/*
- * Author: Daniel Grund, Sebastian Hack, Matthias Braun
- * Date: 29.09.2005
- * Copyright: (c) Universitaet Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief implementation of the spill/reload placement abstraction layer
+ * @author Daniel Grund, Sebastian Hack, Matthias Braun
+ * @date 29.09.2005
+ * @version $Id$
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#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 "irgwalk.h"
#include "array.h"
#include "pdeq.h"
-#include "unionfind.h"
#include "execfreq.h"
+#include "irnodeset.h"
+#include "error.h"
+#include "bearch_t.h"
#include "belive_t.h"
#include "besched_t.h"
#include "bespill.h"
#include "benode_t.h"
#include "bechordal_t.h"
#include "bejavacoal.h"
+#include "bespilloptions.h"
+#include "bestatevent.h"
+#include "bessaconstr.h"
+#include "beirg_t.h"
+#include "beintlive_t.h"
+#include "bemodule.h"
+#include "be_t.h"
-// only rematerialise when costs are less than REMAT_COST_LIMIT
-// TODO determine a good value here...
-#define REMAT_COST_LIMIT 80
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-typedef struct _reloader_t reloader_t;
+#define REMAT_COST_INFINITE 1000
-struct _reloader_t {
+typedef struct reloader_t reloader_t;
+struct reloader_t {
reloader_t *next;
- ir_node *reloader;
+ ir_node *can_spill_after;
+ ir_node *reloader;
+ ir_node *rematted_node;
+ int remat_cost_delta; /** costs needed for rematerialization,
+ compared to placing a reload */
};
-typedef struct _spill_info_t {
- ir_node *spilled_node;
- reloader_t *reloaders;
-
+typedef struct spill_t spill_t;
+struct spill_t {
+ spill_t *next;
+ ir_node *before; /**< spill has to be placed before this node (or earlier) */
ir_node *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 */
+typedef struct spill_info_t spill_info_t;
+struct spill_info_t {
+ ir_node *to_spill; /**< the value that should get spilled */
+ reloader_t *reloaders; /**< list of places where the value should get
+ reloaded */
+ spill_t *spills; /**< list of latest places where spill must be
+ placed */
+ double spill_costs; /**< costs needed for spilling the value */
+ const arch_register_class_t *reload_cls; /** the register class in which the
+ reload should be placed */
+};
- DEBUG_ONLY(firm_dbg_module_t *dbg;)
+struct spill_env_t {
+ const arch_env_t *arch_env;
+ ir_graph *irg;
+ struct obstack obst;
+ be_irg_t *birg;
+ 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 */
+ ir_nodeset_t mem_phis; /**< set of all spilled phis. */
+ ir_exec_freq *exec_freq;
+ unsigned new_nodes_idx; /**< all old nodes idx is smaller than
+ this */
+
+#ifdef FIRM_STATISTICS
+ unsigned spill_count;
+ unsigned reload_count;
+ unsigned remat_count;
+ unsigned spilled_phi_count;
+#endif
};
/**
* Compare two spill infos.
*/
-static int cmp_spillinfo(const void *x, const void *y, size_t size) {
+static int cmp_spillinfo(const void *x, const void *y, size_t size)
+{
const spill_info_t *xx = x;
const spill_info_t *yy = y;
- return xx->spilled_node != yy->spilled_node;
+ (void) size;
+
+ return xx->to_spill != yy->to_spill;
}
/**
* 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) {
+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 = hash_irn(value);
- info.spilled_node = value;
+ info.to_spill = value;
res = set_find(env->spills, &info, sizeof(info), hash);
if (res == NULL) {
- info.reloaders = NULL;
- info.spill = NULL;
+ info.reloaders = NULL;
+ info.spills = NULL;
+ info.spill_costs = -1;
+ info.reload_cls = NULL;
res = set_insert(env->spills, &info, sizeof(info), hash);
}
return res;
}
-DEBUG_ONLY(
-/* Sets the debug module of a spill environment. */
-void be_set_spill_env_dbg_module(spill_env_t *env, firm_dbg_module_t *dbg) {
- env->dbg = dbg;
-}
-)
+spill_env_t *be_new_spill_env(be_irg_t *birg)
+{
+ const arch_env_t *arch_env = &birg->main_env->arch_env;
-/* Creates a new spill environment. */
-spill_env_t *be_new_spill_env(const be_chordal_env_t *chordal_env) {
spill_env_t *env = xmalloc(sizeof(env[0]));
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();
+ env->irg = be_get_birg_irg(birg);
+ env->birg = birg;
+ env->arch_env = arch_env;
+ ir_nodeset_init(&env->mem_phis);
+ env->spill_cost = arch_env->isa->spill_cost;
+ env->reload_cost = arch_env->isa->reload_cost;
+ env->exec_freq = be_get_birg_exec_freq(birg);
obstack_init(&env->obst);
+
+#ifdef FIRM_STATISTICS
+ env->spill_count = 0;
+ env->reload_count = 0;
+ env->remat_count = 0;
+ env->spilled_phi_count = 0;
+#endif
+
return env;
}
-/* Deletes a spill environment. */
-void be_delete_spill_env(spill_env_t *env) {
+void be_delete_spill_env(spill_env_t *env)
+{
del_set(env->spills);
- del_pset(env->mem_phis);
+ ir_nodeset_destroy(&env->mem_phis);
obstack_free(&env->obst, NULL);
