#include "beutil.h"
#include "bearch_t.h"
#include "bespillbelady.h"
-#include "beuses.h"
#include "besched_t.h"
#include "beirgmod.h"
#include "belive_t.h"
int n_blocks; /**< Number of blocks in the graph. */
int n_regs; /**< number of regs in this reg-class */
workset_t *ws; /**< the main workset used while processing a block. ob-allocated */
- be_uses_t *uses; /**< env for the next-use magic */
ir_node *instr; /**< current instruction */
unsigned instr_nr; /**< current instruction number (relative to block start) */
typedef struct _block_info_t {
belady_env_t *bel;
const ir_node *bl;
- ir_node *first_non_in; /**< First node in block which is not a phi. */
workset_t *ws_start, *ws_end;
ir_phase next_uses;
+ ir_node *first_non_in; /**< First node in block which is not a phi. */
+ ir_node *last_ins; /**< The instruction before which end of
+ block reloads will be inserted. */
+
workset_t *entrance_reg; /**< That set will contain all values
transported into the block which
are used before they are displaced.
static INLINE void *new_block_info(belady_env_t *bel, ir_node *bl) {
block_info_t *res = obstack_alloc(&bel->ob, sizeof(*res));
memset(res, 0, sizeof(res[0]));
+ res->first_non_in = NULL;
+ res->last_ins = NULL;
res->bel = bel;
res->bl = bl;
res->entrance_reg = new_workset(bel, &bel->ob);
#define get_block_info(block) ((block_info_t *)get_irn_link(block))
#define set_block_info(block, info) set_irn_link(block, info)
+static INLINE ir_node *block_info_get_last_ins(block_info_t *bi)
+{
+ if (!bi->last_ins)
+ bi->last_ins = be_get_end_of_block_insertion_point(bi->bl);
+
+ return bi->last_ins;
+}
+
typedef struct _next_use_t {
- ir_node *user;
- int step;
- struct _next_use_t *next;
+ unsigned is_first_use : 1; /**< Indicate that this use is the first
+ in the block. Needed to identify
+ transport in values for the global
+ pass. */
+ int step; /**< The time step of the use. */
+ struct _next_use_t *next; /**< The next use int this block
+ or NULL. */
} next_use_t;
static void *next_use_init(ir_phase *phase, ir_node *irn, void *old)
next_use_t *use = phase_alloc(&bi->next_uses, sizeof(use[0]));
assert(step >= 0);
- use->user = irn;
- use->step = step;
- use->next = curr;
+ use->is_first_use = 1;
+ use->step = step;
+ use->next = curr;
+
+ if (curr)
+ curr->is_first_use = 0;
+
phase_set_irn_data(&bi->next_uses, op, use);
}
}
}
+#define get_current_use(bi, irn) phase_get_irn_data(&(bi)->next_uses, (irn))
+
+static INLINE void advance_current_use(block_info_t *bi, const ir_node *irn)
+{
+ next_use_t *use = get_current_use(bi, irn);
+
+ assert(use);
+ phase_set_irn_data(&bi->next_uses, irn, use->next);
+}
+
+
+static INLINE int is_local_phi(const ir_node *irn, const ir_node *bl)
+{
+ return is_Phi(irn) && get_nodes_block(irn) == bl;
+}
+
/**
* Check, if the value is something that is transported into a block.
- * That is, the value is live in or defined by a Phi in the block.
+ * That is, the value is defined elsewhere or defined by a Phi in the block.
* @param env The belady environment.
* @param bl The block in question.
* @param irn The node in question.
* @return 1, if node is something transported into @p bl, 0 if not.
+ * @note The function will only give correct answers in the case
+ * where @p irn is unsed in the block @p bl which is always
+ * the case in our usage scenario.
*/
-static INLINE int is_transport_in(belady_env_t *env, const ir_node *bl, const ir_node *irn)
+static INLINE int is_transport_in(const ir_node *bl, const ir_node *irn)
{
- return (is_Phi(irn) && get_nodes_block(irn) == bl) || be_is_live_in(env->lv, bl, irn);
+ return is_local_phi(irn, bl) || get_nodes_block(irn) != bl;
}
/**
* - as few as possible other values are disposed
* - the worst values get disposed
*
- * TODO Sebastian:
- * Actually, we should displace a value immediately after it was used.
- * If we don't, the cardinality of the workset does not reflect the register pressure.
- * That might be necessary to determine the capacity left in the block.
