From 702fe1d97f05f26a150804c4196875e4367a648a Mon Sep 17 00:00:00 2001 From: Michael Beck Date: Fri, 15 Aug 2008 15:54:48 +0000 Subject: [PATCH] - handle endless loops now - use resource locking functions [r21199] --- ir/opt/combo.c | 92 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 67 insertions(+), 25 deletions(-) diff --git a/ir/opt/combo.c b/ir/opt/combo.c index 3378fe2e9..192260896 100644 --- a/ir/opt/combo.c +++ b/ir/opt/combo.c @@ -2637,7 +2637,7 @@ static int can_exchange(ir_node *pred) { return 1; } return 0; -} +} /* can_exchange */ /** * Block Post-Walker, apply the analysis results on control flow by @@ -2650,26 +2650,49 @@ static void apply_cf(ir_node *block, void *ctx) { ir_node **ins, **in_X; ir_node *phi, *next; - if (block == get_irg_end_block(current_ir_graph) || - block == get_irg_start_block(current_ir_graph)) { + n = get_Block_n_cfgpreds(block); + + if (node->type.tv == tarval_unreachable) { + env->modified = 1; + + for (i = n - 1; i >= 0; --i) { + ir_node *pred = get_Block_cfgpred(block, i); + node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred))); + + if (pred_bl->flagged == 0) { + pred_bl->flagged = 3; + + if (pred_bl->type.tv == tarval_reachable) { + /* + * We will remove an edge from block to its pred. + * This might leave the pred block as an endless loop + */ + if (! is_backedge(block, i)) + keep_alive(pred_bl->node); + } + } + } + /* the EndBlock is always reachable even if the analysis finds out the opposite :-) */ - return; - } - if (node->type.tv == tarval_unreachable) { - /* mark dead blocks */ - set_Block_dead(block); + if (block != get_irg_end_block(current_ir_graph)) { + /* mark dead blocks */ + set_Block_dead(block); + } else { + /* the endblock is unreachable */ + set_irn_in(block, 0, NULL); + } return; } - n = get_Block_n_cfgpreds(block); - if (n == 1) { /* only one predecessor combine */ ir_node *pred = skip_Proj(get_Block_cfgpred(block, 0)); if (can_exchange(pred)) { - exchange(block, get_nodes_block(pred)); + ir_node *new_block = get_nodes_block(pred); + exchange(block, new_block); + node->node = new_block; env->modified = 1; } return; @@ -2683,6 +2706,21 @@ static void apply_cf(ir_node *block, void *ctx) { if (node->type.tv == tarval_reachable) { in_X[k++] = pred; + } else { + node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred))); + + if (pred_bl->flagged == 0) { + pred_bl->flagged = 3; + + if (pred_bl->type.tv == tarval_reachable) { + /* + * We will remove an edge from block to its pred. + * This might leave the pred block as an endless loop + */ + if (! is_backedge(block, i)) + keep_alive(pred_bl->node); + } + } } } if (k >= n) @@ -2712,13 +2750,15 @@ static void apply_cf(ir_node *block, void *ctx) { ins[j++] = get_Phi_pred(phi, i); } } - if (j <= 1) { + if (j == 1) { /* this Phi is replaced by a single predecessor */ ir_node *s = ins[0]; + node_t *phi_node = get_irn_node(phi); node->node = s; DB((dbg, LEVEL_1, "%+F is replaced by %+F because of cf change\n", phi, s)); exchange(phi, s); + phi_node->node = s; env->modified = 1; } else { set_irn_in(phi, j, ins); @@ -2727,12 +2767,14 @@ static void apply_cf(ir_node *block, void *ctx) { } } - if (k <= 1) { + if (k == 1) { /* this Block has only one live predecessor */ ir_node *pred = skip_Proj(in_X[0]); if (can_exchange(pred)) { - exchange(block, get_nodes_block(pred)); + ir_node *new_block = get_nodes_block(pred); + exchange(block, new_block); + node->node = new_block; env->modified = 1; } } else { @@ -2787,7 +2829,7 @@ static void apply_result(ir_node *irn, void *ctx) { if (is_tarval(sel->type.tv) && tarval_is_constant(sel->type.tv)) { /* Cond selector is a constant, make a Jmp */ - ir_node *jmp = new_r_Jmp(current_ir_graph, block->node); + ir_node *jmp = new_r_Jmp(current_ir_graph, block->node); set_irn_node(jmp, node); node->node = jmp; DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, jmp)); @@ -2855,17 +2897,11 @@ static void apply_end(ir_node *end, environment_t *env) { ir_node *ka = get_End_keepalive(end, i); node_t *node = get_irn_node(ka); - /* Use the flagged bits to mark already visited nodes. - * This should not be ready but better safe than sorry. */ - if (node->flagged == 0) { - node->flagged = 3; - - if (! is_Block(ka)) - node = get_irn_node(get_nodes_block(ka)); + if (! is_Block(ka)) + node = get_irn_node(get_nodes_block(ka)); - if (node->type.tv != tarval_unreachable) - in[j++] = ka; - } + if (node->type.tv != tarval_unreachable) + in[j++] = ka; } if (j != n) { set_End_keepalives(end, j, in); @@ -2947,6 +2983,8 @@ void combo(ir_graph *irg) { env.modified = 0; assure_irg_outs(irg); + assure_cf_loop(irg); + /* we have our own value_of function */ set_value_of_func(get_node_tarval); @@ -2954,6 +2992,8 @@ void combo(ir_graph *irg) { set_compute_functions(); DEBUG_ONLY(part_nr = 0); + ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK); + /* create the initial partition and place it on the work list */ env.initial = new_partition(&env); add_to_worklist(env.initial, &env); @@ -3004,6 +3044,8 @@ void combo(ir_graph *irg) { set_irg_loopinfo_inconsistent(irg); } + ir_free_resources(irg, IR_RESOURCE_IRN_LINK); + pmap_destroy(env.type2id_map); del_set(env.opcode2id_map); obstack_free(&env.obst, NULL); -- 2.20.1