+++ /dev/null
-/*
- * 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_copy_propagation_elements.cpp
- *
- * Replaces usage of recently-copied components of variables with the
- * previous copy of the variable.
- *
- * This should reduce the number of MOV instructions in the generated
- * programs and help triggering other optimizations that live in GLSL
- * level.
- */
-
-#include "ir.h"
-#include "ir_rvalue_visitor.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:
- 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)
- {
- return new (mem_ctx) copy_propagation_state(NULL);
- }
-
- copy_propagation_state* clone()
- {
- return new (ralloc_parent(this)) copy_propagation_state(this);
- }
-
- 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->write_mask = write_mask;
- }
-
- ir_variable *var;
- unsigned int write_mask;
-};
-
-class ir_copy_propagation_elements_visitor : public ir_rvalue_visitor {
-public:
- ir_copy_propagation_elements_visitor()
- {
- 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->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 *);
- virtual ir_visitor_status visit_enter(class ir_call *);
- virtual ir_visitor_status visit_enter(class ir_if *);
- virtual ir_visitor_status visit_leave(class ir_swizzle *);
-
- void handle_rvalue(ir_rvalue **rvalue);
-
- void add_copy(ir_assignment *ir);
- void kill(kill_entry *k);
- void handle_if_block(exec_list *instructions, exec_list *kills, bool *killed_all);
-
- copy_propagation_state *state;
-
- /**
- * List of kill_entry: The variables whose values were killed in this
- * block.
- */
- exec_list *kills;
-
- bool progress;
-
- bool killed_all;
-
- /* 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)
-{
- /* Treat entry into a function signature as a completely separate
- * block. Any instructions at global scope will be shuffled into
- * main() at link time, so they're irrelevant to us.
- */
- exec_list *orig_kills = this->kills;
- bool orig_killed_all = this->killed_all;
-
- 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);
-
- delete this->state;
- this->state = orig_state;
-
- ralloc_free(this->kills);
- this->kills = orig_kills;
- this->killed_all = orig_killed_all;
-
- return visit_continue_with_parent;
-}
-
-ir_visitor_status
-ir_copy_propagation_elements_visitor::visit_leave(ir_assignment *ir)
-{
- ir_dereference_variable *lhs = ir->lhs->as_dereference_variable();
- ir_variable *var = ir->lhs->variable_referenced();
-
- kill_entry *k;
-
- 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);
-
- add_copy(ir);
-
- return visit_continue;
-}
-
-ir_visitor_status
-ir_copy_propagation_elements_visitor::visit_leave(ir_swizzle *)
-{
- /* Don't visit the values of swizzles since they are handled while
- * visiting the swizzle itself.
- */
- return visit_continue;
-}
-
-/**
- * Replaces dereferences of ACP RHS variables with ACP LHS variables.
- *
- * This is where the actual copy propagation occurs. Note that the
- * rewriting of ir_dereference means that the ir_dereference instance
- * must not be shared by multiple IR operations!
- */
-void
-ir_copy_propagation_elements_visitor::handle_rvalue(ir_rvalue **ir)
-{
- int swizzle_chan[4];
- ir_dereference_variable *deref_var;
- ir_variable *source[4] = {NULL, NULL, NULL, NULL};
- int source_chan[4] = {0, 0, 0, 0};
- int chans;
- bool noop_swizzle = true;
-
- if (!*ir)
- return;
-
- ir_swizzle *swizzle = (*ir)->as_swizzle();
- if (swizzle) {
- deref_var = swizzle->val->as_dereference_variable();
- if (!deref_var)
- return;
-
- swizzle_chan[0] = swizzle->mask.x;
- swizzle_chan[1] = swizzle->mask.y;
- swizzle_chan[2] = swizzle->mask.z;
- swizzle_chan[3] = swizzle->mask.w;
- chans = swizzle->type->vector_elements;
- } else {
- deref_var = (*ir)->as_dereference_variable();
- if (!deref_var)
- return;
-
- swizzle_chan[0] = 0;
- swizzle_chan[1] = 1;
- swizzle_chan[2] = 2;
- swizzle_chan[3] = 3;
- chans = deref_var->type->vector_elements;
- }
-
- if (this->in_assignee)
- return;
-
- ir_variable *var = deref_var->var;
-
- /* Try to find ACP entries covering swizzle_chan[], hoping they're
- * the same source variable.
- */
-
- 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;
- }
- }
-
- /* Make sure all channels are copying from the same source variable. */
- if (!source[0])
- return;
- for (int c = 1; c < chans; c++) {
- if (source[c] != source[0])
- return;
- }
-
- if (!shader_mem_ctx)
- shader_mem_ctx = ralloc_parent(deref_var);
-
- /* Don't pointlessly replace the rvalue with itself (or a noop swizzle
- * of itself, which would just be deleted by opt_noop_swizzle).