- *
* @p is_usage indicates that the values in new_vals are used (not defined)
* In this case reloads must be performed
*/
static void displace(block_info_t *bi, workset_t *new_vals, int is_usage) {
- belady_env_t *env = bi->bel;
- ir_node *val;
- int i, len, max_allowed, demand, iter;
+ belady_env_t *env = bi->bel;
+ workset_t *ws = env->ws;
+ ir_node **to_insert = alloca(env->n_regs * sizeof(to_insert[0]));
- workset_t *ws = env->ws;
- ir_node **to_insert = alloca(env->n_regs * sizeof(*to_insert));
+ int i, len, max_allowed, demand, iter;
+ ir_node *val;
/*
1. Identify the number of needed slots and the values to reload
to_insert[demand++] = val;
if (is_usage) {
int insert_reload = 1;
+ next_use_t *use = get_current_use(bi, val);
/*
- * if we use a value which is transported in this block,
- * i.e. a phi defined here or a live in, we check if there
- * is room for that guy to survive from the block's entrance
- * to here or not.
+ * if we use a value which is transported in this block, i.e. a
+ * phi defined here or a live in, for the first time, we check
+ * if there is room for that guy to survive from the block's
+ * entrance to here or not.
*/
- if (is_transport_in(env, bi->bl, val)) {
- DBG((dbg, DBG_SPILL, "entrance node %+F, capacity %d:\n", val, bi->pressure));
+ assert(use);
+ assert(sched_get_time_step(env->instr) == use->step);
+ if (is_transport_in(bi->bl, val) && use->is_first_use) {
+ DBG((dbg, DBG_DECIDE, "entrance node %+F, capacity %d:\n", val, bi->pressure));
if (bi->pressure < env->n_regs) {
- ++bi->pressure;
workset_insert(env, bi->entrance_reg, val);
insert_reload = 0;
- DBG((dbg, DBG_SPILL, "... no reload. must be considered at block start\n"));
+ ++bi->pressure;
+ DBG((dbg, DBG_DECIDE, "... no reload. must be considered at block start\n"));
}
}
len = workset_get_length(ws);
max_allowed = env->n_regs - demand;
- DBG((dbg, DBG_DECIDE, " disposing %d values\n", ws->len - max_allowed));
-
/* Only make more free room if we do not have enough */
if (len > max_allowed) {
int curr_step = sched_get_time_step(env->instr);
+
+ DBG((dbg, DBG_DECIDE, " disposing %d values\n", len - max_allowed));
+
/* get current next-use distance */
for (i = 0; i < ws->len; ++i) {
ir_node *val = workset_get_val(ws, i);
next_use_t *use = phase_get_irn_data(&bi->next_uses, val);
assert(use == NULL || use->step >= curr_step);
- workset_set_time(ws, i, use ? (unsigned) (use->step - curr_step) : DEAD);
-#if 0
- unsigned dist = get_distance(env, env->instr, env->instr_nr, workset_get_val(ws, i), !is_usage);
- workset_set_time(ws, i, dist);
-#endif
+ if (!is_usage && use)
+ use = use->next;
+
+ workset_set_time(ws, i, use ? (unsigned) (use->step - curr_step) : DEAD);
}
/* sort entries by increasing nextuse-distance*/
/*
3. Insert the new values into the workset
+ Also, we update the pressure in the block info.
+ That is important for the global pass to decide
+ how many values can live through the block.
