/**
- * Author: Daniel Grund
- * Date: 20.09.2005
+ * Author: Daniel Grund, Matthias Braun
+ * Date: 20.09.2005
* Copyright: (c) Universitaet Karlsruhe
* Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*
#include "irnode.h"
#include "irmode.h"
#include "irgwalk.h"
+#include "irloop.h"
#include "iredges_t.h"
#include "ircons_t.h"
#include "irprintf.h"
#include "belive_t.h"
#include "benode_t.h"
#include "bechordal_t.h"
+#include "bespilloptions.h"
#define DBG_SPILL 1
#define DBG_WSETS 2
#define DBG_SLOTS 32
#define DBG_TRACE 64
#define DBG_WORKSET 128
-#define DEBUG_LVL 0 //(DBG_START | DBG_DECIDE | DBG_WSETS | DBG_FIX | DBG_SPILL)
DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-typedef struct _workset_t workset_t;
+/**
+ * An association between a node and a point in time.
+ */
+typedef struct _loc_t {
+ ir_node *irn; /**< A node. */
+ unsigned time; /**< A use time (see beuses.h). */
+} loc_t;
+
+typedef struct _workset_t {
+ int len; /**< current length */
+ loc_t vals[0]; /**< inlined array of the values/distances in this working set */
+} workset_t;
typedef struct _belady_env_t {
struct obstack ob;
- const be_chordal_env_t *cenv;
const arch_env_t *arch;
const arch_register_class_t *cls;
+ const be_lv_t *lv;
int n_regs; /** number of regs in this reg-class */
workset_t *ws; /**< the main workset used while processing a block. ob-allocated */
spill_env_t *senv; /**< see bespill.h */
} belady_env_t;
-struct _workset_t {
- int len; /**< current length */
- loc_t vals[0]; /**< inlined array of the values/distances in this working set */
-};
+static int loc_compare(const void *a, const void *b)
+{
+ const loc_t *p = a;
+ const loc_t *q = b;
+ return p->time - q->time;
+}
void workset_print(const workset_t *w)
{
int i;
for(i = 0; i < w->len; ++i) {
- ir_printf("%+F %d\n", w->vals[i].irn, w->vals[i].time);
+ ir_fprintf(stderr, "%+F %d\n", w->vals[i].irn, w->vals[i].time);
}
}
int i;
/* check for current regclass */
if (!arch_irn_consider_in_reg_alloc(env->arch, env->cls, val)) {
- DBG((dbg, DBG_WORKSET, "Dropped %+F\n", val));
+ DBG((dbg, DBG_WORKSET, "Skipped %+F\n", val));
return;
}
++i)
#define workset_set_time(ws, i, t) (ws)->vals[i].time=t
+#define workset_get_time(ws, i) (ws)->vals[i].time
#define workset_set_length(ws, length) (ws)->len = length
#define workset_get_length(ws) ((ws)->len)
#define workset_get_val(ws, i) ((ws)->vals[i].irn)
return res;
}
-#define get_block_info(blk) ((block_info_t *)get_irn_link(blk))
-#define set_block_info(blk, info) set_irn_link(blk, info)
+#define get_block_info(block) ((block_info_t *)get_irn_link(block))
+#define set_block_info(block, info) set_irn_link(block, info)
/**
* @return The distance to the next use or 0 if irn has dont_spill flag set
*/
-static INLINE unsigned get_distance(belady_env_t *env, const ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses)
+static INLINE unsigned get_distance(belady_env_t *env, ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses)
{
+ be_next_use_t use;
int flags = arch_irn_get_flags(env->arch, def);
- unsigned dist = be_get_next_use(env->uses, from, from_step, def, skip_from_uses);
assert(! (flags & arch_irn_flags_ignore));
- // we have to keep nonspillable nodes in the workingset
+
+ use = be_get_next_use(env->uses, from, from_step, def, skip_from_uses);
+ if(USES_IS_INFINITE(use.time))
+ return USES_INFINITY;
+
+ /* We have to keep nonspillable nodes in the workingset */
if(flags & arch_irn_flags_dont_spill)
return 0;
- return dist;
+ return use.time;
}
+#if 0
+/**
+ * Fix to remove dead nodes (especially don't spill nodes) from workset.