free(env);
}
-/**
+/*
* ____ _ ____ _ _
* | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
* | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
*
*/
-void be_add_reload(spill_env_t *env, ir_node *to_spill, ir_node *before) {
+void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *before)
+{
+#if 1
+ spill_info_t *spill_info = get_spillinfo(env, to_spill);
+ spill_t *spill;
+ spill_t *s;
+ spill_t *last;
+
+ assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
+ DB((dbg, LEVEL_1, "Add spill of %+F before %+F\n", to_spill, before));
+
+ /* Just for safety make sure that we do not insert the spill in front of a phi */
+ for (; is_Phi(before); before = sched_next(before));
+
+ /* spills that are dominated by others are not needed */
+ last = NULL;
+ s = spill_info->spills;
+ for( ; s != NULL; s = s->next) {
+ /* no need to add this spill if it is dominated by another */
+ if(value_dominates(s->before, before)) {
+ DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->before));
+ return;
+ }
+ /* remove spills that we dominate */
+ if(value_dominates(before, s->before)) {
+ DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->before));
+ if(last != NULL) {
+ last->next = s->next;
+ } else {
+ spill_info->spills = s->next;
+ }
+ } else {
+ last = s;
+ }
+ }
+
+ spill = obstack_alloc(&env->obst, sizeof(spill[0]));
+ spill->before = before;
+ spill->next = spill_info->spills;
+ spill->spill = NULL;
+
+ spill_info->spills = spill;
+#endif
+}
+
+void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before,
+ ir_node *rematted_node)
+{
+ spill_info_t *spill_info;
+ reloader_t *reloader;
+
+ spill_info = get_spillinfo(env, to_spill);
+
+ /* add the remat information */
+ reloader = obstack_alloc(&env->obst, sizeof(reloader[0]));
+ reloader->next = spill_info->reloaders;
+ reloader->reloader = before;
+ reloader->rematted_node = rematted_node;
+ reloader->remat_cost_delta = 0; /* We will never have a cost win over a
+ reload since we're not even allowed to
+ create a reload */
+
+ spill_info->reloaders = reloader;
+
+ DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
+ to_spill, before));
+}
+
+void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before,
+ ir_node *can_spill_after, const arch_register_class_t *reload_cls,
+ int allow_remat)
+{
spill_info_t *info;
reloader_t *rel;
- assert(sched_is_scheduled(before));
- assert(arch_irn_consider_in_reg_alloc(env->arch_env, env->cls, to_spill));
+ assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
info = get_spillinfo(env, to_spill);
- if(is_Phi(to_spill)) {
+ if (is_Phi(to_spill)) {
int i, arity;
- // create spillinfos for the phi arguments
- for(i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
+
+ /* create spillinfos for the phi arguments */
+ for (i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
ir_node *arg = get_irn_n(to_spill, i);
get_spillinfo(env, arg);
}
}
- rel = obstack_alloc(&env->obst, sizeof(rel[0]));
- rel->reloader = before;
- rel->next = info->reloaders;
- info->reloaders = rel;
- be_liveness_add_missing(env->chordal_env->lv);
+ assert(!is_Proj(before) && !be_is_Keep(before));
+
+ /* put reload into list */
+ rel = obstack_alloc(&env->obst, sizeof(rel[0]));
+ rel->next = info->reloaders;
+ rel->reloader = before;
+ rel->rematted_node = NULL;
+ rel->can_spill_after = can_spill_after;
+ rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
+
+ info->reloaders = rel;
+ assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
+ info->reload_cls = reload_cls;
+
+ DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
+ to_spill, before, allow_remat ? "" : " not"));
}
-void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
- ir_node *predblock, *last;
+void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
+ const arch_register_class_t *reload_cls, int allow_remat)
+{
+ be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
- /* simply add the reload to the beginning of the block if we only have 1 predecessor
- * (we don't need to check for phis as there can't be any in a block with only 1 pred)
- */
+}
+
+ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
+{
+ ir_node *last = sched_last(block);
+
+ /* we might have keeps behind the jump... */
+ while(be_is_Keep(last)) {
+ last = sched_prev(last);
+ assert(!sched_is_end(last));
+ }
+
+ assert(is_cfop(last));
+
+ /* add the reload before the (cond-)jump */
+ return last;
+}
+
+static ir_node *skip_keeps_phis(ir_node *node)
+{
+ node = sched_next(node);
+ while(is_Phi(node) || be_is_Keep(node)) {
+ node = sched_next(node);
+ }
+ return node;
+}
+
+/**
+ * Returns the point at which you can insert a node that should be executed
+ * before block @p block when coming from pred @p pos.
