X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fcondeval.c;h=54ddc5a465c192f73e839361e9708f57fac3d584;hb=1a4bb21b7aa32f0bcd282d4c1cdb144aca601fa9;hp=51e0cc53f6e82ca44fbf02b4cc36aff71a46430b;hpb=d35b6a5f0e6ef37e1a17b342ba59ae34fbd64ee0;p=libfirm diff --git a/ir/opt/condeval.c b/ir/opt/condeval.c index 51e0cc53f..54ddc5a46 100644 --- a/ir/opt/condeval.c +++ b/ir/opt/condeval.c @@ -1,21 +1,52 @@ -#ifdef HAVE_CONFIG_H +/* + * 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. + */ + +/** + * @file + * @brief Partial condition evaluation + * @date 10. Sep. 2006 + * @author Christoph Mallon, Matthias Braun + * @version $Id$ + */ #include "config.h" -#endif + +#include "iroptimize.h" #include -#include "array.h" -#include "condeval.h" +#include "array_t.h" #include "debug.h" #include "ircons.h" #include "irgmod.h" #include "irgopt.h" #include "irgwalk.h" #include "irnode.h" +#include "irnode_t.h" #include "iredges.h" +#include "iredges_t.h" +#include "irtools.h" +#include "irgraph.h" #include "tv.h" +#include "opt_confirms.h" -DEBUG_ONLY(static firm_dbg_module_t *dbg); +#undef AVOID_PHIB +DEBUG_ONLY(static firm_dbg_module_t *dbg); /** * Add the new predecessor x to node node, which is either a Block or a Phi @@ -30,43 +61,17 @@ static void add_pred(ir_node* node, ir_node* x) n = get_irn_arity(node); NEW_ARR_A(ir_node*, ins, n + 1); - for (i = 0; i < n; i++) ins[i] = get_irn_n(node, i); + for (i = 0; i < n; i++) + ins[i] = get_irn_n(node, i); ins[n] = x; set_irn_in(node, n + 1, ins); } +static ir_node *ssa_second_def; +static ir_node *ssa_second_def_block; -/** - * Remove predecessor j from node, which is either a Block or a Phi - * returns true if only one predecessor is left - */ -static int remove_pred(ir_node* node, int j) -{ - int n; - - assert(is_Block(node) || is_Phi(node)); - - n = get_irn_arity(node); - if (n == 2) { - ir_node* pred = get_irn_n(node, 1 - j); - - if (is_Block(node)) pred = get_nodes_block(pred); - exchange(node, pred); - return 1; - } else { - ir_node** ins; - int i; - - NEW_ARR_A(ir_node*, ins, n - 1); - for (i = 0; i < j; i++) ins[i] = get_irn_n(node, i); - for (i++; i < n; i++) ins[i - 1] = get_irn_n(node, i); - set_irn_in(node, n - 1, ins); - return 0; - } -} - - -static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode) +static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode, + int first) { int i; int n_cfgpreds; @@ -74,224 +79,655 @@ static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode) ir_node *phi; ir_node **in; - assert(!is_Bad(block)); + /* This is needed because we create bads sometimes */ + if(is_Bad(block)) + return new_Bad(); + + /* 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 + * away and may use the alternative definition */ + if (block == ssa_second_def_block && !first) { + return ssa_second_def; + } - // already processed this block? + /* already processed this block? */ if(irn_visited(block)) { ir_node *value = (ir_node*) get_irn_link(block); return value; } - // blocks with only 1 pred need no phi + irg = get_irn_irg(block); + assert(block != get_irg_start_block(irg)); + + /* a Block with only 1 predecessor needs no Phi */ n_cfgpreds = get_Block_n_cfgpreds(block); if(n_cfgpreds == 1) { ir_node *pred_block = get_Block_cfgpred_block(block, 0); - ir_node *value = search_def_and_create_phis(pred_block, mode); + ir_node *value = search_def_and_create_phis(pred_block, mode, 0); set_irn_link(block, value); mark_irn_visited(block); return value; } - // create a new phi - in = alloca(sizeof(in[0]) * n_cfgpreds); + /* create a new Phi */ + NEW_ARR_A(ir_node*, in, n_cfgpreds); for(i = 0; i < n_cfgpreds; ++i) in[i] = new_Unknown(mode); - irg = get_irn_irg(block); phi = new_r_Phi(irg, block, n_cfgpreds, in, mode); set_irn_link(block, phi); mark_irn_visited(block); - // set phi preds + /* set Phi predecessors */ for(i = 0; i < n_cfgpreds; ++i) { ir_node *pred_block = get_Block_cfgpred_block(block, i); - ir_node *pred_val; + ir_node *pred_val = search_def_and_create_phis(pred_block, mode, 0); - pred_val = search_def_and_create_phis(pred_block, mode); set_irn_n(phi, i, pred_val); } return phi; } - /** - * Given a set of values this function constructs SSA-form for all users of the - * values (the user are determined through the out-edges of the values). + * Given a set of values this function constructs SSA-form for the users of the + * first value (the users are determined through the out-edges of the value). + * Uses the irn_visited flags. Works without using the dominance tree. */ -static void construct_ssa(ir_node * const *vals, int n_vals) +static void construct_ssa(ir_node *orig_block, ir_node *orig_val, + ir_node *second_block, ir_node *second_val) { - int i; ir_graph *irg; ir_mode *mode; + const ir_edge_t *edge; + const ir_edge_t *next; - assert(n_vals > 0); + /* no need to do anything */ + if (orig_val == second_val) + return; - irg = get_irn_irg(vals[0]); + irg = get_irn_irg(orig_val); inc_irg_visited(irg); - mode = get_irn_mode(vals[0]); - for(i = 0; i < n_vals; ++i) { - ir_node *value = vals[i]; - ir_node *value_block = get_nodes_block(value); + mode = get_irn_mode(orig_val); + set_irn_link(orig_block, orig_val); + mark_irn_visited(orig_block); + + ssa_second_def_block = second_block; + 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) { + ir_node *user = get_edge_src_irn(edge); + int j = get_edge_src_pos(edge); + ir_node *user_block = get_nodes_block(user); + ir_node *newval; - assert(get_irn_mode(value) == mode); + /* ignore keeps */ + if (is_End(user)) + continue; + + DB((dbg, LEVEL_3, ">>> Fixing user %+F (pred %d == %+F)\n", user, j, get_irn_n(user, j))); - set_irn_link(value_block, value); - mark_irn_visited(value_block); + if(is_Phi(user)) { + ir_node *pred_block = get_Block_cfgpred_block(user_block, j); + newval = search_def_and_create_phis(pred_block, mode, 1); + } else { + newval = search_def_and_create_phis(user_block, mode, 1); + } + + /* don't fix newly created Phis from the SSA construction */ + if (newval != user) { + DB((dbg, LEVEL_4, ">>>> Setting input %d of %+F to %+F\n", j, user, newval)); + set_irn_n(user, j, newval); + } } +} + +static void split_critical_edge(ir_node *block, int pos) { + ir_graph *irg = get_irn_irg(block); + ir_node *in[1]; + ir_node *new_block; + ir_node *new_jmp; + + in[0] = get_Block_cfgpred(block, pos); + new_block = new_r_Block(irg, 1, in); + new_jmp = new_r_Jmp(irg, new_block); + set_Block_cfgpred(block, pos, new_jmp); +} + +typedef struct condeval_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_node *cnst; + tarval *tv; + ir_visited_t visited_nr; + + ir_node *cnst_pred; /**< the block before the constant */ + int cnst_pos; /**< the pos to the constant block (needed to + kill that edge later) */ +} condeval_env_t; + +static ir_node *copy_and_fix_node(const condeval_env_t *env, ir_node *block, + ir_node *copy_block, int j, ir_node *node) { + int i, arity; + ir_node *copy; + + /* we can evaluate Phis right now, all other nodes get copied */ + if (is_Phi(node)) { + 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); + } + } else { + copy = exact_copy(node); + set_nodes_block(copy, copy_block); + + assert(get_irn_mode(copy) != mode_X); - for(i = 0; i < n_vals; ++i) { - const ir_edge_t *edge; - ir_node *value = vals[i]; + arity = get_irn_arity(copy); + for(i = 0; i < arity; ++i) { + ir_node *pred = get_irn_n(copy, i); + ir_node *new_pred; - foreach_out_edge(value, edge) { - ir_node *user = get_edge_src_irn(edge); - ir_node *user_block = get_nodes_block(user); - ir_node *newval; + if(get_nodes_block(pred) != block) + continue; - newval = search_def_and_create_phis(user_block, mode); - set_irn_n(user, get_edge_src_pos(edge), newval); + if(get_irn_visited(pred) >= env->visited_nr) { + new_pred = get_irn_link(pred); + } else { + new_pred = copy_and_fix_node(env, block, copy_block, j, pred); + } + DB((dbg, LEVEL_2, ">> Set Pred of %+F to %+F\n", copy, new_pred)); + set_irn_n(copy, i, new_pred); } } + + set_irn_link(node, copy); + set_irn_visited(node, env->visited_nr); + + return copy; } +static void copy_and_fix(const condeval_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_Block(node)) { + /* Block->Block edge, should be the MacroBlock edge */ + assert(get_Block_MacroBlock(node) == block && "Block->Block edge found"); + continue; + } + + /* ignore control flow */ + mode = get_irn_mode(node); + if (mode == mode_X || is_Cond(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; + + assert(is_Proj(node)); + + pred = get_Proj_pred(node); + pn = get_Proj_proj(node); + + foreach_out_edge_safe(node, edge, next) { + ir_node *cmp_copy; + ir_node *user = get_edge_src_irn(edge); + int pos = get_edge_src_pos(edge); + ir_node *user_block = get_nodes_block(user); + + if(user_block == block) + continue; + + cmp_copy = exact_copy(pred); + set_nodes_block(cmp_copy, user_block); + copy = new_r_Proj(current_ir_graph, user_block, cmp_copy, mode_b, pn); + set_irn_n(user, pos, copy); + } + continue; + } +#endif + + copy = copy_and_fix_node(env, block, copy_block, j, node); + + /* we might hit values in blocks that have already been processed by a + * 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); + if(prev_copy != NULL) + set_irn_link(node, prev_copy); + } + } + + /* fix data-flow (and reconstruct SSA if needed) */ + foreach_out_edge(block, edge) { + ir_node *node = get_edge_src_irn(edge); + ir_node *copy_node; + ir_mode *mode; + + if (is_Block(node)) { + /* Block->Block edge, should be the MacroBlock edge */ + assert(get_Block_MacroBlock(node) == block && "Block->Block edge found"); + continue; + } + + mode = get_irn_mode(node); + if (mode == mode_X || is_Cond(node)) + continue; +#ifdef AVOID_PHIB + if (mode == mode_b) + continue; +#endif + + DB((dbg, LEVEL_2, ">> Fixing users of %+F\n", node)); + + copy_node = get_irn_link(node); + construct_ssa(block, node, copy_block, copy_node); + } +} -#if 0 /** - * Compare node compares two Const nodes - * Returns true if this direction is taken + * 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 tv_left the left tarval + * @param tv_right the right tarval */ -static int