1 /* Copyright (C) 2002 by Universitaet Karlsruhe
2 ** All rights reserved.
4 ** Authors: Goetz Lindenmaier
6 ** irouts.c --- Compute out edges for ir nodes (also called def-use
15 #include "irgraph_t.h" /* To access irg->outs field (which is private to this module)
16 without public access routine */
18 /**********************************************************************/
19 /** Accessing the out datastructures **/
20 /**********************************************************************/
22 /* returns the number of successors of the node: */
23 inline int get_irn_n_outs (ir_node *node) {
24 return (int)(node->out[0]);
27 /* Access successor n */
28 inline ir_node *get_irn_out (ir_node *node, int pos) {
30 assert(pos >= 0 && pos < get_irn_n_outs(node));
31 return node->out[pos+1];
34 inline void set_irn_out (ir_node *node, int pos, ir_node *out) {
36 assert(pos >= 0 && pos < get_irn_n_outs(node));
37 node->out[pos+1] = out;
41 inline int get_Block_n_cfg_outs (ir_node *bl) {
42 int i, n_cfg_outs = 0;
43 assert(bl && (get_irn_op(bl) == op_Block));
44 for (i = 0; i < (int)bl->out[0]; i++)
45 if ((get_irn_mode(bl->out[i+1]) == mode_X) &&
46 (get_irn_op(bl->out[i+1]) != op_End)) n_cfg_outs++;
51 inline ir_node *get_Block_cfg_out (ir_node *bl, int pos) {
53 assert(bl && (get_irn_op(bl) == op_Block));
54 for (i = 0; i < (int)bl->out[0]; i++)
55 if ((get_irn_mode(bl->out[i+1]) == mode_X) &&
56 (get_irn_op(bl->out[i+1]) != op_End))
58 ir_node *cfop = bl->out[i+1];
59 return cfop->out[0+1];
66 void irg_out_walk_2(ir_node *node, void (pre)(ir_node*, void*),
67 void (post)(ir_node*, void*), void *env) {
71 //printf("++ in walker (%d outs) ", get_irn_n_outs(node)); DDMSG2(node);
74 assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
76 set_irn_visited(node, get_irg_visited(current_ir_graph));
78 if (pre) pre(node, env);
80 for (i = 0; i < get_irn_n_outs(node); i++) {
81 succ = get_irn_out(node, i);
82 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
83 irg_out_walk_2(succ, pre, post, env);
86 if (post) post(node, env);
88 //printf("++ done walking "); DDMSG2(node);
92 void irg_out_walk(ir_node *node,
93 void (pre)(ir_node*, void*), void (post)(ir_node*, void*),
96 if (get_irg_outs_state(current_ir_graph) != no_outs) {
97 inc_irg_visited (current_ir_graph);
98 irg_out_walk_2(node, pre, post, env);
103 void irg_out_block_walk2(ir_node *bl,
104 void (pre)(ir_node*, void*), void (post)(ir_node*, void*),
108 assert(get_irn_opcode(bl) == iro_Block);
110 if(get_Block_block_visited(bl) < get_irg_block_visited(current_ir_graph)) {
111 set_Block_block_visited(bl, get_irg_block_visited(current_ir_graph));
116 for(i = 0; i < get_Block_n_cfg_outs(bl); i++) {
117 /* find the corresponding predecessor block. */
118 ir_node *pred = get_Block_cfg_out(bl, i);
119 assert(get_irn_opcode(pred) == iro_Block);
121 irg_out_block_walk2(pred, pre, post, env);
130 /* Walks only over Block nodes in the graph. Has it's own visited
131 flag, so that it can be interleaved with the other walker. */
132 void irg_out_block_walk(ir_node *node,
133 void (pre)(ir_node*, void*), void (post)(ir_node*, void*),
136 assert((get_irn_op(node) == op_Block) || (get_irn_mode(node) == mode_X));
138 inc_irg_block_visited(current_ir_graph);
140 if (get_irn_mode(node) == mode_X) node = node->out[1];
141 assert(get_irn_opcode(node) == iro_Block);
143 irg_out_block_walk2(node, pre, post, env);
149 /**********************************************************************/
150 /** Building and Removing the out datasturcture **/
152 /** The outs of a graph are allocated in a single, large array. **/
153 /** This allows to allocate and deallocate the memory for the outs **/
154 /** on demand. The large array is separated into many small ones **/
155 /** for each node. Only a single field to reference the out array **/
