]> git.tdb.fi Git - libs/gl.git/blobdiff - source/glsl/optimize.cpp
Fix the return value of ConstantFolder::apply
[libs/gl.git] / source / glsl / optimize.cpp
index 2a9bfb17273aa743c7dd7af8608065f7b66058a0..ed20bb175dcc9277e1ff84e2e1a1734b2279668f 100644 (file)
@@ -1,6 +1,8 @@
 #include <msp/core/raii.h>
 #include <msp/strings/format.h>
+#include <msp/strings/utils.h>
 #include "optimize.h"
+#include "reflect.h"
 
 using namespace std;
 
@@ -8,6 +10,55 @@ namespace Msp {
 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)
@@ -25,7 +76,7 @@ void InlineableFunctionLocator::visit(FunctionCall &call)
                ++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);
        }
 
@@ -34,8 +85,12 @@ void InlineableFunctionLocator::visit(FunctionCall &call)
 
 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);
@@ -66,83 +121,97 @@ void InlineableFunctionLocator::visit(Return &ret)
 
 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;
-       remap_prefix = source_func->name;
+       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);
+       }
 
-       vector<RefPtr<Statement> > inlined;
-       inlined.reserve(src.body.body.size());
-       for(NodeList<Statement>::iterator i=src.body.body.begin(); i!=src.body.body.end(); ++i)
+       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();
 
-               SetForScope<unsigned> set_remap(remap_names, 2);
+               SetForScope<Pass> set_pass(pass, RENAME);
                r_inlined_statement->visit(*this);
-               inlined.push_back(r_inlined_statement);
-       }
 
-       // Insert the variables here to enable further inlinings to avoid conflicts.
-       tgt_blk.variables.insert(variable_map.begin(), variable_map.end());
+               staging_block.body.push_back_nocopy(r_inlined_statement);
+       }
 
-       SetForScope<unsigned> set_remap(remap_names, 1);
-       SetForScope<string> set_prefix(remap_prefix, target_func.name);
-       variable_map.clear();
+       /* 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);
+
+       /* 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);
 
-       tgt_blk.body.insert(ins_pt, inlined.begin(), inlined.end());
+       // 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();
 
-       NodeReorderer().apply(stage, target_func, dependencies);
+       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);
-               if(!variable_map.count(var.name))
-               {
-                       dependencies.insert(var.declaration);
-                       referenced_names.insert(var.name);
-               }
-               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);
+       if(pass==REFERENCED)
                referenced_names.insert(iface.name);
-               iface.declaration->visit(*this);
-       }
 }
 
 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);
 }
 
@@ -150,33 +219,34 @@ void InlineContentInjector::visit(VariableDeclaration &var)
 {
        TraversingVisitor::visit(var);
 
-       if(remap_names)
+       if(pass==RENAME)
        {
-               if(remap_names==2 || referenced_names.count(var.name))
+               /* 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(*target_block, var.name, remap_prefix);
-                       variable_map[var.name] = &var;
-                       var.name = mapped_name;
+                       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(var.type_declaration)
-       {
-               SetFlag set_deps(deps_only);
-               dependencies.insert(var.type_declaration);
-               referenced_names.insert(var.type_declaration->name);
-               var.type_declaration->visit(*this);
-       }
+       else if(pass==REFERENCED)
+               referenced_names.insert(var.type);
 }
 
 void InlineContentInjector::visit(Return &ret)
 {
        TraversingVisitor::visit(ret);
 
-       if(!remap_names && ret.expression)
+       if(pass==INLINE && ret.expression)
        {
-               /* Create a new variable to hold the return value of the inlined
-               function. */
-               r_result_name = get_unused_variable_name(*target_block, "_return", source_func->name);
+               // 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;
@@ -190,7 +260,8 @@ void InlineContentInjector::visit(Return &ret)
 
 FunctionInliner::FunctionInliner():
        current_function(0),
-       r_any_inlined(false)
+       r_any_inlined(false),
+       r_inlined_here(false)
 { }
 
 bool FunctionInliner::apply(Stage &s)
@@ -218,7 +289,7 @@ 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);
@@ -227,20 +298,23 @@ void FunctionInliner::visit(Block &block)
 
 void FunctionInliner::visit(FunctionCall &call)
 {
-       for(NodeArray<Expression>::iterator i=call.arguments.begin(); i!=call.arguments.end(); ++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)
                def = def->definition;
 
