struct schedule_node *last_tmu_write;
struct schedule_node *last_tlb;
struct schedule_node *last_vpm;
+ struct schedule_node *last_uniforms_reset;
enum direction dir;
/* Estimated cycle when the current instruction would start. */
uint32_t time;
break;
case QPU_R_UNIF:
+ add_read_dep(state, state->last_uniforms_reset, n);
+ break;
+
case QPU_R_NOP:
case QPU_R_ELEM_QPU:
case QPU_R_XY_PIXEL_COORD:
}
} else if (is_tmu_write(waddr)) {
add_write_dep(state, &state->last_tmu_write, n);
+ add_read_dep(state, state->last_uniforms_reset, n);
} else if (qpu_waddr_is_tlb(waddr) ||
waddr == QPU_W_MS_FLAGS) {
add_write_dep(state, &state->last_tlb, n);
add_write_dep(state, &state->last_tlb, n);
break;
+ case QPU_W_UNIFORMS_ADDRESS:
+ add_write_dep(state, &state->last_uniforms_reset, n);
+ break;
+
case QPU_W_NOP:
break;
if (sig != QPU_SIG_LOAD_IMM) {
process_raddr_deps(state, n, raddr_a, true);
- if (sig != QPU_SIG_SMALL_IMM)
+ if (sig != QPU_SIG_SMALL_IMM &&
+ sig != QPU_SIG_BRANCH)
process_raddr_deps(state, n, raddr_b, false);
}
switch (sig) {
case QPU_SIG_SW_BREAKPOINT:
case QPU_SIG_NONE:
- case QPU_SIG_THREAD_SWITCH:
- case QPU_SIG_LAST_THREAD_SWITCH:
case QPU_SIG_SMALL_IMM:
case QPU_SIG_LOAD_IMM:
break;
+ case QPU_SIG_THREAD_SWITCH:
+ case QPU_SIG_LAST_THREAD_SWITCH:
+ /* All accumulator contents and flags are undefined after the
+ * switch.
+ */
+ for (int i = 0; i < ARRAY_SIZE(state->last_r); i++)
+ add_write_dep(state, &state->last_r[i], n);
+ add_write_dep(state, &state->last_sf, n);
+
+ /* Scoreboard-locking operations have to stay after the last
+ * thread switch.
+ */
+ add_write_dep(state, &state->last_tlb, n);
+
+ add_write_dep(state, &state->last_tmu_write, n);
+ break;
+
case QPU_SIG_LOAD_TMU0:
case QPU_SIG_LOAD_TMU1:
/* TMU loads are coming from a FIFO, so ordering is important.
add_read_dep(state, state->last_tlb, n);
break;
+ case QPU_SIG_BRANCH:
+ add_read_dep(state, state->last_sf, n);
+ break;
+
case QPU_SIG_PROG_END:
case QPU_SIG_WAIT_FOR_SCOREBOARD:
case QPU_SIG_SCOREBOARD_UNLOCK:
case QPU_SIG_COVERAGE_LOAD:
case QPU_SIG_COLOR_LOAD_END:
case QPU_SIG_ALPHA_MASK_LOAD:
- case QPU_SIG_BRANCH:
fprintf(stderr, "Unhandled signal bits %d\n", sig);
abort();
}
process_cond_deps(state, n, QPU_GET_FIELD(inst, QPU_COND_ADD));
- process_cond_deps(state, n, QPU_GET_FIELD(inst, QPU_COND_ADD));
- if (inst & QPU_SF)
+ process_cond_deps(state, n, QPU_GET_FIELD(inst, QPU_COND_MUL));
+ if ((inst & QPU_SF) && sig != QPU_SIG_BRANCH)
add_write_dep(state, &state->last_sf, n);
}
struct choose_scoreboard {
int tick;
int last_sfu_write_tick;
+ int last_uniforms_reset_tick;
uint32_t last_waddr_a, last_waddr_b;
+ bool tlb_locked;
};
static bool
uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+
+ /* Full immediate loads don't read any registers. */
+ if (sig == QPU_SIG_LOAD_IMM)
+ return false;
+
uint32_t src_muxes[] = {
QPU_GET_FIELD(inst, QPU_ADD_A),
QPU_GET_FIELD(inst, QPU_ADD_B),
}
}
+ if (sig == QPU_SIG_SMALL_IMM &&
