X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Fbe%2Fbespill.c;h=aed7513e00092546e122d9e534b50e3ba77eb33e;hb=6ee1fce95429dbf57fda4455ca5f2cf011ac8190;hp=26569538fe01a84e4b646fbc54ed91d9aceda411;hpb=128a7b6a76583aff8c92ff2a9d639240485226db;p=libfirm diff --git a/ir/be/bespill.c b/ir/be/bespill.c index 26569538f..aed7513e0 100644 --- a/ir/be/bespill.c +++ b/ir/be/bespill.c @@ -1,545 +1,239 @@ /* - * 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. + * This file is part of libFirm. + * Copyright (C) 2012 University of Karlsruhe. */ -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif -#include +/** + * @file + * @brief Spill module selection; Preparation steps + * @author Matthias Braun + * @date 29.09.2005 + */ +#include "config.h" -#include "pset.h" -#include "irnode_t.h" -#include "ircons_t.h" -#include "iredges_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 "unionfind.h" -#include "execfreq.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" - -// only rematerialise when costs are less than REMAT_COST_LIMIT -// TODO determine a good value here... -#define REMAT_COST_LIMIT 80 - -typedef struct _reloader_t reloader_t; +#include "beirg.h" +#include "bearch.h" +#include "benode.h" +#include "besched.h" +#include "bera.h" +#include "beintlive_t.h" -struct _reloader_t { - reloader_t *next; - ir_node *reloader; -}; - -typedef struct _spill_info_t { - ir_node *spilled_node; - reloader_t *reloaders; +#include "lc_opts.h" +#include "lc_opts_enum.h" - ir_node *spill; -} spill_info_t; +DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;) -struct _spill_env_t { +typedef struct be_pre_spill_env_t { + ir_graph *irg; const arch_register_class_t *cls; - const arch_env_t *arch_env; - const be_chordal_env_t *chordal_env; - struct obstack obst; - set *spills; /**< all spill_info_t's, which must be placed */ - pset *mem_phis; /**< set of all special spilled phis. allocated and freed separately */ - - DEBUG_ONLY(firm_dbg_module_t *dbg;) -}; +} 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; -/** - * 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; - return xx->spilled_node != yy->spilled_node; -} + if (req->cls != cls) + continue; + reg = arch_get_irn_register(op); + if (reg == NULL) + continue; -/** - * 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_PTR(value); + /* 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; - info.spilled_node = value; - res = set_find(env->spills, &info, sizeof(info), hash); + if (!arch_register_req_is(req, limited)) + continue; + if (rbitset_is_set(req->limited, reg->index)) + continue; - if (res == NULL) { - info.reloaders = NULL; - info.spill = NULL; - res = set_insert(env->spills, &info, sizeof(info), hash); + 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)); } - 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; -} -) - -/* Creates a new spill environment. */ -spill_env_t *be_new_spill_env(const be_chordal_env_t *chordal_env) { - spill_env_t *env = xmalloc(sizeof(env[0])); - env->spills = new_set(cmp_spillinfo, 1024); - env->cls = chordal_env->cls; - env->chordal_env = chordal_env; - env->arch_env = env->chordal_env->birg->main_env->arch_env; - env->mem_phis = pset_new_ptr_default(); - obstack_init(&env->obst); - return env; -} - -/* Deletes a spill environment. */ -void be_delete_spill_env(spill_env_t *env) { - del_set(env->spills); - del_pset(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) { - spill_info_t *info; - reloader_t *rel; - - assert(sched_is_scheduled(before)); - assert(arch_irn_consider_in_reg_alloc(env->arch_env, env->cls, to_spill)); - - info = get_spillinfo(env, to_spill); + /* 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; - 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) { - 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)); } - } - - 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); -} + ); -void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) { - ir_node *predblock, *last; + /* 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); + ); - /* 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)); + /* no output constraints => we're good */ + if (def_constr == NULL) { return; } - /* 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)); - } - assert(is_cfop(last)); - - // add the reload before the (cond-)jump - be_add_reload(env, to_spill, last); -} - -void be_spill_phi(spill_env_t *env, ir_node *node) { - int i, arity; - - assert(is_Phi(node)); - - pset_insert_ptr(env->mem_phis, node); - - // create spillinfos for the phi arguments - 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); - } -} - -/* - * ____ _ ____ _ _ _ - * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___ - * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __| - * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \ - * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/ - * |_| - */ - -/** - * 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); - } -} - -/** - * 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->spilled_node; - - DBG((env->dbg, LEVEL_1, "%+F\n", to_spill)); - - /* Trying to spill an already spilled value, no need for a new spill - * node then, we can simply connect to the same one for this reload - * - * (although rematerialization code should handle most of these cases - * this can still happen when spilling Phis) + /* + * insert copies for all constrained arguments living through the node + * and being constrained to a register which also occurs in out constraints. */ - if(be_is_Reload(to_spill)) { - spillinfo->spill = get_irn_n(to_spill, be_pos_Reload_mem); - return; - } - - if (arch_irn_is(env->arch_env, to_spill, dont_spill)) { - if (env->chordal_env->opts->vrfy_option == BE_CH_VRFY_WARN) - ir_fprintf(stderr, "Verify warning: spilling 'dont_spill' node %+F\n", to_spill); - else if (env->chordal_env->opts->vrfy_option == BE_CH_VRFY_ASSERT) - assert(0 && "Attempt to spill a node marked 'dont_spill'"); - } - - spillinfo->spill = be_spill(env->arch_env, to_spill); - sched_add_after_insn(to_spill, spillinfo->spill); -} - -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_node *phi = spillinfo->spilled_node; - int i; - int