+ */
+static ir_node *get_block_insertion_point(ir_node *block, int pos)
+{
+ ir_node *predblock;
+
+ /* simply add the reload to the beginning of the block if we only have 1
+ * predecessor. We don't need to check for phis as there can't be any in a
+ * block with only 1 pred. */
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 */
predblock = get_Block_cfgpred_block(block, pos);
- last = sched_last(predblock);
+ return be_get_end_of_block_insertion_point(predblock);
+}
- /* we might have projs and keepanys behind the jump... */
- while(is_Proj(last) || be_is_Keep(last)) {
- last = sched_prev(last);
- assert(!sched_is_end(last));
- }
- assert(is_cfop(last));
+void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill,
+ const ir_node *block,
+ const arch_register_class_t *reload_cls,
+ int allow_remat)
+{
+ ir_node *before = be_get_end_of_block_insertion_point(block);
+ be_add_reload(env, to_spill, before, reload_cls, allow_remat);
+}
- // add the reload before the (cond-)jump
- be_add_reload(env, to_spill, last);
+void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
+ int pos, const arch_register_class_t *reload_cls,
+ int allow_remat)
+{
+ ir_node *before = get_block_insertion_point(block, pos);
+ be_add_reload(env, to_spill, before, reload_cls, allow_remat);
}
-void be_spill_phi(spill_env_t *env, ir_node *node) {
+void be_spill_phi(spill_env_t *env, ir_node *node)
+{
+ ir_node *block;
+ spill_info_t* spill;
int i, arity;
assert(is_Phi(node));
- pset_insert_ptr(env->mem_phis, node);
+ ir_nodeset_insert(&env->mem_phis, node);
- // create spillinfos for the phi arguments
- get_spillinfo(env, node);
+ /* create spills for the phi arguments */
+ block = get_nodes_block(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);
+ ir_node *arg = get_irn_n(node, i);
+ ir_node *insert;
+ //get_spillinfo(env, arg);
+
+ /* some backends have virtual noreg/unknown nodes that are not scheduled
+ * and simply always available. */
+ if(!sched_is_scheduled(arg)) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, i);
+ insert = be_get_end_of_block_insertion_point(pred_block);
+ } else {
+ insert = skip_keeps_phis(arg);
+ }
+
+ be_add_spill(env, arg, insert);
}
}
* |_|
*/
-/**
- * Schedules a node after an instruction. (That is the place after all projs and phis
- * that are scheduled after the instruction)
- * This function also skips phi nodes at the beginning of a block
- */
-static void sched_add_after_insn(ir_node *sched_after, ir_node *node) {
- ir_node *next = sched_next(sched_after);
- while(is_Proj(next) || is_Phi(next)) {
- next = sched_next(next);
- }
- assert(next != NULL);
-
- if(sched_is_end(next)) {
- sched_add_after(sched_last(get_nodes_block(sched_after)), node);
- } else {
- sched_add_before(next, node);
- }
-}
+static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo);
/**
* Creates a spill.