+ QPU_GET_FIELD(inst, QPU_SMALL_IMM) >= QPU_SMALL_IMM_MUL_ROT) {
+ uint32_t mux_a = QPU_GET_FIELD(inst, QPU_MUL_A);
+ uint32_t mux_b = QPU_GET_FIELD(inst, QPU_MUL_B);
+
+ if (scoreboard->last_waddr_a == mux_a + QPU_W_ACC0 ||
+ scoreboard->last_waddr_a == mux_b + QPU_W_ACC0 ||
+ scoreboard->last_waddr_b == mux_a + QPU_W_ACC0 ||
+ scoreboard->last_waddr_b == mux_b + QPU_W_ACC0) {
+ return true;
+ }
+ }
+
+ if (reads_uniform(inst) &&
+ scoreboard->tick - scoreboard->last_uniforms_reset_tick <= 2) {
+ return true;
+ }
+
return false;
}
struct schedule_node *chosen = NULL;
int chosen_prio = 0;
+ /* Don't pair up anything with a thread switch signal -- emit_thrsw()
+ * will handle pairing it along with filling the delay slots.
+ */
+ if (prev_inst) {
+ uint32_t prev_sig = QPU_GET_FIELD(prev_inst->inst->inst,
+ QPU_SIG);
+ if (prev_sig == QPU_SIG_THREAD_SWITCH ||
+ prev_sig == QPU_SIG_LAST_THREAD_SWITCH) {
+ return NULL;
+ }
+ }
+
list_for_each_entry(struct schedule_node, n, schedule_list, link) {
uint64_t inst = n->inst->inst;
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+
+ /* Don't choose the branch instruction until it's the last one
+ * left. XXX: We could potentially choose it before it's the
+ * last one, if the remaining instructions fit in the delay
+ * slots.
+ */
+ if (sig == QPU_SIG_BRANCH &&
+ !list_is_singular(schedule_list)) {
+ continue;
+ }
/* "An instruction must not read from a location in physical
* regfile A or B that was written to by the previous
* that they're compatible.
*/
if (prev_inst) {
+ /* Don't pair up a thread switch signal -- we'll
+ * handle pairing it when we pick it on its own.
+ */
+ if (sig == QPU_SIG_THREAD_SWITCH ||
+ sig == QPU_SIG_LAST_THREAD_SWITCH) {
+ continue;
+ }
+
if (prev_inst->uniform != -1 && n->uniform != -1)
continue;
+ /* Don't merge in something that will lock the TLB.
+ * Hopwefully what we have in inst will release some
+ * other instructions, allowing us to delay the
+ * TLB-locking instruction until later.
+ */
+ if (!scoreboard->tlb_locked && qpu_inst_is_tlb(inst))
+ continue;
+
inst = qpu_merge_inst(prev_inst->inst->inst, inst);
if (!inst)
continue;
(waddr_mul >= QPU_W_SFU_RECIP && waddr_mul <= QPU_W_SFU_LOG)) {
scoreboard->last_sfu_write_tick = scoreboard->tick;
}
+
+ if (waddr_add == QPU_W_UNIFORMS_ADDRESS ||
+ waddr_mul == QPU_W_UNIFORMS_ADDRESS) {
+ scoreboard->last_uniforms_reset_tick = scoreboard->tick;
+ }
+
+ if (qpu_inst_is_tlb(inst))
+ scoreboard->tlb_locked = true;
}
static void
/* Apply some huge latency between texture fetch requests and getting
* their results back.
+ *
+ * FIXME: This is actually pretty bogus. If we do:
+ *
+ * mov tmu0_s, a
+ * <a bit of math>
+ * mov tmu0_s, b
+ * load_tmu0
+ * <more math>
+ * load_tmu0
+ *
+ * we count that as worse than
+ *
+ * mov tmu0_s, a
+ * mov tmu0_s, b
+ * <lots of math>
+ * load_tmu0
+ * <more math>
+ * load_tmu0
+ *
+ * because we associate the first load_tmu0 with the *second* tmu0_s.
