*
*/
-#include "brw_fs.h"
#include "brw_cfg.h"
/** @file brw_cfg.cpp
{
bblock_link *link = (bblock_link *)list->get_tail();
bblock_t *block = link->block;
- link->remove();
+ link->link.remove();
return block;
}
-bblock_t::bblock_t() :
- start_ip(0), end_ip(0), block_num(0)
+static exec_node *
+link(void *mem_ctx, bblock_t *block)
{
- start = NULL;
- end = NULL;
+ bblock_link *l = new(mem_ctx) bblock_link(block);
+ return &l->link;
+}
+bblock_t::bblock_t(cfg_t *cfg) :
+ cfg(cfg), idom(NULL), start_ip(0), end_ip(0), num(0), cycle_count(0)
+{
+ instructions.make_empty();
parents.make_empty();
children.make_empty();
-
- if_inst = NULL;
- else_inst = NULL;
- endif_inst = NULL;
}
void
bblock_t::add_successor(void *mem_ctx, bblock_t *successor)
{
- successor->parents.push_tail(this->make_list(mem_ctx));
- children.push_tail(successor->make_list(mem_ctx));
+ successor->parents.push_tail(::link(mem_ctx, this));
+ children.push_tail(::link(mem_ctx, successor));
}
-bblock_link *
-bblock_t::make_list(void *mem_ctx)
+bool
+bblock_t::is_predecessor_of(const bblock_t *block) const
{
- return new(mem_ctx) bblock_link(this);
+ foreach_list_typed_safe (bblock_link, parent, link, &block->parents) {
+ if (parent->block == this) {
+ return true;
+ }
+ }
+
+ return false;
}
-void
-bblock_t::dump(backend_visitor *v)
+bool
+bblock_t::is_successor_of(const bblock_t *block) const
{
- int ip = this->start_ip;
- for (backend_instruction *inst = (backend_instruction *)this->start;
- inst != this->end->next;
- inst = (backend_instruction *) inst->next) {
- printf("%5d: ", ip);
- v->dump_instruction(inst);
- ip++;
+ foreach_list_typed_safe (bblock_link, child, link, &block->children) {
+ if (child->block == this) {
+ return true;
+ }
}
+
+ return false;
+}
+
+static bool
+ends_block(const backend_instruction *inst)
+{
+ enum opcode op = inst->opcode;
+
+ return op == BRW_OPCODE_IF ||
+ op == BRW_OPCODE_ELSE ||
+ op == BRW_OPCODE_CONTINUE ||
+ op == BRW_OPCODE_BREAK ||
+ op == BRW_OPCODE_WHILE;
}
-cfg_t::cfg_t(backend_visitor *v)
+static bool
+starts_block(const backend_instruction *inst)
{
- create(v->mem_ctx, &v->instructions);
+ enum opcode op = inst->opcode;
+
+ return op == BRW_OPCODE_DO ||
+ op == BRW_OPCODE_ENDIF;
+}
+
+bool
+bblock_t::can_combine_with(const bblock_t *that) const
+{
+ if ((const bblock_t *)this->link.next != that)
+ return false;
+
+ if (ends_block(this->end()) ||
+ starts_block(that->start()))
+ return false;
+
+ return true;
}
-cfg_t::cfg_t(void *mem_ctx, exec_list *instructions)
+void
+bblock_t::combine_with(bblock_t *that)
{
- create(mem_ctx, instructions);
+ assert(this->can_combine_with(that));
+ foreach_list_typed (bblock_link, link, link, &this->children) {
+ assert(link->block == that);
+ }
+ foreach_list_typed (bblock_link, link, link, &that->parents) {
+ assert(link->block == this);
+ }
+
+ this->end_ip = that->end_ip;
+ this->instructions.append_list(&that->instructions);
+
+ this->cfg->remove_block(that);
}
void
-cfg_t::create(void *parent_mem_ctx, exec_list *instructions)
+bblock_t::dump(backend_shader *s) const
+{
+ int ip = this->start_ip;
+ foreach_inst_in_block(backend_instruction, inst, this) {
+ fprintf(stderr, "%5d: ", ip);
+ s->dump_instruction(inst);
+ ip++;
+ }
+}
+
+cfg_t::cfg_t(exec_list *instructions)
{
mem_ctx = ralloc_context(NULL);
block_list.make_empty();
blocks = NULL;
num_blocks = 0;
- ip = 0;
- cur = NULL;
+ idom_dirty = true;
+ cycle_count = 0;
+
+ bblock_t *cur = NULL;
+ int ip = 0;
bblock_t *entry = new_block();
- bblock_t *cur_if = NULL, *cur_else = NULL, *cur_endif = NULL;
- bblock_t *cur_do = NULL, *cur_while = NULL;
- exec_list if_stack, else_stack, endif_stack, do_stack, while_stack;
+ bblock_t *cur_if = NULL; /**< BB ending with IF. */
+ bblock_t *cur_else = NULL; /**< BB ending with ELSE. */
+ bblock_t *cur_endif = NULL; /**< BB starting with ENDIF. */
+ bblock_t *cur_do = NULL; /**< BB starting with DO. */
+ bblock_t *cur_while = NULL; /**< BB immediately following WHILE. */
+ exec_list if_stack, else_stack, do_stack, while_stack;
bblock_t *next;
- set_next_block(entry);
-
- entry->start = (backend_instruction *) instructions->get_head();
-
- foreach_list(node, instructions) {
- backend_instruction *inst = (backend_instruction *)node;
-
- cur->end = inst;
+ set_next_block(&cur, entry, ip);
+ foreach_in_list_safe(backend_instruction, inst, instructions) {
/* set_next_block wants the post-incremented ip */
ip++;
+ inst->exec_node::remove();
+
switch (inst->opcode) {
case BRW_OPCODE_IF:
+ cur->instructions.push_tail(inst);
+
/* Push our information onto a stack so we can recover from
* nested ifs.
