X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fjumpthreading.c;h=f7b76f285460bfcd9016c100f62044f9f630b523;hb=f8ead9acbe48af00885e64a6f2f895d1b6cae434;hp=bc417f53c61ee79480eac63a84688be5f8dd8959;hpb=7547cf525ad54f59d2dc3f39d4b257911c94989b;p=libfirm diff --git a/ir/opt/jumpthreading.c b/ir/opt/jumpthreading.c index bc417f53c..f7b76f285 100644 --- a/ir/opt/jumpthreading.c +++ b/ir/opt/jumpthreading.c @@ -22,13 +22,13 @@ * @brief Path-Sensitive Jump Threading * @date 10. Sep. 2006 * @author Christoph Mallon, Matthias Braun - * @version $Id$ */ #include "config.h" #include "iroptimize.h" #include +#include #include "array_t.h" #include "debug.h" #include "ircons.h" @@ -46,10 +46,11 @@ #include "iropt_dbg.h" #include "irpass.h" #include "vrp.h" +#include "firmstat_t.h" #undef AVOID_PHIB -DEBUG_ONLY(static firm_dbg_module_t *dbg); +DEBUG_ONLY(static firm_dbg_module_t *dbg;) /** * Add the new predecessor x to node node, which is either a Block or a Phi @@ -60,7 +61,7 @@ static void add_pred(ir_node* node, ir_node* x) int n; int i; - assert(is_Block(node) || is_Phi(node)); + assert(is_Block(node)); n = get_irn_arity(node); NEW_ARR_A(ir_node*, ins, n + 1); @@ -83,16 +84,16 @@ static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode, ir_node **in; ir_node *dummy; - /* This is needed because we create bads sometimes */ + /* In case of a bad input to a block we need to return the bad value */ if (is_Bad(block)) { ir_graph *irg = get_irn_irg(block); - return new_r_Bad(irg); + return new_r_Bad(irg, mode); } /* the other defs can't be marked for cases where a user of the original * value is in the same block as the alternative definition. * In this case we mustn't use the alternative definition. - * So we keep a flag that indicated wether we walked at least 1 block + * So we keep a flag that indicated whether we walked at least 1 block * away and may use the alternative definition */ if (block == ssa_second_def_block && !first) { return ssa_second_def; @@ -149,8 +150,6 @@ static void construct_ssa(ir_node *orig_block, ir_node *orig_val, { ir_graph *irg; ir_mode *mode; - const ir_edge_t *edge; - const ir_edge_t *next; /* no need to do anything */ if (orig_val == second_val) @@ -167,7 +166,7 @@ static void construct_ssa(ir_node *orig_block, ir_node *orig_val, ssa_second_def = second_val; /* Only fix the users of the first, i.e. the original node */ - foreach_out_edge_safe(orig_val, edge, next) { + foreach_out_edge_safe(orig_val, edge) { ir_node *user = get_edge_src_irn(edge); int j = get_edge_src_pos(edge); ir_node *user_block = get_nodes_block(user); @@ -194,6 +193,16 @@ static void construct_ssa(ir_node *orig_block, ir_node *orig_val, } } +/** + * jumpthreading produces critical edges, e.g. B-C: + * A A + * \ / \ | + * B => B | + * / \ / \| + * C C + * + * By splitting this critical edge more threadings might be possible. + */ static void split_critical_edge(ir_node *block, int pos) { ir_graph *irg = get_irn_irg(block); @@ -210,7 +219,7 @@ static void split_critical_edge(ir_node *block, int pos) typedef struct jumpthreading_env_t { ir_node *true_block; ir_node *cmp; /**< The Compare node that might be partial evaluated */ - pn_Cmp pnc; /**< The Compare mode of the Compare node. */ + ir_relation relation; /**< The Compare mode of the Compare node. */ ir_node *cnst; ir_tarval *tv; ir_visited_t visited_nr; @@ -232,7 +241,7 @@ static