handle_const_const(ir_node* cnst_left, cnst_right, pn_Cmp pnc) -{ - // TODO -} -#endif +static int eval_cmp_tv(pn_Cmp pnc, tarval *tv_left, tarval *tv_right) { + pn_Cmp cmp_result = tarval_cmp(tv_left, tv_right); + /* does the compare evaluate to true? */ + if (cmp_result == pn_Cmp_False) + return -1; + if ((cmp_result & pnc) != cmp_result) + return 0; + + return 1; +} /** + * returns whether the cmp evaluates to true or false, or can't be evaluated! + * 1: true, 0: false, -1: can't evaluate * + * @param env the environment + * @param cand the candidate node, either a Const or a Confirm */ -static void handle_phi_const(ir_node* block, ir_node* cond_block, ir_node* phi, ir_node* cnst, pn_Cmp pnc) -{ - tarval* tv_cnst; - int n_phi; - int j; +static int eval_cmp(condeval_env_t *env, ir_node *cand) { + if (is_Const(cand)) { + tarval *tv_cand = get_Const_tarval(cand); + tarval *tv_cmp = get_Const_tarval(env->cnst); + + return eval_cmp_tv(env->pnc, tv_cand, tv_cmp); + } else { /* a Confirm */ + tarval *res = computed_value_Cmp_Confirm(env->cmp, cand, env->cnst, env->pnc); + + if (res == tarval_bad) + return -1; + return res == tarval_b_true; + } +} - tv_cnst = get_Const_tarval(cnst); - n_phi = get_Phi_n_preds(phi); - for (j = 0; j < n_phi; j++) { - ir_node* pred; - tarval* tv_phi; - pn_Cmp cmp_val; +/** + * Check for Const or Confirm with Const. + */ +static int is_Const_or_Confirm(const ir_node *node) { + if (is_Confirm(node)) + node = get_Confirm_bound(node); + return is_Const(node); +} - pred = get_Phi_pred(phi, j); - // TODO handle Phi cascades - if (!is_Const(pred)) continue; +/** + * get the tarval of a Const or Confirm with + */ +static tarval *get_Const_or_Confirm_tarval(const ir_node *node) { + if (is_Confirm(node)) { + if (get_Confirm_bound(node)) + node = get_Confirm_bound(node); + } + return get_Const_tarval(node); +} - tv_phi = get_Const_tarval(pred); +static ir_node *find_const_or_confirm(condeval_env_t *env, ir_node *jump, ir_node *value) +{ + ir_node *block = get_nodes_block(jump); - cmp_val = tarval_cmp(tv_phi, tv_cnst); - if (cmp_val == pn_Cmp_False) continue; - if ((cmp_val & pnc) != cmp_val) continue; + if (irn_visited_else_mark(value)) + return NULL; + + if (is_Const_or_Confirm(value)) { + if (eval_cmp(env, value) <= 0) { + return NULL; + } DB(( dbg, LEVEL_1, - "> Found condition evaluation candidate %+F->%+F predecessor %d\n", - block, cond_block, j + "> Found condition evaluation candidate %+F->%+F\n", + env->true_block, block )); -#if 0 // TODO repair data flow and dominance - add_pred(block, get_Block_cfgpred(cond_block, j)); + /* adjust true_block to point directly towards our jump */ + add_pred(env->true_block, jump); - remove_pred(phi, j); - if (remove_pred(cond_block, j)) break; -#endif + split_critical_edge(env->true_block, 0); + + /* we need a bigger visited nr when going back */ + env->visited_nr++; + + return block; } -} + if(is_Phi(value)) { + int i, arity; -/** - * Block-walker: - */ -static void cond_eval(ir_node* block, void* env) + /* the Phi has to be in the same Block as the Jmp */ + if(get_nodes_block(value) != block) { + return NULL; + } + + arity = get_irn_arity(value); + for(i = 0; i < arity; ++i) { + ir_node *copy_block; + ir_node *phi_pred = get_Phi_pred(value, i); + ir_node *cfgpred = get_Block_cfgpred(block, i); + + copy_block = find_const_or_confirm(env, cfgpred, phi_pred); + if(copy_block == NULL) + continue; + + /* copy duplicated nodes in copy_block and fix SSA */ + copy_and_fix(env, block, copy_block, i); + + if(copy_block == get_nodes_block(cfgpred)) { + env->cnst_pred = block; + env->cnst_pos = i; + } + + /* return now as we can't process more possibilities in 1 run */ + return copy_block; + } + } + + return NULL; +} + +static ir_node *find_candidate(condeval_env_t *env, ir_node *jump, + ir_node *value) { - int n_block = get_Block_n_cfgpreds(block); - int i; + ir_node *block = get_nodes_block(jump); + + if (irn_visited_else_mark(value)) { + return NULL; + } + + if (is_Const_or_Confirm(value)) { + tarval *tv = get_Const_or_Confirm_tarval(value); + + if (tv != env->tv) + return NULL; + + DB(( + dbg, LEVEL_1, + "> Found condition evaluation candidate %+F->%+F\n", + env->true_block, block + )); + + /* adjust true_block to point directly towards our jump */ + add_pred(env->true_block, jump); + + split_critical_edge(env->true_block, 0); + + /* we need a bigger visited nr when going back */ + env->visited_nr++; + + return block; + } + if(is_Phi(value)) { + int i, arity; + + /* the Phi has to be in the same Block as the Jmp */ + if(get_nodes_block(value) != block) + return NULL; + + arity = get_irn_arity(value); + for(i = 0; i < arity; ++i) { + ir_node *copy_block; + ir_node *phi_pred = get_Phi_pred(value, i); + ir_node *cfgpred = get_Block_cfgpred(block, i); - for (i = 0; i < n_block; i++) { - ir_node* pred; - ir_node* projx; - ir_node* cond; - ir_node* cmp; - ir_node* left; - ir_node* right; - ir_node* cond_block; - pn_Cmp pnc; - - pred = get_Block_cfgpred(block, i); - if (!is_Proj(pred)) continue; - projx = pred; - - pred = get_Proj_pred(projx); - if (!is_Cond(pred)) continue; - cond = pred; - - pred = get_Cond_selector(cond); - assert(is_Proj(pred)); - // TODO handle switches - if (get_irn_mode(pred) != mode_b) continue; - pnc = get_Proj_proj(pred); - - cmp = get_Proj_pred(pred); - assert(is_Cmp(cmp)); + copy_block = find_candidate(env, cfgpred, phi_pred); + if(copy_block == NULL) + continue; + + /* copy duplicated nodes in copy_block and fix SSA */ + copy_and_fix(env, block, copy_block, i); + + if(copy_block == get_nodes_block(cfgpred)) { + env->cnst_pred = block; + env->cnst_pos = i; + } + + /* return now as we can't process more possibilities in 1 run */ + 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); - assert(get_irn_mode(left) == get_irn_mode(right)); + pnc = get_Proj_proj(value); - if (get_Proj_proj(projx) == 0) { - pnc = get_negated_pnc(pnc, get_irn_mode(left)); + /* we assume that the constant is on the right side, swap left/right + * if needed */ + if(is_Const(left)) { + ir_node *t = left; + left = right; + right = t; + + pnc = get_inversed_pnc(pnc); } -#if 0 // TODO implement - if (is_Const(left) && is_Const(right)) { - if (!handle_const_const()) { - n_block--; - i--; - } - continue; + if(!is_Const(right)) + return 0; + + if(get_nodes_block(left) != block) { + return 0; } -#endif - cond_block = get_nodes_block(cond); - if (is_Phi(left) && is_Const(right)) { - if (get_nodes_block(left) != cond_block) continue; - handle_phi_const(block, cond_block, left, right, pnc); - continue; + + /* 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)); } - if (is_Const(left) && is_Phi(right)) { - if (get_nodes_block(right) != cond_block) continue; - handle_phi_const(block, cond_block, right, left, get_inversed_pnc(pnc)); - continue; + + /* (recursively) look