}
}
+/**
+ * Set a value for max register target.
+ *
+ * Currently this just rounds up to a multiple of full-vec4 (ie. the
+ * granularity that we configure the hw for.. there is no point to
+ * using r3.x if you aren't going to make r3.yzw available). But
+ * in reality there seems to be multiple thresholds that affect the
+ * number of waves.. and we should round up the target to the next
+ * threshold when we round-robin registers, to give postsched more
+ * options. When we understand that better, this is where we'd
+ * implement that.
+ */
+static void
+ra_set_register_target(struct ir3_ra_ctx *ctx, unsigned max_target)
+{
+ const unsigned hvec4 = 4;
+ const unsigned vec4 = 2 * hvec4;
+
+ ctx->max_target = align(max_target, vec4);
+
+ d("New max_target=%u", ctx->max_target);
+}
+
static int
pick_in_range(BITSET_WORD *regs, unsigned min, unsigned max)
{
if (r < 0) {
/* overflow, we need to increase max_target: */
- ctx->max_target++;
+ ra_set_register_target(ctx, ctx->max_target + 1);
return ra_select_reg_merged(n, regs, data);
}
struct ir3_instruction *instr)
{
debug_assert(name < ctx->alloc_count);
+
+ /* split/collect do not actually define any real value */
+ if ((instr->opc == OPC_META_SPLIT) || (instr->opc == OPC_META_COLLECT))
+ return;
+
/* defined on first write: */
if (!ctx->def[name])
ctx->def[name] = instr->ip;
debug_printf("\n");
}
+/* size of one component of instruction result, ie. half vs full: */
+static unsigned
+live_size(struct ir3_instruction *instr)
+{
+ if (is_half(instr)) {
+ return 1;
+ } else if (is_high(instr)) {
+ /* doesn't count towards footprint */
+ return 0;
+ } else {
+ return 2;
+ }
+}
+
+static unsigned
+name_size(struct ir3_ra_ctx *ctx, unsigned name)
+{
+ if (name_is_array(ctx, name)) {
+ struct ir3_array *arr = name_to_array(ctx, name);
+ return arr->half ? 1 : 2;
+ } else {
+ struct ir3_instruction *instr = name_to_instr(ctx, name);
+ /* in scalar pass, each name represents on scalar value,
+ * half or full precision
+ */
+ return live_size(instr);
+ }
+}
+
+static unsigned
+ra_calc_block_live_values(struct ir3_ra_ctx *ctx, struct ir3_block *block)
+{
+ struct ir3_ra_block_data *bd = block->data;
+ unsigned name;
+
+ assert(ctx->name_to_instr);
+
+ /* TODO this gets a bit more complicated in non-scalar pass.. but
+ * possibly a lowball estimate is fine to start with if we do
+ * round-robin in non-scalar pass? Maybe we just want to handle
+ * that in a different fxn?
+ */
+ assert(ctx->scalar_pass);
+
+ BITSET_WORD *live =
+ rzalloc_array(bd, BITSET_WORD, BITSET_WORDS(ctx->alloc_count));
+
+ /* Add the live input values: */
+ unsigned livein = 0;
+ BITSET_FOREACH_SET (name, bd->livein, ctx->alloc_count) {
+ livein += name_size(ctx, name);
+ BITSET_SET(live, name);
+ }
+
+ d("---------------------");
+ d("block%u: LIVEIN: %u", block_id(block), livein);
+
+ unsigned max = livein;
+ int cur_live = max;
+
+ /* Now that we know the live inputs to the block, iterate the
+ * instructions adjusting the current # of live values as we
+ * see their last use:
+ */
+ foreach_instr (instr, &block->instr_list) {
+ if (RA_DEBUG)
+ print_bitset("LIVE", live, ctx->alloc_count);
+ di(instr, "CALC");
+
+ unsigned new_live = 0; /* newly live values */
+ unsigned new_dead = 0; /* newly no-longer live values */
+ unsigned next_dead = 0; /* newly dead following this instr */
+
+ foreach_def (name, ctx, instr) {
+ /* NOTE: checking ctx->def filters out things like split/
+ * collect which are just redefining existing live names
+ * or array writes to already live array elements:
+ */
+ if (ctx->def[name] != instr->ip)
+ continue;
+ new_live += live_size(instr);
+ d("NEW_LIVE: %u (new_live=%u, use=%u)", name, new_live, ctx->use[name]);
+ BITSET_SET(live, name);
+ /* There can be cases where this is *also* the last use
+ * of a value, for example instructions that write multiple
+ * values, only some of which are used. These values are
+ * dead *after* (rather than during) this instruction.