        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;
@@ -249,6 +323,7 @@ void FunctionInliner::visit(FunctionCall &call)
                /* Inlined variables need to be resolved before this function can be
                inlined further. */
                inlineable.erase(current_function);
+               r_inlined_here = true;
        }
 }
 
@@ -256,6 +331,7 @@ void FunctionInliner::visit(FunctionDeclaration &func)
 {
        SetForScope<FunctionDeclaration *> set_func(current_function, &func);
        TraversingVisitor::visit(func);
+       r_inlined_here = false;
 }
 
 void FunctionInliner::visit(Iteration &iter)
@@ -273,15 +349,6 @@ void FunctionInliner::visit(Iteration &iter)
 }
 
 
-ExpressionInliner::ExpressionInfo::ExpressionInfo():
-       expression(0),
-       assign_scope(0),
-       inline_point(0),
-       trivial(false),
-       available(true)
-{ }
-
-
 ExpressionInliner::ExpressionInliner():
        r_ref_info(0),
        r_any_inlined(false),
@@ -487,12 +554,346 @@ void ExpressionInliner::visit(Iteration &iter)
 }
 
 
+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();
+       }
+}
+
+template<typename T>
+T ConstantFolder::evaluate_int_special_op(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>
+void ConstantFolder::convert_to_result(const Variant &value)
+{
+       if(value.check_type<bool>())
+               set_result(static_cast<T>(value.value<bool>()));
+       else if(value.check_type<int>())
+               set_result(static_cast<T>(value.value<int>()));
+       else if(value.check_type<unsigned>())
+               set_result(static_cast<T>(value.value<unsigned>()));
+       else if(value.check_type<float>())
+               set_result(static_cast<T>(value.value<float>()));
+}
+
+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;
+
+       RefPtr<Literal> literal = new Literal;
+       if(r_constant_value.check_type<bool>())
+               literal->token = (r_constant_value.value<bool>() ? "true" : "false");
+       else if(r_constant_value.check_type<int>())
+               literal->token = lexical_cast<string>(r_constant_value.value<int>());
+       else if(r_constant_value.check_type<unsigned>())
+               literal->token = lexical_cast<string>(r_constant_value.value<unsigned>())+"u";
+       else if(r_constant_value.check_type<float>())
+       {
+               literal->token = lexical_cast<string>(r_constant_value.value<float>());
+               if(isnumrc(literal->token))
+                       literal->token += ".0";
+       }
+       else
+       {
+               r_constant = false;
+               return;
+       }
+       literal->value = r_constant_value;
+       expr = literal;
+       r_any_folded = true;
+}
+
+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;
+
+       char oper = unary.oper->token[0];
+       char oper2 = unary.oper->token[1];
+       if(oper=='!')
+       {
+               if(r_constant_value.check_type<bool>())
+                       set_result(!r_constant_value.value<bool>());
+       }
+       else if(oper=='~')
+       {
+               if(r_constant_value.check_type<int>())
+                       set_result(~r_constant_value.value<int>());
+               else if(r_constant_value.check_type<unsigned>())
+                       set_result(~r_constant_value.value<unsigned>());
+       }
+       else if(oper=='-' && !oper2)
+       {
+               if(r_constant_value.check_type<int>())
+                       set_result(-r_constant_value.value<int>());
+               else if(r_constant_value.check_type<unsigned>())
+                       set_result(-r_constant_value.value<unsigned>());
+               else if(r_constant_value.check_type<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;
+
+       // Currently only expressions with both sides of equal types are handled.
+       if(!left_value.check_same_type(r_constant_value))
+               return;
+
+       char oper = binary.oper->token[0];
+       char oper2 = binary.oper->token[1];
+       if(oper=='&' || oper=='|' || oper=='^')
+       {
+               if(oper2==oper && left_value.check_type<bool>())
+                       set_result(evaluate_logical(oper, left_value.value<bool>(), r_constant_value.value<bool>()));
+               else if(!oper2 && left_value.check_type<int>())
+                       set_result(evaluate_logical(oper, left_value.value<int>(), r_constant_value.value<int>()));
+               else if(!oper2 && left_value.check_type<unsigned>())
+                       set_result(evaluate_logical(oper, left_value.value<unsigned>(), r_constant_value.value<unsigned>()));
+       }
