2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Support for ir graph modification.
23 * @author Martin Trapp, Christian Schaefer, Goetz Lindenmaier
31 #include "irgraph_t.h"
36 #include "iredges_t.h"
41 * Turns a node into a "useless" Tuple. The Tuple just forms a tuple
42 * from several inputs.
43 * This is useful if a node returning a tuple is removed, but the Projs
44 * extracting values from the tuple are not available.
46 void turn_into_tuple(ir_node *node, int arity)
48 ir_graph *irg = get_irn_irg(node);
49 ir_node **in = ALLOCAN(ir_node*, arity);
52 /* construct a new in array, with every input being bad */
53 for (i = 0; i < arity; ++i) {
54 in[i] = new_r_Bad(irg);
56 set_irn_in(node, arity, in);
57 set_irn_op(node, op_Tuple);
61 * Insert irnode `new' in place of irnode `old'
62 * Since `new' may be bigger than `old' replace `old'
63 * by an op_Id which is smaller than everything.
65 void exchange(ir_node *old, ir_node *nw)
70 assert(old != nw && "Exchanging node with itself is not allowed");
72 irg = get_irn_irg(old);
73 assert(irg == get_irn_irg(nw) && "New node must be in same irg as old node");
75 hook_replace(old, nw);
78 * If new outs are on, we can skip the id node creation and reroute
79 * the edges from the old node to the new directly.
81 if (edges_activated(irg)) {
82 /* copy all dependencies from old to new */
83 add_irn_deps(nw, old);
85 edges_reroute(old, nw, irg);
86 edges_reroute_kind(old, nw, EDGE_KIND_DEP, irg);
87 edges_node_deleted(old, irg);
90 /* Else, do it the old-fashioned way. */
93 hook_turn_into_id(old);
97 block = is_Block(nw) ? nw : get_nodes_block(nw);
100 panic("cannot find legal block for id");
104 if (get_irn_op(old)->opar == oparity_dynamic) {
105 DEL_ARR_F(get_irn_in(old));
109 old->in = NEW_ARR_D (ir_node *, irg->obst, 2);
115 /*--------------------------------------------------------------------*/
116 /* Functionality for collect_phis */
117 /*--------------------------------------------------------------------*/
120 * Walker: links all Phi nodes to their Blocks lists,
121 * all Proj nodes to there predecessors and all
122 * partBlocks to there MacroBlock header.
124 static void collect_phiprojs_walker(ir_node *n, void *env)
130 ir_node *block = get_nodes_block(n);
131 add_Block_phi(block, n);
132 } else if (is_Proj(n)) {
135 pred = get_Proj_pred(pred);
136 } while (is_Proj(pred));
138 set_irn_link(n, get_irn_link(pred));
139 set_irn_link(pred, n);
140 } else if (is_Block(n)) {
141 ir_node *mbh = get_Block_MacroBlock(n);
144 set_irn_link(n, get_irn_link(mbh));
145 set_irn_link(mbh, n);
150 void collect_phiprojs(ir_graph *irg)
152 assert((ir_resources_reserved(irg) & (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST)) ==
153 (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST));
154 irg_walk_graph(irg, firm_clear_node_and_phi_links, collect_phiprojs_walker, NULL);
157 /*--------------------------------------------------------------------*/
158 /* Functionality for part_block */
159 /*--------------------------------------------------------------------*/
162 * Moves node and all predecessors of node from from_bl to to_bl.
163 * Does not move predecessors of Phi nodes (or block nodes).
165 static void move(ir_node *node, ir_node *from_bl, ir_node *to_bl)
170 set_nodes_block(node, to_bl);
173 if (get_irn_mode(node) == mode_T) {
174 ir_node *proj = get_irn_link(node);
176 if (get_nodes_block(proj) == from_bl)
177 set_nodes_block(proj, to_bl);
178 proj = get_irn_link(proj);
186 arity = get_irn_arity(node);
187 for (i = 0; i < arity; i++) {
188 ir_node *pred = get_irn_n(node, i);
189 if (get_nodes_block(pred) == from_bl)
190 move(pred, from_bl, to_bl);
194 void part_block(ir_node *node)
196 ir_node *new_block, *old_block, *mbh;
197 ir_node *phi, *jmp, *next, *block;
198 ir_graph *rem = current_ir_graph;
200 /* Turn off optimizations so that blocks are not merged again. */
201 int rem_opt = get_opt_optimize();
204 current_ir_graph = get_irn_irg(node);
206 /* Transform the control flow */
207 old_block = get_nodes_block(node);
208 mbh = get_Block_MacroBlock(old_block);
209 new_block = new_Block(get_Block_n_cfgpreds(old_block),
210 get_Block_cfgpred_arr(old_block));
212 if (mbh != old_block) {
213 /* we splitting a partBlock */
214 set_Block_MacroBlock(new_block, mbh);
216 /* we are splitting a header: this creates a new header */
217 set_Block_MacroBlock(new_block, new_block);
220 /* create a jump from new_block to old_block, which is now the lower one */
221 jmp = new_r_Jmp(new_block);
222 set_irn_in(old_block, 1, &jmp);
224 /* move node and its predecessors to new_block */
225 move(node, old_block, new_block);
227 /* move Phi nodes to new_block */
228 phi = get_Block_phis(old_block);
229 set_Block_phis(new_block, phi);
230 set_Block_phis(old_block, NULL);
232 set_nodes_block(phi, new_block);
233 phi = get_Phi_next(phi);
236 /* rewire partBlocks: This is necessary, because old_block is a new MacroBlock
238 if (mbh != old_block) {
239 ir_node *list = NULL;
241 /* move blocks from mbh to old_block if old_block dominates them */
242 block = get_irn_link(mbh);
244 /* mbh's list will be rebuild */
245 set_irn_link(mbh, NULL);
246 /* old_block is a new mbh */
247 set_Block_MacroBlock(old_block, old_block);
249 /* note that we must splice the list of partBlock here */
250 for (; block != NULL; block = next) {
251 ir_node *curr = block;
252 assert(is_Block(curr));
254 next = get_irn_link(block);
256 if (block == old_block) {
257 /* this effectively removed old_block from mbh's list */
261 assert(get_Block_MacroBlock(curr) == mbh);
264 if (curr == old_block) {
265 /* old_block dominates the block, so old_block will be
266 the new macro block header */
267 set_Block_MacroBlock(block, old_block);
268 set_irn_link(block, list);
273 /* leave it in the mbh */
274 set_irn_link(block, get_irn_link(mbh));
275 set_irn_link(mbh, block);
279 assert(get_Block_n_cfgpreds(curr) == 1);
280 curr = get_Block_cfgpred_block(curr, 0);
283 /* beware: do NOT directly manipulate old_block's list, as old_block is
284 in mbh's list and this would destroy the list! */
285 set_irn_link(old_block, list);
287 /* finally add new_block to mbh's list */
288 set_irn_link(new_block, get_irn_link(mbh));
289 set_irn_link(mbh, new_block);
291 /* old_block is the mbh, as well as new_block */
292 set_Block_MacroBlock(new_block, new_block);
295 set_optimize(rem_opt);
296 current_ir_graph = rem;
299 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
300 void kill_node(ir_node *node)
302 ir_graph *irg = get_irn_irg(node);
303 ir_node *bad = get_irg_bad(irg);
306 for (i = get_irn_arity(node) - 1; i >= -1; --i) {
307 set_irn_n(node, i, bad);