+/*
+ * Copyright (C) 1995-2007 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 $Id$
- * Copyright: (c) Universitaet Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#include "execfreq.h"
#include "irnodeset.h"
+#include "bearch_t.h"
#include "belive_t.h"
#include "besched_t.h"
#include "bespill.h"
#include "benodesets.h"
#include "bespilloptions.h"
#include "bestatevent.h"
-#include "beirgmod.h"
+#include "bessaconstr.h"
+#include "beirg_t.h"
+#include "beintlive_t.h"
+#include "bemodule.h"
-// only rematerialise when costs are less than REMAT_COST_LIMIT
-// TODO determine a good value here...
-#define REMAT_COST_LIMIT 10
+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 *rematted_node;
- int allow_remat; /**< the node may be rematted instead of reloaded if global remat option is on */
+ int remat_cost_delta; /** costs needed for rematerialization,
+ compared to placing a reload */
};
-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;
-
- /** the register class in which the reload should be placed */
- const arch_register_class_t *reload_cls;
-} spill_info_t;
+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 */
+ ir_node *spill; /**< the spill node, or a PhiM node */
+ ir_node *old_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 */
+ const arch_register_class_t *reload_cls; /** the register class in which the
+ reload should be placed */
+};
-struct _spill_env_t {
+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 special spilled phis. allocated and freed separately */
-
- DEBUG_ONLY(firm_dbg_module_t *dbg;)
+ 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;
+
+#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;
-}
-
-/**
- * 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);
+ 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 = nodeset_hash(value);
- info.spilled_node = value;
+ info.to_spill = value;
res = set_find(env->spills, &info, sizeof(info), hash);
if (res == NULL) {
return res;
}
-#ifdef DEBUG_libfirm
-/* 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;
-}
-#endif
+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(be_irg_t *birg) {
spill_env_t *env = xmalloc(sizeof(env[0]));
env->spills = new_set(cmp_spillinfo, 1024);
env->irg = be_get_birg_irg(birg);
env->birg = birg;
- env->arch_env = birg->main_env->arch_env;
+ env->arch_env = arch_env;
ir_nodeset_init(&env->mem_phis);
- // TODO, ask backend about costs..., or even ask backend whether we should
- // rematerialize...
- env->spill_cost = 8;
- env->reload_cost = 5;
+ 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);
ir_nodeset_destroy(&env->mem_phis);
obstack_free(&env->obst, NULL);
*
*/
-void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before, ir_node *rematted_node) {
+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;
reloader->next = spill_info->reloaders;
reloader->reloader = before;
reloader->rematted_node = rematted_node;
- reloader->allow_remat = 1;
+ 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((env->dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
+ DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
to_spill, before));
}
void be_add_reload(spill_env_t *env, ir_node *to_spill, ir_node *before,
- const arch_register_class_t *reload_cls, int allow_remat)
+ const arch_register_class_t *reload_cls, int allow_remat)
{
spill_info_t *info;
reloader_t *rel;
}
#if 1
- // hackery... sometimes the morgan algo spilled the value of a phi,
- // the belady algo decides later to spill the whole phi, then sees the
- // spill node and adds a reload for that spill node, problem is the
- // reload gets attach to that same spill (and is totally unnecessary)
+ /* hackery... sometimes the morgan algo spilled the value of a phi,
+ * the belady algo decides later to spill the whole phi, then sees the
+ * spill node and adds a reload for that spill node, problem is the
+ * reload gets attach to that same spill (and is totally unnecessary)
+ */
if (info->old_spill != NULL &&
(before == info->old_spill || value_dominates(before, info->old_spill)))
{
rel->next = info->reloaders;
rel->reloader = before;
rel->rematted_node = NULL;
- rel->allow_remat = allow_remat;
+ if(!allow_remat) {
+ rel->remat_cost_delta = REMAT_COST_INFINITE;
+ } else {
+ rel->remat_cost_delta = 0;
+ }
info->reloaders = rel;
assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
info->reload_cls = reload_cls;