*
* @return a be_Spill node
*/
-static void spill_irn(spill_env_t *env, spill_info_t *spillinfo) {
- 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 rematerialization code should handle most of these cases
- * this can still happen when spilling Phis)
- */
- if(be_is_Reload(to_spill)) {
- spillinfo->spill = get_irn_n(to_spill, be_pos_Reload_mem);
+static void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
+{
+ ir_node *to_spill = spillinfo->to_spill;
+ spill_t *spill;
+
+ /* determine_spill_costs must have been run before */
+ assert(spillinfo->spill_costs >= 0);
+
+ /* some backends have virtual noreg/unknown nodes that are not scheduled
+ * and simply always available. */
+ if(!sched_is_scheduled(to_spill)) {
+ /* override spillinfos or create a new one */
+ spillinfo->spills->spill = new_NoMem();
+ DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
return;
}
- 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'");
- }
+ DBG((dbg, LEVEL_1, "spilling %+F ... \n", to_spill));
+ spill = spillinfo->spills;
+ for( ; spill != NULL; spill = spill->next) {
+ ir_node *block = get_block(spill->before);
+ ir_node *before = spill->before;
+
+ /* place all spills before the reloads (as we can't guarantee the
+ * same order as the be_add_spill and be_add_reload calls.
+ * Also make sure that we do not run into Phis when going up. */
+ while(get_irn_idx(sched_prev(before)) > env->new_nodes_idx && !is_Phi(sched_prev(before))) {
+ before = sched_prev(before);
+ }
- spillinfo->spill = be_spill(env->arch_env, to_spill);
- sched_add_after_insn(to_spill, spillinfo->spill);
+ spill->spill = be_spill(env->arch_env, block, to_spill);
+ sched_add_before(before, spill->spill);
+ DB((dbg, LEVEL_1, "\t%+F before %+F\n", spill->spill, before));
+#ifdef FIRM_STATISTICS
+ env->spill_count++;
+#endif
+ }
+ DBG((dbg, LEVEL_1, "\n"));
}
static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
* @param phi the Phi node that should be spilled
* @param ctx_irn an user of the spilled node
*/
-static void spill_phi(spill_env_t *env, spill_info_t *spillinfo) {
- ir_node *phi = spillinfo->spilled_node;
- int i;
- int arity = get_irn_arity(phi);
- ir_node *block = get_nodes_block(phi);
- ir_node **ins;
+static void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
+{
+ ir_graph *irg = env->irg;
+ ir_node *phi = spillinfo->to_spill;
+ ir_node *block = get_nodes_block(phi);
+ ir_node *unknown;
+ ir_node **ins;
+ spill_t *spill;
+ int i;
+ int arity;
assert(is_Phi(phi));
+ assert(!get_opt_cse());
+ DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
/* build a new PhiM */
- ins = alloca(sizeof(ir_node*) * arity);
+ arity = get_irn_arity(phi);
+ ins = alloca(sizeof(ir_node*) * arity);
+ unknown = new_r_Unknown(irg, mode_M);
for(i = 0; i < arity; ++i) {
- ins[i] = get_irg_bad(env->chordal_env->irg);
+ ins[i] = unknown;
}
- spillinfo->spill = new_r_Phi(env->chordal_env->irg, block, arity, ins, mode_M);
+
+ /* override or replace spills list... */
+ spill = obstack_alloc(&env->obst, sizeof(spill[0]));
+ spill->before = skip_keeps_phis(phi);
+ spill->spill = new_r_Phi(irg, block, arity, ins, mode_M);
+ spill->next = NULL;
+
+ spillinfo->spills = spill;
+#ifdef FIRM_STATISTICS
+ env->spilled_phi_count++;
+#endif
for(i = 0; i < arity; ++i) {
- ir_node *arg = get_irn_n(phi, i);
+ ir_node *arg = get_irn_n(phi, i);
spill_info_t *arg_info = get_spillinfo(env, arg);
+ determine_spill_costs(env, arg_info);
spill_node(env, arg_info);
- set_irn_n(spillinfo->spill, i, arg_info->spill);
+ set_irn_n(spill->spill, i, arg_info->spills->spill);
}
+ DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi,
+ spill->spill));
}
/**
* @param senv the spill environment
* @param to_spill the node that should be spilled
*/
-static void spill_node(spill_env_t *env, spill_info_t *spillinfo) {
+static void spill_node(spill_env_t *env, spill_info_t *spillinfo)
+{
ir_node *to_spill;
- // the node should be tagged for spilling already...