*/
- if_stack.push_tail(cur_if->make_list(mem_ctx));
- else_stack.push_tail(cur_else->make_list(mem_ctx));
- endif_stack.push_tail(cur_endif->make_list(mem_ctx));
+ if_stack.push_tail(link(mem_ctx, cur_if));
+ else_stack.push_tail(link(mem_ctx, cur_else));
cur_if = cur;
cur_else = NULL;
* instructions.
*/
next = new_block();
- next->start = (backend_instruction *)inst->next;
cur_if->add_successor(mem_ctx, next);
- set_next_block(next);
+ set_next_block(&cur, next, ip);
break;
case BRW_OPCODE_ELSE:
+ cur->instructions.push_tail(inst);
+
cur_else = cur;
next = new_block();
- next->start = (backend_instruction *)inst->next;
+ assert(cur_if != NULL);
cur_if->add_successor(mem_ctx, next);
- set_next_block(next);
+ set_next_block(&cur, next, ip);
break;
case BRW_OPCODE_ENDIF: {
- if (cur->start == inst) {
+ if (cur->instructions.is_empty()) {
/* New block was just created; use it. */
cur_endif = cur;
} else {
cur_endif = new_block();
- cur_endif->start = inst;
- cur->end = (backend_instruction *)inst->prev;
cur->add_successor(mem_ctx, cur_endif);
- ip--;
- set_next_block(cur_endif);
- ip++;
+ set_next_block(&cur, cur_endif, ip - 1);
}
- backend_instruction *else_inst = NULL;
- if (cur_else) {
- else_inst = (backend_instruction *)cur_else->end;
+ cur->instructions.push_tail(inst);
+ if (cur_else) {
cur_else->add_successor(mem_ctx, cur_endif);
} else {
+ assert(cur_if != NULL);
cur_if->add_successor(mem_ctx, cur_endif);
}
- assert(cur_if->end->opcode == BRW_OPCODE_IF);
- assert(!else_inst || else_inst->opcode == BRW_OPCODE_ELSE);
- assert(inst->opcode == BRW_OPCODE_ENDIF);
-
- cur_if->if_inst = cur_if->end;
- cur_if->else_inst = else_inst;
- cur_if->endif_inst = inst;
-
- if (cur_else) {
- cur_else->if_inst = cur_if->end;
- cur_else->else_inst = else_inst;
- cur_else->endif_inst = inst;
- }
-
- cur->if_inst = cur_if->end;
- cur->else_inst = else_inst;
- cur->endif_inst = inst;
+ assert(cur_if->end()->opcode == BRW_OPCODE_IF);
+ assert(!cur_else || cur_else->end()->opcode == BRW_OPCODE_ELSE);
/* Pop the stack so we're in the previous if/else/endif */
cur_if = pop_stack(&if_stack);
cur_else = pop_stack(&else_stack);
- cur_endif = pop_stack(&endif_stack);
break;
}
case BRW_OPCODE_DO:
/* Push our information onto a stack so we can recover from
* nested loops.
*/
- do_stack.push_tail(cur_do->make_list(mem_ctx));
- while_stack.push_tail(cur_while->make_list(mem_ctx));
+ do_stack.push_tail(link(mem_ctx, cur_do));
+ while_stack.push_tail(link(mem_ctx, cur_while));
/* Set up the block just after the while. Don't know when exactly
* it will start, yet.