- DBG((env->dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
+ DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
to_spill, before, allow_remat ? "" : " not"));
}
-static ir_node *get_reload_insertion_point(ir_node *block, int pos) {
+/**
+ * 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, *last;
- /* 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)
- */
+ /* 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)));
return sched_first(block);
if(!is_cfop(last)) {
last = sched_next(last);
- // last node must be a cfop, only exception is the start block
+ /* last node must be a cfop, only exception is the start block */
assert(last == get_irg_start_block(get_irn_irg(block)));
}
- // add the reload before the (cond-)jump
+ /* add the reload before the (cond-)jump */
return 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)
+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_reload_insertion_point(block, pos);
+ 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)
+{
spill_info_t* spill;
int i, arity;
ir_nodeset_insert(&env->mem_phis, node);
- // create spillinfos for the phi arguments
+ /* create spillinfos for the phi arguments */
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 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)) {
assert(spill->old_spill == NULL);
spill->old_spill = spill->spill;
*/
/**
- * 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
+ * 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) {
+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)) {
+ while(is_Proj(next) || is_Phi(next) || be_is_Keep(next)) {
next = sched_next(next);
}
assert(next != NULL);
*
* @return a be_Spill node
*/
-static void spill_irn(spill_env_t *env, spill_info_t *spillinfo) {
- optimization_state_t opt;
- ir_node *to_spill = spillinfo->spilled_node;
+static
+void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
+{
+ optimization_state_t opt;
+ ir_node *to_spill = spillinfo->to_spill;
- DBG((env->dbg, LEVEL_1, "spilling %+F ... ", to_spill));
+ DBG((dbg, LEVEL_1, "spilling %+F ... ", 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)
+ * Normally reloads get simply rematerialized instead of spilled again; this
+ * can happen annyway when the reload is the pred of a phi to spill)
*/
if (be_is_Reload(to_spill)) {
spillinfo->spill = get_irn_n(to_spill, be_pos_Reload_mem);
- DB((env->dbg, LEVEL_1, "skip reload, using existing spill %+F\n", spillinfo->spill));
+ DB((dbg, LEVEL_1, "skip reload, using existing spill %+F\n", spillinfo->spill));
return;
}
- if (arch_irn_is(env->arch_env, to_spill, dont_spill)) {
- assert(0 && "Attempt to spill a node marked 'dont_spill'");
+ assert(!(arch_irn_is(env->arch_env, to_spill, dont_spill)
+ && "Attempt to spill a node marked 'dont_spill'"));
+
+ /* some backends have virtual noreg/unknown nodes that are not scheduled */
+ if(!sched_is_scheduled(to_spill)) {
+ spillinfo->spill = new_NoMem();
+ return;
}
+
/*
- We switch on optimizations here to get CSE. This is needed as some backends
- have some extra spill phases and we want to make use of those spills instead
- of creating new ones.
- */
+ * We switch on optimizations here to get CSE. This is needed as the STA
+ * backends has some extra spill phases and we want to make use of those
+ * spills instead of creating new ones.
+ */
save_optimization_state(&opt);
set_optimize(1);
spillinfo->spill = be_spill(env->arch_env, to_spill);
restore_optimization_state(&opt);
if (! sched_is_scheduled(spillinfo->spill)) {
- DB((env->dbg, LEVEL_1, "add spill %+F after %+F\n", spillinfo->spill, to_spill));
+ DB((dbg, LEVEL_1, "add spill %+F after %+F\n", spillinfo->spill, to_spill));
+#ifdef FIRM_STATISTICS
+ env->spill_count++;
+#endif
sched_add_after_insn(to_spill, spillinfo->spill);
- }
- else {
- DB((env->dbg, LEVEL_1, "re-using spill %+F after %+F\n", spillinfo->spill, to_spill));
+ } else {
+ DB((dbg, LEVEL_1, "re-using spill %+F after %+F\n", spillinfo->spill, to_spill));
}
}
-static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
+static
+void spill_node(spill_env_t *env, spill_info_t *spillinfo);
/**
* If the first usage of a Phi result would be out of memory
* @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;
+static
+void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
+{
+ ir_node *phi = spillinfo->to_spill;
int i;
int arity = get_irn_arity(phi);
ir_node *block = get_nodes_block(phi);
assert(is_Phi(phi));