- if(spillinfo->spill != NULL)
+ /* node is already spilled */
+ if(spillinfo->spills != NULL && spillinfo->spills->spill != NULL)
return;
- to_spill = spillinfo->spilled_node;
- if (is_Phi(to_spill) && pset_find_ptr(env->mem_phis, spillinfo->spilled_node)) {
+ to_spill = spillinfo->to_spill;
+
+ if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
spill_phi(env, spillinfo);
} else {
spill_irn(env, spillinfo);
* Tests whether value @p arg is available before node @p reloader
* @returns 1 if value is available, 0 otherwise
*/
-static int is_value_available(spill_env_t *env, ir_node *arg, ir_node *reloader) {
+static int is_value_available(spill_env_t *env, const ir_node *arg,
+ const ir_node *reloader)
+{
if(is_Unknown(arg) || arg == new_NoMem())
return 1;
if(be_is_Spill(arg))
return 1;
- if(arg == get_irg_frame(env->chordal_env->irg))
+ if(arg == get_irg_frame(env->irg))
return 1;
+ /* hack for now (happens when command should be inserted at end of block) */
+ if(is_Block(reloader)) {
+ return 0;
+ }
+
+ /*
+ * Ignore registers are always available
+ */
+ if(arch_irn_is(env->arch_env, arg, ignore)) {
+ return 1;
+ }
+
/* 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)
*/
- 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;
+#if 0
+ /* 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->birg->lv, reloader, arg)) {
+ return 1;
+ }
- /* 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)) {
+ 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;
- }
-
- 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;
- }
}
+#endif
return 0;
}
/**
* Checks whether the node can principally be rematerialized
*/
-static int is_remat_node(spill_env_t *env, ir_node *node) {
+static int is_remat_node(spill_env_t *env, const ir_node *node)
+{
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))
return 1;
- if(be_is_StackParam(node))
- return 1;
-
return 0;
}
* - The costs for the rematerialisation operation is less or equal a limit
*
* Returns the costs needed for rematerialisation or something
- * > REMAT_COST_LIMIT if remat is not possible.
+ * >= REMAT_COST_INFINITE if remat is not possible.
*/
-static int check_remat_conditions_costs(spill_env_t *env, ir_node *spilled, ir_node *reloader, int parentcosts) {
+static int check_remat_conditions_costs(spill_env_t *env,
+ const ir_node *spilled, const ir_node *reloader, int parentcosts)
+{
int i, arity;
int argremats;
int costs = 0;
if(!is_remat_node(env, spilled))
- return REMAT_COST_LIMIT;
+ return REMAT_COST_INFINITE;
if(be_is_Reload(spilled)) {
costs += 2;
} else {
costs += arch_get_op_estimated_cost(env->arch_env, spilled);
}
- if(parentcosts + costs >= REMAT_COST_LIMIT)
- return REMAT_COST_LIMIT;
+ if(parentcosts + costs >= env->reload_cost + env->spill_cost) {
+ return REMAT_COST_INFINITE;
+ }
+ if(arch_irn_is(env->arch_env, spilled, modify_flags)) {
+ return REMAT_COST_INFINITE;
+ }
argremats = 0;
for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
if(is_value_available(env, arg, reloader))
continue;
- // we have to rematerialize the argument as well...
+ /* we have to rematerialize the argument as well */
if(argremats >= 1) {
/* we only support rematerializing 1 argument at the moment,
* so that we don't have to care about register pressure
*/
- return REMAT_COST_LIMIT;
+ return REMAT_COST_INFINITE;
}
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;
+ costs += check_remat_conditions_costs(env, arg, reloader,
+ parentcosts + costs);
+ if(parentcosts + costs >= env->reload_cost + env->spill_cost)
+ return REMAT_COST_INFINITE;
}
return costs;
}
-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);
-
- return costs < REMAT_COST_LIMIT;
-}
-
/**
* Re-materialize a node.