+       else if((oper=='<' || oper=='>') && oper2!=oper)
+       {
+               if(left_value.check_type<int>())
+                       set_result(evaluate_relation(binary.oper->token, left_value.value<int>(), r_constant_value.value<int>()));
+               else if(left_value.check_type<unsigned>())
+                       set_result(evaluate_relation(binary.oper->token, left_value.value<unsigned>(), r_constant_value.value<unsigned>()));
+               else if(left_value.check_type<float>())
+                       set_result(evaluate_relation(binary.oper->token, left_value.value<float>(), r_constant_value.value<float>()));
+       }
+       else if((oper=='=' || oper=='!') && oper2=='=')
+       {
+               if(left_value.check_type<int>())
+                       set_result((left_value.value<int>()==r_constant_value.value<int>()) == (oper=='='));
+               else if(left_value.check_type<unsigned>())
+                       set_result((left_value.value<unsigned>()==r_constant_value.value<unsigned>()) == (oper=='='));
+               else if(left_value.check_type<float>())
+                       set_result((left_value.value<float>()==r_constant_value.value<float>()) == (oper=='='));
+       }
+       else if(oper=='+' || oper=='-' || oper=='*' || oper=='/')
+       {
+               if(left_value.check_type<int>())
+                       set_result(evaluate_arithmetic(oper, left_value.value<int>(), r_constant_value.value<int>()));
+               else if(left_value.check_type<unsigned>())
+                       set_result(evaluate_arithmetic(oper, left_value.value<unsigned>(), r_constant_value.value<unsigned>()));
+               else if(left_value.check_type<float>())
+                       set_result(evaluate_arithmetic(oper, left_value.value<float>(), r_constant_value.value<float>()));
+       }
+       else if(oper=='%' || ((oper=='<' || oper=='>') && oper2==oper))
+       {
+               if(left_value.check_type<int>())
+                       set_result(evaluate_int_special_op(oper, left_value.value<int>(), r_constant_value.value<int>()));
+               else if(left_value.check_type<unsigned>())
+                       set_result(evaluate_int_special_op(oper, left_value.value<unsigned>(), r_constant_value.value<unsigned>()));
+       }
+}
+
+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)
+{
+       if(call.constructor && call.type && call.arguments.size()==1)
+       {
+               const BasicTypeDeclaration *basic = dynamic_cast<const BasicTypeDeclaration *>(call.type);
+               if(basic)
+               {
+                       call.arguments[0]->visit(*this);
+                       bool can_fold = r_constant;
+                       r_constant = false;
+                       if(!can_fold)
+                               return;
+
+                       if(basic->kind==BasicTypeDeclaration::BOOL)
+                               convert_to_result<bool>(r_constant_value);
+                       else if(basic->kind==BasicTypeDeclaration::INT && basic->size==32 && basic->sign)
+                               convert_to_result<int>(r_constant_value);
+                       else if(basic->kind==BasicTypeDeclaration::INT && basic->size==32 && !basic->sign)
+                               convert_to_result<unsigned>(r_constant_value);
+                       else if(basic->kind==BasicTypeDeclaration::FLOAT && basic->size==32)
+                               convert_to_result<float>(r_constant_value);
+
+                       return;
+               }
+       }
+
+       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 ConstantFolder::visit(Iteration &iter)
+{
+       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);
+}
+
+
 void ConstantConditionEliminator::apply(Stage &stage)
 {
        stage.content.visit(*this);
        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);
@@ -503,16 +904,35 @@ void ConstantConditionEliminator::visit(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)
 {
-       if(Literal *literal = dynamic_cast<Literal *>(cond.condition.get()))
-               if(literal->value.check_type<bool>())
-               {
-                       Block &block = (literal->value.value<bool>() ? cond.body : cond.else_body);
-                       current_block->body.splice(insert_point, block.body);
-                       nodes_to_remove.insert(&cond);
-                       return;
-               }
+       ConstantStatus result = check_constant_condition(*cond.condition);
+       if(result!=NOT_CONSTANT)
+       {
+               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;
+       }
 
