* Replaces usage of recently-copied components of variables with the
* previous copy of the variable.
*
- * This pass can be compared with opt_copy_propagation, which operands
- * on arbitrary whole-variable copies. However, in order to handle
- * the copy propagation of swizzled variables or writemasked writes,
- * we want to track things on a channel-wise basis. I found that
- * trying to mix the swizzled/writemasked support here with the
- * whole-variable stuff in opt_copy_propagation.cpp just made a mess,
- * so this is separate despite the ACP handling being somewhat
- * similar.
- *
* This should reduce the number of MOV instructions in the generated
- * programs unless copy propagation is also done on the LIR, and may
- * help anyway by triggering other optimizations that live in the HIR.
+ * programs and help triggering other optimizations that live in GLSL
+ * level.
*/
#include "ir.h"
#include "ir_basic_block.h"
#include "ir_optimization.h"
#include "compiler/glsl_types.h"
+#include "util/hash_table.h"
+#include "util/set.h"
static bool debug = false;
namespace {
-class acp_entry : public exec_node
+class acp_entry
{
public:
- acp_entry(ir_variable *lhs, ir_variable *rhs, int write_mask, int swizzle[4])
+ DECLARE_LINEAR_ZALLOC_CXX_OPERATORS(acp_entry)
+
+ /* If set, rhs_full indicates that this ACP entry represents a
+ * whole-variable copy. The rhs_element[] array will still be filled,
+ * to allow the swizzling from its components in case the variable
+ * was a vector (and to simplify some of the erase() and write_vector()
+ * logic).
+ */
+
+ ir_variable *rhs_full;
+ ir_variable *rhs_element[4];
+ unsigned rhs_channel[4];
+
+ /* Set of variables that use the variable associated with this acp_entry as
+ * RHS. This has the "reverse references" of rhs_full/rhs_element. It is
+ * used to speed up invalidating those references when the acp_entry
+ * changes.
+ */
+ set *dsts;
+};
+
+class copy_propagation_state {
+public:
+ DECLARE_RZALLOC_CXX_OPERATORS(copy_propagation_state);
+
+ static
+ copy_propagation_state* create(void *mem_ctx)
{
- this->lhs = lhs;
- this->rhs = rhs;
- this->write_mask = write_mask;
- memcpy(this->swizzle, swizzle, sizeof(this->swizzle));
+ return new (mem_ctx) copy_propagation_state(NULL);
}
- acp_entry(acp_entry *a)
+ copy_propagation_state* clone()
{
- this->lhs = a->lhs;
- this->rhs = a->rhs;
- this->write_mask = a->write_mask;
- memcpy(this->swizzle, a->swizzle, sizeof(this->swizzle));
+ return new (ralloc_parent(this)) copy_propagation_state(this);
}
- ir_variable *lhs;
- ir_variable *rhs;
- unsigned int write_mask;
- int swizzle[4];
-};
+ void erase_all()
+ {
+ /* Individual elements were allocated from a linear allocator, so will
+ * be destroyed when the state is destroyed.
+ */
+ _mesa_hash_table_clear(acp, NULL);
+ fallback = NULL;
+ }
+
+ void erase(ir_variable *var, unsigned write_mask)
+ {
+ acp_entry *entry = pull_acp(var);
+ entry->rhs_full = NULL;
+
+ for (int i = 0; i < 4; i++) {
+ if (!entry->rhs_element[i])
+ continue;
+ if ((write_mask & (1 << i)) == 0)
+ continue;
+
+ ir_variable *to_remove = entry->rhs_element[i];
+ entry->rhs_element[i] = NULL;
+ remove_unused_var_from_dsts(entry, var, to_remove);
+ }
+
+ /* TODO: Check write mask, and possibly not clear everything. */
+
+ /* For any usage of our variable on the RHS, clear it out. */
+ set_foreach(entry->dsts, set_entry) {
+ ir_variable *dst_var = (ir_variable *)set_entry->key;
