From 33886474d646134f9784771a0ded3510a0180515 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Thu, 28 Feb 2019 10:42:05 -0800 Subject: [PATCH] v3d: Use the DAG datastructure for QPU instruction scheduling. Just a small code reduction from shared infrastructure. --- src/broadcom/compiler/qpu_schedule.c | 186 ++++++++------------- src/gallium/drivers/vc4/vc4_qir_schedule.c | 6 +- 2 files changed, 75 insertions(+), 117 deletions(-) diff --git a/src/broadcom/compiler/qpu_schedule.c b/src/broadcom/compiler/qpu_schedule.c index 8a7d9e84bf6..c7c12063816 100644 --- a/src/broadcom/compiler/qpu_schedule.c +++ b/src/broadcom/compiler/qpu_schedule.c @@ -37,18 +37,16 @@ #include "qpu/qpu_disasm.h" #include "v3d_compiler.h" #include "util/ralloc.h" +#include "util/dag.h" static bool debug; struct schedule_node_child; struct schedule_node { + struct dag_node dag; struct list_head link; struct qinst *inst; - struct schedule_node_child *children; - uint32_t child_count; - uint32_t child_array_size; - uint32_t parent_count; /* Longest cycles + instruction_latency() of any parent of this node. */ uint32_t unblocked_time; @@ -67,11 +65,6 @@ struct schedule_node { uint32_t latency; }; -struct schedule_node_child { - struct schedule_node *node; - bool write_after_read; -}; - /* When walking the instructions in reverse, we need to swap before/after in * add_dep(). */ @@ -79,6 +72,7 @@ enum direction { F, R }; struct schedule_state { const struct v3d_device_info *devinfo; + struct dag *dag; struct schedule_node *last_r[6]; struct schedule_node *last_rf[64]; struct schedule_node *last_sf; @@ -101,37 +95,17 @@ add_dep(struct schedule_state *state, bool write) { bool write_after_read = !write && state->dir == R; + void *edge_data = (void *)(uintptr_t)write_after_read; if (!before || !after) return; assert(before != after); - if (state->dir == R) { - struct schedule_node *t = before; - before = after; - after = t; - } - - for (int i = 0; i < before->child_count; i++) { - if (before->children[i].node == after && - (before->children[i].write_after_read == write_after_read)) { - return; - } - } - - if (before->child_array_size <= before->child_count) { - before->child_array_size = MAX2(before->child_array_size * 2, 16); - before->children = reralloc(before, before->children, - struct schedule_node_child, - before->child_array_size); - } - - before->children[before->child_count].node = after; - before->children[before->child_count].write_after_read = - write_after_read; - before->child_count++; - after->parent_count++; + if (state->dir == F) + dag_add_edge(&before->dag, &after->dag, edge_data); + else + dag_add_edge(&after->dag, &before->dag, edge_data); } static void @@ -425,11 +399,13 @@ calculate_deps(struct schedule_state *state, struct schedule_node *n) } static void -calculate_forward_deps(struct v3d_compile *c, struct list_head *schedule_list) +calculate_forward_deps(struct v3d_compile *c, struct dag *dag, + struct list_head *schedule_list) { struct schedule_state state; memset(&state, 0, sizeof(state)); + state.dag = dag; state.devinfo = c->devinfo; state.dir = F; @@ -438,11 +414,13 @@ calculate_forward_deps(struct v3d_compile *c, struct list_head *schedule_list) } static void -calculate_reverse_deps(struct v3d_compile *c, struct list_head *schedule_list) +calculate_reverse_deps(struct v3d_compile *c, struct dag *dag, + struct list_head *schedule_list) { struct schedule_state state; memset(&state, 0, sizeof(state)); + state.dag = dag; state.devinfo = c->devinfo; state.dir = R; @@ -453,6 +431,7 @@ calculate_reverse_deps(struct v3d_compile *c, struct list_head *schedule_list) } struct choose_scoreboard { + struct dag *dag; int tick; int last_magic_sfu_write_tick; int last_ldvary_tick; @@ -714,7 +693,6 @@ qpu_merge_inst(const struct v3d_device_info *devinfo, static struct schedule_node * choose_instruction_to_schedule(const struct v3d_device_info *devinfo, struct choose_scoreboard *scoreboard, - struct list_head *schedule_list, struct schedule_node *prev_inst) { struct schedule_node *chosen = NULL; @@ -728,7 +706,8 @@ choose_instruction_to_schedule(const struct v3d_device_info *devinfo, return NULL; } - list_for_each_entry(struct