        TraversingVisitor::visit(cond);
 }
@@ -521,14 +941,8 @@ void ConstantConditionEliminator::visit(Iteration &iter)
 {
        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;
@@ -539,40 +953,63 @@ void ConstantConditionEliminator::visit(Iteration &iter)
 }
 
 
-bool UnusedTypeRemover::apply(Stage &stage)
+UnreachableCodeRemover::UnreachableCodeRemover():
+       reachable(true)
+{ }
+
+bool UnreachableCodeRemover::apply(Stage &stage)
 {
        stage.content.visit(*this);
-       NodeRemover().apply(stage, unused_nodes);
-       return !unused_nodes.empty();
+       NodeRemover().apply(stage, unreachable_nodes);
+       return !unreachable_nodes.empty();
 }
 
-void UnusedTypeRemover::visit(Literal &literal)
+void UnreachableCodeRemover::visit(Block &block)
 {
-       unused_nodes.erase(literal.type);
+       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 UnusedTypeRemover::visit(UnaryExpression &unary)
+void UnreachableCodeRemover::visit(FunctionDeclaration &func)
 {
-       unused_nodes.erase(unary.type);
-       TraversingVisitor::visit(unary);
+       TraversingVisitor::visit(func);
+       reachable = true;
 }
 
-void UnusedTypeRemover::visit(BinaryExpression &binary)
+void UnreachableCodeRemover::visit(Conditional &cond)
 {
-       unused_nodes.erase(binary.type);
-       TraversingVisitor::visit(binary);
+       cond.body.visit(*this);
+       bool reachable_if_true = reachable;
+       reachable = true;
+       cond.else_body.visit(*this);
+
+       reachable |= reachable_if_true;
 }
 
-void UnusedTypeRemover::visit(TernaryExpression &ternary)
+void UnreachableCodeRemover::visit(Iteration &iter)
 {
-       unused_nodes.erase(ternary.type);
-       TraversingVisitor::visit(ternary);
+       TraversingVisitor::visit(iter);
+
+       /* Always consider code after a loop reachable, since there's no checking
+       for whether the loop executes. */
+       reachable = true;
 }
 
-void UnusedTypeRemover::visit(FunctionCall &call)
+
+bool UnusedTypeRemover::apply(Stage &stage)
 {
-       unused_nodes.erase(call.type);
-       TraversingVisitor::visit(call);
+       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)
@@ -598,6 +1035,7 @@ void UnusedTypeRemover::visit(StructDeclaration &strct)
 void UnusedTypeRemover::visit(VariableDeclaration &var)
 {
        unused_nodes.erase(var.type_declaration);
+       TraversingVisitor::visit(var);
 }
 
 void UnusedTypeRemover::visit(InterfaceBlock &iface)
@@ -617,7 +1055,10 @@ UnusedVariableRemover::UnusedVariableRemover():
        interface_block(0),
        r_assignment(0),
        assignment_target(false),
-       r_side_effects(false)
+       r_side_effects(false),
+       in_struct(false),
+       composite_reference(false),
+       in_loop(0)
 { }
 
 bool UnusedVariableRemover::apply(Stage &s)
@@ -629,10 +1070,6 @@ bool UnusedVariableRemover::apply(Stage &s)
                if(i->used_by.empty())
                        unused_nodes.insert(i->node);
 