+ acp_entry *dst_entry = pull_acp(dst_var);
+ for (int i = 0; i < 4; i++) {
+ if (dst_entry->rhs_element[i] == var)
+ dst_entry->rhs_element[i] = NULL;
+ }
+ if (dst_entry->rhs_full == var)
+ dst_entry->rhs_full = NULL;
+ _mesa_set_remove(entry->dsts, set_entry);
+ }
+ }
+
+ acp_entry *read(ir_variable *var)
+ {
+ for (copy_propagation_state *s = this; s != NULL; s = s->fallback) {
+ hash_entry *ht_entry = _mesa_hash_table_search(s->acp, var);
+ if (ht_entry)
+ return (acp_entry *) ht_entry->data;
+ }
+ return NULL;
+ }
+
+ void write_elements(ir_variable *lhs, ir_variable *rhs, unsigned write_mask, int swizzle[4])
+ {
+ acp_entry *lhs_entry = pull_acp(lhs);
+ lhs_entry->rhs_full = NULL;
+
+ for (int i = 0; i < 4; i++) {
+ if ((write_mask & (1 << i)) == 0)
+ continue;
+ ir_variable *to_remove = lhs_entry->rhs_element[i];
+ lhs_entry->rhs_element[i] = rhs;
+ lhs_entry->rhs_channel[i] = swizzle[i];
+
+ remove_unused_var_from_dsts(lhs_entry, lhs, to_remove);
+ }
+
+ acp_entry *rhs_entry = pull_acp(rhs);
+ _mesa_set_add(rhs_entry->dsts, lhs);
+ }
+
+ void write_full(ir_variable *lhs, ir_variable *rhs)
+ {
+ acp_entry *lhs_entry = pull_acp(lhs);
+ if (lhs_entry->rhs_full == rhs)
+ return;
+
+ if (lhs_entry->rhs_full) {
+ remove_from_dsts(lhs_entry->rhs_full, lhs);
+ } else if (lhs->type->is_vector()) {
+ for (int i = 0; i < 4; i++) {
+ if (lhs_entry->rhs_element[i])
+ remove_from_dsts(lhs_entry->rhs_element[i], lhs);
+ }
+ }
+
+ lhs_entry->rhs_full = rhs;
+ acp_entry *rhs_entry = pull_acp(rhs);
+ _mesa_set_add(rhs_entry->dsts, lhs);
+
+ if (lhs->type->is_vector()) {
+ for (int i = 0; i < 4; i++) {
+ lhs_entry->rhs_element[i] = rhs;
+ lhs_entry->rhs_channel[i] = i;
+ }
+ }
+ }
+
+ void remove_unused_var_from_dsts(acp_entry *lhs_entry, ir_variable *lhs, ir_variable *var)
+ {
+ if (!var)
+ return;
+
+ /* If lhs still uses var, don't remove anything. */
+ for (int j = 0; j < 4; j++) {
+ if (lhs_entry->rhs_element[j] == var)
+ return;
+ }
+
+ acp_entry *element = pull_acp(var);
+ assert(element);
+ _mesa_set_remove_key(element->dsts, lhs);
+ }
+
+private:
+ explicit copy_propagation_state(copy_propagation_state *fallback)
+ {
+ this->fallback = fallback;
+ /* Use 'this' as context for the table, no explicit destruction
+ * needed later.
+ */
+ acp = _mesa_pointer_hash_table_create(this);
+ lin_ctx = linear_alloc_parent(this, 0);
+ }
+ acp_entry *pull_acp(ir_variable *var)
+ {
+ hash_entry *ht_entry = _mesa_hash_table_search(acp, var);
+ if (ht_entry)
+ return (acp_entry *) ht_entry->data;
+
+ /* If not found, create one and copy data from fallback if available. */
+ acp_entry *entry = new(lin_ctx) acp_entry();
+ _mesa_hash_table_insert(acp, var, entry);
+
+ bool found = false;
+ for (copy_propagation_state *s = fallback; s != NULL; s = s->fallback) {
+ hash_entry *fallback_ht_entry = _mesa_hash_table_search(s->acp, var);
+ if (fallback_ht_entry) {
+ acp_entry *fallback_entry = (acp_entry *) fallback_ht_entry->data;
+ *entry = *fallback_entry;
+ entry->dsts = _mesa_set_clone(fallback_entry->dsts, this);
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ entry->dsts = _mesa_pointer_set_create(this);
+ }
+
+ return entry;
+ }
+
+ void
+ remove_from_dsts(ir_variable *var, ir_variable *to_remove)
+ {
+ acp_entry *entry = pull_acp(var);
+ assert(entry);
+ _mesa_set_remove_key(entry->dsts, to_remove);
+ }
+
+ /** Available Copy to Propagate table, from variable to the entry