*/
if (waddr == QPU_W_TMU0_S) {
if (QPU_GET_FIELD(after, QPU_SIG) == QPU_SIG_LOAD_TMU0)
}
}
-static uint32_t
-schedule_instructions(struct vc4_compile *c, struct list_head *schedule_list)
+/**
+ * Emits a THRSW/LTHRSW signal in the stream, trying to move it up to pair
+ * with another instruction.
+ */
+static void
+emit_thrsw(struct vc4_compile *c,
+ struct choose_scoreboard *scoreboard,
+ uint64_t inst)
{
- struct choose_scoreboard scoreboard;
- uint32_t time = 0;
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
- /* We reorder the uniforms as we schedule instructions, so save the
- * old data off and replace it.
+ /* There should be nothing in a thrsw inst being scheduled other than
+ * the signal bits.
*/
- uint32_t *uniform_data = c->uniform_data;
- enum quniform_contents *uniform_contents = c->uniform_contents;
- c->uniform_contents = ralloc_array(c, enum quniform_contents,
- c->num_uniforms);
- c->uniform_data = ralloc_array(c, uint32_t, c->num_uniforms);
- c->uniform_array_size = c->num_uniforms;
- uint32_t next_uniform = 0;
+ assert(QPU_GET_FIELD(inst, QPU_OP_ADD) == QPU_A_NOP);
+ assert(QPU_GET_FIELD(inst, QPU_OP_MUL) == QPU_M_NOP);
- memset(&scoreboard, 0, sizeof(scoreboard));
- scoreboard.last_waddr_a = ~0;
- scoreboard.last_waddr_b = ~0;
- scoreboard.last_sfu_write_tick = -10;
+ /* Try to find an earlier scheduled instruction that we can merge the
+ * thrsw into.
+ */
+ int thrsw_ip = c->qpu_inst_count;
+ for (int i = 1; i <= MIN2(c->qpu_inst_count, 3); i++) {
+ uint64_t prev_instr = c->qpu_insts[c->qpu_inst_count - i];
+ uint32_t prev_sig = QPU_GET_FIELD(prev_instr, QPU_SIG);
+
+ if (prev_sig == QPU_SIG_NONE)
+ thrsw_ip = c->qpu_inst_count - i;
+ }
+
+ if (thrsw_ip != c->qpu_inst_count) {
+ /* Merge the thrsw into the existing instruction. */
+ c->qpu_insts[thrsw_ip] =
+ QPU_UPDATE_FIELD(c->qpu_insts[thrsw_ip], sig, QPU_SIG);
+ } else {
+ qpu_serialize_one_inst(c, inst);
+ update_scoreboard_for_chosen(scoreboard, inst);
+ }
+
+ /* Fill the delay slots. */
+ while (c->qpu_inst_count < thrsw_ip + 3) {
+ update_scoreboard_for_chosen(scoreboard, qpu_NOP());
+ qpu_serialize_one_inst(c, qpu_NOP());
+ }
+}
+
+static uint32_t
+schedule_instructions(struct vc4_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)
+{
+ uint32_t time = 0;
if (debug) {
fprintf(stderr, "initial deps:\n");
while (!list_empty(schedule_list)) {
struct schedule_node *chosen =
- choose_instruction_to_schedule(&scoreboard,
+ choose_instruction_to_schedule(scoreboard,
schedule_list,
NULL);
struct schedule_node *merge = NULL;
mark_instruction_scheduled(schedule_list, time,
chosen, true);
if (chosen->uniform != -1) {
- c->uniform_data[next_uniform] =
- uniform_data[chosen->uniform];
- c->uniform_contents[next_uniform] =
- uniform_contents[chosen->uniform];
- next_uniform++;
+ c->uniform_data[*next_uniform] =
+ orig_uniform_data[chosen->uniform];
+ c->uniform_contents[*next_uniform] =
+ orig_uniform_contents[chosen->uniform];
+ (*next_uniform)++;
}
- merge = choose_instruction_to_schedule(&scoreboard,
+ merge = choose_instruction_to_schedule(scoreboard,
schedule_list,
chosen);
if (merge) {
inst = qpu_merge_inst(inst, merge->inst->inst);
assert(inst != 0);
if (merge->uniform != -1) {
- c->uniform_data[next_uniform] =
- uniform_data[merge->uniform];
- c->uniform_contents[next_uniform] =
- uniform_contents[merge->uniform];
- next_uniform++;
+ c->uniform_data[*next_uniform] =
+ orig_uniform_data[merge->uniform];