if a pred of a Phi is a constant or a Confirm */ + env->cmp = cmp; + env->pnc = pnc; + env->cnst = right; + + return find_const_or_confirm(env, jump, left); + } + + return NULL; +} + +/** + * Block-walker: searches for the following construct + * + * Const or Phi with constants + * | + * Cmp + * | + * Cond + * / + * ProjX + * / + * Block + */ +static void cond_eval(ir_node* block, void* data) +{ + condeval_env_t env; + int *changed = data; + ir_node *selector; + ir_node *projx; + ir_node *cond; + ir_node *copy_block; + int selector_evaluated; + const ir_edge_t *edge, *next; + ir_node* bad; + size_t cnst_pos; + + if(get_Block_n_cfgpreds(block) != 1) + return; + + projx = get_Block_cfgpred(block, 0); + if (!is_Proj(projx)) + return; + 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) + return; + + /* handle cases that can be immediately evaluated */ + 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); + tarval *tv_left = get_Const_tarval(left); + tarval *tv_right = get_Const_tarval(right); + + selector_evaluated = eval_cmp_tv(pnc, tv_left, tv_right); + if(selector_evaluated < 0) + return; + } } -#if 0 - if (is_Phi(left) && is_Phi(right)) { - // TODO implement + } else if (is_Const_or_Confirm(selector)) { + tarval *tv = get_Const_or_Confirm_tarval(selector); + if(tv == tarval_b_true) { + selector_evaluated = 1; + } else { + assert(tv == tarval_b_false); + selector_evaluated = 0; } -#endif } -} + env.cnst_pred = NULL; + if (get_Proj_proj(projx) == pn_Cond_false) { + env.tv = tarval_b_false; + if(selector_evaluated >= 0) + selector_evaluated = !selector_evaluated; + } else { + env.tv = tarval_b_true; + } + + if(selector_evaluated == 0) { + bad = new_Bad(); + exchange(projx, bad); + *changed = 1; + return; + } else if(selector_evaluated == 1) { + dbg_info *dbgi = get_irn_dbg_info(selector); + ir_node *jmp = new_rd_Jmp(dbgi, current_ir_graph, get_nodes_block(projx)); + exchange(projx, jmp); + *changed = 1; + return; + } + + /* (recursively) look if a pred of a Phi is a constant or a Confirm */ + env.true_block = block; + inc_irg_visited(current_ir_graph); + env.visited_nr = get_irg_visited(current_ir_graph); + + copy_block = find_candidate(&env, projx, selector); + if (copy_block == NULL) + return; + + /* 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_Bad(); + cnst_pos = env.cnst_pos; + + /* shorten Phis */ + foreach_out_edge_safe(env.cnst_pred, edge, next) { + ir_node *node = get_edge_src_irn(edge); + + if(is_Phi(node)) + set_Phi_pred(node, cnst_pos, bad); + } + + set_Block_cfgpred(env.cnst_pred, cnst_pos, bad); + + /* the graph is changed now */ + *changed = 1; +} void opt_cond_eval(ir_graph* irg) { + int changed, rerun; + FIRM_DBG_REGISTER(dbg, "firm.opt.condeval"); - firm_dbg_set_mask(dbg, SET_LEVEL_5); DB((dbg, LEVEL_1, "===> Performing condition evaluation on %+F\n", irg)); remove_critical_cf_edges(irg); - - irg_block_walk_graph(irg, NULL, cond_eval, NULL); + normalize_proj_nodes(irg); + + edges_assure(irg); + ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_IRN_VISITED); + + changed = 0; + do { + rerun = 0; + irg_block_walk_graph(irg, cond_eval, 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); + + /* Dead code might be created. Optimize it away as it is dangerous + * to call optimize_df() an dead code. */ + optimize_cf(irg); + } }