Commit 05413b49 authored by Matthias Braun's avatar Matthias Braun
Browse files

- Fix perform_memop stuff in bechordal_main after adams gammlig commit

- Cleanup remat code a little bit
- Adjust remat cost limit to new costs in ia32 backend
- Don't spill unused livethroughs around blocks anymore in bespill_morgan
  (but only around loops), this makes the code faster smaller and the results
  slightly better as belady performs better for basic blocks
parent 358e2aef
......@@ -209,7 +209,7 @@ typedef struct _arch_inverse_t {
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
......
......@@ -329,10 +329,16 @@ static void memory_operand_walker(ir_node *irn, void *env) {
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) {
......@@ -344,7 +350,7 @@ static void memory_operand_walker(ir_node *irn, void *env) {
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);
}
}
......
......@@ -364,6 +364,7 @@ ir_node *be_new_Reload(const arch_register_class_t *cls, const arch_register_cla
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;
}
......@@ -944,22 +945,18 @@ ir_node *be_reload(const arch_env_t *arch_env, const arch_register_class_t *cls,
{
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;
}
......
......@@ -35,7 +35,7 @@
// 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;
......@@ -45,10 +45,16 @@ struct _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 {
......@@ -84,6 +90,7 @@ static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value) {
if (res == NULL) {
info.reloaders = NULL;
info.spill = NULL;
info.old_spill = NULL;
res = set_insert(env->spills, &info, sizeof(info), hash);
}
......@@ -185,11 +192,19 @@ void be_spill_phi(spill_env_t *env, ir_node *node) {
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;
}
}
/*
......@@ -292,6 +307,17 @@ static void spill_phi(spill_env_t *env, spill_info_t *spillinfo) {
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;
}
}
/**
......@@ -377,15 +403,9 @@ static int is_remat_node(spill_env_t *env, ir_node *node) {
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;
......@@ -416,8 +436,9 @@ static int check_remat_conditions_costs(spill_env_t *env, ir_node *spilled, ir_n
} 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) {
......@@ -435,7 +456,6 @@ static int check_remat_conditions_costs(spill_env_t *env, ir_node *spilled, ir_n
}
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;
......@@ -536,13 +556,10 @@ void be_insert_spills_reloads(spill_env_t *env) {
}
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);
}
......@@ -619,7 +619,7 @@ void be_spill_belady_spill_env(const be_chordal_env_t *chordal_env, spill_env_t
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);
......
......@@ -248,10 +248,6 @@ static bitset_t *construct_block_livethrough_unused(morgan_env_t* env, const ir_
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;
......@@ -344,90 +340,42 @@ static bitset_t *construct_loop_livethrough_unused(morgan_env_t *env, const ir_l
/*---------------------------------------------------------------------------*/
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;
}
......@@ -453,6 +401,7 @@ static int reduce_register_pressure_in_loop(morgan_env_t *env, const ir_loop *lo
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;
......@@ -460,6 +409,7 @@ static int reduce_register_pressure_in_loop(morgan_env_t *env, const ir_loop *lo
}
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;
......
......@@ -703,7 +703,7 @@ static int ia32_possible_memory_operand(const void *self, const ir_node *irn, un
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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