-       for(map<string, InterfaceBlock *>::const_iterator i=s.interface_blocks.begin(); i!=s.interface_blocks.end(); ++i)
-               if(i->second->instance_name.empty())
-                       unused_nodes.insert(i->second);
-
        for(BlockVariableMap::const_iterator i=variables.begin(); i!=variables.end(); ++i)
        {
                if(i->second.output)
@@ -665,19 +1102,90 @@ void UnusedVariableRemover::referenced(const Assignment::Target &target, Node &n
        var_info.referenced = true;
        if(!assignment_target)
        {
+               bool loop_external = false;
                for(vector<AssignmentInfo *>::const_iterator i=var_info.assignments.begin(); i!=var_info.assignments.end(); ++i)
-                       (*i)->used_by.push_back(&node);
+               {
+                       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);
+                               if((*i)->in_loop<in_loop)
+                                       loop_external = true;
+                       }
+               }
+
+               if(loop_external)
+                       loop_ext_refs.push_back(&node);
        }
 }
 
 void UnusedVariableRemover::visit(VariableReference &var)
 {
-       referenced(var.declaration, var);
+       if(composite_reference)
+               r_reference.declaration = var.declaration;
+       else
+               referenced(var.declaration, var);
 }
 
 void UnusedVariableRemover::visit(InterfaceBlockReference &iface)
 {
-       referenced(iface.declaration, iface);
+       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)
+{
+       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)
@@ -691,12 +1199,30 @@ void UnusedVariableRemover::visit(BinaryExpression &binary)
 {
        if(binary.oper->token[0]=='[')
        {
-               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)
@@ -712,6 +1238,7 @@ void UnusedVariableRemover::visit(Assignment &assign)
 
 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. */
@@ -731,6 +1258,7 @@ void UnusedVariableRemover::record_assignment(const Assignment::Target &target,
        AssignmentInfo &assign_info = assignments.back();
        assign_info.node = &node;
        assign_info.target = target;
+       assign_info.in_loop = in_loop;
 
        /* An assignment to the target hides any assignments to the same target or
        its subfields. */
@@ -763,15 +1291,26 @@ void UnusedVariableRemover::visit(ExpressionStatement &expr)
                unused_nodes.insert(&expr);
 }
 
+void UnusedVariableRemover::visit(StructDeclaration &strct)
+{
+       SetFlag set_struct(in_struct);
+       TraversingVisitor::visit(strct);
+}
+
 void UnusedVariableRemover::visit(VariableDeclaration &var)
 {
+       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->name.compare(0, 3, "gl_")));
+               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_")));
 
@@ -780,21 +1319,12 @@ void UnusedVariableRemover::visit(VariableDeclaration &var)
                var_info.initialized = true;
                record_assignment(&var, *var.init_expression);
        }
-       TraversingVisitor::visit(var);
 }
 
 void UnusedVariableRemover::visit(InterfaceBlock &iface)
 {
-       if(iface.instance_name.empty())
-       {
-               SetForScope<InterfaceBlock *> set_block(interface_block, &iface);
-               iface.struct_declaration->members.visit(*this);
-       }
-       else
-       {
-               VariableInfo &var_info = variables[&iface];
-               var_info.output = (iface.interface=="out" && (iface.linked_block || !iface.name.compare(0, 3, "gl_")));
-       }
+       VariableInfo &var_info = variables[&iface];
+       var_info.output = (iface.interface=="out" && (iface.linked_block || !iface.block_name.compare(0, 3, "gl_")));
 }
 
 void UnusedVariableRemover::merge_variables(const BlockVariableMap &other_vars)
@@ -860,7 +1390,18 @@ void UnusedVariableRemover::visit(Conditional &cond)
 void UnusedVariableRemover::visit(Iteration &iter)
 {
        BlockVariableMap saved_vars = variables;
-       TraversingVisitor::visit(iter);
+       vector<Node *> saved_refs;
+       swap(loop_ext_refs, saved_refs);
+       {
+               SetForScope<unsigned> set_loop(in_loop, in_loop+1);
+               TraversingVisitor::visit(iter);
+       }
+       swap(loop_ext_refs, saved_refs);
+
+       /* Visit the external references of the loop again to record assignments
+       done in the loop as used. */
+       for(vector<Node *>::const_iterator i=saved_refs.begin(); i!=saved_refs.end(); ++i)
+               (*i)->visit(*this);
 
        /* Merge assignments from the iteration, without clearing previous state.
        Further analysis is needed to determine which parts of the iteration body