typedef enum _arch_irn_flags_t {
arch_irn_flags_none = 0, /**< Node flags. */
arch_irn_flags_dont_spill = 1, /**< This must not be spilled. */
- arch_irn_flags_rematerializable = 2, /**< This should be replicated instead of spilled/reloaded. */
+ arch_irn_flags_rematerializable = 2, /**< This can be replicated instead of spilled/reloaded. */
arch_irn_flags_ignore = 4, /**< Ignore node during register allocation. */
arch_irn_flags_modify_sp = 8, /**< I modify the stack pointer. */
arch_irn_flags_last = arch_irn_flags_modify_sp
const arch_env_t *aenv = cenv->birg->main_env->arch_env;
const ir_edge_t *edge, *ne;
ir_node *block;
+ ir_node *spill;
if (! be_is_Reload(irn))
return;
+ // only use memory operands, if the reload is only used by 1 node
+ if(get_irn_n_edges(irn) > 1)
+ return;
+
+ spill = be_get_Reload_mem(irn);
block = get_nodes_block(irn);
foreach_out_edge_safe(irn, edge, ne) {
if (get_nodes_block(src) == block && arch_possible_memory_operand(aenv, src, pos)) {
DBG((cenv->dbg, LEVEL_3, "performing memory operand %+F at %+F\n", irn, src));
- arch_perform_memory_operand(aenv, src, irn, pos);
+ arch_perform_memory_operand(aenv, src, spill, pos);
}
}
init_node_attr(res, 2);
be_node_set_reg_class(res, 0, cls_frame);
be_node_set_reg_class(res, -1, cls);
+ be_node_set_flags(res, -1, arch_irn_flags_rematerializable);
return res;
}
{
ir_node *reload;
- ir_node *bl = is_Block(insert) ? insert : get_nodes_block(insert);
- ir_graph *irg = get_irn_irg(bl);
+ ir_node *block = get_nodes_block(insert);
+ ir_graph *irg = get_irn_irg(block);
ir_node *frame = get_irg_frame(irg);
const arch_register_class_t *cls_frame = arch_get_irn_reg_class(arch_env, frame, -1);
assert(be_is_Spill(spill) || (is_Phi(spill) && get_irn_mode(spill) == mode_M));
- reload = be_new_Reload(cls, cls_frame, irg, bl, frame, spill, mode);
+ reload = be_new_Reload(cls, cls_frame, irg, block, frame, spill, mode);
- if(is_Block(insert)) {
- insert = sched_skip(insert, 0, sched_skip_cf_predicator, (void *) arch_env);
- sched_add_after(insert, reload);
- }
+ assert(!is_Block(insert));
- else
- sched_add_before(insert, reload);
+ sched_add_before(insert, reload);
return reload;
}
// only rematerialise when costs are less than REMAT_COST_LIMIT
// TODO determine a good value here...
-#define REMAT_COST_LIMIT 80
+#define REMAT_COST_LIMIT 20
typedef struct _reloader_t reloader_t;
};
typedef struct _spill_info_t {
+ /** the value that should get spilled */
ir_node *spilled_node;
+ /** list of places where the value should get reloaded */
reloader_t *reloaders;
+ /** the spill node, or a PhiM node */
ir_node *spill;
+ /** if we had the value of a phi spilled before but not the phi itself then
+ * this field contains the spill for the phi value */
+ ir_node *old_spill;
} spill_info_t;
struct _spill_env_t {
if (res == NULL) {
info.reloaders = NULL;
info.spill = NULL;
+ info.old_spill = NULL;
res = set_insert(env->spills, &info, sizeof(info), hash);
}
pset_insert_ptr(env->mem_phis, node);
// create spillinfos for the phi arguments
- get_spillinfo(env, node);
+ spill_info_t* spill = get_spillinfo(env, node);
for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
ir_node *arg = get_irn_n(node, i);
get_spillinfo(env, arg);
}
+
+ // if we had a spill for the phi value before, then remove this spill from
+ // schedule, as we will remove it in the insert spill/reload phase
+ if(spill->spill != NULL && !is_Phi(spill->spill)) {
+ //sched_remove(spill->spill);
+ spill->old_spill = spill->spill;
+ spill->spill = NULL;
+ }
}
/*
set_irn_n(spillinfo->spill, i, arg_info->spill);
}
+
+ // rewire reloads from old_spill to phi
+ if(spillinfo->old_spill != NULL) {
+ const ir_edge_t *edge, *next;
+ foreach_out_edge_safe(spillinfo->old_spill, edge, next) {
+ ir_node* reload = get_edge_src_irn(edge);
+ assert(be_is_Reload(reload) || is_Phi(reload));
+ set_irn_n(reload, get_edge_src_pos(edge), spillinfo->spill);
+ }
+ spillinfo->old_spill = NULL;
+ }
}
/**
assert(!be_is_Spill(node));
- if(be_is_Reload(node))
- return 1;
-
- // TODO why does arch_irn_is say rematerializable anyway?