*/
for (i = 0; i < demand; ++i)
workset_insert(env, env->ws, to_insert[i]);
+
+ bi->pressure = MAX(bi->pressure, workset_get_length(env->ws));
+
}
/**
static void belady(ir_node *block, void *data) {
belady_env_t *env = data;
block_info_t *block_info = new_block_info(env, block);
+
workset_t *new_vals;
ir_node *irn;
int iter;
- /* process the block from start to end */
DBG((dbg, DBG_WSETS, "Processing %+F...\n", block_info->bl));
- env->instr_nr = 0;
new_vals = new_workset(env, &env->ob);
- block_info->first_non_in = NULL;
+ workset_clear(env->ws);
+
+ /* build the next use information for this block. */
build_next_uses(block_info);
- workset_clear(env->ws);
+ env->instr_nr = 0;
+ block_info->first_non_in = NULL;
+
+ /* process the block from start to end */
sched_foreach(block, irn) {
int i, arity;
assert(workset_get_length(env->ws) <= env->n_regs && "Too much values in workset!");
}
displace(block_info, new_vals, 1);
- block_info->pressure = MAX(block_info->pressure, workset_get_length(env->ws));
-
/*
* set all used variables to the next use in their next_use_t list
* Also, kill all dead variables from the workset. They are only
*/
for(i = 0, arity = get_irn_arity(irn); i < arity; ++i) {
ir_node *op = get_irn_n(irn, i);
- next_use_t *use = phase_get_irn_data(&block_info->next_uses, op);
+ next_use_t *use = get_current_use(block_info, op);
assert(use);
if (!use->next && !be_is_live_end(env->lv, block, op))
workset_remove(env->ws, op);
- phase_set_irn_data(&block_info->next_uses, op, use->next);
+ advance_current_use(block_info, op);
}
/* allocate all values _defined_ by this instruction */
typedef struct _global_end_state_t {
belady_env_t *env;
- bitset_t *succ_phis;
+ bitset_t *failed_phis;
struct obstack obst;
block_end_state_t *end_info;
unsigned gauge;
int n_regs = bi->bel->n_regs;
int index;
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}can make avail %+F at end of %+F (pressure %d)\n",
+ DBG((dbg, DBG_GLOBAL, "\t%2Dcan make avail %+F at end of %+F (pressure %d)\n",
level, irn, bl, bi->pressure));
/*
* so we can exit safely.
*/
if (bes->costs >= 0.0) {
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}we\'ve been here before\n", level));
+ DBG((dbg, DBG_GLOBAL, "\t%2Dwe\'ve been here before\n", level));
goto end;
}
index = workset_get_index(end, irn);
if (index >= 0) {
unsigned ver = end->vals[index].version;
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}node is in the end set and is %s fixed\n",
- level, ver > ges->version ? "" : "not"));
+ DBG((dbg, DBG_GLOBAL, "\t%2Dnode is in the end set and is %s fixed\n",
+ level, ver > ges->version ? "already" : "not yet"));
/*
* if the version is older, the value is already fixed
* There is just room at the *end*
*/
if (len < n_regs) {
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}the end set has %d free slots\n",
+ DBG((dbg, DBG_GLOBAL, "\t%2Dthe end set has %d free slots\n",
level, n_regs - len));
slot = len;
}
break;
if (i < len) {
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}%+F (slot %d) can be erased from the end set\n",
+ DBG((dbg, DBG_GLOBAL, "\t%2D%+F (slot %d) can be erased from the end set\n",
level, end->vals[i].irn, i));
slot = i;
}
}
- if (slot > 0) {
- int gauge = ges->gauge;
- double reload_here = bi->exec_freq;
- double bring_in = bi->pressure < n_regs ? can_bring_in(ges, bl, irn, level + 1) : HUGE_VAL;
+ if (slot >= 0) {
+ int gauge = ges->gauge;
+ ir_node *ins_before = block_info_get_last_ins(bi);
+ double reload_here = be_get_reload_costs(bi->bel->senv, irn, ins_before);
+ double bring_in = bi->pressure < n_regs ? can_bring_in(ges, bl, irn, level + 1) : HUGE_VAL;
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}there is a free slot. capacity=%d, reload here=%f, bring in=%f\n",
+ DBG((dbg, DBG_GLOBAL, "\t%2Dthere is a free slot. capacity=%d, reload here=%f, bring in=%f\n",
level, n_regs - bi->pressure, reload_here, bring_in));
/*
}
end:
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}-> %f\n", level, bes->costs));
+ DBG((dbg, DBG_GLOBAL, "\t%2D-> %f\n", level, bes->costs));
return bes->costs;
}
int def_block = bl == get_nodes_block(irn);
int phi = is_Phi(irn);
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}can bring in for %+F at block %+F\n", level, irn, bl));
+ DBG((dbg, DBG_GLOBAL, "\t%2Dcan bring in for %+F at block %+F\n", level, irn, bl));
if (phi || !def_block) {
int i, n = get_irn_arity(bl);
}
end:
- DBG((dbg, DBG_GLOBAL, "\t%{firm:indent}-> %f\n", level, glob_costs));
+ DBG((dbg, DBG_GLOBAL, "\t%2D-> %f\n", level, glob_costs));
return glob_costs;
}
* if the variable is live through the block,
* update the pressure indicator.