schedule_node, n, schedule_list, link) { + list_for_each_entry(struct schedule_node, n, &scoreboard->dag->heads, + dag.link) { const struct v3d_qpu_instr *inst = &n->inst->qpu; /* Don't choose the branch instruction until it's the last one @@ -736,7 +715,7 @@ choose_instruction_to_schedule(const struct v3d_device_info *devinfo, * choose it. */ if (inst->type == V3D_QPU_INSTR_TYPE_BRANCH && - !list_is_singular(schedule_list)) { + !list_is_singular(&scoreboard->dag->heads)) { continue; } @@ -871,24 +850,24 @@ update_scoreboard_for_chosen(struct choose_scoreboard *scoreboard, } static void -dump_state(const struct v3d_device_info *devinfo, - struct list_head *schedule_list) +dump_state(const struct v3d_device_info *devinfo, struct dag *dag) { - list_for_each_entry(struct schedule_node, n, schedule_list, link) { + list_for_each_entry(struct schedule_node, n, &dag->heads, dag.link) { fprintf(stderr, " t=%4d: ", n->unblocked_time); v3d_qpu_dump(devinfo, &n->inst->qpu); fprintf(stderr, "\n"); - for (int i = 0; i < n->child_count; i++) { - struct schedule_node *child = n->children[i].node; + util_dynarray_foreach(&n->dag.edges, struct dag_edge, edge) { + struct schedule_node *child = + (struct schedule_node *)edge->child; if (!child) continue; fprintf(stderr, " - "); v3d_qpu_dump(devinfo, &child->inst->qpu); fprintf(stderr, " (%d parents, %c)\n", - child->parent_count, - n->children[i].write_after_read ? 'w' : 'r'); + child->dag.parent_count, + edge->data ? 'w' : 'r'); } } } @@ -957,59 +936,56 @@ instruction_latency(struct schedule_node *before, struct schedule_node *after) /** Recursive computation of the delay member of a node. */ static void -compute_delay(struct schedule_node *n) +compute_delay(struct dag_node *node, void *state) { - if (!n->child_count) { - n->delay = 1; - } else { - for (int i = 0; i < n->child_count; i++) { - if (!n->children[i].node->delay) - compute_delay(n->children[i].node); - n->delay = MAX2(n->delay, - n->children[i].node->delay + - instruction_latency(n, n->children[i].node)); - } + struct schedule_node *n = (struct schedule_node *)node; + + n->delay = 1; + + util_dynarray_foreach(&n->dag.edges, struct dag_edge, edge) { + struct schedule_node *child = + (struct schedule_node *)edge->child; + + n->delay = MAX2(n->delay, (child->delay + + instruction_latency(n, child))); + } +} + +/* Removes a DAG head, but removing only the WAR edges. (dag_prune_head() + * should be called on it later to finish pruning the other edges). + */ +static void +pre_remove_head(struct dag *dag, struct schedule_node *n) +{ + list_delinit(&n->dag.link); + + util_dynarray_foreach(&n->dag.edges, struct dag_edge, edge) { + if (edge->data) + dag_remove_edge(dag, edge); } } static void -mark_instruction_scheduled(struct list_head *schedule_list, +mark_instruction_scheduled(struct dag *dag, uint32_t time, - struct schedule_node *node, - bool war_only) + struct schedule_node *node) { if (!node) return; - for (int i = node->child_count - 1; i >= 0; i--) { + util_dynarray_foreach(&node->dag.edges, struct dag_edge, edge) { struct schedule_node *child = - node->children[i].node; + (struct schedule_node *)edge->child; if (!child) continue; - if (war_only && !node->children[i].write_after_read) - continue; - - /* If the requirement is only that the node not appear before - * the last read of its destination, then it can be scheduled - * immediately after (or paired with!) the thing reading the - * destination. - */ - uint32_t latency = 0; - if (!war_only) { - latency = instruction_latency(node, - node->children[i].node); - } + uint32_t latency = instruction_latency(node, child); child->unblocked_time = MAX2(child->unblocked_time, time + latency); - child->parent_count--; - if (child->parent_count == 0) - list_add(&child->link, schedule_list); - - node->children[i].node = NULL; } + dag_prune_head(dag, &node->dag); } static void @@ -1223,7 +1199,6 @@ static uint32_t schedule_instructions(struct v3d_compile *c, struct choose_scoreboard *scoreboard, struct qblock *block, - struct list_head *schedule_list, enum quniform_contents *orig_uniform_contents, uint32_t *orig_uniform_data, uint32_t *next_uniform) @@ -1231,23 +1206,10 @@ schedule_instructions(struct v3d_compile *c, const struct v3d_device_info *devinfo = c->devinfo; uint32_t time = 0; - if (debug) { - fprintf(stderr, "initial deps:\n"); - dump_state(devinfo, schedule_list); - fprintf(stderr, "\n"); - } - - /* Remove non-DAG heads from the list. */ - list_for_each_entry_safe(struct schedule_node, n, schedule_list, link) { - if (n->parent_count != 0) - list_del(&n->link); - } - - while (!list_empty(schedule_list)) { + while (!list_empty(&scoreboard->dag->heads)) { struct schedule_node *chosen = choose_instruction_to_schedule(devinfo, scoreboard, - schedule_list, NULL); struct schedule_node *merge = NULL; @@ -1260,7 +1222,7 @@ schedule_instructions(struct v3d_compile *c, if (debug) { fprintf(stderr, "t=%4d: current list:\n", time); - dump_state(devinfo, schedule_list); + dump_state(devinfo, scoreboard->dag); fprintf(stderr, "t=%4d: chose: ", time); v3d_qpu_dump(devinfo, inst); fprintf(stderr, "\n"); @@ -1278,17 +1240,14 @@ schedule_instructions(struct v3d_compile *c, */ if (chosen) { time = MAX2(chosen->unblocked_time, time); - list_del(&chosen->link); - mark_instruction_scheduled(schedule_list, time, - chosen, true); + pre_remove_head(scoreboard->dag, chosen); while ((merge = choose_instruction_to_schedule(devinfo, scoreboard, - schedule_list, chosen))) { time = MAX2(merge->unblocked_time, time); - list_del(&merge->link); + pre_remove_head(scoreboard->dag, chosen); list_addtail(&merge->link, &merged_list); (void)qpu_merge_inst(devinfo, inst, inst, &merge->inst->qpu); @@ -1334,11 +1293,10 @@ schedule_instructions(struct v3d_compile *c, * be scheduled. Update the children's unblocked time for this * DAG edge as we do so. */ - mark_instruction_scheduled(schedule_list, time, chosen, false); + mark_instruction_scheduled(scoreboard->dag, time, chosen); list_for_each_entry(struct schedule_node, merge, &merged_list, link) { - mark_instruction_scheduled(schedule_list, time, merge, - false); + mark_instruction_scheduled(scoreboard->dag, time, merge); /* The merged VIR instruction doesn't get re-added to the * block, so free it now. @@ -1380,9 +1338,10 @@ qpu_schedule_instructions_block(struct v3d_compile *c, uint32_t *next_uniform) { void *mem_ctx = ralloc_context(NULL); - struct list_head schedule_list; + scoreboard->dag = dag_create(NULL); + struct list_head setup_list; - list_inithead(&schedule_list); + list_inithead(&setup_list); /* Wrap each instruction in a scheduler structure. */ while (!list_empty(&block->instructions)) { @@ -1390,26 +1349,25 @@ qpu_schedule_instructions_block(struct v3d_compile *c, struct schedule_node *n = rzalloc(mem_ctx, struct schedule_node); + dag_init_node(scoreboard->dag, &n->dag); n->inst = qinst; list_del(&qinst->link); - list_addtail(&n->link, &schedule_list); + list_addtail(&n->link, &setup_list); } - calculate_forward_deps(c, &schedule_list); - calculate_reverse_deps(c, &schedule_list); + calculate_forward_deps(c, scoreboard->dag, &setup_list); + calculate_reverse_deps(c, scoreboard->dag, &setup_list); - list_for_each_entry(struct schedule_node, n, &schedule_list, link) { - compute_delay(n); - } + dag_traverse_bottom_up(scoreboard->dag, compute_delay, NULL); uint32_t cycles = schedule_instructions(c, scoreboard, block, - &schedule_list, orig_uniform_contents, orig_uniform_data, next_uniform); - ralloc_free(mem_ctx); + ralloc_free(scoreboard->dag); + scoreboard->dag = NULL; return cycles; } diff --git a/src/gallium/drivers/vc4/vc4_qir_schedule.c b/src/gallium/drivers/vc4/vc4_qir_schedule.c index 28f65a9af93..cbd993ceb32 100644 --- a/src/gallium/drivers/vc4/vc4_qir_schedule.c +++ b/src/gallium/drivers/vc4/vc4_qir_schedule.c @@ -536,9 +536,9 @@ dump_state(struct vc4_compile *c, struct schedule_state *state) fprintf(stderr, " (%d cost)\n", get_register_pressure_cost(state, n->inst)); - util_dynarray_foreach(&n->dag.children, struct schedule_node *, - childp) { - struct schedule_node *child = *childp; + util_dynarray_foreach(&n->dag.edges, struct dag_edge, edge) { + struct schedule_node *child = + (struct schedule_node *)edge->child; fprintf(stderr, " - "); qir_dump_inst(c, child->inst); fprintf(stderr, " (%d parents)\n", -- 2.30.2