- if(be_is_Barrier(node))
- return 0;
-
- if(arch_irn_is(arch_env, node, rematerializable))
+ if(arch_irn_is(arch_env, node, rematerializable)) {
return 1;
+ }
if(be_is_StackParam(node))
return 1;
} else {
costs += arch_get_op_estimated_cost(env->arch_env, spilled);
}
- if(parentcosts + costs >= REMAT_COST_LIMIT)
+ if(parentcosts + costs >= REMAT_COST_LIMIT) {
return REMAT_COST_LIMIT;
+ }
argremats = 0;
for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
}
argremats++;
- // TODO can we get more accurate costs than +1?
costs += check_remat_conditions_costs(env, arg, reloader, parentcosts + costs);
if(parentcosts + costs >= REMAT_COST_LIMIT)
return REMAT_COST_LIMIT;
}
del_pset(values);
- }
- // reloads are placed now, but we might reuse the spill environment for further spilling decisions
- del_set(env->spills);
- env->spills = new_set(cmp_spillinfo, 1024);
+ si->reloaders = NULL;
+ }
be_remove_dead_nodes_from_schedule(env->chordal_env->irg);
- //be_liveness_add_missing(env->chordal_env->lv);
be_liveness_recompute(env->chordal_env->lv);
}
belady_env_t env;
FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
- //firm_dbg_set_mask(dbg, DBG_WSETS);
+ //firm_dbg_set_mask(dbg, DBG_START);
/* init belady env */
obstack_init(&env.ob);
ir_node *irn = be_lv_get_irn(env->cenv->lv, block, i);
int node_idx;
- /*
- if(!live_is_in(li) || !live_is_out(li))
- continue;
- */
if(!consider_for_spilling(env->arch, env->cls, irn))
continue;
/*---------------------------------------------------------------------------*/
static int reduce_register_pressure_in_block(morgan_env_t *env, const ir_node* block, int loop_unused_spills_possible) {
- int pressure;
- ir_node *irn;
- int max_pressure = 0;
- int spills_needed;
+ ir_node *node;
+ int max_pressure;
int loop_unused_spills_needed;
- block_attr_t *block_attr = get_block_attr(env, block);
- int block_unused_spills_possible = bitset_popcnt(block_attr->livethrough_unused);
- int unused_spills_possible = loop_unused_spills_possible + block_unused_spills_possible;
pset *live_nodes = pset_new_ptr_default();
be_liveness_end_of_block(env->cenv->lv, env->arch, env->cls, block, live_nodes);
- pressure = pset_count(live_nodes);
+ max_pressure = pset_count(live_nodes);
DBG((dbg, DBG_LIVE, "Reduce pressure to %d In Block %+F:\n", env->registers_available, block));
/**
- * Walk over all irns in the schedule and check register pressure for each of them
+ * Determine register pressure in block
*/
- sched_foreach_reverse(block, irn) {
- // do we need more spills than possible with unused libethroughs?