+ */
+static void fix_dead_values(workset_t *ws, ir_node *irn) {
+ int idx;
+ ir_node *node;
+ ir_node *block = get_nodes_block(irn);
+
+ DBG((dbg, DBG_DECIDE, "fixing dead values at %+F:\n", irn));
+
+ workset_foreach(ws, node, idx) {
+ const ir_edge_t *edge;
+ int fixme = 1;
+
+ /* skip already fixed nodes */
+ if (workset_get_time(ws, idx) == INT_MAX)
+ continue;
+
+ /* check all users */
+ foreach_out_edge(node, edge) {
+ ir_node *user = get_edge_src_irn(edge);
+
+ if ((get_nodes_block(user) != block) || /* user is in a different block */
+ (sched_is_scheduled(user) && sched_comes_after(irn, user)) || /* user is scheduled after irn */
+ user == irn) /* irn is the user */
+ { /* => don't fix distance */
+ fixme = 0;
+ break;
+ }
+ }
+
+ /* all users scheduled prior to current irn in in same block as irn -> fix */
+ if (fixme) {
+ workset_set_time(ws, idx, INT_MAX);
+ DBG((dbg, DBG_DECIDE, "\tfixing time for %+F to INT_MAX\n", node));
+ }
+ }
+
+}
+#endif
+
/**
* Performs the actions necessary to grant the request that:
* - new_vals can be held in registers
*/
static void displace(belady_env_t *env, workset_t *new_vals, int is_usage) {
ir_node *val;
- int i, len, max_allowed, demand, iter;
- workset_t *ws = env->ws;
- ir_node **to_insert = alloca(env->n_regs * sizeof(*to_insert));
+ int i, len, max_allowed, demand, iter;
+
+ workset_t *ws = env->ws;
+ ir_node **to_insert = alloca(env->n_regs * sizeof(*to_insert));
/*
- * 1. Identify the number of needed slots and the values to reload
- */
+ 1. Identify the number of needed slots and the values to reload
+ */
demand = 0;
workset_foreach(new_vals, val, iter) {
/* mark value as used */
if (is_usage)
pset_insert_ptr(env->used, val);
- if (!workset_contains(ws, val)) {
+ if (! workset_contains(ws, val)) {
DBG((dbg, DBG_DECIDE, " insert %+F\n", val));
to_insert[demand++] = val;
- if (is_usage)
- be_add_reload(env->senv, val, env->instr);
- } else {
+ if (is_usage) {
+ DBG((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, env->instr));
+ be_add_reload(env->senv, val, env->instr, env->cls, 1);
+ }
+ }
+ else {
assert(is_usage || "Defined value already in workset?!?");
DBG((dbg, DBG_DECIDE, " skip %+F\n", val));
}
DBG((dbg, DBG_DECIDE, " demand = %d\n", demand));
/*
- * 2. Make room for at least 'demand' slots
- */
- len = workset_get_length(ws);
+ 2. Make room for at least 'demand' slots
+ */
+ 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) {
/* get current next-use distance */
- for (i=0; i<ws->len; ++i)
- workset_set_time(ws, i, get_distance(env, env->instr, env->instr_nr, workset_get_val(ws, i), !is_usage));
+ for (i = 0; i < ws->len; ++i) {
+ unsigned dist = get_distance(env, env->instr, env->instr_nr, workset_get_val(ws, i), !is_usage);
+ workset_set_time(ws, i, dist);
+ }
+
+#if 0
+ /*
+ FIX for don't spill nodes:
+ Problem is that get_distance always returns 0 for those nodes even if they are not
+ needed anymore (all their usages have already been visited).
+ Even if we change this behavior, get_distance doesn't distinguish between not
+ used anymore (dead) and live out of block.
+ Solution: Set distances of all nodes having all their usages in schedule prior to
+ current instruction to MAX_INT.