+ */
+ if (ctx->use[name] != instr->ip)
+ continue;
+ next_dead += live_size(instr);
+ d("NEXT_DEAD: %u (next_dead=%u)", name, next_dead);
+ BITSET_CLEAR(live, name);
+ }
+
+ /* To be more resilient against special cases where liverange
+ * is extended (like first_non_input), rather than using the
+ * foreach_use() iterator, we iterate the current live values
+ * instead:
+ */
+ BITSET_FOREACH_SET (name, live, ctx->alloc_count) {
+ /* Is this the last use? */
+ if (ctx->use[name] != instr->ip)
+ continue;
+ new_dead += name_size(ctx, name);
+ d("NEW_DEAD: %u (new_dead=%u)", name, new_dead);
+ BITSET_CLEAR(live, name);
+ }
+
+ cur_live += new_live;
+ cur_live -= new_dead;
+
+ assert(cur_live >= 0);
+ d("CUR_LIVE: %u", cur_live);
+
+ max = MAX2(max, cur_live);
+
+ /* account for written values which are not used later,
+ * but after updating max (since they are for one cycle
+ * live)
+ */
+ cur_live -= next_dead;
+ assert(cur_live >= 0);
+
+ if (RA_DEBUG) {
+ unsigned cnt = 0;
+ BITSET_FOREACH_SET (name, live, ctx->alloc_count) {
+ cnt += name_size(ctx, name);
+ }
+ assert(cur_live == cnt);
+ }
+ }
+
+ d("block%u max=%u", block_id(block), max);
+
+ /* the remaining live should match liveout (for extra sanity testing): */
+ if (RA_DEBUG) {
+ unsigned liveout = 0;
+ BITSET_FOREACH_SET (name, bd->liveout, ctx->alloc_count) {
+ liveout += name_size(ctx, name);
+ BITSET_CLEAR(live, name);
+ }
+
+ if (cur_live != liveout) {
+ print_bitset("LEAKED", live, ctx->alloc_count);
+ /* TODO there are a few edge cases where live-range extension
+ * tells us a value is livein. But not used by the block or
+ * liveout for the block. Possibly a bug in the liverange
+ * extension. But for now leave the assert disabled:
+ assert(cur_live == liveout);
+ */
+ }
+ }
+
+ ralloc_free(live);
+
+ return max;
+}
+
+static unsigned
+ra_calc_max_live_values(struct ir3_ra_ctx *ctx)
+{
+ unsigned max = 0;
+
+ foreach_block (block, &ctx->ir->block_list) {
+ unsigned block_live = ra_calc_block_live_values(ctx, block);
+ max = MAX2(max, block_live);
+ }
+
+ return max;
+}
+
static void
ra_add_interference(struct ir3_ra_ctx *ctx)
{
}
}
+ if (ctx->name_to_instr) {
+ unsigned max = ra_calc_max_live_values(ctx);
+ ra_set_register_target(ctx, max);
+ }
+
for (unsigned i = 0; i < ctx->alloc_count; i++) {
for (unsigned j = 0; j < ctx->alloc_count; j++) {
if (intersects(ctx->def[i], ctx->use[i],
}
}
-static void
-account_assignment(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr)
-{
- struct ir3_ra_instr_data *id;
- struct ir3_register *dst = instr->regs[0];
- unsigned max;
-
- if (is_high(instr))
- return;
-
- if (dst->flags & IR3_REG_ARRAY) {
- struct ir3_array *arr =
- ir3_lookup_array(ctx->ir, dst->array.id);
- max = arr->reg + arr->length;
- } else if ((id = &ctx->instrd[instr->ip]) && id->defn) {
- unsigned name = scalar_name(ctx, id->defn, 0);
- unsigned r = ra_get_node_reg(ctx->g, name);
- max = ctx->set->ra_reg_to_gpr[r] + id->off + dest_regs(id->defn);
- } else {
- return;
- }
-
- if (is_half(instr)) {
- ctx->max_half_assigned = MAX2(ctx->max_half_assigned, max);
- } else {
- ctx->max_assigned = MAX2(ctx->max_assigned, max);
- }
-}
-
/* helper to determine which regs to assign in which pass: */
static bool
should_assign(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr)
struct ir3_register *reg;
if (writes_gpr(instr)) {
- account_assignment(ctx, instr);
if (should_assign(ctx, instr)) {
reg_assign(ctx, instr->regs[0], instr);
if (instr->regs[0]->flags & IR3_REG_HALF)
}
}
-/* Target is calculated in terms of half-regs (with a full reg
- * consisting of two half-regs).
- */
-static void
-ra_calc_merged_register_target(struct ir3_ra_ctx *ctx)
-{
- const unsigned vec4 = 2 * 4; // 8 half-regs
- unsigned t = MAX2(2 * ctx->max_assigned, ctx->max_half_assigned);
-
- /* second RA pass may have saved some regs, let's try to reclaim
- * the benefit by adjusting the target downwards slightly:
- */
- if (ir3_has_latency_to_hide(ctx->ir)) {
- if (t > 8 * vec4) {
- t -= 2 * vec4;
- } else if (t > 6 * vec4) {
- t -= vec4;
- }
- }
-
- ctx->max_target = t;
-}
-
static int
ir3_ra_pass(struct ir3_shader_variant *v, struct ir3_instruction **precolor,
- unsigned nprecolor, bool scalar_pass, unsigned *target)
+ unsigned nprecolor, bool scalar_pass)
{
struct ir3_ra_ctx ctx = {
.v = v,
};
int ret;
- if (scalar_pass) {
- ctx.max_target = *target;
- }
-
ra_init(&ctx);
ra_add_interference(&ctx);
ra_precolor(&ctx, precolor, nprecolor);
ret = ra_alloc(&ctx);
ra_destroy(&ctx);
- /* In the first pass, calculate the target register usage used in the
- * second (scalar) pass:
- */
- if (!scalar_pass) {
- /* TODO: round-robin support for pre-a6xx: */
- if (ctx.ir->compiler->gpu_id >= 600) {
- ra_calc_merged_register_target(&ctx);
- }
- *target = ctx.max_target;
- }
-
return ret;
}
ir3_ra(struct ir3_shader_variant *v, struct ir3_instruction **precolor,
unsigned nprecolor)
{
- unsigned target = 0;
int ret;
/* First pass, assign the vecN (non-scalar) registers: */
- ret = ir3_ra_pass(v, precolor, nprecolor, false, &target);
+ ret = ir3_ra_pass(v, precolor, nprecolor, false);
if (ret)
return ret;
}
/* Second pass, assign the scalar registers: */
- ret = ir3_ra_pass(v, precolor, nprecolor, true, &target);
+ ret = ir3_ra_pass(v, precolor, nprecolor, true);
if (ret)
return ret;
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