- DBG((env->dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
+ DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
/* build a new PhiM */
ins = alloca(sizeof(ir_node*) * arity);
for(i = 0; i < arity; ++i) {
ins[i] = get_irg_bad(env->irg);
}
spillinfo->spill = new_r_Phi(env->irg, block, arity, ins, mode_M);
+#ifdef FIRM_STATISTICS
+ env->spilled_phi_count++;
+#endif
for(i = 0; i < arity; ++i) {
ir_node *arg = get_irn_n(phi, i);
set_irn_n(spillinfo->spill, i, arg_info->spill);
}
- DBG((env->dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi, spillinfo->spill));
+ DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi, spillinfo->spill));
- // rewire reloads from old_spill to phi
+ /* rewire reloads from old_spill to phi */
if (spillinfo->old_spill != NULL) {
const ir_edge_t *edge, *next;
ir_node *old_spill = spillinfo->old_spill;
- DBG((env->dbg, LEVEL_1, "old spill found, rewiring reloads:\n"));
+ DBG((dbg, LEVEL_1, "old spill found, rewiring reloads:\n"));
foreach_out_edge_safe(old_spill, edge, next) {
ir_node *reload = get_edge_src_irn(edge);
int pos = get_edge_src_pos(edge);
- DBG((env->dbg, LEVEL_1, "\tset input %d of %+F to %+F\n", pos, reload, spillinfo->spill));
+ DBG((dbg, LEVEL_1, "\tset input %d of %+F to %+F\n", pos, reload, spillinfo->spill));
assert(be_is_Reload(reload) || is_Phi(reload));
set_irn_n(reload, pos, spillinfo->spill);
}
- DBG((env->dbg, LEVEL_1, "\tset input of %+F to BAD\n", old_spill));
+ DBG((dbg, LEVEL_1, "\tset input of %+F to BAD\n", old_spill));
set_irn_n(old_spill, be_pos_Spill_val, new_Bad());
- //sched_remove(old_spill);
+ /* sched_remove(old_spill); */
spillinfo->old_spill = NULL;
}
}
* @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...
+ /* the node should be tagged for spilling already... */
if(spillinfo->spill != NULL)
return;
- to_spill = spillinfo->spilled_node;
- assert(sched_is_scheduled(to_spill) && "Node to be spilled must be scheduled!");
+ to_spill = spillinfo->to_spill;
+
if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
spill_phi(env, spillinfo);
} else {
* 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, ir_node *arg, ir_node *reloader)
+{
if(is_Unknown(arg) || arg == new_NoMem())
return 1;
if(arg == get_irg_frame(env->irg))
return 1;
- // hack for now (happens when command should be inserted at end of block)
+ /* hack for now (happens when command should be inserted at end of block) */
if(is_Block(reloader)) {
return 0;
}
return 1;
}
-#if 0
/* the following test does not work while spilling,
* because the liveness info is not adapted yet to the effects of the
* additional spills/reloads.
*/
-
+#if 0
/* we want to remat before the insn reloader
* thus an arguments is alive if
* - it interferes with the reloaders result
/**
* 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, ir_node *node)
+{
const arch_env_t *arch_env = env->arch_env;
assert(!be_is_Spill(node));
- if(arch_irn_is(arch_env, node, rematerializable)) {
- return 1;
- }
-
- if(be_is_StackParam(node))
+ if(arch_irn_is(arch_env, node, rematerializable))
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, ir_node *spilled,
+ 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;
}
argremats = 0;
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++;
costs += check_remat_conditions_costs(env, arg, reloader, parentcosts + costs);
- if(parentcosts + costs >= REMAT_COST_LIMIT)
- return REMAT_COST_LIMIT;
+ 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, 0);
-
- 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;
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->irg, bl,
- get_irn_op(spilled),
- get_irn_mode(spilled),
- get_irn_arity(spilled),
- ins);
+ get_irn_op(spilled), get_irn_mode(spilled),
+ get_irn_arity(spilled), ins);
copy_node_attr(spilled, res);
new_backedge_info(res);
sched_reset(res);
- DBG((env->dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
+ DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
/* insert in schedule */
sched_add_before(reloader, res);
+#ifdef FIRM_STATISTICS
+ env->remat_count++;
+#endif
return res;
}
-int be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before) {
- spill_info_t *spill_info;
+double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *after)
+{
+ ir_node *block = get_nodes_block(after);
+ double freq = get_block_execfreq(env->exec_freq, block);
+
+ return env->spill_cost * freq;
+}
+
+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?
