Source code
Revision control
Copy as Markdown
Other Tools
/*
* Copyright © 2016 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 ir_array_refcount.cpp
*
* Provides a visitor which produces a list of variables referenced.
*/
#include "ir.h"
#include "ir_visitor.h"
#include "ir_array_refcount.h"
#include "compiler/glsl_types.h"
#include "util/hash_table.h"
ir_array_refcount_visitor::ir_array_refcount_visitor()
: last_array_deref(0), derefs(0), num_derefs(0), derefs_size(0)
{
this->mem_ctx = ralloc_context(NULL);
this->ht = _mesa_pointer_hash_table_create(NULL);
}
static void
free_entry(struct hash_entry *entry)
{
ir_array_refcount_entry *ivre = (ir_array_refcount_entry *) entry->data;
delete ivre;
}
ir_array_refcount_visitor::~ir_array_refcount_visitor()
{
ralloc_free(this->mem_ctx);
_mesa_hash_table_destroy(this->ht, free_entry);
}
ir_array_refcount_entry::ir_array_refcount_entry(ir_variable *var)
: var(var), is_referenced(false)
{
num_bits = MAX2(1, var->type->arrays_of_arrays_size());
bits = new BITSET_WORD[BITSET_WORDS(num_bits)];
memset(bits, 0, BITSET_WORDS(num_bits) * sizeof(bits[0]));
/* Count the "depth" of the arrays-of-arrays. */
array_depth = 0;
for (const glsl_type *type = var->type;
type->is_array();
type = type->fields.array) {
array_depth++;
}
}
ir_array_refcount_entry::~ir_array_refcount_entry()
{
delete [] bits;
}
ir_array_refcount_entry *
ir_array_refcount_visitor::get_variable_entry(ir_variable *var)
{
assert(var);
struct hash_entry *e = _mesa_hash_table_search(this->ht, var);
if (e)
return (ir_array_refcount_entry *)e->data;
ir_array_refcount_entry *entry = new ir_array_refcount_entry(var);
_mesa_hash_table_insert(this->ht, var, entry);
return entry;
}
array_deref_range *
ir_array_refcount_visitor::get_array_deref()
{
if ((num_derefs + 1) * sizeof(array_deref_range) > derefs_size) {
void *ptr = reralloc_size(mem_ctx, derefs, derefs_size + 4096);
if (ptr == NULL)
return NULL;
derefs_size += 4096;
derefs = (array_deref_range *)ptr;
}
array_deref_range *d = &derefs[num_derefs];
num_derefs++;
return d;
}
ir_visitor_status
ir_array_refcount_visitor::visit_enter(ir_dereference_array *ir)
{
/* It could also be a vector or a matrix. Individual elements of vectors
* are natrices are not tracked, so bail.
*/
if (!ir->array->type->is_array())
return visit_continue;
/* If this array dereference is a child of an array dereference that was
* already visited, just continue on. Otherwise, for an arrays-of-arrays
* dereference like x[1][2][3][4], we'd process the [1][2][3][4] sequence,
* the [1][2][3] sequence, the [1][2] sequence, and the [1] sequence. This
* ensures that we only process the full sequence.
*/
if (last_array_deref && last_array_deref->array == ir) {
last_array_deref = ir;
return visit_continue;
}
last_array_deref = ir;
num_derefs = 0;
ir_rvalue *rv = ir;
while (rv->ir_type == ir_type_dereference_array) {
ir_dereference_array *const deref = rv->as_dereference_array();
assert(deref != NULL);
assert(deref->array->type->is_array());
ir_rvalue *const array = deref->array;
const ir_constant *const idx = deref->array_index->as_constant();
array_deref_range *const dr = get_array_deref();
dr->size = array->type->array_size();
if (idx != NULL) {
dr->index = idx->get_int_component(0);
} else {
/* An unsized array can occur at the end of an SSBO. We can't track
* accesses to such an array, so bail.
*/
if (array->type->array_size() == 0)
return visit_continue;
dr->index = dr->size;
}
rv = array;
}
ir_dereference_variable *const var_deref = rv->as_dereference_variable();
/* If the array being dereferenced is not a variable, bail. At the very
* least, ir_constant and ir_dereference_record are possible.
*/
if (var_deref == NULL)
return visit_continue;
ir_array_refcount_entry *const entry =
this->get_variable_entry(var_deref->var);
if (entry == NULL)
return visit_stop;
link_util_mark_array_elements_referenced(derefs, num_derefs,
entry->array_depth,
entry->bits);
return visit_continue;
}
ir_visitor_status
ir_array_refcount_visitor::visit(ir_dereference_variable *ir)
{
ir_variable *const var = ir->variable_referenced();
ir_array_refcount_entry *entry = this->get_variable_entry(var);
entry->is_referenced = true;
return visit_continue;
}
ir_visitor_status
ir_array_refcount_visitor::visit_enter(ir_function_signature *ir)
{
/* We don't want to descend into the function parameters and
* dead-code eliminate them, so just accept the body here.
*/
visit_list_elements(this, &ir->body);
return visit_continue_with_parent;
}