X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;ds=sidebyside;f=ir%2Flower%2Flower_switch.c;h=e5f3744156542e6a3054e17403c0be0c6e304210;hb=b1ac8fe5c7b3b462f66a99e6c780be9826414b7d;hp=1c794554224d08a59c3d6ebae2413418c197fa49;hpb=014476c446ab6fd72461c764c018fa401e5f88c1;p=libfirm diff --git a/ir/lower/lower_switch.c b/ir/lower/lower_switch.c index 1c7945542..e5f374415 100644 --- a/ir/lower/lower_switch.c +++ b/ir/lower/lower_switch.c @@ -1,279 +1,490 @@ /* - * Copyright (C) 1995-2008 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. + * Copyright (C) 2012 University of Karlsruhe. */ /** * @file * @brief Lowering of Switches if necessary or advantageous. * @author Moritz Kroll - * @version $Id$ */ - -#ifdef HAVE_CONFIG_H #include "config.h" -#endif #include +#include +#include "array_t.h" #include "ircons.h" #include "irgopt.h" #include "irgwalk.h" #include "irnode_t.h" #include "irouts.h" +#include "irpass_t.h" +#include "lowering.h" +#include "error.h" +#include "irnodeset.h" -#define foreach_out_irn(irn, i, outirn) for(i = get_irn_n_outs(irn) - 1;\ +#define foreach_out_irn(irn, i, outirn) for (i = get_irn_n_outs(irn) - 1;\ i >= 0 && (outirn = get_irn_out(irn, i)); --i) -typedef struct walk_env { - unsigned spare_size; /**< the allowed spare size for table switches */ - struct obstack obst; /**< the obstack where data is allocated on */ - int changed; /**< indicates whether a change was performed */ +typedef struct walk_env_t { + ir_nodeset_t processed; + ir_mode *selector_mode; + unsigned spare_size; /**< the allowed spare size for table switches */ + unsigned small_switch; + bool changed; /**< indicates whether a change was performed */ } walk_env_t; -typedef struct case_data { - long value; - ir_node *target; +typedef struct case_data_t { + const ir_switch_table_entry *entry; + ir_node *target; } case_data_t; -typedef struct ifcas_env { - ir_node *sel; - int defindex; - ir_node **defusers; /**< the Projs pointing to the default case */ -} ifcas_env_t; +typedef struct switch_info_t { + ir_node *switchn; + ir_tarval *switch_min; + ir_tarval *switch_max; + ir_node *default_block; + unsigned num_cases; + case_data_t *cases; + ir_node **defusers; /**< the Projs pointing to the default case */ +} switch_info_t; /** - * Evaluate a switch and decide whether we should build a table switch. - * - * @param cond The Cond node representing the switch. - * @param spare_size Allowed spare size for table switches in machine words. - * (Default in edgfe: 128) + * analyze enough to decide if we should lower the switch */ -static int should_do_table_switch(ir_node *cond, unsigned spare_size) +static void analyse_switch0(switch_info_t *info, ir_node *switchn) +{ + const ir_switch_table *table = get_Switch_table(switchn); + size_t n_entries = ir_switch_table_get_n_entries(table); + ir_mode *mode = get_irn_mode(get_Switch_selector(switchn)); + ir_tarval *switch_min = get_mode_max(mode); + ir_tarval *switch_max = get_mode_min(mode); + unsigned num_cases = 0; + + for (size_t e = 0; e < n_entries; ++e) { + const ir_switch_table_entry *entry + = ir_switch_table_get_entry_const(table, e); + if (entry->pn == 0) + continue; + + if (tarval_cmp(entry->min, switch_min) == ir_relation_less) + switch_min = entry->min; + if (tarval_cmp(entry->max, switch_max) == ir_relation_greater) + switch_max = entry->max; + + ++num_cases; + } + + info->switchn = switchn; + info->switch_min = switch_min; + info->switch_max = switch_max; + info->num_cases = num_cases; +} + +static int casecmp(const void *a, const