+ c->uniform_contents[*next_uniform] =
+ orig_uniform_contents[merge->uniform];
+ (*next_uniform)++;
}
if (debug) {
fprintf(stderr, "\n");
}
- qpu_serialize_one_inst(c, inst);
-
- update_scoreboard_for_chosen(&scoreboard, inst);
-
/* Now that we've scheduled a new instruction, some of its
* children can be promoted to the list of instructions ready to
* be scheduled. Update the children's unblocked time for this
mark_instruction_scheduled(schedule_list, time, chosen, false);
mark_instruction_scheduled(schedule_list, time, merge, false);
- scoreboard.tick++;
+ if (QPU_GET_FIELD(inst, QPU_SIG) == QPU_SIG_THREAD_SWITCH ||
+ QPU_GET_FIELD(inst, QPU_SIG) == QPU_SIG_LAST_THREAD_SWITCH) {
+ emit_thrsw(c, scoreboard, inst);
+ } else {
+ qpu_serialize_one_inst(c, inst);
+ update_scoreboard_for_chosen(scoreboard, inst);
+ }
+
+ scoreboard->tick++;
time++;
- }
- assert(next_uniform == c->num_uniforms);
+ if (QPU_GET_FIELD(inst, QPU_SIG) == QPU_SIG_BRANCH) {
+ block->branch_qpu_ip = c->qpu_inst_count - 1;
+ /* Fill the delay slots.
+ *
+ * We should fill these with actual instructions,
+ * instead, but that will probably need to be done
+ * after this, once we know what the leading
+ * instructions of the successors are (so we can
+ * handle A/B register file write latency)
+ */
+ inst = qpu_NOP();
+ update_scoreboard_for_chosen(scoreboard, inst);
+ qpu_serialize_one_inst(c, inst);
+ qpu_serialize_one_inst(c, inst);
+ qpu_serialize_one_inst(c, inst);
+ }
+ }
return time;
}
-uint32_t
-qpu_schedule_instructions(struct vc4_compile *c)
+static uint32_t
+qpu_schedule_instructions_block(struct vc4_compile *c,
+ struct choose_scoreboard *scoreboard,
+ struct qblock *block,
+ enum quniform_contents *orig_uniform_contents,
+ uint32_t *orig_uniform_data,
+ uint32_t *next_uniform)
{
void *mem_ctx = ralloc_context(NULL);
struct list_head schedule_list;
list_inithead(&schedule_list);
- if (debug) {
- fprintf(stderr, "Pre-schedule instructions\n");
- list_for_each_entry(struct queued_qpu_inst, q,
- &c->qpu_inst_list, link) {
- vc4_qpu_disasm(&q->inst, 1);
- fprintf(stderr, "\n");
- }
- fprintf(stderr, "\n");
- }
-
/* Wrap each instruction in a scheduler structure. */
- uint32_t next_uniform = 0;
- while (!list_empty(&c->qpu_inst_list)) {
+ uint32_t next_sched_uniform = *next_uniform;
+ while (!list_empty(&block->qpu_inst_list)) {
struct queued_qpu_inst *inst =
- (struct queued_qpu_inst *)c->qpu_inst_list.next;
+ (struct queued_qpu_inst *)block->qpu_inst_list.next;
struct schedule_node *n = rzalloc(mem_ctx, struct schedule_node);
n->inst = inst;
if (reads_uniform(inst->inst)) {
- n->uniform = next_uniform++;
+ n->uniform = next_sched_uniform++;
} else {
n->uniform = -1;
}
list_del(&inst->link);
list_addtail(&n->link, &schedule_list);
}
- assert(next_uniform == c->num_uniforms);
calculate_forward_deps(c, &schedule_list);
calculate_reverse_deps(c, &schedule_list);
compute_delay(n);
}
- uint32_t cycles = schedule_instructions(c, &schedule_list);
+ uint32_t cycles = schedule_instructions(c, scoreboard, block,
+ &schedule_list,
+ orig_uniform_contents,
+ orig_uniform_data,
+ next_uniform);
+
+ ralloc_free(mem_ctx);
+
+ return cycles;
+}
+
+static void
+qpu_set_branch_targets(struct vc4_compile *c)
+{
+ qir_for_each_block(block, c) {
+ /* The end block of the program has no branch. */
+ if (!block->successors[0])
+ continue;
+
+ /* If there was no branch instruction, then the successor
+ * block must follow immediately after this one.
