/*
- * 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) 1995-2007 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 $Id$
*/
#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 "entity_t.h"
#include "irgwalk.h"
#include "array.h"
#include "pdeq.h"
-#include "unionfind.h"
#include "execfreq.h"
+#include "irnodeset.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 "benodesets.h"
+#include "bespilloptions.h"
+#include "bestatevent.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
-#define REMAT_COST_LIMIT 4
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-/* This enables re-computation of values. Current state: Unfinished and buggy. */
-#undef BUGGY_REMAT
+#define REMAT_COST_INFINITE 1000
-typedef struct _reloader_t reloader_t;
-
-struct _reloader_t {
+typedef struct reloader_t reloader_t;
+struct reloader_t {
reloader_t *next;
- ir_node *reloader;
+ 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;
-
- ir_node *spill;
-} spill_info_t;
-
-struct _spill_env_t {
- const arch_register_class_t *cls;
- 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 */
+ 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 */
+};
- 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;
+
+#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 = nodeset_hash(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.old_spill = NULL;
+ 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->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_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_reload(spill_env_t *env, ir_node *to_spill, ir_node *before,
+ 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->chordal_env->birg->main_env->arch_env, env->cls, to_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);
}
+
+#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)
+ */
+ if (info->old_spill != NULL &&
+ (before == info->old_spill || value_dominates(before, info->old_spill)))
+ {
+ printf("spilledphi hack was needed...\n");
+ before = sched_next(info->old_spill);
+ }
+#endif
+ }
+
+ 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;
+ if(!allow_remat) {
+ rel->remat_cost_delta = REMAT_COST_INFINITE;
+ } else {
+ rel->remat_cost_delta = 0;
}
- 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);
+ 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;
+static ir_node *get_end_of_block_insertion_point(ir_node *block)
+{
+ ir_node *last = sched_last(block);
- /* 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)
- */
+ /* 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));
+ }
+
+ if(!is_cfop(last)) {
+ last = sched_next(last);
+ /* 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 */
+ return last;
+}
+
+/**
+ * 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 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, ir_node *block,
+ const arch_register_class_t *reload_cls,
+ int allow_remat)
+{
+ ir_node *before = 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)
+{
+ 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 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(spill->spill != NULL && !is_Phi(spill->spill)) {
+ assert(spill->old_spill == NULL);
+ spill->old_spill = spill->spill;
+ spill->spill = NULL;
+ }
}
/*
*/
/**
- * 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) {
- const be_main_env_t *mainenv = env->chordal_env->birg->main_env;
- 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, "%+F\n", 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 rematerialisation 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)) {
+ if (be_is_Reload(to_spill)) {
spillinfo->spill = get_irn_n(to_spill, be_pos_Reload_mem);
+ DB((dbg, LEVEL_1, "skip reload, using existing spill %+F\n", spillinfo->spill));
return;
}
- spillinfo->spill = be_spill(mainenv->arch_env, to_spill);
- sched_add_after_insn(to_spill, spillinfo->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 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((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((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((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->chordal_env->irg);
+ ins[i] = get_irg_bad(env->irg);
}
- spillinfo->spill = new_r_Phi(env->chordal_env->irg, block, arity, ins, mode_M);
+ 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((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi, spillinfo->spill));
+
+ /* 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((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((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((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); */
+ 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;
- 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, ir_node *arg, 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.
+ */
#if 0
/* we want to remat before the insn reloader
* thus an arguments is alive if
* - it interferes with the reloaders result
- * or
* - or it is (last-) used by reloader itself
*/
- int i, m;
-
- if (values_interfere(reloader, arg))
+ if (values_interfere(env->birg->lv, reloader, arg)) {
return 1;
+ }
- for (i=0, m=get_irn_arity(reloader); i<m; ++i) {
+ 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;
}
-
- /* arg is not alive before reloader */
- return 0;
#endif
- return 0;
+ return 0;
}
/**
* Checks whether the node can principally be rematerialized
*/
-static int is_remat_node(spill_env_t *env, ir_node *node) {
- const arch_env_t *arch_env = env->chordal_env->birg->main_env->arch_env;
+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(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, 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 if(is_Proj(spilled)) {
- costs += 0;
} else {
- costs += 1;
+ costs += arch_get_op_estimated_cost(env->arch_env, spilled);
+ }
+ if(parentcosts + costs >= env->reload_cost + env->spill_cost) {
+ return REMAT_COST_INFINITE;
}
- if(parentcosts + costs >= REMAT_COST_LIMIT)
- return REMAT_COST_LIMIT;
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;
+ 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));
- ir_printf("Insert remat %+F for %+F before reloader %+F(%s)\n", res, spilled, reloader, get_irg_dump_name(get_irn_irg(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 *after)
+{
+ ir_node *block = get_nodes_block(after);
+ double freq = get_block_execfreq(env->exec_freq, block);
+ (void) to_spill;
+
+ 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? */
+ int costs = check_remat_conditions_costs(env, to_spill, before, 0);
+ if(costs < env->reload_cost)
+ return costs * freq;
+ }
+
+ return env->reload_cost * freq;
+}
+
+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->chordal_env->birg->main_env->arch_env;
- spill_info_t *si;
+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 */
+ 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 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;
+ }
+
+ 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) {
+ 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));
+ }
- /* go through all reloads for this spill */
- for(rld = si->reloaders; rld; rld = rld->next) {
- ir_node *new_val;
+ if(all_remat_costs < 0) {
+ DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
+ all_remat_costs));
+ force_remat = 1;
+ }
+ }
- if (check_remat_conditions(env, si->spilled_node, rld->reloader)) {
- new_val = do_remat(env, si->spilled_node, rld->reloader);
+ /* 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);
+ if (si->spill == NULL) {
+ spill_node(env, si);
+ }
+
+ /* create a reload */
+ 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", 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);
}
- 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);
+}
+
+void be_init_spill(void)
+{
+ FIRM_DBG_REGISTER(dbg, "firm.be.spill");
}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);
projects / libfirm / blobdiff