*
* @param spilled the node that was spilled
* @param reloader a irn that requires a reload
*/
-static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader) {
+static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader)
+{
int i, arity;
ir_node *res;
- ir_node *bl = get_nodes_block(reloader);
+ ir_node *bl;
ir_node **ins;
+ if(is_Block(reloader)) {
+ bl = reloader;
+ } else {
+ bl = get_nodes_block(reloader);
+ }
+
ins = alloca(get_irn_arity(spilled) * sizeof(ins[0]));
for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
ir_node *arg = get_irn_n(spilled, i);
ins[i] = arg;
} else {
ins[i] = do_remat(env, arg, reloader);
+#ifdef FIRM_STATISTICS
+ /* don't count the recursive call as remat */
+ env->remat_count--;
+#endif
}
}
/* create a copy of the node */
- res = new_ir_node(get_irn_dbg_info(spilled), env->chordal_env->irg, bl,
- get_irn_op(spilled),
- get_irn_mode(spilled),
- get_irn_arity(spilled),
- ins);
+ res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
+ get_irn_op(spilled), get_irn_mode(spilled),
+ 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));
+ DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
- /* insert in schedule */
- assert(!is_Block(reloader));
- sched_add_before(reloader, res);
+ if (! is_Proj(res)) {
+ /* insert in schedule */
+ sched_reset(res);
+ sched_add_before(reloader, res);
+#ifdef FIRM_STATISTICS
+ env->remat_count++;
+#endif
+ }
return res;
}
+double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
+{
+ ir_node *block = get_nodes_block(before);
+ double freq = get_block_execfreq(env->exec_freq, block);
+ (void) to_spill;
+
+ return env->spill_cost * freq;
+}
+
+unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
+ const ir_node *before)
+{
+ if(be_do_remats) {
+ /* is the node rematerializable? */
+ unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0);
+ if(costs < (unsigned) env->reload_cost)
+ return costs;
+ }
+
+ return env->reload_cost;
+}
+
+double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
+{
+ ir_node *block = get_nodes_block(before);
+ double freq = get_block_execfreq(env->exec_freq, block);
+
+ if(be_do_remats) {
+ /* is the node rematerializable? */
+ int costs = check_remat_conditions_costs(env, to_spill, before, 0);
+ if(costs < env->reload_cost)
+ return costs * freq;
+ }
+
+ return env->reload_cost * freq;
+}
+
+int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat,
+ const ir_node *before)
+{
+ return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
+}
+
+double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
+ ir_node *block, int pos)
+{
+ ir_node *before = get_block_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->arch_env;
- spill_info_t *si;
+/**
+ * analyzes how to best spill a node and determine costs for that
+ */
+static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo)
+{
+ ir_node *to_spill = spillinfo->to_spill;
+ ir_node *spill_block;
+ spill_t *spill;
+ double spill_execfreq;
+
+ /* already calculated? */
+ if(spillinfo->spill_costs >= 0)
+ return;
+
+ assert(! arch_irn_is(env->arch_env, to_spill, dont_spill));
+ assert(!be_is_Reload(to_spill));
+
+ /* some backends have virtual noreg/unknown nodes that are not scheduled
+ * and simply always available.
+ * TODO: this is kinda hairy, the NoMem is correct for an Unknown as Phi
+ * predecessor (of a PhiM) but this test might match other things too...
+ */
+ if(!sched_is_scheduled(to_spill)) {
+ /* override spillinfos or create a new one */
+ spill_t *spill = obstack_alloc(&env->obst, sizeof(spill[0]));
+ spill->before = NULL;
+ spill->next = NULL;
+ spill->spill = new_NoMem();
+
+ spillinfo->spills = spill;
+ spillinfo->spill_costs = 0;
+
+ DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
+ return;
+ }
+
+ spill_block = get_nodes_block(to_spill);
+ spill_execfreq = get_block_execfreq(env->exec_freq, spill_block);
+
+ if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
+ /* TODO calculate correct costs...
+ * (though we can't remat this node anyway so no big problem) */
+ spillinfo->spill_costs = env->spill_cost * spill_execfreq;
+ return;
+ }
+
+ if(spillinfo->spills != NULL) {
+ spill_t *s;
+ double spills_execfreq;
+
+ /* calculate sum of executaion frequencies of individual spills */
+ spills_execfreq = 0;
+ s = spillinfo->spills;
+ for( ; s != NULL; s = s->next) {
+ ir_node *spill_block = s->before;
+ double freq;
+
+ if(!is_Block(spill_block)) {
+ spill_block = get_nodes_block(spill_block);
+ }
+ freq = get_block_execfreq(env->exec_freq, spill_block);
+
+ spills_execfreq += freq;
+ }
+
+ DB((dbg, LEVEL_1, "%+F: latespillcosts %f after def: %f\n", to_spill,
+ spills_execfreq * env->spill_cost,
+ spill_execfreq * env->spill_cost));
+
+ /* multi-/latespill is advantageous -> return*/
+ if(spills_execfreq < spill_execfreq) {
+ DB((dbg, LEVEL_1, "use latespills for %+F\n", to_spill));
+ spillinfo->spill_costs = spills_execfreq * env->spill_cost;
+ return;
+ }
+ }
+
+ /* override spillinfos or create a new one */
+ spill = obstack_alloc(&env->obst, sizeof(spill[0]));
+ spill->before = skip_keeps_phis(to_spill);
+ spill->next = NULL;
+ spill->spill = NULL;
+
+ spillinfo->spills = spill;
+ spillinfo->spill_costs = spill_execfreq * env->spill_cost;
+ DB((dbg, LEVEL_1, "spill %+F after definition\n", to_spill));
+}
+
+void make_spill_locations_dominate_irn(spill_env_t *env, ir_node *irn)
+{
+ const spill_info_t *si = get_spillinfo(env, irn);
+ ir_node *start_block = get_irg_start_block(get_irn_irg(irn));
+ int n_blocks = get_Block_dom_max_subtree_pre_num(start_block);
+ bitset_t *reloads = bitset_alloca(n_blocks);
+ reloader_t *r;
+ spill_t *s;
+
+ if (si == NULL)
+ return;
+
+ /* Fill the bitset with the dominance pre-order numbers
+ * of the blocks the reloads are located in. */
+ for (r = si->reloaders; r != NULL; r = r->next) {
+ ir_node *bl = get_nodes_block(r->reloader);
+ bitset_set(reloads, get_Block_dom_tree_pre_num(bl));
+ }
+
+ /* Now, cancel out all the blocks that are dominated by each spill.
