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/*
* Copyright © 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file opt_dead_functions.cpp
*
* Eliminates unused functions from the linked program.
*/
#include "ir.h"
#include "ir_visitor.h"
#include "ir_expression_flattening.h"
#include "compiler/glsl_types.h"
namespace {
class signature_entry : public exec_node
{
public:
signature_entry(ir_function_signature *sig)
{
this->signature = sig;
this->used = false;
}
ir_function_signature *signature;
bool used;
};
class ir_dead_functions_visitor : public ir_hierarchical_visitor {
public:
ir_dead_functions_visitor()
{
this->mem_ctx = ralloc_context(NULL);
}
~ir_dead_functions_visitor()
{
ralloc_free(this->mem_ctx);
}
virtual ir_visitor_status visit_enter(ir_function_signature *);
virtual ir_visitor_status visit_enter(ir_call *);
signature_entry *get_signature_entry(ir_function_signature *var);
/* List of signature_entry */
exec_list signature_list;
void *mem_ctx;
};
} /* unnamed namespace */
signature_entry *
ir_dead_functions_visitor::get_signature_entry(ir_function_signature *sig)
{
foreach_in_list(signature_entry, entry, &this->signature_list) {
if (entry->signature == sig)
return entry;
}
signature_entry *entry = new(mem_ctx) signature_entry(sig);
this->signature_list.push_tail(entry);
return entry;
}
ir_visitor_status
ir_dead_functions_visitor::visit_enter(ir_function_signature *ir)
{
signature_entry *entry = this->get_signature_entry(ir);
if (strcmp(ir->function_name(), "main") == 0) {
entry->used = true;
}
return visit_continue;
}
ir_visitor_status
ir_dead_functions_visitor::visit_enter(ir_call *ir)
{
signature_entry *entry = this->get_signature_entry(ir->callee);
entry->used = true;
return visit_continue;
}
bool
do_dead_functions(exec_list *instructions)
{
ir_dead_functions_visitor v;
bool progress = false;
visit_list_elements(&v, instructions);
/* Now that we've figured out which function signatures are used, remove
* the unused ones, and remove function definitions that have no more
* signatures.
*/
foreach_in_list_safe(signature_entry, entry, &v.signature_list) {
if (!entry->used) {
entry->signature->remove();
delete entry->signature;
progress = true;
}
delete(entry);
}
/* We don't just do this above when we nuked a signature because of
* const pointers.
*/
foreach_in_list_safe(ir_instruction, ir, instructions) {
ir_function *func = ir->as_function();
if (func && func->signatures.is_empty()) {
/* At this point (post-linking), the symbol table is no
* longer in use, so not removing the function from the
* symbol table should be OK.
*/
func->remove();
delete func;
progress = true;
}
}
return progress;
}