- int spills_needed = pressure - env->registers_available - unused_spills_possible;
- if(spills_needed > 0) {
- DBG((dbg, DBG_PRESSURE, "\tWARNING %d more spills needed at %+F\n", spills_needed, irn));
- // TODO further spills needed
- //assert(0);
- }
- if(pressure > max_pressure) {
- max_pressure = pressure;
- }
+ sched_foreach_reverse(block, node) {
+ int pressure;
- /* Register pressure is only important until we reach the first phi (the rest of the block
- * will only be phis.)
- */
- if(is_Phi(irn))
+ if(is_Phi(node))
break;
- // update pressure
- be_liveness_transfer(env->arch, env->cls, irn, live_nodes);
+ be_liveness_transfer(env->arch, env->cls, node, live_nodes);
pressure = pset_count(live_nodes);
+ if(pressure > max_pressure)
+ max_pressure = pressure;
}
+ del_pset(live_nodes);
DBG((dbg, DBG_PRESSURE, "\tMax Pressure in %+F: %d\n", block, max_pressure));
- /*
- * Calculate number of spills from loop_unused_spills_possible that we want to use,
- * and spill unused livethroughs from the block if we still don't have enough registers
- */
- spills_needed = max_pressure - env->registers_available;
- if(spills_needed < 0) {
- loop_unused_spills_needed = 0;
- } else if(spills_needed > loop_unused_spills_possible) {
- int i, spills;
- int block_unused_spills_needed;
+ loop_unused_spills_needed = max_pressure - env->registers_available;
+ if(loop_unused_spills_needed < 0) {
+ loop_unused_spills_needed = 0;
+ } else if(loop_unused_spills_needed > loop_unused_spills_possible) {
loop_unused_spills_needed = loop_unused_spills_possible;
- block_unused_spills_needed = spills_needed - loop_unused_spills_possible;
- if(block_unused_spills_needed > block_unused_spills_possible) {
- block_unused_spills_needed = block_unused_spills_possible;
- }
-
- spills = 0;
- /*
- * Spill/Reload unused livethroughs from the block
- */
- bitset_foreach(block_attr->livethrough_unused, i) {
- ir_node *to_spill;
- const ir_edge_t *edge;
-
- if(spills >= block_unused_spills_needed)
- break;
-
- to_spill = get_idx_irn(env->irg, i);
- foreach_block_succ(block, edge) {
- DBG((dbg, DBG_PRESSURE, "Spilling node %+F around block %+F\n", to_spill, block));
- be_add_reload_on_edge(env->senv, to_spill, edge->src, edge->pos);
- }
- spills++;
- }
- } else {
- loop_unused_spills_needed = spills_needed;
}
- del_pset(live_nodes);
-
DBG((dbg, DBG_PRESSURE, "Unused spills for Block %+F needed: %d\n", block, loop_unused_spills_needed));
return loop_unused_spills_needed;
}
int needed;
assert(is_Block(elem.node));
needed = reduce_register_pressure_in_block(env, elem.node, spills_possible);
+ assert(needed >= 0);
assert(needed <= spills_possible);
if(needed > spills_needed)
spills_needed = needed;
}
case k_ir_loop: {
int needed = reduce_register_pressure_in_loop(env, elem.son, spills_possible);
+ assert(needed >= 0);
assert(needed <= spills_possible);
if(needed > spills_needed)
spills_needed = needed;
get_irn_arity(irn) != 5 || /* must be a binary operation */
get_ia32_op_type(irn) != ia32_Normal || /* must not already be a addressmode irn */
! (get_ia32_am_support(irn) & ia32_am_Source) || /* must be capable of source addressmode */
- (i != 2 && i != 3) || /* a "real" operand position must be requested */
+ (i != 2 && i != 3) || /* a "real" operand position must be requested */
(i == 2 && ! is_ia32_commutative(irn)) || /* if first operand requested irn must be commutative */
is_ia32_use_frame(irn)) /* must not already use frame */
return 0;
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