+ * containing the current sources that can be used. */
+ hash_table *acp;
+
+ /** When a state is cloned, entries are copied on demand from fallback. */
+ copy_propagation_state *fallback;
+
+ void *lin_ctx;
+};
class kill_entry : public exec_node
{
public:
+ /* override operator new from exec_node */
+ DECLARE_LINEAR_ZALLOC_CXX_OPERATORS(kill_entry)
+
kill_entry(ir_variable *var, int write_mask)
{
this->var = var;
this->progress = false;
this->killed_all = false;
this->mem_ctx = ralloc_context(NULL);
+ this->lin_ctx = linear_alloc_parent(this->mem_ctx, 0);
this->shader_mem_ctx = NULL;
- this->acp = new(mem_ctx) exec_list;
this->kills = new(mem_ctx) exec_list;
+ this->state = copy_propagation_state::create(mem_ctx);
}
~ir_copy_propagation_elements_visitor()
{
ralloc_free(mem_ctx);
}
+ virtual ir_visitor_status visit(ir_dereference_variable *);
+
+ void handle_loop(ir_loop *, bool keep_acp);
virtual ir_visitor_status visit_enter(class ir_loop *);
virtual ir_visitor_status visit_enter(class ir_function_signature *);
virtual ir_visitor_status visit_leave(class ir_assignment *);
void add_copy(ir_assignment *ir);
void kill(kill_entry *k);
- void handle_if_block(exec_list *instructions);
+ void handle_if_block(exec_list *instructions, exec_list *kills, bool *killed_all);
+
+ copy_propagation_state *state;
- /** List of acp_entry: The available copies to propagate */
- exec_list *acp;
/**
* List of kill_entry: The variables whose values were killed in this
* block.
/* Context for our local data structures. */
void *mem_ctx;
+ void *lin_ctx;
/* Context for allocating new shader nodes. */
void *shader_mem_ctx;
};
} /* unnamed namespace */
+ir_visitor_status
+ir_copy_propagation_elements_visitor::visit(ir_dereference_variable *ir)
+{
+ if (this->in_assignee)
+ return visit_continue;
+
+ const acp_entry *entry = state->read(ir->var);
+ if (entry && entry->rhs_full) {
+ ir->var = (ir_variable *) entry->rhs_full;
+ progress = true;
+ }
+
+ return visit_continue;
+}
+
ir_visitor_status
ir_copy_propagation_elements_visitor::visit_enter(ir_function_signature *ir)
{
* block. Any instructions at global scope will be shuffled into
* main() at link time, so they're irrelevant to us.
*/
- exec_list *orig_acp = this->acp;
exec_list *orig_kills = this->kills;
bool orig_killed_all = this->killed_all;
- this->acp = new(mem_ctx) exec_list;
this->kills = new(mem_ctx) exec_list;
this->killed_all = false;
+ copy_propagation_state *orig_state = state;
+ this->state = copy_propagation_state::create(mem_ctx);
+
visit_list_elements(this, &ir->body);
- ralloc_free(this->acp);
- ralloc_free(this->kills);
+ delete this->state;
+ this->state = orig_state;
+ ralloc_free(this->kills);
this->kills = orig_kills;
- this->acp = orig_acp;
this->killed_all = orig_killed_all;
return visit_continue_with_parent;
ir_dereference_variable *lhs = ir->lhs->as_dereference_variable();
ir_variable *var = ir->lhs->variable_referenced();
- if (var->type->is_scalar() || var->type->is_vector()) {
- kill_entry *k;
+ kill_entry *k;
- if (lhs)
- k = new(this->kills) kill_entry(var, ir->write_mask);
- else
- k = new(this->kills) kill_entry(var, ~0);
+ if (lhs && var->type->is_vector())
+ k = new(this->lin_ctx) kill_entry(var, ir->write_mask);
+ else
+ k = new(this->lin_ctx) kill_entry(var, ~0);
- kill(k);
- }
+ kill(k);
add_copy(ir);
/* Try to find ACP entries covering swizzle_chan[], hoping they're
* the same source variable.
