set_result(evaluate_arithmetic(oper, left_value.value<float>(), r_constant_value.value<float>()));
+ }
+ else if(oper=='%' || ((oper=='<' || oper=='>') && oper2==oper))
+ {
+ if(left_kind!=BasicTypeDeclaration::INT)
+ return;
+
+ if(oper=='%')
+ set_result(left_value.value<int>()%r_constant_value.value<int>());
+ else if(oper=='<')
+ set_result(left_value.value<int>()<<r_constant_value.value<int>());
+ else if(oper=='>')
+ set_result(left_value.value<int>()>>r_constant_value.value<int>());
+ }
+}
+
+void ConstantFolder::visit(Assignment &assign)
+{
+ TraversingVisitor::visit(assign);
+ r_constant = false;
+}
+
+void ConstantFolder::visit(TernaryExpression &ternary)
+{
+ TraversingVisitor::visit(ternary);
+ r_constant = false;
+}
+
+void ConstantFolder::visit(FunctionCall &call)
+{
+ TraversingVisitor::visit(call);
+ r_constant = false;
+}
+
+void ConstantFolder::visit(VariableDeclaration &var)
+{
+ if(iteration_init && var.init_expression)
+ {
+ visit(var.init_expression);
+ if(r_constant)
+ {
+ /* Record the value of a constant initialization expression of an
+ iteration, so it can be used to evaluate the loop condition. */
+ iteration_var = &var;
+ iter_init_value = r_constant_value;
+ }
+ }
+ else
+ TraversingVisitor::visit(var);
}
-void ExpressionInliner::visit(Return &ret)
+void ConstantFolder::visit(Iteration &iter)
{
- if(ret.expression)
- visit_and_record(ret.expression, 0, false);
+ SetForScope<Block *> set_block(current_block, &iter.body);
+
+ /* The iteration variable is not normally inlined into expressions, so we
+ process it specially here. If the initial value causes the loop condition
+ to evaluate to false, then the expression can be folded. */
+ iteration_var = 0;
+ if(iter.init_statement)
+ {
+ SetFlag set_init(iteration_init);
+ iter.init_statement->visit(*this);
+ }
+
+ if(iter.condition)
+ {
+ visit(iter.condition);
+ if(r_constant && r_constant_value.check_type<bool>() && !r_constant_value.value<bool>())
+ {
+ RefPtr<Literal> literal = new Literal;
+ literal->token = "false";
+ literal->value = r_constant_value;
+ iter.condition = literal;
+ }
+ }
+ iteration_var = 0;
+
+ iter.body.visit(*this);
+ if(iter.loop_expression)
+ visit(iter.loop_expression);
}
NodeRemover().apply(stage, nodes_to_remove);
}
+ConstantConditionEliminator::ConstantStatus ConstantConditionEliminator::check_constant_condition(const Expression &expr)
+{
+ if(const Literal *literal = dynamic_cast<const Literal *>(&expr))
+ if(literal->value.check_type<bool>())
+ return (literal->value.value<bool>() ? CONSTANT_TRUE : CONSTANT_FALSE);
+ return NOT_CONSTANT;
+}
+
void ConstantConditionEliminator::visit(Block &block)
{
SetForScope<Block *> set_block(current_block, &block);
}
}
+void ConstantConditionEliminator::visit(RefPtr<Expression> &expr)
+{
+ r_ternary_result = 0;
+ expr->visit(*this);
+ if(r_ternary_result)
+ expr = r_ternary_result;
+ r_ternary_result = 0;
+}
+
+void ConstantConditionEliminator::visit(TernaryExpression &ternary)
+{
+ ConstantStatus result = check_constant_condition(*ternary.condition);
+ if(result!=NOT_CONSTANT)
+ r_ternary_result = (result==CONSTANT_TRUE ? ternary.true_expr : ternary.false_expr);
+ else
+ r_ternary_result = 0;
+}
+
void ConstantConditionEliminator::visit(Conditional &cond)
{
- ExpressionEvaluator eval;
- cond.condition->visit(eval);
- if(eval.is_result_valid())
+ ConstantStatus result = check_constant_condition(*cond.condition);
+ if(result!=NOT_CONSTANT)
{
- Block &block = (eval.get_result() ? cond.body : cond.else_body);
+ Block &block = (result==CONSTANT_TRUE ? cond.body : cond.else_body);
+ // TODO should check variable names for conflicts. Potentially reuse InlineContentInjector?