+ */
+ if (block->branch_qpu_ip == ~0) {
+ assert(block->end_qpu_ip + 1 ==
+ block->successors[0]->start_qpu_ip);
+ continue;
+ }
+
+ /* Set the branch target for the block that doesn't follow
+ * immediately after ours.
+ */
+ uint64_t *branch_inst = &c->qpu_insts[block->branch_qpu_ip];
+ assert(QPU_GET_FIELD(*branch_inst, QPU_SIG) == QPU_SIG_BRANCH);
+ assert(QPU_GET_FIELD(*branch_inst, QPU_BRANCH_TARGET) == 0);
+
+ uint32_t branch_target =
+ (block->successors[0]->start_qpu_ip -
+ (block->branch_qpu_ip + 4)) * sizeof(uint64_t);
+ *branch_inst = (*branch_inst |
+ QPU_SET_FIELD(branch_target, QPU_BRANCH_TARGET));
+
+ /* Make sure that the if-we-don't-jump successor was scheduled
+ * just after the delay slots.
+ */
+ if (block->successors[1]) {
+ assert(block->successors[1]->start_qpu_ip ==
+ block->branch_qpu_ip + 4);
+ }
+ }
+}
+
+uint32_t
+qpu_schedule_instructions(struct vc4_compile *c)
+{
+ /* We reorder the uniforms as we schedule instructions, so save the
+ * old data off and replace it.
+ */
+ uint32_t *uniform_data = c->uniform_data;
+ enum quniform_contents *uniform_contents = c->uniform_contents;
+ c->uniform_contents = ralloc_array(c, enum quniform_contents,
+ c->num_uniforms);
+ c->uniform_data = ralloc_array(c, uint32_t, c->num_uniforms);
+ c->uniform_array_size = c->num_uniforms;
+ uint32_t next_uniform = 0;
+
+ struct choose_scoreboard scoreboard;
+ memset(&scoreboard, 0, sizeof(scoreboard));
+ scoreboard.last_waddr_a = ~0;
+ scoreboard.last_waddr_b = ~0;
+ scoreboard.last_sfu_write_tick = -10;
+ scoreboard.last_uniforms_reset_tick = -10;
+
+ if (debug) {
+ fprintf(stderr, "Pre-schedule instructions\n");
+ qir_for_each_block(block, c) {
+ fprintf(stderr, "BLOCK %d\n", block->index);
+ list_for_each_entry(struct queued_qpu_inst, q,
+ &block->qpu_inst_list, link) {
+ vc4_qpu_disasm(&q->inst, 1);
+ fprintf(stderr, "\n");
+ }
+ }
+ fprintf(stderr, "\n");
+ }
+
+ uint32_t cycles = 0;
+ qir_for_each_block(block, c) {
+ block->start_qpu_ip = c->qpu_inst_count;
+ block->branch_qpu_ip = ~0;
+
+ cycles += qpu_schedule_instructions_block(c,
+ &scoreboard,
+ block,
+ uniform_contents,
+ uniform_data,
+ &next_uniform);
+
+ block->end_qpu_ip = c->qpu_inst_count - 1;
+ }
+
+ qpu_set_branch_targets(c);
+
+ assert(next_uniform == c->num_uniforms);
if (debug) {
fprintf(stderr, "Post-schedule instructions\n");
fprintf(stderr, "\n");
}
- ralloc_free(mem_ctx);
-
return cycles;
}