*/
cur_while = new_block();
- /* Set up our immediately following block, full of "then"
- * instructions.
- */
- next = new_block();
- next->start = (backend_instruction *)inst->next;
- cur->add_successor(mem_ctx, next);
- cur_do = next;
+ if (cur->instructions.is_empty()) {
+ /* New block was just created; use it. */
+ cur_do = cur;
+ } else {
+ cur_do = new_block();
+
+ cur->add_successor(mem_ctx, cur_do);
- set_next_block(next);
+ set_next_block(&cur, cur_do, ip - 1);
+ }
+
+ cur->instructions.push_tail(inst);
break;
case BRW_OPCODE_CONTINUE:
+ cur->instructions.push_tail(inst);
+
+ assert(cur_do != NULL);
cur->add_successor(mem_ctx, cur_do);
next = new_block();
- next->start = (backend_instruction *)inst->next;
if (inst->predicate)
cur->add_successor(mem_ctx, next);
- set_next_block(next);
+ set_next_block(&cur, next, ip);
break;
case BRW_OPCODE_BREAK:
+ cur->instructions.push_tail(inst);
+
+ assert(cur_while != NULL);
cur->add_successor(mem_ctx, cur_while);
next = new_block();
- next->start = (backend_instruction *)inst->next;
if (inst->predicate)
cur->add_successor(mem_ctx, next);
- set_next_block(next);
+ set_next_block(&cur, next, ip);
break;
case BRW_OPCODE_WHILE:
- cur_while->start = (backend_instruction *)inst->next;
+ cur->instructions.push_tail(inst);
+ assert(cur_do != NULL && cur_while != NULL);
cur->add_successor(mem_ctx, cur_do);
- set_next_block(cur_while);
+
+ if (inst->predicate)
+ cur->add_successor(mem_ctx, cur_while);
+
+ set_next_block(&cur, cur_while, ip);
/* Pop the stack so we're in the previous loop */
cur_do = pop_stack(&do_stack);
break;
default:
+ cur->instructions.push_tail(inst);
break;
}
}
- cur->end_ip = ip;
+ cur->end_ip = ip - 1;
make_block_array();
}
ralloc_free(mem_ctx);
}
+void
+cfg_t::remove_block(bblock_t *block)
+{
+ foreach_list_typed_safe (bblock_link, predecessor, link, &block->parents) {
+ /* Remove block from all of its predecessors' successor lists. */
+ foreach_list_typed_safe (bblock_link, successor, link,
+ &predecessor->block->children) {
+ if (block == successor->block) {
+ successor->link.remove();
+ ralloc_free(successor);
+ }
+ }
+
+ /* Add removed-block's successors to its predecessors' successor lists. */
+ foreach_list_typed (bblock_link, successor, link, &block->children) {
+ if (!successor->block->is_successor_of(predecessor->block)) {
+ predecessor->block->children.push_tail(link(mem_ctx,
+ successor->block));
+ }
+ }
+ }
+
+ foreach_list_typed_safe (bblock_link, successor, link, &block->children) {
+ /* Remove block from all of its childrens' parents lists. */
+ foreach_list_typed_safe (bblock_link, predecessor, link,
+ &successor->block->parents) {
+ if (block == predecessor->block) {
+ predecessor->link.remove();
+ ralloc_free(predecessor);
+ }
+ }
+
+ /* Add removed-block's predecessors to its successors' predecessor lists. */
+ foreach_list_typed (bblock_link, predecessor, link, &block->parents) {
+ if (!predecessor->block->is_predecessor_of(successor->block)) {
+ successor->block->parents.push_tail(link(mem_ctx,
+ predecessor->block));
+ }
+ }
+ }
+
+ block->link.remove();
+
+ for (int b = block->num; b < this->num_blocks - 1; b++) {
+ this->blocks[b] = this->blocks[b + 1];
+ this->blocks[b]->num = b;
+ }
+
+ this->blocks[this->num_blocks - 1]->num = this->num_blocks - 2;
+ this->num_blocks--;
+ idom_dirty = true;
+}
+
bblock_t *
cfg_t::new_block()
{
- bblock_t *block = new(mem_ctx) bblock_t();
+ bblock_t *block = new(mem_ctx) bblock_t(this);
return block;
}
void
-cfg_t::set_next_block(bblock_t *block)
+cfg_t::set_next_block(bblock_t **cur, bblock_t *block, int ip)
{
- if (cur) {
- assert(cur->end->next == block->start);
