2 * Interblock liveness analysis.
3 * @author Sebastian Hack
11 #include "iredges_t.h"
13 #include "irprintf_t.h"
18 FIRM_IMPL2(is_live_in, int, const ir_node *, const ir_node *)
19 FIRM_IMPL2(is_live_out, int, const ir_node *, const ir_node *)
20 FIRM_IMPL2(is_live_end, int, const ir_node *, const ir_node *)
22 /** The offset of the liveness information in a firm node. */
23 size_t live_irg_data_offset = 0;
25 void be_liveness_init(void)
27 live_irg_data_offset = register_additional_graph_data(sizeof(irn_live_t));
30 static INLINE void mark_live_in(ir_node *block, const ir_node *irn)
32 _get_or_set_live(block, irn, live_state_in);
35 static INLINE void mark_live_out(ir_node *block, const ir_node *irn)
37 _get_or_set_live(block, irn, live_state_out | live_state_end);
40 static INLINE void mark_live_end(ir_node *block, const ir_node *irn)
42 _get_or_set_live(block, irn, live_state_end);
46 * Mark a node (value) live out at a certain block. Do this also
47 * transitively, i.e. if the block is not the block of the value's
48 * definition, all predecessors are also marked live.
49 * @param def The node (value).
50 * @param block The block to mark the value live out of.
51 * @param visited A set were all visited blocks are recorded.
52 * @param is_true_out Is the node real out there or only live at the end
55 static void live_end_at_block(ir_node *def, ir_node *block,
56 pset *visited, int is_true_out)
58 mark_live_end(block, def);
60 mark_live_out(block, def);
62 if(!pset_find_ptr(visited, block)) {
64 pset_insert_ptr(visited, block);
67 * If this block is not the definition block, we have to go up
70 if(get_nodes_block(def) != block) {
73 mark_live_in(block, def);
75 for(i = 0, n = get_irn_arity(block); i < n; ++i)
76 live_end_at_block(def, get_Block_cfgpred_block(block, i), visited, 1);
83 * Liveness analysis for a value.
84 * This functions is meant to be called by a firm walker, to compute the
85 * set of all blocks a value is live in.
86 * @param irn The node (value).
89 static void liveness_for_node(ir_node *irn, void *env)
91 const ir_edge_t *edge;
95 /* Don't compute liveness information for non-data nodes. */
96 if(!is_data_node(irn))
99 visited = pset_new_ptr(512);
100 def_block = get_nodes_block(irn);
102 /* Go over all uses of the value */
103 foreach_out_edge(irn, edge) {
104 ir_node *use = edge->src;
108 * If the usage is no data node, skip this use, since it does not
109 * affect the liveness of the node.
111 if(!is_data_node(use))
114 /* Get the block where the usage is in. */
115 use_block = get_nodes_block(use);
118 * If the use is a phi function, determine the corresponding block
119 * through which the value reaches the phi function and mark the
120 * value as live out of that block.
123 ir_node *pred_block = get_Block_cfgpred_block(use_block, edge->pos);
124 live_end_at_block(irn, pred_block, visited, 0);
128 * Else, the value is live in at this block. Mark it and call live
129 * out on the predecessors.
131 else if(def_block != use_block) {
134 mark_live_in(use_block, irn);
136 for(i = 0, n = get_irn_arity(use_block); i < n; ++i) {
137 ir_node *pred_block = get_nodes_block(get_irn_n(use_block, i));
138 live_end_at_block(irn, pred_block, visited, 1);
146 static int cmp_irn_live(const void *a, const void *b, size_t size)
148 const irn_live_t *p = a;
149 const irn_live_t *q = b;
151 return !(p->block == q->block && p->irn == q->irn);
154 static int (*old_dump_block_func)(ir_node *self, FILE *F, dump_reason_t reason) = NULL;
156 static int dump_block_func(ir_node *self, FILE *F, dump_reason_t reason)
159 case dump_node_opcode_txt:
160 fprintf(F, get_irn_opname(self));
162 case dump_node_mode_txt:
163 fprintf(F, get_irn_modename(self));
165 case dump_node_nodeattr_txt:
167 case dump_node_info_txt:
168 if(!get_irg_live_info(get_irn_irg(self))->live)
171 fprintf(F, "liveness information:\n");
174 live_foreach(self, li) {
175 ir_fprintf(F, "%+F", li->irn);
191 void be_liveness(ir_graph *irg)
193 irg_live_info_t *live_info = get_irg_live_info(irg);
195 del_set(live_info->live);
197 live_info->live = new_set(cmp_irn_live, 8192);
198 irg_walk_graph(irg, liveness_for_node, NULL, NULL);
200 old_dump_block_func = op_Block->ops.dump_node;
201 op_Block->ops.dump_node = dump_block_func;
204 static void dump_liveness_walker(ir_node *bl, void *data)
207 const irn_live_t *li;
210 ir_fprintf(f, "%+F\n", bl);
211 live_foreach(bl, li) {
223 ir_fprintf(f, "\t%+20F %s\n", li->irn, buf);
227 void be_liveness_dump(ir_graph *irg, FILE *f)
229 irg_block_walk_graph(irg, dump_liveness_walker, NULL, f);
232 void be_liveness_dumpto(ir_graph *irg, const char *cls_name)
236 ir_snprintf(buf, sizeof(buf), "%F_%s-live.txt", irg, cls_name);
237 if((f = fopen(buf, "wt")) != NULL) {
238 be_liveness_dump(irg, f);
243 static void dom_check(ir_node *irn, void *data)
245 if(!is_Block(irn) && irn != get_irg_end(get_irn_irg(irn))) {
247 ir_node *bl = get_nodes_block(irn);
249 for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
250 ir_node *op = get_irn_n(irn, i);
251 ir_node *def_bl = get_nodes_block(op);
252 ir_node *use_bl = bl;
255 use_bl = get_Block_cfgpred_block(bl, i);
257 if(!block_dominates(def_bl, use_bl)) {
258 ir_fprintf(stderr, "%+F in %+F must dominate %+F for user %+F\n", op, def_bl, use_bl, irn);
265 void be_check_dominance(ir_graph *irg)
267 irg_walk_graph(irg, dom_check, NULL, NULL);