- */
- if (source[0] == var && noop_swizzle)
- return;
-
- if (debug) {
- printf("Copy propagation from:\n");
- (*ir)->print();
- }
-
- deref_var = new(shader_mem_ctx) ir_dereference_variable(source[0]);
- *ir = new(shader_mem_ctx) ir_swizzle(deref_var,
- source_chan[0],
- source_chan[1],
- source_chan[2],
- source_chan[3],
- chans);
- progress = true;
-
- if (debug) {
- printf("to:\n");
- (*ir)->print();
- printf("\n");
- }
-}
-
-
-ir_visitor_status
-ir_copy_propagation_elements_visitor::visit_enter(ir_call *ir)
-{
- /* Do copy propagation on call parameters, but skip any out params */
- foreach_two_lists(formal_node, &ir->callee->parameters,
- actual_node, &ir->actual_parameters) {
- ir_variable *sig_param = (ir_variable *) formal_node;
- ir_rvalue *ir = (ir_rvalue *) actual_node;
- if (sig_param->data.mode != ir_var_function_out
- && sig_param->data.mode != ir_var_function_inout) {
- ir->accept(this);
- }
- }
-
- 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, exec_list *kills, bool *killed_all)
-{
- exec_list *orig_kills = this->kills;
- bool orig_killed_all = this->killed_all;
-
- this->kills = kills;
- this->killed_all = false;
-
- /* Populate the initial acp with a copy of the original */
- copy_propagation_state *orig_state = state;
- this->state = orig_state->clone();
-
- visit_list_elements(this, instructions);
-
- delete this->state;
- this->state = orig_state;
-
- *killed_all = this->killed_all;
- this->kills = orig_kills;
- this->killed_all = orig_killed_all;
-}
-
-ir_visitor_status
-ir_copy_propagation_elements_visitor::visit_enter(ir_if *ir)
-{
- ir->condition->accept(this);
-
- 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;
-}
-
-void
-ir_copy_propagation_elements_visitor::handle_loop(ir_loop *ir, bool keep_acp)
-{
- exec_list *orig_kills = this->kills;
- bool orig_killed_all = this->killed_all;
-
- this->kills = new(mem_ctx) exec_list;
- this->killed_all = false;
-
- copy_propagation_state *orig_state = state;
-
- 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;
- this->killed_all = this->killed_all || orig_killed_all;
-
- foreach_in_list_safe(kill_entry, k, new_kills) {
- kill(k);
- }
-
- 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;
-}
-
-/* Remove any entries currently in the ACP for this kill. */
-void
-ir_copy_propagation_elements_visitor::kill(kill_entry *k)
-{
- state->erase(k->var, k->write_mask);
-
- /* If we were on a list, remove ourselves before inserting */
- if (k->next)
- k->remove();
-
- this->kills->push_tail(k);
-}
-
-/**
- * Adds directly-copied channels between vector variables to the available
- * copy propagation list.
- */
-void
-ir_copy_propagation_elements_visitor::add_copy(ir_assignment *ir)
-{
- {
- 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();
- if (!swiz)
- return;
-
- rhs = swiz->val->as_dereference_variable();
- if (!rhs)
- return;
-
- orig_swizzle[0] = swiz->mask.x;
- orig_swizzle[1] = swiz->mask.y;
- orig_swizzle[2] = swiz->mask.z;
- 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.
- */
- int j = 0;
- for (int i = 0; i < 4; i++) {
- if (ir->write_mask & (1 << i))
- swizzle[i] = orig_swizzle[j++];
- }
-
- int write_mask = ir->write_mask;
- if (lhs->var == rhs->var) {
- /* If this is a copy from the variable to itself, then we need
- * to be sure not to include the updated channels from this
- * instruction in the set of new source channels to be
- * copy-propagated from.
- */
- for (int i = 0; i < 4; i++) {
- if (ir->write_mask & (1 << orig_swizzle[i]))
- write_mask &= ~(1 << i);
- }
- }
-
- if (lhs->var->data.precise != rhs->var->data.precise)
- return;
-
- state->write_elements(lhs->var, rhs->var, write_mask, swizzle);
-}
-
-bool
-do_copy_propagation_elements(exec_list *instructions)
-{
- ir_copy_propagation_elements_visitor v;
-
- visit_list_elements(&v, instructions);
-
- return v.progress;
-}
projects / platform / upstream / mesa.git / commitdiff