X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbespillbelady.c;h=203edf2ef099e4fababa48ae0b1e1e604e919007;hb=3f807bf48426a29da4129ff29c44a4b4690c45f6;hp=f9f9dbca799d3ca54b14b2bf81233e5a05df0bd2;hpb=d3f168815dafaf8d700f2544cfa37a0074184a72;p=libfirm diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c index f9f9dbca7..203edf2ef 100644 --- a/ir/be/bespillbelady.c +++ b/ir/be/bespillbelady.c @@ -220,16 +220,17 @@ static INLINE void workset_remove(workset_t *workset, ir_node *val) } } -static INLINE int workset_contains(const workset_t *ws, const ir_node *val) +static INLINE const loc_t *workset_contains(const workset_t *ws, + const ir_node *val) { int i; - for(i=0; ilen; ++i) { + for (i = 0; i < ws->len; ++i) { if (ws->vals[i].node == val) - return 1; + return &ws->vals[i]; } - return 0; + return NULL; } /** @@ -281,11 +282,11 @@ static INLINE unsigned get_distance(ir_node *from, unsigned from_step, assert(! (flags & arch_irn_flags_ignore)); use = be_get_next_use(uses, from, from_step, def, skip_from_uses); - if(USES_IS_INFINITE(use.time)) + if (USES_IS_INFINITE(use.time)) return USES_INFINITY; /* We have to keep nonspillable nodes in the workingset */ - if(flags & arch_irn_flags_dont_spill) + if (flags & arch_irn_flags_dont_spill) return 0; costs = be_get_reload_costs_no_weight(senv, def, use.before); @@ -307,6 +308,7 @@ static INLINE unsigned get_distance(ir_node *from, unsigned from_step, static void displace(workset_t *new_vals, int is_usage) { ir_node **to_insert = alloca(n_regs * sizeof(to_insert[0])); + bool *spilled = alloca(n_regs * sizeof(spilled[0])); ir_node *val; int i; int len; @@ -317,6 +319,8 @@ static void displace(workset_t *new_vals, int is_usage) /* 1. Identify the number of needed slots and the values to reload */ demand = 0; workset_foreach(new_vals, val, iter) { + bool reloaded = false; + /* mark value as used */ if (is_usage) ir_nodeset_insert(&used, val); @@ -326,6 +330,7 @@ static void displace(workset_t *new_vals, int is_usage) if (is_usage) { DB((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr)); be_add_reload(senv, val, instr, cls, 1); + reloaded = true; } } else { DB((dbg, DBG_DECIDE, " %+F already in workset\n", val)); @@ -334,7 +339,9 @@ static void displace(workset_t *new_vals, int is_usage) * spilled */ workset_remove(ws, val); } - to_insert[demand++] = val; + spilled[demand] = reloaded; + to_insert[demand] = val; + ++demand; } /* 2. Make room for at least 'demand' slots */ @@ -344,8 +351,10 @@ static void displace(workset_t *new_vals, int is_usage) /* Only make more free room if we do not have enough */ if (spills_needed > 0) { +#ifndef PLACE_SPILLS ir_node *curr_bb = get_nodes_block(instr); workset_t *ws_start = get_block_info(curr_bb)->start_workset; +#endif DB((dbg, DBG_DECIDE, " disposing %d values\n", spills_needed)); @@ -359,9 +368,6 @@ static void displace(workset_t *new_vals, int is_usage) /* sort entries by increasing nextuse-distance*/ workset_sort(ws); - /* Logic for not needed live-ins: If a value is disposed - * before its first usage, remove it from start workset - * We don't do this for phis though */ for (i = len - spills_needed; i < len; ++i) { ir_node *val = ws->vals[i].node; @@ -369,15 +375,23 @@ static void displace(workset_t *new_vals, int is_usage) workset_get_time(ws, i))); #ifdef PLACE_SPILLS - if(!USES_IS_INFINITE(ws->vals[i].time) && !ws->vals[i].spilled) { - be_add_spill(senv, val, instr); + if (!USES_IS_INFINITE(ws->vals[i].time) && !ws->vals[i].spilled) { + ir_node *after_pos = sched_prev(instr); + DB((dbg, DBG_DECIDE, "Spill %+F after node %+F\n", val, + after_pos)); + be_add_spill(senv, val, after_pos); } #endif +#ifndef PLACE_SPILLS + /* Logic for not needed live-ins: If a value is disposed + * before its first use, remove it from start workset + * We don't do this for phis though */ if (!is_Phi(val) && ! ir_nodeset_contains(&used, val)) { workset_remove(ws_start, val); DB((dbg, DBG_DECIDE, " (and removing %+F from start workset)\n", val)); } +#endif } /* kill the last 'demand' entries in the array */ @@ -388,7 +402,65 @@ static void displace(workset_t *new_vals, int is_usage) for (i = 0; i < demand; ++i) { ir_node *val = to_insert[i]; - workset_insert(ws, val, false); + workset_insert(ws, val, spilled[i]); + } +} + +enum { + AVAILABLE_EVERYWHERE, + AVAILABLE_NOWHERE, + AVAILABLE_PARTLY, + AVAILABLE_UNKNOWN +}; + +static unsigned available_in_all_preds(workset_t* const* pred_worksets, + size_t n_pred_worksets, + const ir_node *value, bool is_local_phi) +{ + size_t i; + bool avail_everywhere = true; + bool avail_nowhere = true; + + assert(n_pred_worksets > 0); + + /* value available in all preds? */ + for (i = 0; i < n_pred_worksets; ++i) { + bool found = false; + const workset_t *p_workset = pred_worksets[i]; + int p_len = workset_get_length(p_workset); + int p_i; + const ir_node *l_value; + + if (is_local_phi) { + assert(is_Phi(value)); + l_value = get_irn_n(value, i); + } else { + l_value = value; + } + + for (p_i = 0; p_i < p_len; ++p_i) { + const loc_t *p_l = &p_workset->vals[p_i]; + if (p_l->node != l_value) + continue; + + found = true; + break; + } + + if (found) { + avail_nowhere = false; + } else { + avail_everywhere = false; + } + } + + if (avail_everywhere) { + assert(!avail_nowhere); + return AVAILABLE_EVERYWHERE; + } else if (avail_nowhere) { + return AVAILABLE_NOWHERE; + } else { + return AVAILABLE_PARTLY; } } @@ -400,7 +472,7 @@ static void displace(workset_t *new_vals, int is_usage) * @param loop the loop of the node */ static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node, - ir_loop *loop) + ir_loop *loop, unsigned available) { be_next_use_t next_use; loc_t loc; @@ -415,27 +487,35 @@ static loc_t to_take_or_not_to_take(ir_node* first, ir_node *node, } /* We have to keep nonspillable nodes in the workingset */ - if(arch_irn_get_flags(arch_env, node) & arch_irn_flags_dont_spill) { + if (arch_irn_get_flags(arch_env, node) & arch_irn_flags_dont_spill) { loc.time = 0; DB((dbg, DBG_START, " %+F taken (dontspill node)\n", node, loc.time)); return loc; } next_use = be_get_next_use(uses, first, 0, node, 0); - if(USES_IS_INFINITE(next_use.time)) { + if (USES_IS_INFINITE(next_use.time)) { // the nodes marked as live in shouldn't be dead, so it must be a phi assert(is_Phi(node)); loc.time = USES_INFINITY; DB((dbg, DBG_START, " %+F not taken (dead)\n", node)); - if(is_Phi(node)) { - be_spill_phi(senv, node); - } return loc; } loc.time = next_use.time; - if(next_use.outermost_loop >= get_loop_depth(loop)) { + if (available == AVAILABLE_EVERYWHERE) { + DB((dbg, DBG_START, " %+F taken (%u, live in all preds)\n", node, + loc.time)); + return loc; + } else if(available == AVAILABLE_NOWHERE) { + DB((dbg, DBG_START, " %+F not taken (%u, live in no pred)\n", node, + loc.time)); + loc.time = USES_INFINITY; + return loc; + } + + if (next_use.outermost_loop >= get_loop_depth(loop)) { DB((dbg, DBG_START, " %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop)); } else { @@ -465,6 +545,23 @@ static void decide_start_workset(const ir_node *block) unsigned pressure; int arity; workset_t **pred_worksets; + bool all_preds_known; + + /* check predecessors */ + arity = get_irn_arity(block); + pred_worksets = alloca(sizeof(pred_worksets[0]) * arity); + all_preds_known = true; + for(i = 0; i < arity; ++i) { + ir_node *pred_block = get_Block_cfgpred_block(block, i); + block_info_t *pred_info = get_block_info(pred_block); + + if (pred_info == NULL) { + pred_worksets[i] = NULL; + all_preds_known = false; + } else { + pred_worksets[i] = pred_info->end_workset; + } + } /* Collect all values living at start of block */ starters = NEW_ARR_F(loc_t, 0); @@ -475,24 +572,43 @@ static void decide_start_workset(const ir_node *block) /* check all Phis first */ sched_foreach(block, node) { + unsigned available; + if (! is_Phi(node)) break; + if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node)) + continue; + + if (all_preds_known) { + available = available_in_all_preds(pred_worksets, arity, node, true); + } else { + available = AVAILABLE_UNKNOWN; + } - loc = to_take_or_not_to_take(first, node, loop); + loc = to_take_or_not_to_take(first, node, loop, available); if (! USES_IS_INFINITE(loc.time)) { if (USES_IS_PENDING(loc.time)) ARR_APP1(loc_t, delayed, loc); else ARR_APP1(loc_t, starters, loc); + } else { + be_spill_phi(senv, node); } } /* check all Live-Ins */ be_lv_foreach(lv, block, be_lv_state_in, i) { ir_node *node = be_lv_get_irn(lv, block, i); + unsigned available; + + if (all_preds_known) { + available = available_in_all_preds(pred_worksets, arity, node, false); + } else { + available = AVAILABLE_UNKNOWN; + } - loc = to_take_or_not_to_take(first, node, loop); + loc = to_take_or_not_to_take(first, node, loop, available); if (! USES_IS_INFINITE(loc.time)) { if (USES_IS_PENDING(loc.time)) @@ -511,10 +627,12 @@ static void decide_start_workset(const ir_node *block) /* so far we only put nodes into the starters list that are used inside * the loop. If register pressure in the loop is low then we can take some * values and let them live through the loop */ + DB((dbg, DBG_START, "Loop pressure %d, taking %d delayed vals\n", + pressure, free_slots)); if (free_slots > 0) { qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare); - for (i = 0; i < ARR_LEN(delayed) && i < free_slots; ++i) { + for (i = 0; i < ARR_LEN(delayed) && free_slots > 0; ++i) { int p, arity; loc_t *loc = & delayed[i]; @@ -539,6 +657,7 @@ static void decide_start_workset(const ir_node *block) DB((dbg, DBG_START, " delayed %+F taken\n", loc->node)); ARR_APP1(loc_t, starters, *loc); loc->node = NULL; + --free_slots; skip_delayed: ; } @@ -548,7 +667,7 @@ static void decide_start_workset(const ir_node *block) * but not in the start workset */ for (i = ARR_LEN(delayed) - 1; i >= 0; --i) { ir_node *node = delayed[i].node; - if(node == NULL || !is_Phi(node) || get_nodes_block(node) != block) + if (node == NULL || !is_Phi(node) || get_nodes_block(node) != block) continue; DB((dbg, DBG_START, " spilling delayed phi %+F\n", node)); @@ -579,21 +698,8 @@ static void decide_start_workset(const ir_node *block) DEL_ARR_F(starters); /* determine spill status of the values: If there's 1 pred block (which - * is no backedge) where the value is reloaded then we must set it to - * reloaded here. We place spills in all pred where the value was not yet - * reloaded to be sure we have a spill on each path */ - arity = get_irn_arity(block); - pred_worksets = alloca(sizeof(pred_worksets[0]) * arity); - for(i = 0; i < arity; ++i) { - ir_node *pred_block = get_Block_cfgpred_block(block, i); - block_info_t *pred_info = get_block_info(pred_block); - - if(pred_info == NULL) - pred_worksets[i] = NULL; - else - pred_worksets[i] = pred_info->end_workset; - } - + * is no backedge) where the value is spilled then we must set it to + * spilled here. */ for(i = 0; i < ws_count; ++i) { loc_t *loc = &ws->vals[i]; ir_node *value = loc->node; @@ -601,7 +707,7 @@ static void decide_start_workset(const ir_node *block) int n; /* phis from this block aren't spilled */ - if(get_nodes_block(value) == block) { + if (get_nodes_block(value) == block) { assert(is_Phi(value)); loc->spilled = false; continue; @@ -626,48 +732,87 @@ static void decide_start_workset(const ir_node *block) if (l->spilled) { spilled = true; - goto determined_spill; } break; } - if (p >= p_len) { - spilled = true; - goto determined_spill; - } } -determined_spill: - if (spilled) { - for (n = 0; n < arity; ++n) { - workset_t *pred_workset = pred_worksets[n]; - int p_len; - int p; + loc->spilled = spilled; + } +} + +#if 0 +static void decide_start_workset2(const ir_node *block) +{ + int arity; + workset_t **pred_worksets; + int p; + int i; + int len; + + /* check if all predecessors are known */ + arity = get_irn_arity(block); + pred_worksets = alloca(sizeof(pred_worksets[0]) * arity); + for (i = 0; i < arity; ++i) { + ir_node *pred_block = get_Block_cfgpred_block(block, i); + block_info_t *pred_info = get_block_info(pred_block); + + if (pred_info == NULL) { + /* not all predecessors known, use decide_start_workset */ + decide_start_workset(block); + return; + } + + pred_worksets[i] = pred_info->end_workset; + } + + /* we construct a new workset */ + workset_clear(ws); + + /* take values live in all pred blocks */ + len = workset_get_length(pred_worksets[0]); + for (p = 0; p < len; ++p) { + const loc_t *l = &pred_worksets[0]->vals[p]; + ir_node *value; + bool spilled = false; - if (pred_workset == NULL) + if (USES_IS_INFINITE(l->time)) + continue; + + /* value available in all preds? */ + value = l->node; + for (i = 1; i < arity; ++i) { + bool found = false; + workset_t *p_workset = pred_worksets[i]; + int p_len = workset_get_length(p_workset); + int p_i; + + for (p_i = 0; p_i < p_len; ++p_i) { + const loc_t *p_l = &p_workset->vals[p_i]; + if (p_l->node != value) continue; - p_len = workset_get_length(pred_workset); - for (p = 0; p < p_len; ++p) { - loc_t *l = &pred_workset->vals[p]; - - if (l->node != value) - continue; - - if (!l->spilled) { - ir_node *pred_block = get_Block_cfgpred_block(block, n); - ir_node *insert_point - = be_get_end_of_block_insertion_point(pred_block); - DB((dbg, DBG_SPILL, "Spill %+F before %+F\n", node, - insert_point)); - be_add_spill(senv, value, insert_point); - } - break; - } + found = true; + if (p_l->spilled) + spilled = true; + break; } + + if (!found) + break; + } + + /* it was available in all preds */ + if (i >= arity) { + workset_insert(ws, value, spilled); } - loc->spilled = spilled; } + + /* Copy the best ones from starters to start workset */ + ws_count = MIN(ARR_LEN(starters), n_regs); + workset_bulk_fill(ws, ws_count, starters); } +#endif /** * For the given block @p block, decide for each values @@ -686,7 +831,7 @@ static void belady(ir_node *block) const ir_edge_t *edge; /* no need to process a block twice */ - if(get_block_info(block) != NULL) { + if (get_block_info(block) != NULL) { return; } @@ -697,18 +842,18 @@ static