void *b) { - long default_pn; - int i; - ir_node *proj; - long switch_min = LONG_MAX, switch_max = LONG_MIN; - unsigned long spare, num_cases = 0; - - /* TODO: Minimum size for jump table? */ - if(get_irn_n_outs(cond) <= 4) + const case_data_t *cda = (const case_data_t*)a; + const case_data_t *cdb = (const case_data_t*)b; + const ir_switch_table_entry *ea = cda->entry; + const ir_switch_table_entry *eb = cdb->entry; + + if (ea == eb) return 0; - default_pn = get_Cond_defaultProj(cond); + if (tarval_cmp(ea->max, eb->min) == ir_relation_less) + return -1; + /* cases must be non overlapping, so the only remaining case is greater */ + assert(tarval_cmp(ea->min, eb->max) == ir_relation_greater); + return 1; +} - foreach_out_irn(cond, i, proj) { - long pn = get_Proj_proj(proj); - if(pn == default_pn) +/** + * Analyse the stuff that anayse_switch0() left out + */ +static void analyse_switch1(switch_info_t *info) +{ + const ir_node *switchn = info->switchn; + const ir_switch_table *table = get_Switch_table(switchn); + size_t n_entries = ir_switch_table_get_n_entries(table); + unsigned n_outs = get_Switch_n_outs(switchn); + ir_node **targets = XMALLOCNZ(ir_node*, n_outs); + unsigned num_cases = info->num_cases; + case_data_t *cases = XMALLOCN(case_data_t, num_cases); + unsigned c = 0; + size_t e; + int i; + ir_node *proj; + + foreach_out_irn(switchn, i, proj) { + long pn = get_Proj_proj(proj); + ir_node *target = get_irn_out(proj, 0); + + assert((unsigned)pn < n_outs); + assert(targets[(unsigned)pn] == NULL); + targets[(unsigned)pn] = target; + } + + for (e = 0; e < n_entries; ++e) { + const ir_switch_table_entry *entry + = ir_switch_table_get_entry_const(table, e); + if (entry->pn == 0) continue; - if(pn < switch_min) - switch_min = pn; - if(pn > switch_max) - switch_max = pn; - num_cases++; + cases[c].entry = entry; + cases[c].target = targets[entry->pn]; + ++c; } + assert(c == num_cases); /* - * Here we have: num_cases and [switch_min, switch_max] interval. - * We do an if-cascade if there are too many spare numbers. + * Switch should be transformed into an if cascade. + * So first order the cases, so we can do a binary search on them. */ - spare = (unsigned long) switch_max - (unsigned long) switch_min - num_cases + 1; - return spare < spare_size; + qsort(cases, num_cases, sizeof(cases[0]), casecmp); + + info->default_block = targets[pn_Switch_default]; + info->cases = cases; + free(targets); } -static int casecmp(const void *a, const void *b) +static void normalize_table(ir_node *switchn, ir_mode *new_mode, + ir_tarval *delta) +{ + ir_switch_table *table = get_Switch_table(switchn); + size_t n_entries = ir_switch_table_get_n_entries(table); + size_t e; + /* adapt switch_table */ + for (e = 0; e < n_entries; ++e) { + ir_switch_table_entry *entry = ir_switch_table_get_entry(table, e); + ir_tarval *min = entry->min; + + if (entry->pn == 0) + continue; + + min = tarval_convert_to(min, new_mode); + if (delta != NULL) + min = tarval_sub(min, delta, NULL); + + if (entry->min == entry->max) { + entry->min = min; + entry->max = min; + } else { + ir_tarval *max = entry->max; + max = tarval_convert_to(max, new_mode); + if (delta != NULL) + max = tarval_sub(max, delta, NULL); + entry->min = min; + entry->max = max; + } + } +} + +static void create_out_of_bounds_check(switch_info_t *info) { - return ((case_data_t *) a)->value - ((case_data_t *) b)->value; + ir_node *switchn = info->switchn; + ir_graph *irg = get_irn_irg(switchn); + dbg_info *dbgi = get_irn_dbg_info(switchn); + ir_node *selector = get_Switch_selector(switchn); + ir_node *block = get_nodes_block(switchn); + ir_node **default_preds = NEW_ARR_F(ir_node*, 0); + ir_node *default_block = NULL; + ir_node *max_const; + ir_node *proj_true; + ir_node *proj_false; + ir_node *cmp; + ir_node *oob_cond; + ir_node *in[1]; + ir_node *new_block; + int i; + ir_node *proj; + size_t n_default_preds; + + assert(tarval_is_null(info->switch_min)); + + /* check for out-of-bounds */ + max_const = new_r_Const(irg, info->switch_max); + cmp = new_rd_Cmp(dbgi, block, selector, max_const, ir_relation_less_equal); + oob_cond = new_rd_Cond(dbgi, block, cmp); + proj_true = new_r_Proj(oob_cond, mode_X, pn_Cond_true); + proj_false = new_r_Proj(oob_cond, mode_X, pn_Cond_false); + + ARR_APP1(ir_node*, default_preds, proj_false); + + /* create new block containing the switch */ + in[0] = proj_true; + new_block = new_r_Block(irg, 1, in); + set_nodes_block(switchn, new_block); + + /* adjust projs */ + foreach_out_irn(switchn, i, proj) { + long pn = get_Proj_proj(proj); + if (pn == pn_Switch_default) { + assert(default_block == NULL); + default_block = get_irn_out(proj, 0); + ARR_APP1(ir_node*, default_preds, proj); + } + set_nodes_block(proj, new_block); + } + + /* adapt default block */ + n_default_preds = ARR_LEN(default_preds); + if (n_default_preds > 1) { + /* create new intermediate blocks so we don't have critical edges */ + size_t p; + for (p = 0; p < n_default_preds; ++p) { + ir_node *pred = default_preds[p]; + ir_node *split_block; + ir_node *block_in[1]; + + block_in[0] = pred; + split_block = new_r_Block(irg, 1, block_in); + + default_preds[p] = new_r_Jmp(split_block); + } + } + set_irn_in(default_block, n_default_preds, default_preds); + + DEL_ARR_F(default_preds); + + clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE); +} + +/** + * normalize switch to work on an unsigned input with the first case at 0 + */ +static void normalize_switch(switch_info_t *info, ir_mode *selector_mode) +{ + ir_node *switchn = info->switchn; + ir_graph *irg = get_irn_irg(switchn); + ir_node *block = get_nodes_block(switchn); + ir_node *selector = get_Switch_selector(switchn); + ir_mode *mode = get_irn_mode(selector); + ir_tarval *delta = NULL; + bool needs_normalize = false; + + ir_tarval *min = info->switch_min; + if (mode_is_signed(mode)) { + mode = find_unsigned_mode(mode); + selector = new_r_Conv(block, selector, mode); + min = tarval_convert_to(min, mode); + info->switch_min = min; + info->switch_max = tarval_convert_to(info->switch_max, mode); + needs_normalize = true; + } + + /* normalize so switch_min is at 0 */ + if (min != get_mode_null(mode)) { + ir_node *min_const = new_r_Const(irg, min); + dbg_info *dbgi = get_irn_dbg_info(switchn); + selector = new_rd_Sub(dbgi, block, selector, min_const, mode); + + info->switch_max = tarval_sub(info->switch_max, min, mode); + info->switch_min = get_mode_null(mode); + delta = min; + + needs_normalize = true; + } + + /* if we have a selector_mode set, then the we will have a switch node, + * we have to construct an out-of-bounds check then and after that convert + * the switch/selector to the backends desired switch mode */ + if (selector_mode != NULL) { + set_Switch_selector(switchn, selector); + create_out_of_bounds_check(info); + + selector = new_r_Conv(block, selector, selector_mode); + mode = selector_mode; + info->switch_min = tarval_convert_to(info->switch_min, mode); + info->switch_max = tarval_convert_to(info->switch_max, mode); + if (delta != NULL) + delta = tarval_convert_to(delta, mode); + needs_normalize = true; + } + + if (needs_normalize) { + set_Switch_selector(switchn, selector); + normalize_table(switchn, mode, delta); + } +} + +/** + * Create an if (selector == caseval) Cond node (and handle the special case + * of ranged cases) + */ +static ir_node *create_case_cond(const ir_switch_table_entry *entry, + dbg_info *dbgi, ir_node *block, + ir_node *selector) +{ + ir_graph *irg = get_irn_irg(block); + ir_node *minconst = new_r_Const(irg, entry->min); + ir_node *cmp; + + if (entry->min == entry->max) { + cmp = new_rd_Cmp(dbgi, block, selector, minconst, ir_relation_equal); + } else { + ir_tarval *adjusted_max = tarval_sub(entry->max, entry->min, NULL); + ir_node *sub = new_rd_Sub(dbgi, block, selector, minconst, + get_tarval_mode(adjusted_max)); + ir_node *maxconst = new_r_Const(irg, adjusted_max); + cmp = new_rd_Cmp(dbgi, block, sub, maxconst, ir_relation_less_equal); + } + + return new_rd_Cond(dbgi, block, cmp); } /** * Creates an if cascade realizing binary search. */ -static void create_if_cascade(ifcas_env_t *env, ir_node *curblock, - case_data_t *curcases, int numcases) +static void create_if_cascade(switch_info_t *info, ir_node *block, + case_data_t *curcases, unsigned numcases) { - set_cur_block(curblock); - - if(numcases == 1) - { - /* only one case: "if(sel == val) goto target else goto default;" */ - ir_node *val = new_Const_long(get_irn_mode(env->sel), curcases[0].value); - ir_node *cmp = new_Cmp(env->sel, val); - ir_node *proj = new_Proj(cmp, mode_b, pn_Cmp_Eq); - ir_node *cond = new_Cond(proj); - set_Block_cfgpred(curcases[0].target, 0, new_Proj(cond, mode_X, pn_Cond_true)); - env->defusers[env->defindex++] = new_Proj(cond, mode_X, pn_Cond_false); - } else if(numcases == 2) { - /* only two cases: "if(sel == val[0]) goto target[0];" */ - ir_node *val = new_Const_long(get_irn_mode(env->sel), curcases[0].value); - ir_node *cmp = new_Cmp(env->sel, val); - ir_node *proj = new_Proj(cmp, mode_b, pn_Cmp_Eq); - ir_node *cond = new_Cond(proj); + ir_graph *irg = get_irn_irg(block); + const ir_node *switchn = info->switchn; + dbg_info *dbgi = get_irn_dbg_info(switchn); + ir_node *selector = get_Switch_selector(switchn); + + if (numcases == 0) { + /* zero cases: "goto default;" */ + ARR_APP1(ir_node*, info->defusers, new_r_Jmp(block)); + } else if (numcases == 1) { + /*only one case: "if (sel == val) goto target else goto default;"*/ + const ir_switch_table_entry *entry = curcases[0].entry; + ir_node *cond = create_case_cond(entry, dbgi, block, selector); + ir_node *trueproj = new_r_Proj(cond, mode_X, pn_Cond_true); + ir_node *falseproj = new_r_Proj(cond, mode_X, pn_Cond_false); + + set_Block_cfgpred(curcases[0].target, 0, trueproj); + ARR_APP1(ir_node*, info->defusers, falseproj); + } else if (numcases == 2) { + /* only two cases: "if (sel == val[0]) goto target[0];" */ + const ir_switch_table_entry *entry0 = curcases[0].entry; + const ir_switch_table_entry *entry1 = curcases[1].entry; + ir_node *cond = create_case_cond(entry0, dbgi, block, selector); + ir_node *trueproj = new_r_Proj(cond, mode_X, pn_Cond_true); + ir_node *falseproj = new_r_Proj(cond, mode_X, pn_Cond_false); ir_node *in[1]; ir_node *neblock; - set_Block_cfgpred(curcases[0].target, 0, new_Proj(cond, mode_X, pn_Cond_true)); - in[0] = new_Proj(cond, mode_X, pn_Cond_false); - neblock = new_Block(1, in); - - /* second part: "else if(sel == val[1]) goto target[1] else goto default;" */ - val = new_Const_long(get_irn_mode(env->sel), curcases[1].value); - cmp = new_Cmp(env->sel, val); - proj = new_Proj(cmp, mode_b, pn_Cmp_Eq); - cond = new_Cond(proj); - set_Block_cfgpred(curcases[1].target, 0, new_Proj(cond, mode_X, pn_Cond_true)); - env->defusers[env->defindex++] = new_Proj(cond, mode_X, pn_Cond_false); + set_Block_cfgpred(curcases[0].target, 0, trueproj); + + in[0] = falseproj; + neblock = new_r_Block(irg, 1, in); + + /* second part: "else if (sel == val[1]) goto target[1] else goto default;" */ + cond = create_case_cond(entry1, dbgi, neblock, selector); + trueproj = new_r_Proj(cond, mode_X, pn_Cond_true); + falseproj = new_r_Proj(cond, mode_X, pn_Cond_false); + set_Block_cfgpred(curcases[1].target, 0, trueproj); + ARR_APP1(ir_node*, info->defusers, falseproj); } else { /* recursive case: split cases in the middle */ - int midcase = numcases / 2; - ir_node *val = new_Const_long(get_irn_mode(env->sel), curcases[midcase].value); - ir_node *cmp = new_Cmp(env->sel, val); - ir_node *proj = new_Proj(cmp, mode_b, pn_Cmp_Lt); - ir_node *cond = new_Cond(proj); + unsigned midcase = numcases / 2; + const ir_switch_table_entry *entry = curcases[midcase].entry; + ir_node *val = new_r_Const(irg, entry->min); + ir_node *cmp = new_rd_Cmp(dbgi, block, selector, val, ir_relation_less); + ir_node *cond = new_rd_Cond(dbgi, block, cmp); ir_node *in[1]; ir_node *ltblock; ir_node *geblock; - in[0] = new_Proj(cond, mode_X, pn_Cond_true); - ltblock = new_Block(1, in); + in[0] = new_r_Proj(cond, mode_X, pn_Cond_true); + ltblock = new_r_Block(irg, 1, in); - set_cur_block(curblock); - in[0] = new_Proj(cond, mode_X, pn_Cond_false); - geblock = new_Block(1, in); + in[0] = new_r_Proj(cond, mode_X, pn_Cond_false); + geblock = new_r_Block(irg, 1, in); - create_if_cascade(env, ltblock, curcases, midcase); - create_if_cascade(env, geblock, curcases + midcase, numcases - midcase); + create_if_cascade(info, ltblock, curcases, midcase); + create_if_cascade(info, geblock, curcases + midcase, numcases - midcase); } } /** - * Block-Walker: searches for Cond nodes with a non-boolean mode + * Block-Walker: searches for Switch nodes */ -static void find_cond_nodes(ir_node *block, void *ctx) +static void find_switch_nodes(ir_node *block, void *ctx) { - walk_env_t *env = ctx; - ir_node *projx; - ir_node *cond; - ir_node *sel; - ir_mode *sel_mode; - long default_pn; - int i, j = 0, numcases; - ir_node *proj; - case_data_t *cases; - ir_node *condblock; - ir_node *defblock = NULL; - ifcas_env_t ifcas_env; - - if(get_Block_n_cfgpreds(block) != 1) + walk_env_t *env = (walk_env_t *)ctx; + ir_node *projx; + ir_node *switchn; + switch_info_t info; + + /* because we split critical blocks only blocks with 1 predecessors may + * contain Proj->Cond nodes */ + if (get_Block_n_cfgpreds(block) != 1) return; projx = get_Block_cfgpred(block, 0); - if(!is_Proj(projx)) + if (!is_Proj(projx)) return; assert(get_irn_mode(projx) == mode_X); - cond = get_Proj_pred(projx); - if(!is_Cond(cond)) + switchn = get_Proj_pred(projx); + if (!is_Switch(switchn)) return; - sel = get_Cond_selector(cond); - sel_mode = get_irn_mode(sel); - - if(sel_mode == mode_b) /* not a switch? */ + if (ir_nodeset_contains(&env->processed, switchn)) return; + ir_nodeset_insert(&env->processed, switchn); - if(should_do_table_switch(cond, env->spare_size)) - return; + analyse_switch0(&info, switchn); /* - * Switch should be transformed into an if cascade. - * So first order the cases, so we can do a binary search on them. + * Here we have: num_cases and [switch_min, switch_max] interval. + * We do an if-cascade if there are too many spare numbers. */ - - numcases = get_irn_n_outs(cond) - 1; // does not contain default case - cases = obstack_alloc(&env->obst, numcases * sizeof(*cases)); - - default_pn = get_Cond_defaultProj(cond); - ifcas_env.sel = sel; - ifcas_env.defindex = 0; - NEW_ARR_A(ir_node*, ifcas_env.defusers, numcases); - - foreach_out_irn(cond, i, proj) { - long pn = get_Proj_proj(proj); - ir_node *target = get_irn_out(proj, 0); - assert(get_Block_n_cfgpreds(target) == 1 && "Encountered critical edge in switch"); - - if(pn == default_pn) - { - defblock = target; - continue; - } - - cases[j].value = pn; - cases[j].target = target; - j++; + ir_mode *mode = get_irn_mode(get_Switch_selector(switchn)); + ir_tarval *spare = tarval_sub(info.switch_max, info.switch_min, mode); + mode = find_unsigned_mode(mode); + spare = tarval_convert_to(spare, mode); + ir_tarval *num_cases_minus_one + = new_tarval_from_long(info.num_cases-1, mode); + spare = tarval_sub(spare, num_cases_minus_one, mode); + ir_tarval *spare_size = new_tarval_from_long(env->spare_size, mode); + bool lower_switch = (info.num_cases <= env->small_switch + || (tarval_cmp(spare, spare_size) & ir_relation_greater_equal)); + + if (!lower_switch) { + /* we won't decompose the switch. But we must add an out-of-bounds + * check */ + normalize_switch(&info, env->selector_mode); + return; } - assert(defblock != NULL && "Switch without default proj"); - qsort(cases, numcases, sizeof(*cases), casecmp); + normalize_switch(&info, NULL); + analyse_switch1(&info); /* Now create the if cascade */ - condblock = get_nodes_block(cond); - create_if_cascade(&ifcas_env, condblock, cases, numcases); + env->changed = true; + info.defusers = NEW_ARR_F(ir_node*, 0); + block = get_nodes_block(switchn); + create_if_cascade(&info, block, info.cases, info.num_cases); /* Connect new default case users */ - set_irn_in(defblock, ifcas_env.defindex, ifcas_env.defusers); + set_irn_in(info.default_block, ARR_LEN(info.defusers), info.defusers); - obstack_free(&env->obst, cases); + DEL_ARR_F(info.defusers); + xfree(info.cases); + clear_irg_properties(get_irn_irg(block), IR_GRAPH_PROPERTY_NO_CRITICAL_EDGES + | IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE); } -/** - * Lowers all Switches (Cond nodes with non-boolean mode) depending on spare_size. - * They will either remain the same or be converted into if-cascades. - * - * @param irg The ir graph to be lowered. - * @param spare_size Allowed spare size for table switches in machine words. - * (Default in edgfe: 128) - */ -void lower_switch(ir_graph *irg, unsigned spare_size) +void lower_switch(ir_graph *irg, unsigned small_switch, unsigned spare_size, + ir_mode *selector_mode) { - walk_env_t env; - ir_graph *rem = current_ir_graph; + if (mode_is_signed(selector_mode)) + panic("expected unsigned mode for switch selector"); - current_ir_graph = irg; - - obstack_init(&env.obst); - env.spare_size = spare_size; + walk_env_t env; + env.selector_mode = selector_mode; + env.spare_size = spare_size; + env.small_switch = small_switch; + env.changed = false; + ir_nodeset_init(&env.processed); remove_critical_cf_edges(irg); assure_irg_outs(irg); - irg_block_walk_graph(irg, find_cond_nodes, NULL, &env); - - if(env.changed) { - /* control flow changed */ - set_irg_outs_inconsistent(irg); - set_irg_doms_inconsistent(irg); - set_irg_extblk_inconsistent(irg); - set_irg_loopinfo_inconsistent(irg); - } - - obstack_free(&env.obst, NULL); - current_ir_graph = rem; + irg_block_walk_graph(irg, find_switch_nodes, NULL, &env); + ir_nodeset_destroy(&env.processed); }