#include "irnode_t.h"
#include "ircons_t.h"
#include "iredges_t.h"
+#include "irbackedge_t.h"
+#include "irprintf.h"
#include "ident_t.h"
#include "type_t.h"
#include "entity_t.h"
#include "benode_t.h"
#include "bechordal_t.h"
#include "bejavacoal.h"
+#include "benodesets.h"
+#include "bespilloptions.h"
+#include "bestatevent.h"
// only rematerialise when costs are less than REMAT_COST_LIMIT
-#define REMAT_COST_LIMIT 4
-
-/* This enables re-computation of values. Current state: Unfinished and buggy. */
-#undef BUGGY_REMAT
+// TODO determine a good value here...
+#define REMAT_COST_LIMIT 10
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 {
const arch_register_class_t *cls;
+ const arch_env_t *arch_env;
const be_chordal_env_t *chordal_env;
struct obstack obst;
- set *spills; /**< all spill_info_t's, which must be placed */
- pset *mem_phis; /**< set of all special spilled phis. allocated and freed separately */
+ int spill_cost; /**< the cost of a single spill node */
+ int reload_cost; /**< the cost of a reload node */
+ set *spills; /**< all spill_info_t's, which must be placed */
+ pset *mem_phis; /**< set of all special spilled phis. allocated and freed separately */
DEBUG_ONLY(firm_dbg_module_t *dbg;)
};
return xx->spilled_node != yy->spilled_node;
}
+/**
+ * Returns spill info for a specific value (returns NULL if the info doesn't
+ * exist yet)
+ */
+static spill_info_t *find_spillinfo(const spill_env_t *env, ir_node *value) {
+ spill_info_t info;
+ int hash = nodeset_hash(value);
+
+ info.spilled_node = value;
+
+ return set_find(env->spills, &info, sizeof(info), hash);
+}
+
/**
* Returns spill info for a specific value (the value that is to be spilled)
*/
static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value) {
spill_info_t info, *res;
- int hash = HASH_PTR(value);
+ int hash = nodeset_hash(value);
info.spilled_node = value;
res = set_find(env->spills, &info, sizeof(info), hash);
if (res == NULL) {
info.reloaders = NULL;
info.spill = NULL;
+ info.old_spill = NULL;
res = set_insert(env->spills, &info, sizeof(info), hash);
}
env->spills = new_set(cmp_spillinfo, 1024);
env->cls = chordal_env->cls;
env->chordal_env = chordal_env;
+ env->arch_env = env->chordal_env->birg->main_env->arch_env;
env->mem_phis = pset_new_ptr_default();
+ // TODO, ask backend about costs...
+ env->spill_cost = 8;
+ env->reload_cost = 5;
obstack_init(&env->obst);
return env;
}
free(env);
}
-/**
+/*
* ____ _ ____ _ _
* | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
* | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
reloader_t *rel;
assert(sched_is_scheduled(before));
- assert(arch_irn_consider_in_reg_alloc(env->chordal_env->birg->main_env->arch_env, env->cls, to_spill));
+ assert(arch_irn_consider_in_reg_alloc(env->arch_env, env->cls, to_spill));
info = get_spillinfo(env, to_spill);
rel->reloader = before;
rel->next = info->reloaders;
info->reloaders = rel;
- be_liveness_add_missing(env->chordal_env->lv);
}
-void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
+static ir_node *get_reload_insertion_point(ir_node *block, int pos) {
ir_node *predblock, *last;
/* simply add the reload to the beginning of the block if we only have 1 predecessor
*/
if(get_Block_n_cfgpreds(block) == 1) {
assert(!is_Phi(sched_first(block)));
- be_add_reload(env, to_spill, sched_first(block));
- return;
+ return sched_first(block);
}
/* We have to reload the value in pred-block */
last = sched_prev(last);
assert(!sched_is_end(last));
}
- assert(is_cfop(last));
+
+ if(!is_cfop(last)) {
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *startblock = get_irg_start_block(irg);
+
+ // last node must be a cfop, only exception is the start block
+ assert(last == startblock);
+ }
// add the reload before the (cond-)jump
- be_add_reload(env, to_spill, last);
+ return last;
+}
+
+void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
+ ir_node *before = get_reload_insertion_point(block, pos);
+ be_add_reload(env, to_spill, before);
}
void be_spill_phi(spill_env_t *env, ir_node *node) {
+ spill_info_t* spill;
int i, arity;
assert(is_Phi(node));
pset_insert_ptr(env->mem_phis, node);
// create spillinfos for the phi arguments
- get_spillinfo(env, node);
+ 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)) {
+ spill->old_spill = spill->spill;
+ spill->spill = NULL;
+ }
}
/*
* @return a be_Spill node
*/
static void spill_irn(spill_env_t *env, spill_info_t *spillinfo) {
- const be_main_env_t *mainenv = env->chordal_env->birg->main_env;
ir_node *to_spill = spillinfo->spilled_node;
DBG((env->dbg, LEVEL_1, "%+F\n", to_spill));
/* Trying to spill an already spilled value, no need for a new spill
* node then, we can simply connect to the same one for this reload
*
- * (although rematerialisation code should handle most of these cases
+ * (although rematerialization code should handle most of these cases
* this can still happen when spilling Phis)
*/
if(be_is_Reload(to_spill)) {
return;
}
- spillinfo->spill = be_spill(mainenv->arch_env, to_spill);
+ if (arch_irn_is(env->arch_env, to_spill, dont_spill)) {
+ if (env->chordal_env->opts->vrfy_option == BE_CH_VRFY_WARN)
+ ir_fprintf(stderr, "Verify warning: spilling 'dont_spill' node %+F\n", to_spill);
+ else if (env->chordal_env->opts->vrfy_option == BE_CH_VRFY_ASSERT)
+ assert(0 && "Attempt to spill a node marked 'dont_spill'");
+ }
+
+ spillinfo->spill = be_spill(env->arch_env, to_spill);
sched_add_after_insn(to_spill, spillinfo->spill);
}
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;
+ }
}
/**
if(arg == get_irg_frame(env->chordal_env->irg))
return 1;
-#if 0
- /* we want to remat before the insn reloader
- * thus an arguments is alive if
- * - it interferes with the reloaders result
- * or
- * - or it is (last-) used by reloader itself
+ /* the following test does not work while spilling,
+ * because the liveness info is not adapted yet to the effects of the
+ * additional spills/reloads.