ir_node *copy_and_fix_node(const jumpthreading_env_t *env, copy = get_Phi_pred(node, j); /* we might have to evaluate a Phi-cascade */ if (get_irn_visited(copy) >= env->visited_nr) { - copy = get_irn_link(copy); + copy = (ir_node*)get_irn_link(copy); } } else { copy = exact_copy(node); @@ -249,7 +258,7 @@ static ir_node *copy_and_fix_node(const jumpthreading_env_t *env, continue; if (get_irn_visited(pred) >= env->visited_nr) { - new_pred = get_irn_link(pred); + new_pred = (ir_node*)get_irn_link(pred); } else { new_pred = copy_and_fix_node(env, block, copy_block, j, pred); } @@ -267,24 +276,28 @@ static ir_node *copy_and_fix_node(const jumpthreading_env_t *env, static void copy_and_fix(const jumpthreading_env_t *env, ir_node *block, ir_node *copy_block, int j) { - const ir_edge_t *edge; - /* Look at all nodes in the cond_block and copy them into pred */ foreach_out_edge(block, edge) { ir_node *node = get_edge_src_irn(edge); ir_node *copy; ir_mode *mode; + if (is_End(node)) { + /* edge is a Keep edge. If the end block is unreachable via normal + * control flow, we must maintain end's reachability with Keeps. + */ + keep_alive(copy_block); + continue; + } /* ignore control flow */ mode = get_irn_mode(node); - if (mode == mode_X || is_Cond(node)) + if (mode == mode_X || is_Cond(node) || is_Switch(node)) continue; #ifdef AVOID_PHIB /* we may not copy mode_b nodes, because this could produce Phi with * mode_bs which can't be handled in all backends. Instead we duplicate * the node and move it to its users */ if (mode == mode_b) { - const ir_edge_t *edge, *next; ir_node *pred; int pn; @@ -293,7 +306,7 @@ static void copy_and_fix(const jumpthreading_env_t *env, ir_node *block, pred = get_Proj_pred(node); pn = get_Proj_proj(node); - foreach_out_edge_safe(node, edge, next) { + foreach_out_edge_safe(node, edge) { ir_node *cmp_copy; ir_node *user = get_edge_src_irn(edge); int pos = get_edge_src_pos(edge); @@ -317,7 +330,7 @@ static void copy_and_fix(const jumpthreading_env_t *env, ir_node *block, * recursive find_phi_with_const() call */ assert(get_irn_visited(copy) <= env->visited_nr); if (get_irn_visited(copy) >= env->visited_nr) { - ir_node *prev_copy = get_irn_link(copy); + ir_node *prev_copy = (ir_node*)get_irn_link(copy); if (prev_copy != NULL) set_irn_link(node, prev_copy); } @@ -330,7 +343,7 @@ static void copy_and_fix(const jumpthreading_env_t *env, ir_node *block, ir_mode *mode; mode = get_irn_mode(node); - if (mode == mode_X || is_Cond(node)) + if (mode == mode_X || is_Cond(node) || is_Switch(node)) continue; #ifdef AVOID_PHIB if (mode == mode_b) @@ -339,56 +352,73 @@ static void copy_and_fix(const jumpthreading_env_t *env, ir_node *block, DB((dbg, LEVEL_2, ">> Fixing users of %+F\n", node)); - copy_node = get_irn_link(node); + copy_node = (ir_node*)get_irn_link(node); construct_ssa(block, node, copy_block, copy_node); } + + /* make sure new nodes are kept alive if old nodes were */ + ir_graph *irg = get_irn_irg(block); + ir_node *end = get_irg_end(irg); + for (int i = 0, arity = get_End_n_keepalives(end); i < arity; ++i) { + ir_node *keep = get_End_keepalive(end, i); + if (get_irn_visited(keep) < env->visited_nr || is_Block(keep)) + continue; + ir_node *copy = get_irn_link(keep); + add_End_keepalive(end, copy); + } } /** * returns whether the cmp evaluates to true or false, or can't be evaluated! * 1: true, 0: false, -1: can't