current_block->body.splice(insert_point, block.body);
nodes_to_remove.insert(&cond);
return;
{
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())
+ ConstantStatus result = check_constant_condition(*iter.condition);
+ if(result==CONSTANT_FALSE)
{
nodes_to_remove.insert(&iter);
return;
}
-UnusedVariableRemover::VariableInfo::VariableInfo():
- local(false),
- conditionally_assigned(false),
- referenced(false)
+UnreachableCodeRemover::UnreachableCodeRemover():
+ reachable(true)
{ }
+bool UnreachableCodeRemover::apply(Stage &stage)
+{
+ stage.content.visit(*this);
+ NodeRemover().apply(stage, unreachable_nodes);
+ return !unreachable_nodes.empty();
+}
+
+void UnreachableCodeRemover::visit(Block &block)
+{
+ NodeList<Statement>::iterator i = block.body.begin();
+ for(; (reachable && i!=block.body.end()); ++i)
+ (*i)->visit(*this);
+ for(; i!=block.body.end(); ++i)
+ unreachable_nodes.insert(i->get());
+}
+
+void UnreachableCodeRemover::visit(FunctionDeclaration &func)
+{
+ TraversingVisitor::visit(func);
+ reachable = true;
+}
+
+void UnreachableCodeRemover::visit(Conditional &cond)
+{
+ cond.body.visit(*this);
+ bool reachable_if_true = reachable;
+ reachable = true;
+ cond.else_body.visit(*this);
+
+ reachable |= reachable_if_true;
+}
+
+void UnreachableCodeRemover::visit(Iteration &iter)
+{
+ TraversingVisitor::visit(iter);
+
+ /* Always consider code after a loop reachable, since there's no checking
+ for whether the loop executes. */
+ reachable = true;
+}
+
+
+bool UnusedTypeRemover::apply(Stage &stage)
+{
+ stage.content.visit(*this);
+ NodeRemover().apply(stage, unused_nodes);
+ return !unused_nodes.empty();
+}
+
+void UnusedTypeRemover::visit(RefPtr<Expression> &expr)
+{
+ unused_nodes.erase(expr->type);
+ TraversingVisitor::visit(expr);
+}
+
+void UnusedTypeRemover::visit(BasicTypeDeclaration &type)
+{
+ if(type.base_type)
+ unused_nodes.erase(type.base_type);
+ unused_nodes.insert(&type);
+}
+
+void UnusedTypeRemover::visit(ImageTypeDeclaration &type)
+{
+ if(type.base_type)
+ unused_nodes.erase(type.base_type);
+ unused_nodes.insert(&type);
+}
+
+void UnusedTypeRemover::visit(StructDeclaration &strct)
+{
+ unused_nodes.insert(&strct);
+ TraversingVisitor::visit(strct);
+}
+
+void UnusedTypeRemover::visit(VariableDeclaration &var)
+{
+ unused_nodes.erase(var.type_declaration);
+ TraversingVisitor::visit(var);
+}
+
+void UnusedTypeRemover::visit(InterfaceBlock &iface)
+{
+ unused_nodes.erase(iface.type_declaration);
+}
+
+void UnusedTypeRemover::visit(FunctionDeclaration &func)
+{
+ unused_nodes.erase(func.return_type_declaration);
+ TraversingVisitor::visit(func);
+}
+
UnusedVariableRemover::UnusedVariableRemover():
- aggregate(0),
+ stage(0),
+ interface_block(0),
r_assignment(0),
assignment_target(false),
- r_assign_to_subfield(false),
- r_side_effects(false)
+ r_side_effects(false),
+ in_struct(false),
+ composite_reference(false)
{ }
-bool UnusedVariableRemover::apply(Stage &stage)
+bool UnusedVariableRemover::apply(Stage &s)
{
- variables.push_back(BlockVariableMap());
- stage.content.visit(*this);
- BlockVariableMap &global_variables = variables.back();
- for(BlockVariableMap::iterator i=global_variables.begin(); i!=global_variables.end(); ++i)
+ stage = &s;
+ s.content.visit(*this);
+
+ for(list<AssignmentInfo>::const_iterator i=assignments.begin(); i!=assignments.end(); ++i)
+ if(i->used_by.empty())
+ unused_nodes.insert(i->node);
+
+ for(BlockVariableMap::const_iterator i=variables.begin(); i!=variables.end(); ++i)
{
- /* Don't remove output variables which are used by the next stage or the
- graphics API. */
- if(i->first->interface=="out" && (stage.type==Stage::FRAGMENT || i->first->linked_declaration || !i->first->name.compare(0, 3, "gl_")))
- continue;
+ if(i->second.output)
+ {
+ /* The last visible assignments of output variables are used by the
+ next stage or the API. */
+ for(vector<AssignmentInfo *>::const_iterator j=i->second.assignments.begin(); j!=i->second.assignments.end(); ++j)
+ unused_nodes.erase((*j)->node);
+ }
- // Mark other unreferenced global variables as unused.