+ */
+ fix_dead_values(ws, env->instr);
+#endif
/* sort entries by increasing nextuse-distance*/
workset_sort(ws);
- /* Logic for not needed live-ins: If a value is disposed
- * before its first usage, remove it from start workset
- * We don't do this for phis though
- */
- for (i=max_allowed; i<ws->len; ++i) {
+ /*
+ Logic for not needed live-ins: If a value is disposed
+ before its first usage, remove it from start workset
+ We don't do this for phis though
+ */
+ for (i = max_allowed; i < ws->len; ++i) {
ir_node *irn = ws->vals[i].irn;
- if(is_Phi(irn))
+ DBG((dbg, DBG_DECIDE, " disposing %+F (%u)\n", irn, workset_get_time(ws, i)));
+
+ if (is_Phi(irn))
continue;
- if (!pset_find_ptr(env->used, irn)) {
- ir_node *curr_bb = get_nodes_block(env->instr);
+ if (! pset_find_ptr(env->used, irn)) {
+ ir_node *curr_bb = get_nodes_block(env->instr);
workset_t *ws_start = get_block_info(curr_bb)->ws_start;
workset_remove(ws_start, irn);
- DBG((dbg, DBG_DECIDE, " dispose %+F dumb\n", irn));
- } else {
- DBG((dbg, DBG_DECIDE, " dispose %+F\n", irn));
+ DBG((dbg, DBG_DECIDE, " (and removing %+F from start workset)\n", irn));
}
}
}
/*
- * 3. Insert the new values into the workset
- */
- for(i = 0; i < demand; ++i)
+ 3. Insert the new values into the workset
+ */
+ for (i = 0; i < demand; ++i)
workset_insert(env, env->ws, to_insert[i]);
}
-static void belady(ir_node *blk, void *env);
+static void belady(ir_node *block, void *env);
+
+static loc_t to_take_or_not_to_take(belady_env_t *env, ir_node* first, ir_node *node, ir_node *block, ir_loop *loop) {
+ be_next_use_t next_use;
+ loc_t loc;
+ loc.time = USES_INFINITY;
+
+ if (!arch_irn_consider_in_reg_alloc(env->arch, env->cls, node)) {
+ loc.time = USES_INFINITY;
+ return loc;
+ }
+
+ loc.irn = node;
+
+ /* We have to keep nonspillable nodes in the workingset */
+ if(arch_irn_get_flags(env->arch, node) & arch_irn_flags_dont_spill) {
+ loc.time = 0;
+ DBG((dbg, DBG_START, " %+F taken (dontspill node)\n", node, loc.time));
+ return loc;
+ }
+
+ next_use = be_get_next_use(env->uses, first, 0, node, 0);
+ if(USES_IS_INFINITE(next_use.time)) {
+ // the nodes marked as live in shouldn't be dead, so it must be a phi
+ loc.time = USES_INFINITY;
+ DBG((dbg, DBG_START, " %+F not taken (dead)\n", node));
+ assert(is_Phi(node));
+ return loc;
+ }
+
+ loc.time = next_use.time;
+
+ if(next_use.outermost_loop >= get_loop_depth(loop)) {
+ DBG((dbg, DBG_START, " %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop));
+ return loc;
+ // ARR_APP1(loc_t, starters, loc);
+ } else {
+ loc.time = USES_INFINITY;
+ DBG((dbg, DBG_START, " %+F not taken (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
+ return loc;
+ }
+}
/*
- * Computes set of live-ins for each block with multiple predecessors and
- * places copies in the predecessors when phis get spilled
+ * Computes set of live-ins for each block with multiple predecessors
+ * and notifies spill algorithm which phis need to be spilled
*/
-static void place_copy_walker(ir_node *block, void *data) {
+static void compute_live_ins(ir_node *block, void *data) {
belady_env_t *env = data;
block_info_t *block_info;
ir_node *first, *irn;
loc_t loc, *starters;
int i, len, ws_count;
+ ir_loop *loop = get_irn_loop(block);
+ const be_lv_t *lv = env->lv;
if(get_Block_n_cfgpreds(block) == 1 && get_irg_start_block(get_irn_irg(block)) != block)
return;
/* Collect all values living at start of block */
starters = NEW_ARR_F(loc_t, 0);
+ /* rebuild schedule time information, because it seems to be broken */
+ // Matze: is this still true?