arity = get_irn_arity(phi); - ir_node *block = get_nodes_block(phi); - ir_node **ins; - - assert(is_Phi(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); - } - spillinfo->spill = new_r_Phi(env->chordal_env->irg, block, arity, ins, mode_M); - - for(i = 0; i < arity; ++i) { - ir_node *arg = get_irn_n(phi, i); - spill_info_t *arg_info = get_spillinfo(env, arg); - - spill_node(env, arg_info); + 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; - set_irn_n(spillinfo->spill, i, arg_info->spill); - } -} + rbitset_copy(tmp, req->limited, cls->n_regs); + rbitset_and(tmp, def_constr, cls->n_regs); -/** - * 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; + if (rbitset_is_empty(tmp, cls->n_regs)) + continue; - // the node should be tagged for spilling already... - if(spillinfo->spill != NULL) - return; + /* + * 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; - to_spill = spillinfo->spilled_node; - if (is_Phi(to_spill) && pset_find_ptr(env->mem_phis, spillinfo->spilled_node)) { - spill_phi(env, spillinfo); - } else { - spill_irn(env, spillinfo); - } + 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); + ); } -/* - * - * ____ _ _ _ _ - * | _ \ ___ _ __ ___ __ _| |_ ___ _ __(_) __ _| (_)_______ - * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_ / _ \ - * | _ < __/ | | | | | (_| | || __/ | | | (_| | | |/ / __/ - * |_| \_\___|_| |_| |_|\__,_|\__\___|_| |_|\__,_|_|_/___\___| - * - */ - -/** - * 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) { - 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)) - return 1; - - /* the following test does not work while spilling, - * because the liveness info is not adapted yet to the effects of the - * additional spills/reloads. - * - * So we can only do this test for ignore registers (of our register class) - */ - if(arch_get_irn_reg_class(env->arch_env, arg, -1) == env->chordal_env->cls - && arch_irn_is(env->arch_env, arg, ignore)) { - int i, arity; - - /* we want to remat before the insn reloader - * thus an arguments is alive if - * - it interferes with the reloaders result - * - or it is (last-) used by reloader itself - */ - if (values_interfere(env->chordal_env->lv, reloader, arg)) { - 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; - } +static void pre_spill_prepare_constr_walker(ir_node *block, void *data) +{ + be_pre_spill_env_t *env = (be_pre_spill_env_t*)data; + sched_foreach(block, node) { + prepare_constr_insn(env, node); } - - 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->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; +void be_pre_spill_prepare_constr(ir_graph *irg, + const arch_register_class_t *cls) +{ + be_pre_spill_env_t env; + memset(&env, 0, sizeof(env)); + env.irg = irg; + env.cls = cls; - if(arch_irn_is(arch_env, node, rematerializable)) - return 1; + be_assure_live_sets(irg); - if(be_is_StackParam(node)) - return 1; - - return 0; + irg_block_walk_graph(irg, pre_spill_prepare_constr_walker, NULL, &env); } -/** - * 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_LIMIT if remat is not possible. - */ -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; - - 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; - - argremats = 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)) - 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_LIMIT; - } - 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; - } +int be_coalesce_spill_slots = 1; +int be_do_remats = 1; - return costs; -} +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 int check_remat_conditions(spill_env_t *env, ir_node *spilled, ir_node *reloader) { - int costs = check_remat_conditions_costs(env, spilled, reloader, 1); +static be_module_list_entry_t *spillers = NULL; +static const be_spiller_t *selected_spiller = NULL; - return costs < REMAT_COST_LIMIT; +void be_register_spiller(const char *name, be_spiller_t *spiller) +{ + if (selected_spiller == NULL) + selected_spiller = spiller; + be_add_module_to_list(&spillers, name, spiller); } -/** - * 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) { - int i, arity; - ir_node *res; - ir_node *bl = get_nodes_block(reloader); - ir_node **ins; - - 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); - } - } - - /* 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); - copy_node_attr(spilled, res); - - DBG((env->dbg, LEVEL_1, "Insert remat %+F before reloader %+F\n", res, reloader)); +void be_do_spill(ir_graph *irg, const arch_register_class_t *cls) +{ + assert(selected_spiller != NULL); - /* insert in schedule */ - assert(!is_Block(reloader)); - sched_add_before(reloader, res); - - return res; + selected_spiller->spill(irg, cls); } -/* - * ___ _ ____ _ _ - * |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___ - * | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __| - * | || | | \__ \ __/ | | |_ | _ < __/ | (_) | (_| | (_| \__ \ - * |___|_| |_|___/\___|_| \__| |_| \_\___|_|\___/ \__,_|\__,_|___/ - * - */ - -void be_insert_spills_reloads(spill_env_t *env) { - const arch_env_t *arch_env = env->arch_env; - spill_info_t *si; - - /* 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)) { - reloader_t *rld; - ir_mode *mode = get_irn_mode(si->spilled_node); - pset *values = pset_new_ptr(16); - - /* go through all reloads for this spill */ - for(rld = si->reloaders; rld; rld = rld->next) { - ir_node *new_val; - - if (check_remat_conditions(env, si->spilled_node, rld->reloader)) { - new_val = do_remat(env, si->spilled_node, 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); - } - - DBG((env->dbg, LEVEL_1, " %+F of %+F before %+F\n", new_val, si->spilled_node, rld->reloader)); - pset_insert_ptr(values, new_val); - } - - 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); - } +BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spilloptions) +void be_init_spilloptions(void) +{ + 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"); - del_pset(values); - } + lc_opt_add_table(spill_grp, be_spill_options); + be_add_module_list_opt(be_grp, "spiller", "spill algorithm", + &spillers, (void**) &selected_spiller); - // 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); + FIRM_DBG_REGISTER(dbg, "firm.be.spillprepare"); }