+ * If the bitset is not empty after that, we have reloads that are
+ * not dominated by any spill. */
+ for (s = si->spills; s != NULL; s = s->next) {
+ ir_node *bl = get_nodes_block(s->before);
+ int start = get_Block_dom_tree_pre_num(bl);
+ int end = get_Block_dom_max_subtree_pre_num(bl);
+
+ bitset_clear_range(reloads, start, end);
+ }
+
+ if (!bitset_is_empty(reloads))
+ be_add_spill(env, si->to_spill, sched_next(si->to_spill));
+}
+
+void be_insert_spills_reloads(spill_env_t *env)
+{
+ ir_graph *irg = env->irg;
+ const arch_env_t *arch_env = env->arch_env;
+ const ir_exec_freq *exec_freq = env->exec_freq;
+ spill_info_t *si;
+ ir_nodeset_iterator_t iter;
+ ir_node *node;
+
+ BE_TIMER_PUSH(t_ra_spill_apply);
+
+ env->new_nodes_idx = get_irg_last_idx(irg);
+
+ /* create all phi-ms first, this is needed so, that phis, hanging on
+ spilled phis work correctly */
+ foreach_ir_nodeset(&env->mem_phis, node, iter) {
+ spill_info_t *info = get_spillinfo(env, node);
+ spill_node(env, info);
+ }
/* 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)) {
+ for (si = set_first(env->spills); si; si = set_next(env->spills)) {
reloader_t *rld;
- ir_mode *mode = get_irn_mode(si->spilled_node);
- pset *values = pset_new_ptr(16);
+ ir_node *to_spill = si->to_spill;
+ ir_mode *mode = get_irn_mode(to_spill);
+ ir_node **copies = NEW_ARR_F(ir_node*, 0);
+ double all_remat_costs = 0; /** costs when we would remat all nodes */
+ int force_remat = 0;
+
+ DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
+
+ determine_spill_costs(env, si);
+
+ /* determine possibility of rematerialisations */
+ if(be_do_remats) {
+ /* calculate cost savings for each indivial value when it would
+ be rematted instead of reloaded */
+ for (rld = si->reloaders; rld != NULL; rld = rld->next) {
+ double freq;
+ int remat_cost;
+ int remat_cost_delta;
+ ir_node *block;
+ ir_node *reloader = rld->reloader;
+
+ if(rld->rematted_node != NULL) {
+ DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
+ rld->rematted_node, reloader));
+ continue;
+ }
+ if(rld->remat_cost_delta >= REMAT_COST_INFINITE) {
+ DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
+ reloader));
+ all_remat_costs = REMAT_COST_INFINITE;
+ continue;
+ }
+
+ remat_cost = check_remat_conditions_costs(env, to_spill,
+ reloader, 0);
+ if(remat_cost >= REMAT_COST_INFINITE) {
+ DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
+ reloader));
+ rld->remat_cost_delta = REMAT_COST_INFINITE;
+ all_remat_costs = REMAT_COST_INFINITE;
+ continue;
+ }
+
+ remat_cost_delta = remat_cost - env->reload_cost;
+ rld->remat_cost_delta = remat_cost_delta;
+ block = is_Block(reloader) ? reloader : get_nodes_block(reloader);
+ freq = get_block_execfreq(exec_freq, block);
+ all_remat_costs += remat_cost_delta * freq;
+ DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
+ "%d (rel %f)\n", reloader, remat_cost_delta,
+ remat_cost_delta * freq));
+ }
+ if(all_remat_costs < REMAT_COST_INFINITE) {
+ /* we don't need the costs for the spill if we can remat
+ all reloaders */
+ all_remat_costs -= si->spill_costs;
- /* go through all reloads for this spill */
- for(rld = si->reloaders; rld; rld = rld->next) {
- ir_node *new_val;
+ DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
+ env->spill_cost, si->spill_costs));
+ }
- if (check_remat_conditions(env, si->spilled_node, rld->reloader)) {
- new_val = do_remat(env, si->spilled_node, rld->reloader);
+ if(all_remat_costs < 0) {
+ DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