*/
- bi->pressure = MAX(bi->pressure + bes->live_through, workset_get_length(bes->end_state));
+ bi->pressure += bes->live_through;
idx = workset_get_index(bes->end_state, bes->irn);
ir_node *irn;
int i;
- DBG((dbg, DBG_GLOBAL, "fixing block borders at %+F (%fHz)\n", block, bi->exec_freq));
+ DBG((dbg, DBG_GLOBAL, "fixing block borders at %+F (%f)\n", block, bi->exec_freq));
/* process all variables which shall be in a reg at
* the beginning of the block in the order of the next use. */
workset_foreach(bi->entrance_reg, irn, i) {
- int is_entrance_phi = is_Phi(irn) && get_nodes_block(irn) == block;
+ double local_costs = be_get_reload_costs(env->senv, irn, bi->first_non_in);
double bring_in_costs;
- /* reset the gauge and begin the search */
- ges->gauge = 0;
- --ges->version;
+ /* reset the gauge and create a new version. */
+ ges->gauge = 0;
+ ges->version -= 1;
DBG((dbg, DBG_GLOBAL, "\ttrans in var %+F, version %x\n", irn, ges->version));
- bring_in_costs = can_bring_in(ges, block, irn, 0);
+ bring_in_costs = can_bring_in(ges, block, irn, 1);
+
+ DBG((dbg, DBG_GLOBAL, "\tbring in: %f, local: %f", bring_in_costs, local_costs));
- /* we were not able to let the value arrive
+ /*
+ * we were not able to let the value arrive
* in a register at the entrance of the block
- * so we have to do the reload locally */
- if (bring_in_costs > bi->exec_freq) {
- DBG((dbg, DBG_GLOBAL, "\tbring in: %f, local: %f -> doing reload at beginning\n",
- bring_in_costs, bi->exec_freq));
+ * or it is too costly, so we have to do the reload locally
+ */
+ if (bring_in_costs > local_costs) {
+ DBG((dbg, DBG_GLOBAL, " -> do local reload\n"));
be_add_reload(env->senv, irn, bi->first_non_in, env->cls, 1);
- }
- else {
/*
- * Mark this phi as succeeded.
- * It was not replaced by a reload at the block's entrance
- * and thus is not phi_spilled.
+ * if the transport-in was a phi (that is actually used in block)
+ * it will no longer remain and we have to spill it completely.
*/
- if (is_entrance_phi)
- bitset_add_irn(ges->succ_phis, irn);
+ if (is_local_phi(irn, block))
+ bitset_add_irn(ges->failed_phis, irn);
+ }
+ else {
+ DBG((dbg, DBG_GLOBAL, " -> do remote reload\n"));
materialize_and_commit_end_state(ges);
}
+
+ DBG((dbg, DBG_GLOBAL, "\n"));
}
}
int i;
obstack_init(&ges.obst);
- ges.gauge = 0;
- ges.env = env;
- ges.version = -1;
- ges.end_info = NEW_ARR_F(block_end_state_t, env->n_blocks);
- ges.succ_phis = bitset_irg_obstack_alloc(&env->ob, env->irg);
+ ges.gauge = 0;
+ ges.env = env;
+ ges.version = -1;
+ ges.end_info = NEW_ARR_F(block_end_state_t, env->n_blocks);
+ ges.failed_phis = bitset_irg_obstack_alloc(&env->ob, env->irg);
/*
* sort the blocks according to execution frequency.
break;
if (arch_irn_consider_in_reg_alloc(env->arch, env->cls, irn)
- && !bitset_contains_irn(ges.succ_phis, irn))
+ && bitset_contains_irn(ges.failed_phis, irn))
be_spill_phi(env->senv, irn);
}
}
}
void be_spill_belady_spill_env2(be_irg_t *birg, const arch_register_class_t *cls, spill_env_t *spill_env) {
- belady_env_t env;
ir_graph *irg = be_get_birg_irg(birg);
+ belady_env_t env;
int i, n_regs;
/* some special classes contain only ignore regs, nothing to do then */
env.lv = be_get_birg_liveness(birg);
env.n_regs = n_regs;
env.ws = new_workset(&env, &env.ob);
- env.uses = be_begin_uses(irg, env.lv);
env.senv = spill_env ? spill_env : be_new_spill_env(birg);
env.ef = be_get_birg_exec_freq(birg);
env.n_blocks = 0;
obstack_ptr_grow(&env.ob, NULL);
env.blocks = obstack_finish(&env.ob);
- /* Fix high register pressure with belady algorithm */
+ /* Fix high register pressure in blocks with belady algorithm */
for (i = 0; i < env.n_blocks; ++i)
belady(env.blocks[i], &env);
/* clean up */
if(spill_env == NULL)
be_delete_spill_env(env.senv);
- be_end_uses(env.uses);
+
obstack_free(&env.ob, NULL);
}
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