+ /* is the node rematerializable? */
int costs = check_remat_conditions_costs(env, to_spill, before, 0);
- if(costs < REMAT_COST_LIMIT)
- return costs;
+ if(costs < env->reload_cost)
+ return costs * freq;
}
- // 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;
+ return env->reload_cost * freq;
}
-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);
+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;
- int remats = 0;
- int reloads = 0;
- int spills = 0;
- spill_info_t *si;
- ir_nodeset_iterator_t iter;
- ir_node *node;
+void be_insert_spills_reloads(spill_env_t *env)
+{
+ 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;
/* create all phi-ms first, this is needed so, that phis, hanging on
spilled phis work correctly */
/* process each spilled node */
for (si = set_first(env->spills); si; si = set_next(env->spills)) {
reloader_t *rld;
- ir_node *spilled_node = si->spilled_node;
- ir_mode *mode = get_irn_mode(spilled_node);
- ir_node **copies = NEW_ARR_F(ir_node*, 0);
+ 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 possibility of rematerialisations */
+ if(be_do_remats) {
+ 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;
+ }
- DBG((env->dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", spilled_node));
+ 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 = 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) {
+ ir_node *block = get_nodes_block(to_spill);
+ double freq = get_block_execfreq(exec_freq, block);
+ /* we don't need the costs for the spill if we can remat
+ all reloaders */
+ all_remat_costs -= env->spill_cost * freq;
+
+ DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
+ env->spill_cost, env->spill_cost * freq));
+ }
+
+ 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; rld = rld->next) {
- ir_node *copy; /* a reaload is a "copy" of the original value */
+ 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;
- remats++;
sched_add_before(rld->reloader, copy);
- } else if (be_do_remats && rld->allow_remat &&
- check_remat_conditions(env, spilled_node, rld->reloader)) {
- copy = do_remat(env, spilled_node, rld->reloader);
- remats++;
+ } 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 */
if (si->spill == NULL) {
spill_node(env, si);
- spills++;
}
/* create a reload */
- copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode, si->spill);
- reloads++;
+ copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode,
+ si->spill);
+#ifdef FIRM_STATISTICS
+ env->reload_count++;
+#endif
}
- DBG((env->dbg, LEVEL_1, " %+F of %+F before %+F\n",
- copy, spilled_node, rld->reloader));
+ DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
+ copy, to_spill, rld->reloader));
ARR_APP1(ir_node*, copies, copy);
}
/* if we had any reloads or remats, then we need to reconstruct the
* SSA form for the spilled value */
if (ARR_LEN(copies) > 0) {
- /* Matze: used mem_phis as ignore uses in the past, I don't see how
- one of the mem_phis can be a use of the spilled value...
- so I changed this to NULL now */
- be_ssa_construction(
- be_get_birg_dom_front(env->birg),
- be_get_birg_liveness(env->birg),
- spilled_node, ARR_LEN(copies), copies,
- NULL, 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);
}
DEL_ARR_F(copies);
#ifdef FIRM_STATISTICS
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_stat_ev("spill_spills", env->spill_count);
+ be_stat_ev("spill_reloads", env->reload_count);
+ be_stat_ev("spill_remats", env->remat_count);
+ be_stat_ev("spill_spilled_phis", env->spilled_phi_count);
}
-#endif /* FIRM_STATISTICS */
+#endif
be_remove_dead_nodes_from_schedule(env->irg);
- /* Matze: In theory be_ssa_construction should take care of the livenes...
+ /* Matze: In theory be_ssa_construction should take care of the liveness...
* try to disable this again in the future */
be_invalidate_liveness(env->birg);
}
+
+void be_init_spill(void)
+{
+ FIRM_DBG_REGISTER(dbg, "firm.be.spill");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);