- if(!i->second.referenced)
+ if(!i->second.output && !i->second.referenced)
{
- unused_nodes.insert(i->first);
- clear_assignments(i->second, true);
+ // Don't remove variables from inside interface blocks.
+ if(!i->second.interface_block)
+ unused_nodes.insert(i->first);
}
+ else if(i->second.interface_block)
+ // Interface blocks are kept if even one member is used.
+ unused_nodes.erase(i->second.interface_block);
}
- variables.pop_back();
- NodeRemover().apply(stage, unused_nodes);
+ NodeRemover().apply(s, unused_nodes);
return !unused_nodes.empty();
}
-void UnusedVariableRemover::visit(VariableReference &var)
+void UnusedVariableRemover::referenced(const Assignment::Target &target, Node &node)
{
- map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
- if(i!=aggregates.end())
- unused_nodes.erase(i->second);
-
- if(var.declaration && !assignment_target)
+ VariableInfo &var_info = variables[target.declaration];
+ var_info.referenced = true;
+ if(!assignment_target)
{
- VariableInfo &var_info = variables.back()[var.declaration];
- // Previous assignments are used by this reference.
- clear_assignments(var_info, false);
- var_info.referenced = true;
+ for(vector<AssignmentInfo *>::const_iterator i=var_info.assignments.begin(); i!=var_info.assignments.end(); ++i)
+ {
+ bool covered = true;
+ for(unsigned j=0; (covered && j<(*i)->target.chain_len && j<target.chain_len); ++j)
+ {
+ Assignment::Target::ChainType type1 = static_cast<Assignment::Target::ChainType>((*i)->target.chain[j]&0xC0);
+ Assignment::Target::ChainType type2 = static_cast<Assignment::Target::ChainType>(target.chain[j]&0xC0);
+ if(type1==Assignment::Target::SWIZZLE || type2==Assignment::Target::SWIZZLE)
+ {
+ unsigned index1 = (*i)->target.chain[j]&0x3F;
+ unsigned index2 = target.chain[j]&0x3F;
+ if(type1==Assignment::Target::SWIZZLE && type2==Assignment::Target::SWIZZLE)
+ covered = index1&index2;
+ else if(type1==Assignment::Target::ARRAY && index1<4)
+ covered = index2&(1<<index1);
+ else if(type2==Assignment::Target::ARRAY && index2<4)
+ covered = index1&(1<<index2);
+ /* If it's some other combination (shouldn't happen), leave
+ covered as true */
+ }
+ else
+ covered = ((*i)->target.chain[j]==target.chain[j]);
+ }
+ if(covered)
+ (*i)->used_by.push_back(&node);
+ }
}
}
+void UnusedVariableRemover::visit(VariableReference &var)
+{
+ if(composite_reference)
+ r_reference.declaration = var.declaration;
+ else
+ referenced(var.declaration, var);
+}
+
void UnusedVariableRemover::visit(InterfaceBlockReference &iface)
{
- unused_nodes.erase(iface.declaration);
+ if(composite_reference)
+ r_reference.declaration = iface.declaration;
+ else
+ referenced(iface.declaration, iface);
+}
+
+void UnusedVariableRemover::visit_composite(Expression &expr)
+{
+ if(!composite_reference)
+ r_reference = Assignment::Target();
+
+ SetFlag set_composite(composite_reference);
+ expr.visit(*this);
}
void UnusedVariableRemover::visit(MemberAccess &memacc)
{
- if(assignment_target)
- r_assign_to_subfield = true;
- TraversingVisitor::visit(memacc);
- unused_nodes.erase(memacc.declaration);
+ visit_composite(*memacc.left);
+
+ add_to_chain(r_reference, Assignment::Target::MEMBER, memacc.index);
+