*/
- foreach_in_list(acp_entry, entry, this->acp) {
- if (var == entry->lhs) {
- for (int c = 0; c < chans; c++) {
- if (entry->write_mask & (1 << swizzle_chan[c])) {
- source[c] = entry->rhs;
- source_chan[c] = entry->swizzle[swizzle_chan[c]];
-
- if (source_chan[c] != swizzle_chan[c])
- noop_swizzle = false;
- }
- }
+
+ const acp_entry *entry = state->read(var);
+ if (entry) {
+ for (int c = 0; c < chans; c++) {
+ unsigned index = swizzle_chan[c];
+ ir_variable *src = entry->rhs_element[index];
+ if (!src)
+ continue;
+ source[c] = src;
+ source_chan[c] = entry->rhs_channel[index];
+ if (source_chan[c] != swizzle_chan[c])
+ noop_swizzle = false;
}
}
}
}
- /* Since we're unlinked, we don't (necessarily) know the side effects of
- * this call. So kill all copies.
- */
- acp->make_empty();
- this->killed_all = true;
+ if (!ir->callee->is_intrinsic()) {
+ state->erase_all();
+ this->killed_all = true;
+ } else {
+ if (ir->return_deref) {
+ kill(new(this->lin_ctx) kill_entry(ir->return_deref->var, ~0));
+ }
+
+ foreach_two_lists(formal_node, &ir->callee->parameters,
+ actual_node, &ir->actual_parameters) {
+ ir_variable *sig_param = (ir_variable *) formal_node;
+ if (sig_param->data.mode == ir_var_function_out ||
+ sig_param->data.mode == ir_var_function_inout) {
+ ir_rvalue *ir = (ir_rvalue *) actual_node;
+ ir_variable *var = ir->variable_referenced();
+ kill(new(this->lin_ctx) kill_entry(var, ~0));
+ }
+ }
+ }
return visit_continue_with_parent;
}
void
-ir_copy_propagation_elements_visitor::handle_if_block(exec_list *instructions)
+ir_copy_propagation_elements_visitor::handle_if_block(exec_list *instructions, exec_list *kills, bool *killed_all)
{
- exec_list *orig_acp = this->acp;
exec_list *orig_kills = this->kills;
bool orig_killed_all = this->killed_all;
- this->acp = new(mem_ctx) exec_list;
- this->kills = new(mem_ctx) exec_list;
+ this->kills = kills;
this->killed_all = false;
/* Populate the initial acp with a copy of the original */
- foreach_in_list(acp_entry, a, orig_acp) {
- this->acp->push_tail(new(this->acp) acp_entry(a));
- }
+ copy_propagation_state *orig_state = state;
+ this->state = orig_state->clone();
visit_list_elements(this, instructions);
- if (this->killed_all) {
- orig_acp->make_empty();
- }
+ delete this->state;
+ this->state = orig_state;
- exec_list *new_kills = this->kills;
+ *killed_all = this->killed_all;
this->kills = orig_kills;
- ralloc_free(this->acp);
- this->acp = orig_acp;
- this->killed_all = this->killed_all || orig_killed_all;
-
- /* Move the new kills into the parent block's list, removing them
- * from the parent's ACP list in the process.
- */
- foreach_in_list_safe(kill_entry, k, new_kills) {
- kill(k);
- }
-
- ralloc_free(new_kills);
+ this->killed_all = orig_killed_all;
}
ir_visitor_status
{
ir->condition->accept(this);
- handle_if_block(&ir->then_instructions);
- handle_if_block(&ir->else_instructions);
+ exec_list *new_kills = new(mem_ctx) exec_list;
+ bool then_killed_all = false;
+ bool else_killed_all = false;
+
+ handle_if_block(&ir->then_instructions, new_kills, &then_killed_all);
+ handle_if_block(&ir->else_instructions, new_kills, &else_killed_all);
+
+ if (then_killed_all || else_killed_all) {
+ state->erase_all();
+ killed_all = true;
+ } else {
+ foreach_in_list_safe(kill_entry, k, new_kills)
+ kill(k);
+ }
+
+ ralloc_free(new_kills);
/* handle_if_block() already descended into the children. */
return visit_continue_with_parent;
}
-ir_visitor_status
-ir_copy_propagation_elements_visitor::visit_enter(ir_loop *ir)
+void
+ir_copy_propagation_elements_visitor::handle_loop(ir_loop *ir, bool keep_acp)
{
- exec_list *orig_acp = this->acp;
exec_list *orig_kills = this->kills;
bool orig_killed_all = this->killed_all;
- /* FINISHME: For now, the initial acp for loops is totally empty.