+ all_remat_costs));
+ force_remat = 1;
+ }
+ }
+
+ /* go through all reloads for this spill */
+ for (rld = si->reloaders; rld != NULL; rld = rld->next) {
+ ir_node *copy; /* a reload is a "copy" of the original value */
+
+ if (rld->rematted_node != NULL) {
+ copy = rld->rematted_node;
+ sched_add_before(rld->reloader, copy);
+ } else if (be_do_remats &&
+ (force_remat || rld->remat_cost_delta < 0)) {
+ copy = do_remat(env, to_spill, rld->reloader);
} else {
/* make sure we have a spill */
spill_node(env, si);
- /* do a reload */
- new_val = be_reload(arch_env, env->cls, rld->reloader, mode, si->spill);
+ /* create a reload, use the first spill for now SSA
+ * reconstruction for memory comes below */
+ assert(si->spills != NULL);
+ copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode,
+ si->spills->spill);
+#ifdef FIRM_STATISTICS
+ env->reload_count++;
+#endif
}
- DBG((env->dbg, LEVEL_1, " %+F of %+F before %+F\n", new_val, si->spilled_node, rld->reloader));
- pset_insert_ptr(values, new_val);
+ DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
+ copy, to_spill, rld->reloader));
+ ARR_APP1(ir_node*, copies, copy);
}
- if(pset_count(values) > 0) {
- /* introduce copies, rewire the uses */
- pset_insert_ptr(values, si->spilled_node);
- be_ssa_constr_set_ignore(env->chordal_env->dom_front, env->chordal_env->lv, values, env->mem_phis);
+ /* if we had any reloads or remats, then we need to reconstruct the
+ * SSA form for the spilled value */
+ if (ARR_LEN(copies) > 0) {
+ be_ssa_construction_env_t senv;
+ /* be_lv_t *lv = be_get_birg_liveness(env->birg); */
+
+ be_ssa_construction_init(&senv, env->birg);
+ be_ssa_construction_add_copy(&senv, to_spill);
+ be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
+ be_ssa_construction_fix_users(&senv, to_spill);
+
+#if 0
+ /* no need to enable this as long as we invalidate liveness
+ after this function... */
+ be_ssa_construction_update_liveness_phis(&senv);
+ be_liveness_update(to_spill);
+ len = ARR_LEN(copies);
+ for(i = 0; i < len; ++i) {
+ be_liveness_update(lv, copies[i]);
+ }
+#endif
+ be_ssa_construction_destroy(&senv);
+ }
+ /* need to reconstruct SSA form if we had multiple spills */
+ if (si->spills != NULL && si->spills->next != NULL) {
+ spill_t *spill;
+ int spill_count = 0;
+
+ be_ssa_construction_env_t senv;
+
+ be_ssa_construction_init(&senv, env->birg);
+ spill = si->spills;
+ for( ; spill != NULL; spill = spill->next) {
+ /* maybe we rematerialized the value and need no spill */
+ if(spill->spill == NULL)
+ continue;
+ be_ssa_construction_add_copy(&senv, spill->spill);
+ spill_count++;
+ }
+ if(spill_count > 1) {
+ /* all reloads are attached to the first spill, fix them now */
+ be_ssa_construction_fix_users(&senv, si->spills->spill);
+ }
+
+ be_ssa_construction_destroy(&senv);
}
- del_pset(values);
+ DEL_ARR_F(copies);
+ 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);
+ stat_ev_dbl("spill_spills", env->spill_count);
+ stat_ev_dbl("spill_reloads", env->reload_count);
+ stat_ev_dbl("spill_remats", env->remat_count);
+ stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
+
+ /* Matze: In theory be_ssa_construction should take care of the liveness...
+ * try to disable this again in the future */
+ be_liveness_invalidate(env->birg->lv);
+
+ be_remove_dead_nodes_from_schedule(env->birg);
+
+ BE_TIMER_POP(t_ra_spill_apply);
}
+
+void be_init_spill(void)
+{
+ FIRM_DBG_REGISTER(dbg, "firm.be.spill");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);
projects / libfirm / blobdiff