+ //sched_renumber(block);
+
DBG((dbg, DBG_START, "Living at start of %+F:\n", block));
first = sched_first(block);
+
sched_foreach(block, irn) {
if(!is_Phi(irn))
break;
- if(!arch_irn_consider_in_reg_alloc(env->arch, env->cls, irn))
- continue;
- loc.irn = irn;
- loc.time = get_distance(env, first, 0, irn, 0);
- ARR_APP1(loc_t, starters, loc);
- DBG((dbg, DBG_START, " %+F:\n", irn));
+ loc = to_take_or_not_to_take(env, first, irn, block, loop);
+
+ if(!USES_IS_INFINITE(loc.time)) {
+ ARR_APP1(loc_t, starters, loc);
+ } else {
+ be_spill_phi(env->senv, irn);
+ }
}
- be_lv_foreach(env->cenv->lv, block, be_lv_state_in, i) {
- ir_node *irn = be_lv_get_irn(env->cenv->lv, block, i);
- if (!arch_irn_consider_in_reg_alloc(env->arch, env->cls, irn))
- continue;
+ be_lv_foreach(lv, block, be_lv_state_in, i) {
+ ir_node *node = be_lv_get_irn(lv, block, i);
- loc.irn = irn;
- loc.time = get_distance(env, first, 0, irn, 0);
- ARR_APP1(loc_t, starters, loc);
- DBG((dbg, DBG_START, " %+F:\n", irn));
+ loc = to_take_or_not_to_take(env, first, node, block, loop);
+
+ if(!USES_IS_INFINITE(loc.time)) {
+ ARR_APP1(loc_t, starters, loc);
+ }
}
// Sort start values by first use
workset_bulk_fill(block_info->ws_start, ws_count, starters);
/* The phis of this block which are not in the start set have to be spilled later. */
- for (i = ws_count, len = ARR_LEN(starters); i < len; ++i) {
+ len = ARR_LEN(starters);
+ for (i = ws_count; i < len; ++i) {
irn = starters[i].irn;
if (!is_Phi(irn) || get_nodes_block(irn) != block)
continue;
}
/**
- * Collects all values live-in at block @p blk and all phi results in this block.
+ * Collects all values live-in at block @p block and all phi results in this block.
* Then it adds the best values (at most n_regs) to the blocks start_workset.
* The phis among the remaining values get spilled: Introduce psudo-copies of
* their args to break interference and make it possible to spill them to the
/**
- * For the given block @p blk, decide for each values
+ * For the given block @p block, decide for each values
* whether it is used from a register or is reloaded
* before the use.
*/
workset_copy(env, env->ws, block_info->ws_start);
DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
workset_foreach(env->ws, irn, iter)
- DBG((dbg, DBG_WSETS, " %+F\n", irn));
+ DBG((dbg, DBG_WSETS, " %+F (%u)\n", irn, workset_get_time(env->ws, iter)));
/* process the block from start to end */
DBG((dbg, DBG_WSETS, "Processing...\n"));
block_info->processed = 1;
DBG((dbg, DBG_WSETS, "End workset for %+F:\n", block));
workset_foreach(block_info->ws_end, irn, iter)
- DBG((dbg, DBG_WSETS, " %+F\n", irn));
+ DBG((dbg, DBG_WSETS, " %+F (%u)\n", irn, workset_get_time(block_info->ws_end, iter)));
}
/**
* about the set of live-ins. Thus we must adapt the
* live-outs to the live-ins at each block-border.