void belady(ir_node *block) ir_node *pred_block = get_Block_cfgpred_block(block, i); block_info_t *pred_info = get_block_info(pred_block); - if(pred_info == NULL) { + if (pred_info == NULL) { /* process predecessor first (it will be in the queue already) */ - if(!is_backedge(block, i)) { + if (!is_backedge(block, i)) { return; } has_backedges = 1; } } (void) has_backedges; - if(arity == 0) { + if (arity == 0) { workset_clear(ws); - } else if(arity == 1) { + } else if (arity == 1) { ir_node *pred_block = get_Block_cfgpred_block(block, 0); block_info_t *pred_info = get_block_info(pred_block); @@ -836,7 +981,7 @@ static void fix_block_borders(ir_node *block, void *data) int iter2; bool found = false; workset_foreach(start_workset, n2, iter2) { - if(n2 == node) { + if (n2 == node) { found = true; break; } @@ -850,42 +995,58 @@ static void fix_block_borders(ir_node *block, void *data) continue; #ifdef PLACE_SPILLS - if(be_is_live_in(lv, block, node) + if (be_is_live_in(lv, block, node) && !pred_end_workset->vals[iter].spilled) { ir_node *insert_point; if (arity > 1) { insert_point = be_get_end_of_block_insertion_point(pred); + insert_point = sched_prev(insert_point); } else { - insert_point = sched_first(block); - assert(!is_Phi(insert_point)); + insert_point = block; } - DB((dbg, DBG_SPILL, "Spill %+F before %+F\n", node, + DB((dbg, DBG_SPILL, "Spill %+F after %+F\n", node, insert_point)); be_add_spill(senv, node, insert_point); } #endif } - /* reload missing values in predecessors */ + /* reload missing values in predecessors, add missing spills */ workset_foreach(start_workset, node, iter) { + const loc_t *l = &start_workset->vals[iter]; + const loc_t *pred_loc; + /* if node is a phi of the current block we reload * the corresponding argument, else node itself */ - if(is_Phi(node) && block == get_nodes_block(node)) { + if (is_Phi(node) && get_nodes_block(node) == block) { node = get_irn_n(node, i); + assert(!l->spilled); /* we might have unknowns as argument for the phi */ - if(!arch_irn_consider_in_reg_alloc(arch_env, cls, node)) + if (!arch_irn_consider_in_reg_alloc(arch_env, cls, node)) continue; } /* check if node is in a register at end of pred */ - if(workset_contains(pred_end_workset, node)) - continue; - - /* node is not in memory at the end of pred -> reload it */ - DB((dbg, DBG_FIX, " reload %+F\n", node)); - DB((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i)); - be_add_reload_on_edge(senv, node, block, i, cls, 1); + pred_loc = workset_contains(pred_end_workset, node); + if (pred_loc != NULL) { +#ifdef PLACE_SPILLS + /* we might have to spill value on this path */ + if (!pred_loc->spilled && l->spilled) { + ir_node *insert_point + = be_get_end_of_block_insertion_point(pred); + insert_point = sched_prev(insert_point); + DB((dbg, DBG_SPILL, "Spill %+F after %+F\n", node, + insert_point)); + be_add_spill(senv, node, insert_point); + } +#endif + } else { + /* node is not in register at the end of pred -> reload it */ + DB((dbg, DBG_FIX, " reload %+F\n", node)); + DB((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i)); + be_add_reload_on_edge(senv, node, block, i, cls, 1); + } } } } @@ -897,7 +1058,7 @@ static void be_spill_belady(be_irg_t *birg, const arch_register_class_t *rcls) be_liveness_assure_sets(be_assure_liveness(birg)); /* construct control flow loop tree */ - if(! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) { + if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) { construct_cf_backedges(irg); }