- * We could go through once, then go through again with the acp
- * cloned minus the killed entries after the first run through.
- */
- this->acp = new(mem_ctx) exec_list;
this->kills = new(mem_ctx) exec_list;
this->killed_all = false;
- visit_list_elements(this, &ir->body_instructions);
+ copy_propagation_state *orig_state = state;
- if (this->killed_all) {
- orig_acp->make_empty();
+ if (keep_acp) {
+ /* Populate the initial acp with a copy of the original */
+ this->state = orig_state->clone();
+ } else {
+ this->state = copy_propagation_state::create(mem_ctx);
}
+ visit_list_elements(this, &ir->body_instructions);
+
+ delete this->state;
+ this->state = orig_state;
+
+ if (this->killed_all)
+ this->state->erase_all();
+
exec_list *new_kills = this->kills;
this->kills = orig_kills;
- ralloc_free(this->acp);
- this->acp = orig_acp;
this->killed_all = this->killed_all || orig_killed_all;
foreach_in_list_safe(kill_entry, k, new_kills) {
}
ralloc_free(new_kills);
+}
+
+ir_visitor_status
+ir_copy_propagation_elements_visitor::visit_enter(ir_loop *ir)
+{
+ handle_loop(ir, false);
+ handle_loop(ir, true);
/* already descended into the children. */
return visit_continue_with_parent;
void
ir_copy_propagation_elements_visitor::kill(kill_entry *k)
{
- foreach_in_list_safe(acp_entry, entry, acp) {
- if (entry->lhs == k->var) {
- entry->write_mask = entry->write_mask & ~k->write_mask;
- if (entry->write_mask == 0) {
- entry->remove();
- continue;
- }
- }
- if (entry->rhs == k->var) {
- entry->remove();
- }
- }
+ state->erase(k->var, k->write_mask);
/* If we were on a list, remove ourselves before inserting */
if (k->next)
k->remove();
- ralloc_steal(this->kills, k);
this->kills->push_tail(k);
}
void
ir_copy_propagation_elements_visitor::add_copy(ir_assignment *ir)
{
- acp_entry *entry;
- int orig_swizzle[4] = {0, 1, 2, 3};
- int swizzle[4];
-
if (ir->condition)
return;
+ {
+ ir_variable *lhs_var = ir->whole_variable_written();
+ ir_dereference_variable *rhs = ir->rhs->as_dereference_variable();
+
+ if (lhs_var != NULL && rhs && rhs->var != NULL && lhs_var != rhs->var) {
+ if (lhs_var->data.mode == ir_var_shader_storage ||
+ lhs_var->data.mode == ir_var_shader_shared ||
+ rhs->var->data.mode == ir_var_shader_storage ||
+ rhs->var->data.mode == ir_var_shader_shared ||
+ lhs_var->data.precise != rhs->var->data.precise) {
+ return;
+ }
+ state->write_full(lhs_var, rhs->var);
+ return;
+ }
+ }
+
+ int orig_swizzle[4] = {0, 1, 2, 3};
+ int swizzle[4];
+
ir_dereference_variable *lhs = ir->lhs->as_dereference_variable();
if (!lhs || !(lhs->type->is_scalar() || lhs->type->is_vector()))
return;
+ if (lhs->var->data.mode == ir_var_shader_storage ||
+ lhs->var->data.mode == ir_var_shader_shared)
+ return;
+
ir_dereference_variable *rhs = ir->rhs->as_dereference_variable();
if (!rhs) {
ir_swizzle *swiz = ir->rhs->as_swizzle();
orig_swizzle[3] = swiz->mask.w;
}
+ if (rhs->var->data.mode == ir_var_shader_storage ||
+ rhs->var->data.mode == ir_var_shader_shared)
+ return;
+
/* Move the swizzle channels out to the positions they match in the
* destination. We don't want to have to rewrite the swizzle[]
* array every time we clear a bit of the write_mask.
}
}
- entry = new(this->mem_ctx) acp_entry(lhs->var, rhs->var, write_mask,
- swizzle);
- this->acp->push_tail(entry);
+ if (lhs->var->data.precise != rhs->var->data.precise)
+ return;
+
+ state->write_elements(lhs->var, rhs->var, write_mask, swizzle);
}
bool
projects / mesa.git / blobdiff