- cur->end_ip = ip - 1;
+ if (*cur) {
+ (*cur)->end_ip = ip - 1;
}
block->start_ip = ip;
- block->block_num = num_blocks++;
- block_list.push_tail(block->make_list(mem_ctx));
- cur = block;
+ block->num = num_blocks++;
+ block_list.push_tail(&block->link);
+ *cur = block;
}
void
blocks = ralloc_array(mem_ctx, bblock_t *, num_blocks);
int i = 0;
- foreach_list(block_node, &block_list) {
- bblock_link *link = (bblock_link *)block_node;
- blocks[i++] = link->block;
+ foreach_block (block, this) {
+ blocks[i++] = block;
}
assert(i == num_blocks);
}
void
-cfg_t::dump(backend_visitor *v)
+cfg_t::dump(backend_shader *s)
+{
+ if (idom_dirty)
+ calculate_idom();
+
+ foreach_block (block, this) {
+ if (block->idom)
+ fprintf(stderr, "START B%d IDOM(B%d)", block->num, block->idom->num);
+ else
+ fprintf(stderr, "START B%d IDOM(none)", block->num);
+
+ foreach_list_typed(bblock_link, link, link, &block->parents) {
+ fprintf(stderr, " <-B%d",
+ link->block->num);
+ }
+ fprintf(stderr, "\n");
+ if (s != NULL)
+ block->dump(s);
+ fprintf(stderr, "END B%d", block->num);
+ foreach_list_typed(bblock_link, link, link, &block->children) {
+ fprintf(stderr, " ->B%d",
+ link->block->num);
+ }
+ fprintf(stderr, "\n");
+ }
+}
+
+/* Calculates the immediate dominator of each block, according to "A Simple,
+ * Fast Dominance Algorithm" by Keith D. Cooper, Timothy J. Harvey, and Ken
+ * Kennedy.
+ *
+ * The authors claim that for control flow graphs of sizes normally encountered
+ * (less than 1000 nodes) that this algorithm is significantly faster than
+ * others like Lengauer-Tarjan.
+ */
+void
+cfg_t::calculate_idom()
{
- for (int b = 0; b < this->num_blocks; b++) {
- bblock_t *block = this->blocks[b];
- printf("START B%d", b);
- foreach_list(node, &block->parents) {
- bblock_link *link = (bblock_link *)node;
- printf(" <-B%d", link->block->block_num);
+ foreach_block(block, this) {
+ block->idom = NULL;
+ }
+ blocks[0]->idom = blocks[0];
+
+ bool changed;
+ do {
+ changed = false;
+
+ foreach_block(block, this) {
+ if (block->num == 0)
+ continue;
+
+ bblock_t *new_idom = NULL;
+ foreach_list_typed(bblock_link, parent, link, &block->parents) {
+ if (parent->block->idom) {
+ if (new_idom == NULL) {
+ new_idom = parent->block;
+ } else if (parent->block->idom != NULL) {
+ new_idom = intersect(parent->block, new_idom);
+ }
+ }
+ }
+
+ if (block->idom != new_idom) {
+ block->idom = new_idom;
+ changed = true;
+ }
}
- printf("\n");
- block->dump(v);
- printf("END B%d", b);
- foreach_list(node, &block->children) {
- bblock_link *link = (bblock_link *)node;
- printf(" ->B%d", link->block->block_num);
+ } while (changed);
+
+ idom_dirty = false;
+}
+
+bblock_t *
+cfg_t::intersect(bblock_t *b1, bblock_t *b2)
+{
+ /* Note, the comparisons here are the opposite of what the paper says
+ * because we index blocks from beginning -> end (i.e. reverse post-order)
+ * instead of post-order like they assume.
+ */
+ while (b1->num != b2->num) {
+ while (b1->num > b2->num)
+ b1 = b1->idom;
+ while (b2->num > b1->num)
+ b2 = b2->idom;
+ }
+ assert(b1);
+ return b1;
+}
+
+void
+cfg_t::dump_cfg()
+{
+ printf("digraph CFG {\n");
+ for (int b = 0; b < num_blocks; b++) {
+ bblock_t *block = this->blocks[b];
+
+ foreach_list_typed_safe (bblock_link, child, link, &block->children) {
+ printf("\t%d -> %d\n", b, child->block->num);
+ }
+ }
+ printf("}\n");
+}
+
+void
+cfg_t::dump_domtree()
+{
+ printf("digraph DominanceTree {\n");
+ foreach_block(block, this) {
+ if (block->idom) {
+ printf("\t%d -> %d\n", block->idom->num, block->num);
}
- printf("\n");
}
+ printf("}\n");
}
projects / mesa.git / blobdiff