+ if(!composite_reference && r_reference.declaration)
+ referenced(r_reference, memacc);
+}
+
+void UnusedVariableRemover::visit(Swizzle &swizzle)
+{
+ visit_composite(*swizzle.left);
+
+ unsigned mask = 0;
+ for(unsigned i=0; i<swizzle.count; ++i)
+ mask |= 1<<swizzle.components[i];
+ add_to_chain(r_reference, Assignment::Target::SWIZZLE, mask);
+
+ if(!composite_reference && r_reference.declaration)
+ referenced(r_reference, swizzle);
}
void UnusedVariableRemover::visit(UnaryExpression &unary)
{
if(binary.oper->token[0]=='[')
{
- if(assignment_target)
- r_assign_to_subfield = true;
- binary.left->visit(*this);
- SetFlag set(assignment_target, false);
- binary.right->visit(*this);
+ visit_composite(*binary.left);
+
+ {
+ SetFlag clear_assignment(assignment_target, false);
+ SetFlag clear_composite(composite_reference, false);
+ binary.right->visit(*this);
+ }
+
+ add_to_chain(r_reference, Assignment::Target::ARRAY, 0x3F);
+
+ if(!composite_reference && r_reference.declaration)
+ referenced(r_reference, binary);
}
else
+ {
+ SetFlag clear_composite(composite_reference, false);
TraversingVisitor::visit(binary);
+ }
+}
+
+void UnusedVariableRemover::visit(TernaryExpression &ternary)
+{
+ SetFlag clear_composite(composite_reference, false);
+ TraversingVisitor::visit(ternary);
}
void UnusedVariableRemover::visit(Assignment &assign)
{
{
- SetFlag set(assignment_target, !assign.self_referencing);
+ SetFlag set(assignment_target, (assign.oper->token[0]=='='));
assign.left->visit(*this);
}
assign.right->visit(*this);
void UnusedVariableRemover::visit(FunctionCall &call)
{
+ SetFlag clear_composite(composite_reference, false);
TraversingVisitor::visit(call);
/* Treat function calls as having side effects so expression statements
consisting of nothing but a function call won't be optimized away. */
r_side_effects = true;
-}
-void UnusedVariableRemover::record_assignment(VariableDeclaration &var, Node &node, bool chained)
-{
- VariableInfo &var_info = variables.back()[&var];
- /* An assignment which completely replaces the value of the variable causes
- any previous unreferenced assignments to be unused. */
- if(!chained)
- clear_assignments(var_info, true);
- var_info.assignments.push_back(&node);
- var_info.conditionally_assigned = false;
+ if(stage->type==Stage::GEOMETRY && call.name=="EmitVertex")
+ {
+ for(map<Statement *, VariableInfo>::const_iterator i=variables.begin(); i!=variables.end(); ++i)
+ if(i->second.output)
+ referenced(i->first, call);
+ }
}
-void UnusedVariableRemover::clear_assignments(VariableInfo &var_info, bool mark_unused)
+void UnusedVariableRemover::record_assignment(const Assignment::Target &target, Node &node)
{
- if(mark_unused)
+ assignments.push_back(AssignmentInfo());
+ AssignmentInfo &assign_info = assignments.back();
+ assign_info.node = &node;
+ assign_info.target = target;
+
+ /* An assignment to the target hides any assignments to the same target or
+ its subfields. */
+ VariableInfo &var_info = variables[target.declaration];
+ for(unsigned i=0; i<var_info.assignments.size(); ++i)
{
- for(vector<Node *>::iterator i=var_info.assignments.begin(); i!=var_info.assignments.end(); ++i)
- unused_nodes.insert(*i);
