X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespill.c;h=2d370a558b64347a7544a676b7662856d32e34a7;hb=2520206c7812537b08088ffac1aa6c94d1446ded;hp=2d7b656506756059698b7aa148a223586c89c881;hpb=7265436f72042fe59361e82eaffa79379fb5384b;p=libfirm diff --git a/ir/be/bespill.c b/ir/be/bespill.c index 2d7b65650..2d370a558 100644 --- a/ir/be/bespill.c +++ b/ir/be/bespill.c @@ -1,10 +1,28 @@ +/* + * 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" @@ -27,7 +45,9 @@ #include "pdeq.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" @@ -39,117 +59,126 @@ #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 -// 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 *can_spill_after; 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 */ +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; - /** 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 */ + 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 */ +}; -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; + 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; -} - -/** - * 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; + (void) size; - 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) { - info.reloaders = NULL; - info.spill = NULL; - info.old_spill = NULL; - info.reload_cls = 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; } -#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); @@ -165,27 +194,73 @@ void be_delete_spill_env(spill_env_t *env) { * */ -void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before, ir_node *rematted_node) { +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; + + DB((dbg, LEVEL_1, "Add spill of %+F before %+F\n", to_spill, 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->allow_remat = 1; + 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((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) +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; @@ -200,42 +275,65 @@ void be_add_reload(spill_env_t *env, ir_node *to_spill, ir_node *before, 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; - rel->allow_remat = allow_remat; + 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((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")); } +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); + +} + +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, *last; +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 @@ -247,32 +345,29 @@ static ir_node *get_block_insertion_point(ir_node *block, int pos) { /* We have to reload the value in pred-block */ predblock = get_Block_cfgpred_block(block, pos); - last = sched_last(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)); - } - - 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))); - } + return be_get_end_of_block_insertion_point(predblock); +} - // add the reload before the (cond-)jump - return 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); } -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_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; @@ -280,19 +375,24 @@ void be_spill_phi(spill_env_t *env, ir_node *node) { ir_nodeset_insert(&env->mem_phis, node); - // create spillinfos for the phi arguments + /* 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); + } - // 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; + be_add_spill(env, arg, insert); } } @@ -305,24 +405,7 @@ void be_spill_phi(spill_env_t *env, ir_node *node) { * |_| */ -/** - * 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. @@ -333,49 +416,43 @@ static void sched_add_after_insn(ir_node *sched_after, ir_node *node) { * * @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; - - DBG((env->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 - * - * 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)); - return; - } +static void spill_irn(spill_env_t *env, spill_info_t *spillinfo) +{ + ir_node *to_spill = spillinfo->to_spill; + spill_t *spill; - assert(!(arch_irn_is(env->arch_env, to_spill, dont_spill) - && "Attempt to spill a node marked 'dont_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 */ + /* some backends have virtual noreg/unknown nodes that are not scheduled + * and simply always available. */ if(!sched_is_scheduled(to_spill)) { - spillinfo->spill = new_NoMem(); + /* 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; } + DBG((dbg, LEVEL_1, "spilling %+F ... ", to_spill)); + spill = spillinfo->spills; + for( ; spill != NULL; spill = spill->next) { + ir_node *block = get_block(spill->before); + ir_node *before = spill->before; - /* - 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. - */ - 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)); - 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)); + /* place all spills before the reloads (as we can't guarantee the + * same order as the be_add_spill and be_add_reload calls */ + while(get_irn_idx(sched_prev(before)) > env->new_nodes_idx) { + before = sched_prev(before); + } + + 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); @@ -390,54 +467,51 @@ 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)); - DBG((env->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->irg); + ins[i] = unknown; } - spillinfo->spill = new_r_Phi(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); - } - DBG((env->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((env->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)); - - 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)); - set_irn_n(old_spill, be_pos_Spill_val, new_Bad()); - //sched_remove(old_spill); - spillinfo->old_spill = NULL; + 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)); } /** @@ -446,14 +520,15 @@ static void spill_phi(spill_env_t *env, spill_info_t *spillinfo) { * @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; + to_spill = spillinfo->to_spill; if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) { spill_phi(env, spillinfo); @@ -476,7 +551,9 @@ static void spill_node(spill_env_t *env, spill_info_t *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; @@ -486,7 +563,7 @@ static int is_value_available(spill_env_t *env, ir_node *arg, ir_node *reloader) 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; } @@ -498,12 +575,11 @@ static int is_value_available(spill_env_t *env, ir_node *arg, ir_node *reloader) 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 @@ -527,16 +603,13 @@ static int is_value_available(spill_env_t *env, ir_node *arg, ir_node *reloader) /** * 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(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; @@ -550,23 +623,28 @@ static int is_remat_node(spill_env_t *env, ir_node *node) { * - 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; @@ -576,29 +654,24 @@ static int check_remat_conditions_costs(spill_env_t *env, ir_node *spilled, ir_n 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; + 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, 0); - - return costs < REMAT_COST_LIMIT; -} - /** * Re-materialize a node. * @@ -606,7 +679,8 @@ static int check_remat_conditions(spill_env_t *env, ir_node *spilled, ir_node *r * @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; @@ -626,46 +700,67 @@ static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader) 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); + if (! is_Proj(res)) { + /* insert in schedule */ + sched_reset(res); + 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 *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; +} + +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->reload_cost * freq; +} - return env->spill_cost + env->reload_cost; +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; } -int be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int 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); } @@ -679,14 +774,104 @@ int be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *bl * */ -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; +/** + * 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 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; + + 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 */ @@ -698,38 +883,100 @@ void be_insert_spills_reloads(spill_env_t *env) { /* 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_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; + } - 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 = 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; + + DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n", + env->spill_cost, si->spill_costs)); + } + + 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++; - } + spill_node(env, si); - /* create a reload */ - copy = be_reload(arch_env, si->reload_cls, rld->reloader, mode, si->spill); - reloads++; + /* 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", - 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); } @@ -740,15 +987,15 @@ void be_insert_spills_reloads(spill_env_t *env) { /* be_lv_t *lv = be_get_birg_liveness(env->birg); */ be_ssa_construction_init(&senv, env->birg); - be_ssa_construction_add_copy(&senv, spilled_node); + be_ssa_construction_add_copy(&senv, to_spill); be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies)); - be_ssa_construction_fix_users(&senv, spilled_node); + 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(spilled_node); + be_liveness_update(to_spill); len = ARR_LEN(copies); for(i = 0; i < len; ++i) { be_liveness_update(lv, copies[i]); @@ -756,21 +1003,49 @@ void be_insert_spills_reloads(spill_env_t *env) { #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_ARR_F(copies); si->reloaders = NULL; } -#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); - } -#endif /* FIRM_STATISTICS */ + 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); - 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); + 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);