156 /** is stored in each node and a field referencing the large out **/
157 /** array in irgraph. The 0 field of each out array contains the **/
158 /** size of this array. This saves memory in the irnodes themselves.**/
159 /** The construction does two passes over the graph. The first pass **/
160 /** counts the overall number of outs and the outs of each node. It **/
161 /** stores the outs of each node in the out reference of the node. **/
162 /** Then the large array is allocated. The second iteration chops **/
163 /** the large array into smaller parts, sets the out edges and **/
164 /** recounts the out edges. **/
165 /**********************************************************************/
168 /* Returns the amount of out edges for not yet visited successors. */
169 int count_outs(ir_node *n) {
173 set_irn_visited(n, get_irg_visited(current_ir_graph));
174 n->out = (ir_node **) 1; /* Space for array size. */
176 if ((get_irn_op(n) == op_Block)) start = 0; else start = -1;
177 res = get_irn_arity(n) - start +1; /* --1 or --0; 1 for array size. */
178 for (i = start; i < get_irn_arity(n); i++) {
179 /* Optimize Tuples. They annoy if walking the cfg. */
180 succ = skip_Tuple(get_irn_n(n, i));
181 set_irn_n(n, i, succ);
182 /* count outs for successors */
183 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
184 res += count_outs(succ);
186 succ->out = (ir_node **)( (int)succ->out +1);
191 ir_node **set_out_edges(ir_node *n, ir_node **free) {
192 int n_outs, start, i;
195 set_irn_visited(n, get_irg_visited(current_ir_graph));
197 /* Allocate my array */
198 n_outs = (int) n->out;
200 free = &free[n_outs];
201 /* We count the successors again, the space will be sufficient.
202 We use this counter to remember the position for the next back
204 n->out[0] = (ir_node *)0;
206 if (get_irn_op(n) == op_Block) start = 0; else start = -1;
207 for (i = start; i < get_irn_arity(n); i++) {
208 succ = get_irn_n(n, i);
210 if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
211 free = set_out_edges(succ, free);
212 /* Remember our back edge */
213 succ->out[get_irn_n_outs(succ)+1] = n;
214 succ->out[0] = (ir_node *) (get_irn_n_outs(succ) + 1);
219 inline void fix_start_proj(ir_graph *irg) {
220 ir_node *proj, *startbl;
222 if (get_Block_n_cfg_outs(get_irg_start_block(irg))) {
223 startbl = get_irg_start_block(irg);
224 for (i = 0; i < get_irn_n_outs(startbl); i++)
225 if (get_irn_mode(get_irn_out(startbl, i)) == mode_X)
226 proj = get_irn_out(startbl, i);
227 if (get_irn_out(proj, 0) == startbl) {
228 assert(get_irn_n_outs(proj) == 2);
229 set_irn_out(proj, 0, get_irn_out(proj, 1));
230 set_irn_out(proj, 1, startbl);
235 void compute_outs(ir_graph *irg) {
236 ir_graph *rem = current_ir_graph;
239 current_ir_graph = irg;
241 /* Update graph state */
242 assert(get_irg_phase_state(current_ir_graph) != phase_building);
243 current_ir_graph->outs_state = outs_consistent;
245 /* This first iteration counts the overall number of out edges and the
246 number of out edges for each node. */
247 inc_irg_visited(irg);
248 n_out_edges = count_outs(get_irg_end(irg));
250 /* allocate memory for all out edges. */
251 irg->outs = (ir_node **) malloc (n_out_edges * sizeof(ir_node *));
253 /* The second iteration splits the irg->outs array into smaller arrays
254 for each node and writes the back edges into this array. */
255 inc_irg_visited(irg);
256 set_out_edges(get_irg_end(irg), irg->outs);
258 /* We want that the out of ProjX from Start contains the next block at
259 position 1, the Start block at position 2. This is necessary for
260 the out block walker. */
263 current_ir_graph = rem;
266 void free_outs(ir_graph *irg) {
268 /* Update graph state */
269 assert(get_irg_phase_state(current_ir_graph) != phase_building);
270 current_ir_graph->outs_state = no_outs;
272 if (irg->outs) free(irg->outs);