+ const Assignment::Target &t = var_info.assignments[i]->target;
+
+ bool subfield = (t.chain_len>=target.chain_len);
+ for(unsigned j=0; (subfield && j<target.chain_len); ++j)
+ subfield = (t.chain[j]==target.chain[j]);
+
+ if(subfield)
+ var_info.assignments.erase(var_info.assignments.begin()+i);
+ else
+ ++i;
}
- var_info.assignments.clear();
+
+ var_info.assignments.push_back(&assign_info);
}
void UnusedVariableRemover::visit(ExpressionStatement &expr)
{
r_assignment = 0;
- r_assign_to_subfield = false;
r_side_effects = false;
TraversingVisitor::visit(expr);
- if(r_assignment && r_assignment->target_declaration)
- record_assignment(*r_assignment->target_declaration, expr, (r_assignment->self_referencing || r_assign_to_subfield));
+ if(r_assignment && r_assignment->target.declaration)
+ record_assignment(r_assignment->target, expr);
if(!r_side_effects)
unused_nodes.insert(&expr);
}
void UnusedVariableRemover::visit(StructDeclaration &strct)
{
- SetForScope<Node *> set(aggregate, &strct);
- unused_nodes.insert(&strct);
+ SetFlag set_struct(in_struct);
TraversingVisitor::visit(strct);
}
void UnusedVariableRemover::visit(VariableDeclaration &var)
{
- if(aggregate)
- aggregates[&var] = aggregate;
+ TraversingVisitor::visit(var);
+
+ if(in_struct)
+ return;
+
+ VariableInfo &var_info = variables[&var];
+ var_info.interface_block = interface_block;
+
+ /* Mark variables as output if they're used by the next stage or the
+ graphics API. */
+ if(interface_block)
+ var_info.output = (interface_block->interface=="out" && (interface_block->linked_block || !interface_block->block_name.compare(0, 3, "gl_")));
else
+ var_info.output = (var.interface=="out" && (stage->type==Stage::FRAGMENT || var.linked_declaration || !var.name.compare(0, 3, "gl_")));
+
+ if(var.init_expression)
{
- variables.back()[&var].local = true;
- if(var.init_expression)
- record_assignment(var, *var.init_expression, false);
+ var_info.initialized = true;
+ record_assignment(&var, *var.init_expression);
}
- unused_nodes.erase(var.type_declaration);
- TraversingVisitor::visit(var);
}
void UnusedVariableRemover::visit(InterfaceBlock &iface)
{
- SetForScope<Node *> set(aggregate, &iface);
- unused_nodes.insert(&iface);
- TraversingVisitor::visit(iface);
+ VariableInfo &var_info = variables[&iface];
+ var_info.output = (iface.interface=="out" && (iface.linked_block || !iface.block_name.compare(0, 3, "gl_")));
}
-void UnusedVariableRemover::visit(FunctionDeclaration &func)
+void UnusedVariableRemover::merge_variables(const BlockVariableMap &other_vars)
{
- variables.push_back(BlockVariableMap());
-
- for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
- (*i)->visit(*this);
- func.body.visit(*this);
+ for(BlockVariableMap::const_iterator i=other_vars.begin(); i!=other_vars.end(); ++i)
+ {
+ BlockVariableMap::iterator j = variables.find(i->first);
+ if(j!=variables.end())
+ {
+ /* The merged blocks started as copies of each other so any common
+ assignments must be in the beginning. */
+ unsigned k = 0;
+ for(; (k<i->second.assignments.size() && k<j->second.assignments.size()); ++k)
+ if(i->second.assignments[k]!=j->second.assignments[k])
+ break;
+
+ // Remaining assignments are unique to each block; merge them.