*/
-static void fix_block_borders(ir_node *blk, void *data) {
+static void fix_block_borders(ir_node *block, void *data) {
belady_env_t *env = data;
workset_t *wsb;
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *startblock = get_irg_start_block(irg);
int i, max, iter, iter2;
+ if(block == startblock)
+ return;
+
DBG((dbg, DBG_FIX, "\n"));
- DBG((dbg, DBG_FIX, "Fixing %+F\n", blk));
+ DBG((dbg, DBG_FIX, "Fixing %+F\n", block));
- wsb = get_block_info(blk)->ws_start;
+ wsb = get_block_info(block)->ws_start;
/* process all pred blocks */
- for (i=0, max=get_irn_arity(blk); i<max; ++i) {
- ir_node *irnb, *irnp, *pred = get_Block_cfgpred_block(blk, i);
+ for (i=0, max=get_irn_arity(block); i<max; ++i) {
+ ir_node *irnb, *irnp, *pred = get_Block_cfgpred_block(block, i);
workset_t *wsp = get_block_info(pred)->ws_end;
DBG((dbg, DBG_FIX, " Pred %+F\n", pred));
workset_foreach(wsb, irnb, iter) {
/* if irnb is a phi of the current block we reload
* the corresponding argument, else irnb itself */
- if(is_Phi(irnb) && blk == get_nodes_block(irnb)) {
+ if(is_Phi(irnb) && block == get_nodes_block(irnb)) {
irnb = get_irn_n(irnb, i);
// we might have unknowns as argument for the phi
/* irnb is not in memory at the end of pred, so we have to reload it */
DBG((dbg, DBG_FIX, " reload %+F\n", irnb));
- be_add_reload_on_edge(env->senv, irnb, blk, i);
+ DBG((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", irnb, block, i));
+ be_add_reload_on_edge(env->senv, irnb, block, i, env->cls, 1);
next_value:
/*epsilon statement :)*/;
}
}
-void be_spill_belady(const be_chordal_env_t *chordal_env) {
- be_spill_belady_spill_env(chordal_env, NULL);
+void be_spill_belady(be_irg_t *birg, const arch_register_class_t *cls) {
+ be_spill_belady_spill_env(birg, cls, NULL);
}
-void be_spill_belady_spill_env(const be_chordal_env_t *chordal_env, spill_env_t *spill_env) {
+void be_spill_belady_spill_env(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);
FIRM_DBG_REGISTER(dbg, "firm.be.spill.belady");
- //firm_dbg_set_mask(dbg, DBG_WSETS);
+ //firm_dbg_set_mask(dbg, DBG_SPILL);
+
+ be_assure_liveness(birg);
/* init belady env */
obstack_init(&env.ob);
- env.cenv = chordal_env;
- env.arch = chordal_env->birg->main_env->arch_env;
- env.cls = chordal_env->cls;
- env.n_regs = arch_count_non_ignore_regs(env.arch, env.cls);
+ env.arch = birg->main_env->arch_env;
+ env.cls = cls;
+ env.lv = be_get_birg_liveness(birg);
+ env.n_regs = env.cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
env.ws = new_workset(&env, &env.ob);
- env.uses = be_begin_uses(chordal_env->irg, chordal_env->lv, chordal_env->birg->main_env->arch_env, env.cls);
+ env.uses = be_begin_uses(irg, env.lv);
if(spill_env == NULL) {
- env.senv = be_new_spill_env(chordal_env);
+ env.senv = be_new_spill_env(birg);
} else {
env.senv = spill_env;
}
DEBUG_ONLY(be_set_spill_env_dbg_module(env.senv, dbg);)
- DBG((dbg, LEVEL_1, "running on register class: %s\n", env.cls->name));
-
- be_clear_links(chordal_env->irg);
+ be_clear_links(irg);
/* Decide which phi nodes will be spilled and place copies for them into the graph */
- irg_block_walk_graph(chordal_env->irg, place_copy_walker, NULL, &env);
- be_place_copies(env.senv);
+ irg_block_walk_graph(irg, compute_live_ins, NULL, &env);
/* Fix high register pressure with belady algorithm */
- irg_block_walk_graph(chordal_env->irg, NULL, belady, &env);
+ irg_block_walk_graph(irg, NULL, belady, &env);
/* belady was block-local, fix the global flow by adding reloads on the edges */
- irg_block_walk_graph(chordal_env->irg, fix_block_borders, NULL, &env);
+ irg_block_walk_graph(irg, fix_block_borders, NULL, &env);
/* Insert spill/reload nodes into the graph and fix usages */
be_insert_spills_reloads(env.senv);
- be_remove_dead_nodes_from_schedule(chordal_env->irg);
- be_liveness_recompute(chordal_env->lv);
-
/* clean up */
if(spill_env == NULL)
be_delete_spill_env(env.senv);
be_end_uses(env.uses);
obstack_free(&env.ob, NULL);
}
+
+static void be_spill_belady_oldinterface(const be_chordal_env_t *chordal_env)
+{
+ be_spill_belady(chordal_env->birg, chordal_env->cls);
+}
+
+void be_init_spillbelady(void)
+{
+ static be_spiller_t belady_spiller = {
+ be_spill_belady_oldinterface
+ };
+
+ be_register_spiller("belady", &belady_spiller);
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);