/** * This function returns the last definition of a value. In case * this value was last defined in a previous block, Phi nodes are * inserted. If the part of the firm graph containing the definition * is not yet constructed, a dummy Phi node is returned. * * @param block the current block * @param pos the value number of the value searched * @param mode the mode of this value (needed for Phi construction) */ static ir_node *get_r_value_internal(ir_node *block, int pos, ir_mode *mode) { ir_node *res = block->attr.block.graph_arr[pos]; if (res != NULL) return res; /* in a matured block we can immediately determine the phi arguments */ if (get_Block_matured(block)) { ir_graph *const irg = get_irn_irg(block); int const arity = get_irn_arity(block); /* no predecessors: use unknown value */ if (arity == 0) { if (block == get_irg_start_block(irg)) { if (default_initialize_local_variable != NULL) { ir_node *rem = get_r_cur_block(irg); set_r_cur_block(irg, block); res = default_initialize_local_variable(irg, mode, pos - 1); set_r_cur_block(irg, rem); } else { res = new_r_Unknown(irg, mode); } } else { goto bad; /* unreachable block, use Bad */ } /* one predecessor just use its value */ } else if (arity == 1) { ir_node *cfgpred = get_Block_cfgpred(block, 0); if (is_Bad(cfgpred)) { bad: res = new_r_Bad(irg, mode); } else { ir_node *cfgpred_block = get_nodes_block(cfgpred); res = get_r_value_internal(cfgpred_block, pos, mode); } } else { /* multiple predecessors construct Phi */ res = new_rd_Phi0(NULL, block, mode, pos); /* enter phi0 into our variable value table to break cycles * arising from set_phi_arguments */ block->attr.block.graph_arr[pos] = res; res = set_phi_arguments(res, pos); } } else { /* in case of immature block we have to keep a Phi0 */ res = new_rd_Phi0(NULL, block, mode, pos); /* enqueue phi so we can set arguments once the block matures */ res->attr.phi.next = block->attr.block.phis; block->attr.block.phis = res; } block->attr.block.graph_arr[pos] = res; return res; }
/** * Returns backarray if the node can have backedges, else returns * NULL. * * Does not assert whether the backarray is correct -- use * very careful! */ static bitset_t *mere_get_backarray(const ir_node *n) { switch (get_irn_opcode(n)) { case iro_Block: if (!get_Block_matured(n)) return NULL; assert(n->attr.block.backedge != NULL); return n->attr.block.backedge; case iro_Phi: assert(n->attr.phi.u.backedge != NULL); return n->attr.phi.u.backedge; default: break; } return NULL; }
void mature_immBlock(ir_node *block) { if (get_Block_matured(block)) return; set_Block_matured(block, 1); /* Create final in-array for the block. */ ir_graph *const irg = get_irn_irg(block); if (block->attr.block.dynamic_ins) { /* Attach a Bad predecessor if there is no other. This is necessary to * fulfill the invariant that all nodes can be found through reverse * edges from the start block. */ ir_node **new_in; struct obstack *const obst = get_irg_obstack(irg); size_t n_preds = ARR_LEN(block->in) - 1; if (n_preds == 0) { n_preds = 1; new_in = NEW_ARR_D(ir_node*, obst, 2); new_in[0] = NULL; new_in[1] = new_r_Bad(irg, mode_X); } else {