+ j->second.assignments.insert(j->second.assignments.end(), i->second.assignments.begin()+k, i->second.assignments.end());
+ j->second.referenced |= i->second.referenced;
+ }
+ else
+ variables.insert(*i);
+ }
+}
- BlockVariableMap &block_variables = variables.back();
+void UnusedVariableRemover::visit(FunctionDeclaration &func)
+{
+ if(func.body.body.empty())
+ return;
- /* Mark global variables as conditionally assigned so assignments in other
- functions won't be removed. */
- for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
- if(!i->second.local)
- i->second.conditionally_assigned = true;
+ BlockVariableMap saved_vars = variables;
+ // Assignments from other functions should not be visible.
+ for(BlockVariableMap::iterator i=variables.begin(); i!=variables.end(); ++i)
+ i->second.assignments.resize(i->second.initialized);
+ TraversingVisitor::visit(func);
+ swap(variables, saved_vars);
+ merge_variables(saved_vars);
/* Always treat function parameters as referenced. Removing unused
parameters is not currently supported. */
for(NodeArray<VariableDeclaration>::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
- block_variables[i->get()].referenced = true;
-
- merge_down_variables();
-}
-
-void UnusedVariableRemover::merge_down_variables()
-{
- BlockVariableMap &parent_variables = variables[variables.size()-2];
- BlockVariableMap &block_variables = variables.back();
- for(BlockVariableMap::iterator i=block_variables.begin(); i!=block_variables.end(); ++i)
{
- if(i->second.local)
- {
- if(!i->second.referenced)
- unused_nodes.insert(i->first);
- /* Any unreferenced assignments when a variable runs out of scope
- become unused. */
- clear_assignments(i->second, true);
- continue;
- }
-
- BlockVariableMap::iterator j = parent_variables.find(i->first);
- if(j==parent_variables.end())
- parent_variables.insert(*i);
- else
- {
- // Merge a non-local variable's state into the parent scope.
- if(i->second.referenced || !i->second.conditionally_assigned)
- clear_assignments(j->second, !i->second.referenced);
- j->second.conditionally_assigned = i->second.conditionally_assigned;
- j->second.referenced |= i->second.referenced;
- j->second.assignments.insert(j->second.assignments.end(), i->second.assignments.begin(), i->second.assignments.end());
- }
+ BlockVariableMap::iterator j = variables.find(i->get());
+ if(j!=variables.end())
+ j->second.referenced = true;
}
- variables.pop_back();
}
void UnusedVariableRemover::visit(Conditional &cond)
{
cond.condition->visit(*this);
- variables.push_back(BlockVariableMap());
+ BlockVariableMap saved_vars = variables;
cond.body.visit(*this);
-
- BlockVariableMap if_variables;
- swap(variables.back(), if_variables);
+ swap(saved_vars, variables);
cond.else_body.visit(*this);
- // Combine variables from both branches.
- BlockVariableMap &else_variables = variables.back();
- for(BlockVariableMap::iterator i=else_variables.begin(); i!=else_variables.end(); ++i)
- {
- BlockVariableMap::iterator j = if_variables.find(i->first);
- if(j!=if_variables.end())
- {
- // The variable was found in both branches.
- i->second.assignments.insert(i->second.assignments.end(), j->second.assignments.begin(), j->second.assignments.end());
- i->second.conditionally_assigned |= j->second.conditionally_assigned;
- if_variables.erase(j);
- }
- else
- // Mark variables found in only one branch as conditionally assigned.
- i->second.conditionally_assigned = true;
- }
-
- /* Move variables which were only used in the if block into the combined
- block. */
- for(BlockVariableMap::iterator i=if_variables.begin(); i!=if_variables.end(); ++i)
- {
- i->second.conditionally_assigned = true;
- else_variables.insert(*i);
- }
-
- merge_down_variables();
+ /* Visible assignments after the conditional is the union of those visible
+ at the end of the if and else blocks. If there was no else block, then it's
+ the union of the if block and the state before it. */
+ merge_variables(saved_vars);
}
void UnusedVariableRemover::visit(Iteration &iter)
{
- variables.push_back(BlockVariableMap());
+ BlockVariableMap saved_vars = variables;
TraversingVisitor::visit(iter);
- merge_down_variables();
+
+ /* Merge assignments from the iteration, without clearing previous state.
+ Further analysis is needed to determine which parts of the iteration body
+ are always executed, if any. */
+ merge_variables(saved_vars);
}