X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespill.c;h=419e8ef07cdada5c18a59e89889f014982f02995;hb=1b4cac3471b02b63e9656cd8c876f067766fe482;hp=edebe354fb84064e250d7f357a1a83d552037b7a;hpb=44d51ff21a4a48494fd8e42dd10f5b489b4fca78;p=libfirm diff --git a/ir/be/bespill.c b/ir/be/bespill.c index edebe354f..419e8ef07 100644 --- a/ir/be/bespill.c +++ b/ir/be/bespill.c @@ -19,1078 +19,235 @@ /** * @file - * @brief implementation of the spill/reload placement abstraction layer - * @author Daniel Grund, Sebastian Hack, Matthias Braun - * @date 29.09.2005 - * @version $Id$ + * @brief Spill module selection; Preparation steps + * @author Matthias Braun + * @date 29.09.2005 */ -#ifdef HAVE_CONFIG_H #include "config.h" -#endif -#include -#include - -#include "pset.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 "irtools.h" #include "debug.h" +#include "iredges_t.h" +#include "raw_bitset.h" +#include "statev_t.h" #include "irgwalk.h" -#include "array.h" -#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" +#include "bemodule.h" +#include "be.h" #include "belive_t.h" -#include "benode_t.h" -#include "bechordal_t.h" -#include "bejavacoal.h" -#include "bespilloptions.h" -#include "bestatevent.h" -#include "bessaconstr.h" -#include "beirg_t.h" +#include "beirg.h" +#include "bearch.h" +#include "benode.h" +#include "besched.h" +#include "bera.h" #include "beintlive_t.h" -#include "bemodule.h" -#include "be_t.h" - -DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;) - -#define REMAT_COST_INFINITE 1000 - -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 remat_cost_delta; /** costs needed for rematerialization, - compared to placing a reload */ -}; - -typedef struct spill_t spill_t; -struct spill_t { - spill_t *next; - ir_node *after; /**< spill has to be placed after this node (or earlier) */ - ir_node *spill; -}; - -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 { - 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) -{ - const spill_info_t *xx = x; - const spill_info_t *yy = y; - (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) -{ - spill_info_t info, *res; - int hash = hash_irn(value); - - info.to_spill = value; - res = set_find(env->spills, &info, sizeof(info), hash); - if (res == 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; -} - -spill_env_t *be_new_spill_env(be_irg_t *birg) -{ - const arch_env_t *arch_env = birg->main_env->arch_env; - - 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 = arch_env; - ir_nodeset_init(&env->mem_phis); - env->spill_cost = arch_env->spill_cost; - env->reload_cost = arch_env->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; -} +#include "lc_opts.h" +#include "lc_opts_enum.h" -void be_delete_spill_env(spill_env_t *env) -{ - del_set(env->spills); - ir_nodeset_destroy(&env->mem_phis); - obstack_free(&env->obst, NULL); - free(env); -} +DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;) -/* - * ____ _ ____ _ _ - * | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___ - * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __| - * | __/| | (_| | (_| __/ | _ < __/ | (_) | (_| | (_| \__ \ - * |_| |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/ - * - */ +typedef struct be_pre_spill_env_t { + ir_graph *irg; + const arch_register_class_t *cls; +} be_pre_spill_env_t; + +static void prepare_constr_insn(be_pre_spill_env_t *env, ir_node *node) +{ + const arch_register_class_t *cls = env->cls; + ir_node *block = get_nodes_block(node); + const ir_graph *irg = env->irg; + be_irg_t *birg = be_birg_from_irg(irg); + be_lv_t *lv = be_get_irg_liveness(irg); + unsigned *def_constr = NULL; + int arity = get_irn_arity(node); + + /* Insert a copy for constraint inputs attached to a value which can't + * fulfill the constraint + * (typical example: stack pointer as input to copyb) + * TODO: This really just checks precolored registers at the moment and + * ignores the general case of not matching in/out constraints + */ + for (int i = 0; i < arity; ++i) { + ir_node *op = get_irn_n(node, i); + const arch_register_req_t *req = arch_get_irn_register_req_in(node, i); + const arch_register_t *reg; + ir_node *copy; -void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *after) -{ - spill_info_t *spill_info = get_spillinfo(env, to_spill); - spill_t *spill; - spill_t *s; - spill_t *last; + if (req->cls != cls) + continue; + reg = arch_get_irn_register(op); + if (reg == NULL) + continue; - assert(! arch_irn_is(env->arch_env, to_spill, dont_spill)); - DB((dbg, LEVEL_1, "Add spill of %+F after %+F\n", to_spill, after)); + /* Precolored with an ignore register (which is not virtual). */ + if (reg->type & arch_register_type_virtual || + rbitset_is_set(birg->allocatable_regs, reg->global_index)) + continue; - /* Just for safety make sure that we do not insert the spill in front of a phi */ - assert(!is_Phi(sched_next(after))); + if (!arch_register_req_is(req, limited)) + continue; + if (rbitset_is_set(req->limited, reg->index)) + continue; - /* 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->after, after)) { - DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->after)); - return; - } - /* remove spills that we dominate */ - if(value_dominates(after, s->after)) { - DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->after)); - if(last != NULL) { - last->next = s->next; - } else { - spill_info->spills = s->next; - } - } else { - last = s; - } + copy = be_new_Copy(block, op); + stat_ev_int("constr_copy", 1); + sched_add_before(node, copy); + set_irn_n(node, i, copy); + DBG((dbg, LEVEL_3, "inserting ignore arg copy %+F for %+F pos %d\n", + copy, node, i)); } - spill = obstack_alloc(&env->obst, sizeof(spill[0])); - spill->after = after; - spill->next = spill_info->spills; - spill->spill = NULL; - - spill_info->spills = spill; -} - -void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before, - ir_node *rematted_node) -{ - spill_info_t *spill_info; - reloader_t *reloader; - - spill_info = get_spillinfo(env, to_spill); - - /* add the remat information */ - reloader = obstack_alloc(&env->obst, sizeof(reloader[0])); - reloader->next = spill_info->reloaders; - reloader->reloader = before; - reloader->rematted_node = rematted_node; - reloader->remat_cost_delta = 0; /* We will never have a cost win over a - reload since we're not even allowed to - create a reload */ - - spill_info->reloaders = reloader; - - DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n", - to_spill, before)); -} - -void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before, - ir_node *can_spill_after, const arch_register_class_t *reload_cls, - int allow_remat) -{ - spill_info_t *info; - reloader_t *rel; - - assert(! arch_irn_is(env->arch_env, to_spill, dont_spill)); - - info = get_spillinfo(env, to_spill); - - if (is_Phi(to_spill)) { - int i, arity; + /* insert copies for nodes that occur constrained more than once. */ + be_foreach_use(node, cls, req, in, in_req_, + if (!arch_register_req_is(req, limited)) + continue; - /* 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); + for (int i2 = i_ + 1; i2 < arity; ++i2) { + ir_node *in2; + const arch_register_req_t *req2; + + req2 = arch_get_irn_register_req_in(node, i2); + if (req2->cls != cls) + continue; + if (!arch_register_req_is(req2, limited)) + continue; + + in2 = get_irn_n(node, i2); + if (in2 != in) + continue; + + /* if the constraint is the same, no copy is necessary + * TODO generalise unequal but overlapping constraints */ + if (rbitsets_equal(req->limited, req2->limited, cls->n_regs)) + continue; + + ir_node *copy = be_new_Copy(block, in); + stat_ev_int("constr_copy", 1); + + sched_add_before(node, copy); + set_irn_n(node, i2, copy); + DBG((dbg, LEVEL_3, + "inserting multiple constr copy %+F for %+F pos %d\n", + copy, node, i2)); } - } - - assert(!is_Proj(before) && !be_is_Keep(before)); - - /* put reload into list */ - rel = obstack_alloc(&env->obst, sizeof(rel[0])); - rel->next = info->reloaders; - rel->reloader = before; - rel->rematted_node = NULL; - rel->can_spill_after = can_spill_after; - rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE; + ); - info->reloaders = rel; - assert(info->reload_cls == NULL || info->reload_cls == reload_cls); - info->reload_cls = reload_cls; - - DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n", - to_spill, before, allow_remat ? "" : " not")); -} - -void be_add_reload(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) -{ - while(true) { - ir_node *next = sched_next(node); - if(!is_Phi(next) && !be_is_Keep(next)) - break; - node = next; - } - return node; -} - -/** - * Returns the point at which you can insert a node that should be executed - * before block @p block when coming from pred @p pos. - */ -static ir_node *get_block_insertion_point(ir_node *block, int pos) -{ - ir_node *predblock; - - /* simply add the reload to the beginning of the block if we only have 1 - * predecessor. We don't need to check for phis as there can't be any in a - * block with only 1 pred. */ - if(get_Block_n_cfgpreds(block) == 1) { - assert(!is_Phi(sched_first(block))); - return sched_first(block); - } - - /* We have to reload the value in pred-block */ - predblock = get_Block_cfgpred_block(block, pos); - return be_get_end_of_block_insertion_point(predblock); -} - -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) -{ - 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) -{ - ir_node *block; - spill_info_t* spill; - int i, arity; - - assert(is_Phi(node)); - - ir_nodeset_insert(&env->mem_phis, node); - - /* create spills for the phi arguments */ - block = get_nodes_block(node); - spill = get_spillinfo(env, node); - for(i = 0, arity = get_irn_arity(node); i < arity; ++i) { - ir_node *arg = get_irn_n(node, i); - 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); - insert = sched_prev(insert); - } else { - insert = skip_keeps_phis(arg); + /* collect all registers occurring in out constraints. */ + be_foreach_definition(node, cls, def, req, + (void)def; + if (!arch_register_req_is(req, limited)) + continue; + if (def_constr == NULL) { + def_constr = rbitset_alloca(cls->n_regs); } + rbitset_or(def_constr, req->limited, cls->n_regs); + ); - be_add_spill(env, arg, insert); - } -} - -/* - * ____ _ ____ _ _ _ - * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___ - * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __| - * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \ - * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/ - * |_| - */ - -static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo); - -/** - * Creates a spill. - * - * @param senv the spill environment - * @param irn the node that should be spilled - * @param ctx_irn an user of the spilled node - * - * @return a be_Spill node - */ -static void spill_irn(spill_env_t *env, spill_info_t *spillinfo) -{ - ir_node *to_spill = spillinfo->to_spill; - spill_t *spill; - - /* determine_spill_costs must have been run before */ - assert(spillinfo->spill_costs >= 0); - - /* some backends have virtual noreg/unknown nodes that are not scheduled - * and simply always available. */ - if(!sched_is_scheduled(to_spill)) { - /* override spillinfos or create a new one */ - spillinfo->spills->spill = new_NoMem(); - DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill)); + /* no output constraints => we're good */ + if (def_constr == NULL) { return; } - DBG((dbg, LEVEL_1, "spilling %+F ... \n", to_spill)); - spill = spillinfo->spills; - for( ; spill != NULL; spill = spill->next) { - ir_node *after = spill->after; - ir_node *block = get_block(after); - - after = skip_keeps_phis(after); - - spill->spill = be_spill(env->arch_env, block, to_spill); - sched_add_after(after, spill->spill); - DB((dbg, LEVEL_1, "\t%+F after %+F\n", spill->spill, after)); -#ifdef FIRM_STATISTICS - env->spill_count++; -#endif - } - DBG((dbg, LEVEL_1, "\n")); -} - -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 - * there is no sense in allocating a register for it. - * Thus we spill it and all its operands to the same spill slot. - * Therefore the phi/dataB becomes a phi/Memory - * - * @param senv the spill environment - * @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_graph *irg = env->irg; - ir_node *phi = spillinfo->to_spill; - ir_node *block = get_nodes_block(phi); - ir_node *unknown; - ir_node **ins; - spill_t *spill; - int i; - int arity; - - assert(is_Phi(phi)); - assert(!get_opt_cse()); - DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi)); - - /* build a new PhiM */ - 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] = unknown; - } - - /* override or replace spills list... */ - spill = obstack_alloc(&env->obst, sizeof(spill[0])); - spill->after = 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); - spill_info_t *arg_info = get_spillinfo(env, arg); - - determine_spill_costs(env, arg_info); - spill_node(env, arg_info); - - 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)); -} - -/** - * Spill a node. - * - * @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) -{ - ir_node *to_spill; - - /* node is already spilled */ - if(spillinfo->spills != NULL && spillinfo->spills->spill != NULL) - return; - - 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, const ir_node *arg, - const ir_node *reloader) -{ - if(is_Unknown(arg) || arg == new_NoMem()) - return 1; - - if(be_is_Spill(arg)) - return 1; - - if(arg == get_irg_frame(env->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 + * insert copies for all constrained arguments living through the node + * and being constrained to a register which also occurs in out constraints. */ - 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 it is (last-) used by reloader itself - */ - if (values_interfere(env->birg->lv, reloader, arg)) { - return 1; - } - - arity = get_irn_arity(reloader); - for (i = 0; i < arity; ++i) { - ir_node *rel_arg = get_irn_n(reloader, i); - if (rel_arg == arg) - return 1; - } -#endif - - return 0; -} - -/** - * Checks whether the node can principally be rematerialized - */ -static int is_remat_node(spill_env_t *env, 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; - - return 0; -} - -/** - * Check if a node is rematerializable. This tests for the following conditions: - * - * - The node itself is rematerializable - * - All arguments of the node are available or also rematerialisable - * - The costs for the rematerialisation operation is less or equal a limit - * - * Returns the costs needed for rematerialisation or something - * >= REMAT_COST_INFINITE if remat is not possible. - */ -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_INFINITE; - - if(be_is_Reload(spilled)) { - costs += 2; - } else { - costs += arch_get_op_estimated_cost(env->arch_env, spilled); - } - 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; - } + unsigned *const tmp = rbitset_alloca(cls->n_regs); + be_foreach_use(node, cls, req, in, in_req_, + /* Check, if + * 1) the operand is constrained. + * 2) lives through the node. + * 3) is constrained to a register occurring in out constraints. + */ + if (!arch_register_req_is(req, limited)) + continue; + if (!be_values_interfere(lv, node, in)) + continue; - argremats = 0; - for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) { - ir_node *arg = get_irn_n(spilled, i); + rbitset_copy(tmp, req->limited, cls->n_regs); + rbitset_and(tmp, def_constr, cls->n_regs); - if(is_value_available(env, arg, reloader)) + if (rbitset_is_empty(tmp, cls->n_regs)) continue; - /* 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_INFINITE; - } - argremats++; - - costs += check_remat_conditions_costs(env, arg, reloader, - parentcosts + costs); - if(parentcosts + costs >= env->reload_cost + env->spill_cost) - return REMAT_COST_INFINITE; - } + /* + * only create the copy if the operand is no copy. + * this is necessary since the assure constraints phase inserts + * Copies and Keeps for operands which must be different from the + * results. Additional copies here would destroy this. + */ + if (be_is_Copy(in)) + continue; - return costs; + ir_node *copy = be_new_Copy(block, in); + sched_add_before(node, copy); + set_irn_n(node, i_, copy); + DBG((dbg, LEVEL_3, "inserting constr copy %+F for %+F pos %d\n", + copy, node, i_)); + be_liveness_update(lv, in); + ); } -/** - * Re-materialize a node. - * - * @param senv the spill environment - * @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 void pre_spill_prepare_constr_walker(ir_node *block, void *data) { - int i, arity; - ir_node *res; - 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); - - if(is_value_available(env, arg, 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); - copy_node_attr(spilled, res); - new_backedge_info(res); - - DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader)); - - if (! is_Proj(res)) { - /* insert in schedule */ - sched_reset(res); - sched_add_before(reloader, res); -#ifdef FIRM_STATISTICS - env->remat_count++; -#endif + be_pre_spill_env_t *env = (be_pre_spill_env_t*)data; + sched_foreach(block, node) { + prepare_constr_insn(env, node); } - - return res; } -double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before) +void be_pre_spill_prepare_constr(ir_graph *irg, + const arch_register_class_t *cls) { - ir_node *block = get_nodes_block(before); - double freq = get_block_execfreq(env->exec_freq, block); - (void) to_spill; - - return env->spill_cost * freq; -} + be_pre_spill_env_t env; + memset(&env, 0, sizeof(env)); + env.irg = irg; + env.cls = cls; -unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill, - const ir_node *before) -{ - if(be_do_remats) { - /* is the node rematerializable? */ - unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0); - if(costs < (unsigned) env->reload_cost) - return costs; - } + be_assure_live_sets(irg); - return env->reload_cost; + irg_block_walk_graph(irg, pre_spill_prepare_constr_walker, NULL, &env); } -double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before) -{ - ir_node *block = get_nodes_block(before); - double freq = get_block_execfreq(env->exec_freq, block); - - if(be_do_remats) { - /* is the node rematerializable? */ - int costs = check_remat_conditions_costs(env, to_spill, before, 0); - if(costs < env->reload_cost) - return costs * freq; - } - return env->reload_cost * freq; -} -int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat, - const ir_node *before) -{ - return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE; -} +int be_coalesce_spill_slots = 1; +int be_do_remats = 1; -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); -} +static const lc_opt_table_entry_t be_spill_options[] = { + LC_OPT_ENT_BOOL ("coalesce_slots", "coalesce the spill slots", &be_coalesce_spill_slots), + LC_OPT_ENT_BOOL ("remat", "try to rematerialize values instead of reloading", &be_do_remats), + LC_OPT_LAST +}; -/* - * ___ _ ____ _ _ - * |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___ - * | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __| - * | || | | \__ \ __/ | | |_ | _ < __/ | (_) | (_| | (_| \__ \ - * |___|_| |_|___/\___|_| \__| |_| \_\___|_|\___/ \__,_|\__,_|___/ - * - */ +static be_module_list_entry_t *spillers = NULL; +static const be_spiller_t *selected_spiller = NULL; -/** - * 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) +void be_register_spiller(const char *name, be_spiller_t *spiller) { - 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->after = 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 = get_block(s->after); - double 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->after = 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)); + if (selected_spiller == NULL) + selected_spiller = spiller; + be_add_module_to_list(&spillers, name, spiller); } -void make_spill_locations_dominate_irn(spill_env_t *env, ir_node *irn) +void be_do_spill(ir_graph *irg, const arch_register_class_t *cls) { - const spill_info_t *si = get_spillinfo(env, irn); - ir_node *start_block = get_irg_start_block(get_irn_irg(irn)); - int n_blocks = get_Block_dom_max_subtree_pre_num(start_block); - bitset_t *reloads = bitset_alloca(n_blocks); - reloader_t *r; - spill_t *s; - - if (si == NULL) - return; - - /* Fill the bitset with the dominance pre-order numbers - * of the blocks the reloads are located in. */ - for (r = si->reloaders; r != NULL; r = r->next) { - ir_node *bl = get_nodes_block(r->reloader); - bitset_set(reloads, get_Block_dom_tree_pre_num(bl)); - } + assert(selected_spiller != NULL); - /* Now, cancel out all the blocks that are dominated by each spill. - * If the bitset is not empty after that, we have reloads that are - * not dominated by any spill. */ - for (s = si->spills; s != NULL; s = s->next) { - ir_node *bl = get_nodes_block(s->after); - int start = get_Block_dom_tree_pre_num(bl); - int end = get_Block_dom_max_subtree_pre_num(bl); - - bitset_clear_range(reloads, start, end); - } - - if (!bitset_is_empty(reloads)) - be_add_spill(env, si->to_spill, si->to_spill); + selected_spiller->spill(irg, cls); } -void be_insert_spills_reloads(spill_env_t *env) +BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spilloptions) +void be_init_spilloptions(void) { - const arch_env_t *arch_env = env->arch_env; - const ir_exec_freq *exec_freq = env->exec_freq; - spill_info_t *si; - ir_nodeset_iterator_t iter; - ir_node *node; - - BE_TIMER_PUSH(t_ra_spill_apply); - - /* 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 */ - for (si = set_first(env->spills); si; si = set_next(env->spills)) { - reloader_t *rld; - 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; + lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be"); + lc_opt_entry_t *spill_grp = lc_opt_get_grp(be_grp, "spill"); - 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; - } + lc_opt_add_table(spill_grp, be_spill_options); + be_add_module_list_opt(be_grp, "spiller", "spill algorithm", + &spillers, (void**) &selected_spiller); - 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 != 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); - - /* 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((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) { - be_ssa_construction_env_t senv; - /* be_lv_t *lv = be_get_birg_liveness(env->birg); */ - - be_ssa_construction_init(&senv, env->birg); - be_ssa_construction_add_copy(&senv, to_spill); - be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies)); - be_ssa_construction_fix_users(&senv, to_spill); - -#if 0 - /* no need to enable this as long as we invalidate liveness - after this function... */ - be_ssa_construction_update_liveness_phis(&senv); - be_liveness_update(to_spill); - len = ARR_LEN(copies); - for(i = 0; i < len; ++i) { - be_liveness_update(lv, copies[i]); - } -#endif - be_ssa_construction_destroy(&senv); - } - /* need to reconstruct SSA form if we had multiple spills */ - if (si->spills != NULL && si->spills->next != NULL) { - spill_t *spill; - int spill_count = 0; - - be_ssa_construction_env_t senv; - - be_ssa_construction_init(&senv, env->birg); - spill = si->spills; - for( ; spill != NULL; spill = spill->next) { - /* maybe we rematerialized the value and need no spill */ - if(spill->spill == NULL) - continue; - be_ssa_construction_add_copy(&senv, spill->spill); - spill_count++; - } - if(spill_count > 1) { - /* all reloads are attached to the first spill, fix them now */ - be_ssa_construction_fix_users(&senv, si->spills->spill); - } - - be_ssa_construction_destroy(&senv); - } - - DEL_ARR_F(copies); - si->reloaders = NULL; - } - - stat_ev_dbl("spill_spills", env->spill_count); - stat_ev_dbl("spill_reloads", env->reload_count); - stat_ev_dbl("spill_remats", env->remat_count); - stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count); - - /* Matze: In theory be_ssa_construction should take care of the liveness... - * try to disable this again in the future */ - be_liveness_invalidate(env->birg->lv); - - be_remove_dead_nodes_from_schedule(env->birg); - - BE_TIMER_POP(t_ra_spill_apply); + FIRM_DBG_REGISTER(dbg, "firm.be.spillprepare"); } - -void be_init_spill(void) -{ - FIRM_DBG_REGISTER(dbg, "firm.be.spill"); -} - -BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);