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
32 #include "irgraph_t.h"
37 #include "iredges_t.h"
42 * Turns a node into a "useless" Tuple. The Tuple just forms a tuple
43 * from several inputs.
44 * This is useful if a node returning a tuple is removed, but the Projs
45 * extracting values from the tuple are not available.
47 void turn_into_tuple(ir_node *node, int arity)
49 ir_graph *irg = get_irn_irg(node);
50 ir_node **in = ALLOCAN(ir_node*, arity);
53 /* construct a new in array, with every input being bad */
54 for (i = 0; i < arity; ++i) {
55 in[i] = new_r_Bad(irg);
57 set_irn_in(node, arity, in);
58 set_irn_op(node, op_Tuple);
62 * Insert irnode `new' in place of irnode `old'
63 * Since `new' may be bigger than `old' replace `old'
64 * by an op_Id which is smaller than everything.
66 void exchange(ir_node *old, ir_node *nw)
71 assert(old != nw && "Exchanging node with itself is not allowed");
73 irg = get_irn_irg(old);
74 assert(irg == get_irn_irg(nw) && "New node must be in same irg as old node");
76 hook_replace(old, nw);
79 * If new outs are on, we can skip the id node creation and reroute
80 * the edges from the old node to the new directly.
82 if (edges_activated(irg)) {
83 /* copy all dependencies from old to new */
84 add_irn_deps(nw, old);
86 edges_reroute(old, nw, irg);
87 edges_reroute_kind(old, nw, EDGE_KIND_DEP, irg);
88 edges_node_deleted(old, irg);
91 /* Else, do it the old-fashioned way. */
94 hook_turn_into_id(old);
98 block = is_Block(nw) ? nw : get_nodes_block(nw);
101 panic("cannot find legal block for id");
105 if (get_irn_op(old)->opar == oparity_dynamic) {
106 DEL_ARR_F(get_irn_in(old));
110 old->in = NEW_ARR_D (ir_node *, irg->obst, 2);
116 /*--------------------------------------------------------------------*/
117 /* Functionality for collect_phis */
118 /*--------------------------------------------------------------------*/
121 * Walker: links all Phi nodes to their Blocks lists,
122 * all Proj nodes to there predecessors and all
123 * partBlocks to there MacroBlock header.
125 static void collect_phiprojs_walker(ir_node *n, void *env)
131 ir_node *block = get_nodes_block(n);
132 add_Block_phi(block, n);
133 } else if (is_Proj(n)) {
136 pred = get_Proj_pred(pred);
137 } while (is_Proj(pred));
139 set_irn_link(n, get_irn_link(pred));
140 set_irn_link(pred, n);
141 } else if (is_Block(n)) {
142 ir_node *mbh = get_Block_MacroBlock(n);
145 set_irn_link(n, get_irn_link(mbh));
146 set_irn_link(mbh, n);
151 void collect_phiprojs(ir_graph *irg)
153 assert((ir_resources_reserved(irg) & (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST)) ==
154 (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST));
155 irg_walk_graph(irg, firm_clear_node_and_phi_links, collect_phiprojs_walker, NULL);
158 /*--------------------------------------------------------------------*/
159 /* Functionality for part_block */
160 /*--------------------------------------------------------------------*/
163 * Moves node and all predecessors of node from from_bl to to_bl.
164 * Does not move predecessors of Phi nodes (or block nodes).
166 static void move(ir_node *node, ir_node *from_bl, ir_node *to_bl)
171 set_nodes_block(node, to_bl);
174 if (get_irn_mode(node) == mode_T) {
175 ir_node *proj = get_irn_link(node);
177 if (get_nodes_block(proj) == from_bl)
178 set_nodes_block(proj, to_bl);
179 proj = get_irn_link(proj);
187 arity = get_irn_arity(node);
188 for (i = 0; i < arity; i++) {
189 ir_node *pred = get_irn_n(node, i);
190 if (get_nodes_block(pred) == from_bl)
191 move(pred, from_bl, to_bl);
195 void part_block(ir_node *node)
197 ir_node *new_block, *old_block, *mbh;
198 ir_node *phi, *jmp, *next, *block;
199 ir_graph *rem = current_ir_graph;
201 /* Turn off optimizations so that blocks are not merged again. */
202 int rem_opt = get_opt_optimize();
205 current_ir_graph = get_irn_irg(node);
207 /* Transform the control flow */
208 old_block = get_nodes_block(node);
209 mbh = get_Block_MacroBlock(old_block);
210 new_block = new_Block(get_Block_n_cfgpreds(old_block),
211 get_Block_cfgpred_arr(old_block));
213 if (mbh != old_block) {
214 /* we splitting a partBlock */
215 set_Block_MacroBlock(new_block, mbh);
217 /* we are splitting a header: this creates a new header */
218 set_Block_MacroBlock(new_block, new_block);
221 /* create a jump from new_block to old_block, which is now the lower one */
222 jmp = new_r_Jmp(new_block);
223 set_irn_in(old_block, 1, &jmp);
225 /* move node and its predecessors to new_block */
226 move(node, old_block, new_block);
228 /* move Phi nodes to new_block */
229 phi = get_Block_phis(old_block);
230 set_Block_phis(new_block, phi);
231 set_Block_phis(old_block, NULL);
233 set_nodes_block(phi, new_block);
234 phi = get_Phi_next(phi);
237 /* rewire partBlocks: This is necessary, because old_block is a new MacroBlock
239 if (mbh != old_block) {
240 ir_node *list = NULL;
242 /* move blocks from mbh to old_block if old_block dominates them */
243 block = get_irn_link(mbh);
245 /* mbh's list will be rebuild */
246 set_irn_link(mbh, NULL);
247 /* old_block is a new mbh */
248 set_Block_MacroBlock(old_block, old_block);
250 /* note that we must splice the list of partBlock here */
251 for (; block != NULL; block = next) {
252 ir_node *curr = block;
253 assert(is_Block(curr));
255 next = get_irn_link(block);
257 if (block == old_block) {
258 /* this effectively removed old_block from mbh's list */
262 assert(get_Block_MacroBlock(curr) == mbh);
265 if (curr == old_block) {
266 /* old_block dominates the block, so old_block will be
267 the new macro block header */
268 set_Block_MacroBlock(block, old_block);
269 set_irn_link(block, list);
274 /* leave it in the mbh */
275 set_irn_link(block, get_irn_link(mbh));
276 set_irn_link(mbh, block);
280 assert(get_Block_n_cfgpreds(curr) == 1);
281 curr = get_Block_cfgpred_block(curr, 0);
284 /* beware: do NOT directly manipulate old_block's list, as old_block is
285 in mbh's list and this would destroy the list! */
286 set_irn_link(old_block, list);
288 /* finally add new_block to mbh's list */
289 set_irn_link(new_block, get_irn_link(mbh));
290 set_irn_link(mbh, new_block);
292 /* old_block is the mbh, as well as new_block */
293 set_Block_MacroBlock(new_block, new_block);
296 set_optimize(rem_opt);
297 current_ir_graph = rem;
300 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
301 void kill_node(ir_node *node)
303 ir_graph *irg = get_irn_irg(node);
304 ir_node *bad = get_irg_bad(irg);
307 for (i = get_irn_arity(node) - 1; i >= -1; --i) {
308 set_irn_n(node, i, bad);