evaluate * - * @param pnc the compare mode of the Compare + * @param relation the compare mode of the Compare * @param tv_left the left tarval * @param tv_right the right tarval */ -static int eval_cmp_tv(pn_Cmp pnc, ir_tarval *tv_left, ir_tarval *tv_right) +static int eval_cmp_tv(ir_relation relation, ir_tarval *tv_left, + ir_tarval *tv_right) { - pn_Cmp cmp_result = tarval_cmp(tv_left, tv_right); + ir_relation cmp_result = tarval_cmp(tv_left, tv_right); /* does the compare evaluate to true? */ - if (cmp_result == pn_Cmp_False) + if (cmp_result == ir_relation_false) return -1; - if ((cmp_result & pnc) != cmp_result) - return 0; + if ((cmp_result & relation) != 0) + return 1; - return 1; + return 0; } +#if 0 +/* Matze: disabled, check first if the compare still is correct */ + /** * returns whether the cmp evaluates to true or false according to vrp * information , or can't be evaluated! * 1: true, 0: false, -1: can't evaluate * - * @param pnc the compare mode of the Compare - * @param left the left node - * @param right the right node + * @param relation the compare mode of the Compare + * @param left the left node + * @param right the right node */ -static int eval_cmp_vrp(pn_Cmp pnc, ir_node *left, ir_node *right) +static int eval_cmp_vrp(ir_relation relation, ir_node *left, ir_node *right) { - pn_Cmp cmp_result = vrp_cmp(left, right); + ir_relation cmp_result = vrp_cmp(left, right); /* does the compare evaluate to true? */ - if (cmp_result == pn_Cmp_False) { + if (cmp_result == ir_relation_false) return -1; - } - if ((cmp_result & pnc) != cmp_result) { - if ((cmp_result & pnc) != 0) { + + if ((cmp_result & relation) != cmp_result) { + if ((cmp_result & relation) != 0) { return -1; } return 0; } return 1; } +#endif + /** * returns whether the cmp evaluates to true or false, or can't be evaluated! * 1: true, 0: false, -1: can't evaluate @@ -399,12 +429,12 @@ static int eval_cmp_vrp(pn_Cmp pnc, ir_node *left, ir_node *right) static int eval_cmp(jumpthreading_env_t *env, ir_node *cand) { if (is_Const(cand)) { - ir_tarval *tv_cand = get_Const_tarval(cand); - ir_tarval *tv_cmp = get_Const_tarval(env->cnst); + ir_tarval *tv_cand = get_Const_tarval(cand); + ir_tarval *tv_cmp = get_Const_tarval(env->cnst); - return eval_cmp_tv(env->pnc, tv_cand, tv_cmp); + return eval_cmp_tv(env->relation, tv_cand, tv_cmp); } else { /* a Confirm */ - ir_tarval *res = computed_value_Cmp_Confirm(env->cmp, cand, env->cnst, env->pnc); + ir_tarval *res = computed_value_Cmp_Confirm(env->cmp, cand, env->cnst, env->relation); if (res == tarval_bad) return -1; @@ -443,14 +473,13 @@ static ir_node *find_const_or_confirm(jumpthreading_env_t *env, ir_node *jump, return NULL; if (is_Const_or_Confirm(value)) { - if (eval_cmp(env, value) <= 0) { + if (eval_cmp(env, value) <= 0) return NULL; - } DB(( dbg, LEVEL_1, "> Found jump threading candidate %+F->%+F\n", - env->true_block, block + block, env->true_block )); /* adjust true_block to point directly towards our jump */ @@ -468,9 +497,8 @@ static ir_node *find_const_or_confirm(jumpthreading_env_t *env, ir_node *jump, int i, arity; /* the Phi has to be in the same Block as the Jmp */ - if (get_nodes_block(value) != block) { + if (get_nodes_block(value) != block) return NULL; - } arity = get_irn_arity(value); for (i = 0; i < arity; ++i) { @@ -516,7 +544,7 @@ static ir_node *find_candidate(jumpthreading_env_t *env, ir_node *jump, DB(( dbg, LEVEL_1, "> Found jump threading candidate %+F->%+F\n", - env->true_block, block + block, env->true_block )); /* adjust true_block to point directly towards our jump */ @@ -558,17 +586,11 @@ static ir_node *find_candidate(jumpthreading_env_t *env, ir_node *jump, return copy_block; } } - if (is_Proj(value)) { - ir_node *left; - ir_node *right; - int pnc; - ir_node *cmp = get_Proj_pred(value); - if (!is_Cmp(cmp)) - return NULL; - - left = get_Cmp_left(cmp); - right = get_Cmp_right(cmp); - pnc = get_Proj_proj(value); + if (is_Cmp(value)) { + ir_node *cmp = value; + ir_node *left = get_Cmp_left(cmp); + ir_node *right = get_Cmp_right(cmp); + ir_relation relation = get_Cmp_relation(cmp); /* we assume that the constant is on the right side, swap left/right * if needed */ @@ -577,25 +599,24 @@ static ir_node *find_candidate(jumpthreading_env_t *env, ir_node *jump, left = right; right = t; - pnc = get_inversed_pnc(pnc); + relation = get_inversed_relation(relation); } if (!is_Const(right)) - return 0; + return NULL; - if (get_nodes_block(left) != block) { - return 0; - } + if (get_nodes_block(left) != block) + return NULL; /* negate condition when we're looking for the false block */ if (env->tv == tarval_b_false) { - pnc = get_negated_pnc(pnc, get_irn_mode(right)); + relation = get_negated_relation(relation); } /* (recursively) look if a pred of a Phi is a constant or a Confirm */ - env->cmp = cmp; - env->pnc = pnc; - env->cnst = right; + env->cmp = cmp; + env->relation = relation; + env->cnst = right; return find_const_or_confirm(env, jump, left); } @@ -619,17 +640,17 @@ static ir_node *find_candidate(jumpthreading_env_t *env, ir_node *jump, static void thread_jumps(ir_node* block, void* data) { jumpthreading_env_t env; - int *changed = data; + bool *changed = (bool*)data; ir_node *selector; ir_node *projx; ir_node *cond; ir_node *copy_block; int selector_evaluated; - const ir_edge_t *edge, *next; ir_graph *irg; - ir_node *bad; - size_t cnst_pos; + ir_node *badX; + int cnst_pos; + /* we do not deal with Phis, so restrict this to exactly one cfgpred */ if (get_Block_n_cfgpreds(block) != 1) return; @@ -639,38 +660,32 @@ static void thread_jumps(ir_node* block, void* data) assert(get_irn_mode(projx) == mode_X); cond = get_Proj_pred(projx); - if (!is_Cond(cond)) - return; - - selector = get_Cond_selector(cond); /* TODO handle switch Conds */ - if (get_irn_mode(selector) != mode_b) + if (!is_Cond(cond)) return; /* handle cases that can be immediately evaluated */ + selector = get_Cond_selector(cond); selector_evaluated = -1; - if (is_Proj(selector)) { - ir_node *cmp = get_Proj_pred(selector); - if (is_Cmp(cmp)) { - ir_node *left = get_Cmp_left(cmp); - ir_node *right = get_Cmp_right(cmp); - if (is_Const(left) && is_Const(right)) { - int pnc = get_Proj_proj(selector); - ir_tarval *tv_left = get_Const_tarval(left); - ir_tarval *tv_right = get_Const_tarval(right); - - selector_evaluated = eval_cmp_tv(pnc, tv_left, tv_right); - } - if (selector_evaluated < 0) { - /* This is only the case if the predecessor nodes are not - * constant or the comparison could not be evaluated. - * Try with VRP information now. - */ - int pnc = get_Proj_proj(selector); - - selector_evaluated = eval_cmp_vrp(pnc, left, right); - } + if (is_Cmp(selector)) { + ir_node *left = get_Cmp_left(selector); + ir_node *right = get_Cmp_right(selector); + if (is_Const(left) && is_Const(right)) { + ir_relation relation = get_Cmp_relation(selector); + ir_tarval *tv_left = get_Const_tarval(left); + ir_tarval *tv_right = get_Const_tarval(right); + + selector_evaluated = eval_cmp_tv(relation, tv_left, tv_right); } +#if 0 + if (selector_evaluated < 0) { + /* This is only the case if the predecessor nodes are not + * constant or the comparison could not be evaluated. + * Try with VRP information now. + */ + selector_evaluated = eval_cmp_vrp(relation, left, right); + } +#endif } else if (is_Const_or_Confirm(selector)) { ir_tarval *tv = get_Const_or_Confirm_tarval(selector); if (tv == tarval_b_true) { @@ -692,16 +707,16 @@ static void thread_jumps(ir_node* block, void* data) if (selector_evaluated == 0) { ir_graph *irg = get_irn_irg(block); - bad = new_r_Bad(irg); + ir_node *bad = new_r_Bad(irg, mode_X); exchange(projx, bad); - *changed = 1; + *changed = true; return; } else if (selector_evaluated == 1) { dbg_info *dbgi = get_irn_dbg_info(selector); ir_node *jmp = new_rd_Jmp(dbgi, get_nodes_block(projx)); DBG_OPT_JUMPTHREADING(projx, jmp); exchange(projx, jmp); - *changed = 1; + *changed = true; return; } @@ -715,60 +730,59 @@ static void thread_jumps(ir_node* block, void* data) if (copy_block == NULL) return; + /* We might thread the condition block of an infinite loop, + * such that there is no path to End anymore. */ + keep_alive(block); + /* we have to remove the edge towards the pred as the pred now * jumps into the true_block. We also have to shorten Phis * in our block because of this */ - bad = new_r_Bad(irg); + badX = new_r_Bad(irg, mode_X); cnst_pos = env.cnst_pos; /* shorten Phis */ - foreach_out_edge_safe(env.cnst_pred, edge, next) { + foreach_out_edge_safe(env.cnst_pred, edge) { ir_node *node = get_edge_src_irn(edge); - if (is_Phi(node)) + if (is_Phi(node)) { + ir_node *bad = new_r_Bad(irg, get_irn_mode(node)); set_Phi_pred(node, cnst_pos, bad); + } } - set_Block_cfgpred(env.cnst_pred, cnst_pos, bad); + set_Block_cfgpred(env.cnst_pred, cnst_pos, badX); /* the graph is changed now */ - *changed = 1; + *changed = true; } void opt_jumpthreading(ir_graph* irg) { - int changed, rerun; + bool changed; + bool rerun; + + assure_irg_properties(irg, + IR_GRAPH_PROPERTY_NO_UNREACHABLE_CODE + | IR_GRAPH_PROPERTY_CONSISTENT_OUT_EDGES + | IR_GRAPH_PROPERTY_NO_CRITICAL_EDGES); FIRM_DBG_REGISTER(dbg, "firm.opt.jumpthreading"); DB((dbg, LEVEL_1, "===> Performing jumpthreading on %+F\n", irg)); - remove_critical_cf_edges(irg); - - edges_assure(irg); ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_IRN_VISITED); - changed = 0; + changed = false; do { - rerun = 0; + rerun = false; irg_block_walk_graph(irg, thread_jumps, NULL, &rerun); changed |= rerun; } while (rerun); ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_IRN_VISITED); - if (changed) { - /* control flow changed, some blocks may become dead */ - set_irg_outs_inconsistent(irg); - set_irg_doms_inconsistent(irg); - set_irg_extblk_inconsistent(irg); - set_irg_loopinfo_inconsistent(irg); - set_irg_entity_usage_state(irg, ir_entity_usage_not_computed); - - /* Dead code might be created. Optimize it away as it is dangerous - * to call optimize_df() an dead code. */ - optimize_cf(irg); - } + confirm_irg_properties(irg, + changed ? IR_GRAPH_PROPERTIES_NONE : IR_GRAPH_PROPERTIES_ALL); } /* Creates an ir_graph pass for opt_jumpthreading. */