+ *
+ * So we can only do this test for ignore registers (of our register class)
*/
- int i, m;
-
- if (values_interfere(reloader, arg))
- return 1;
+ if(arch_get_irn_reg_class(env->arch_env, arg, -1) == env->chordal_env->cls
+ && arch_irn_is(env->arch_env, arg, ignore)) {
+ int i, arity;
- for (i=0, m=get_irn_arity(reloader); i<m; ++i) {
- ir_node *rel_arg = get_irn_n(reloader, i);
- if (rel_arg == arg)
+ /* we want to remat before the insn reloader
+ * thus an arguments is alive if
+ * - it interferes with the reloaders result
+ * - or it is (last-) used by reloader itself
+ */
+ if (values_interfere(env->chordal_env->lv, reloader, arg)) {
return 1;
- }
+ }
- /* arg is not alive before reloader */
- return 0;
-#endif
+ arity = get_irn_arity(reloader);
+ for (i = 0; i < arity; ++i) {
+ ir_node *rel_arg = get_irn_n(reloader, i);
+ if (rel_arg == arg)
+ return 1;
+ }
+ }
- return 0;
+ return 0;
}
/**
* Checks whether the node can principally be rematerialized
*/
static int is_remat_node(spill_env_t *env, ir_node *node) {
- const arch_env_t *arch_env = env->chordal_env->birg->main_env->arch_env;
+ const arch_env_t *arch_env = env->arch_env;
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;
if(be_is_Reload(spilled)) {
costs += 2;
- } else if(is_Proj(spilled)) {
- costs += 0;
} else {
- costs += 1;
+ 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;
}
static int check_remat_conditions(spill_env_t *env, ir_node *spilled, ir_node *reloader) {
- int costs = check_remat_conditions_costs(env, spilled, reloader, 1);
+ int costs = check_remat_conditions_costs(env, spilled, reloader, 0);
return costs < REMAT_COST_LIMIT;
}
get_irn_arity(spilled),
ins);
copy_node_attr(spilled, res);
+ new_backedge_info(res);
DBG((env->dbg, LEVEL_1, "Insert remat %+F before reloader %+F\n", res, reloader));
- ir_printf("Insert remat %+F for %+F before reloader %+F(%s)\n", res, spilled, reloader, get_irg_dump_name(get_irn_irg(reloader)));
/* insert in schedule */
assert(!is_Block(reloader));
return res;
}
+int be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before) {
+ spill_info_t *spill_info;
+
+ if(be_do_remats) {
+ // is the node rematerializable?
+ int costs = check_remat_conditions_costs(env, to_spill, before, 0);
+ if(costs < REMAT_COST_LIMIT)
+ return costs;
+ }
+
+ // do we already have a spill?
+ spill_info = find_spillinfo(env, to_spill);
+ if(spill_info != NULL && spill_info->spill != NULL)
+ return env->reload_cost;
+
+ return env->spill_cost + env->reload_cost;
+}
+
+int be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
+ ir_node *before = get_reload_insertion_point(block, pos);
+ return be_get_reload_costs(env, to_spill, before);
+}
+
/*
* ___ _ ____ _ _
* |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___
*/
void be_insert_spills_reloads(spill_env_t *env) {
- const arch_env_t *arch_env = env->chordal_env->birg->main_env->arch_env;
+ const arch_env_t *arch_env = env->arch_env;
spill_info_t *si;
+ int remats = 0;
+ int reloads = 0;
+ int spills = 0;
/* process each spilled node */
- DBG((env->dbg, LEVEL_1, "Insert spills and reloads:\n"));
for(si = set_first(env->spills); si; si = set_next(env->spills)) {
reloader_t *rld;
ir_mode *mode = get_irn_mode(si->spilled_node);
for(rld = si->reloaders; rld; rld = rld->next) {
ir_node *new_val;
- if (check_remat_conditions(env, si->spilled_node, rld->reloader)) {
+ if (be_do_remats && check_remat_conditions(env, si->spilled_node, rld->reloader)) {
new_val = do_remat(env, si->spilled_node, rld->reloader);
+ remats++;
} else {
/* make sure we have a spill */
- spill_node(env, si);
+ if(si->spill == NULL) {
+ spill_node(env, si);
+ spills++;
+ }
- /* do a reload */
+ /* create a reload */
new_val = be_reload(arch_env, env->cls, rld->reloader, mode, si->spill);
+ reloads++;
}
DBG((env->dbg, LEVEL_1, " %+F of %+F before %+F\n", new_val, si->spilled_node, rld->reloader));
}
del_pset(values);
+
+ si->reloaders = NULL;
}
- // 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);
+ if(be_stat_ev_is_active()) {
+ be_stat_ev("spill_spills", spills);
+ be_stat_ev("spill_reloads", reloads);
+ be_stat_ev("spill_remats", remats);
+ }
+
+ be_remove_dead_nodes_from_schedule(env->chordal_env->irg);
+ be_liveness_recompute(env->chordal_env->lv);
}