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)
50 set_irn_op(node, op_Tuple);
51 if (get_irn_arity(node) == arity) {
54 ir_graph *irg = get_irn_irg(node);
55 ir_node *block = get_nodes_block(node);
56 edges_node_deleted(node, irg);
57 /* Allocate new array, don't free old in_array, it's on the obstack. */
58 node->in = NEW_ARR_D(ir_node *, irg->obst, arity+1);
59 /* clear the new in array, else edge_notify tries to delete garbage */
60 memset(node->in, 0, (arity+1) * sizeof(node->in[0]));
61 /* set the block back */
62 set_nodes_block(node, block);
67 * Insert irnode `new' in place of irnode `old'
68 * Since `new' may be bigger than `old' replace `old'
69 * by an op_Id which is smaller than everything.
71 void exchange(ir_node *old, ir_node *nw)
76 assert(old != nw && "Exchanging node with itself is not allowed");
78 irg = get_irn_irg(old);
79 assert(irg == get_irn_irg(nw) && "New node must be in same irg as old node");
81 hook_replace(old, nw);
84 * If new outs are on, we can skip the id node creation and reroute
85 * the edges from the old node to the new directly.
87 if (edges_activated(irg)) {
88 /* copy all dependencies from old to new */
89 add_irn_deps(nw, old);
91 edges_reroute(old, nw, irg);
92 edges_reroute_kind(old, nw, EDGE_KIND_DEP, irg);
93 edges_node_deleted(old, irg);
96 /* Else, do it the old-fashioned way. */
99 hook_turn_into_id(old);
103 block = is_Block(nw) ? nw : get_nodes_block(nw);
106 panic("cannot find legal block for id");
110 if (get_irn_op(old)->opar == oparity_dynamic) {
111 DEL_ARR_F(get_irn_in(old));
115 old->in = NEW_ARR_D (ir_node *, irg->obst, 2);
121 /*--------------------------------------------------------------------*/
122 /* Functionality for collect_phis */
123 /*--------------------------------------------------------------------*/
126 * Walker: links all Phi nodes to their Blocks lists,
127 * all Proj nodes to there predecessors and all
128 * partBlocks to there MacroBlock header.
130 static void collect_phiprojs_walker(ir_node *n, void *env)
136 ir_node *block = get_nodes_block(n);
137 add_Block_phi(block, n);
138 } else if (is_Proj(n)) {
141 pred = get_Proj_pred(pred);
142 } while (is_Proj(pred));
144 set_irn_link(n, get_irn_link(pred));
145 set_irn_link(pred, n);
146 } else if (is_Block(n)) {
147 ir_node *mbh = get_Block_MacroBlock(n);
150 set_irn_link(n, get_irn_link(mbh));
151 set_irn_link(mbh, n);
156 void collect_phiprojs(ir_graph *irg)
158 assert((ir_resources_reserved(irg) & (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST)) ==
159 (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST));
160 irg_walk_graph(irg, firm_clear_node_and_phi_links, collect_phiprojs_walker, NULL);
163 /*--------------------------------------------------------------------*/
164 /* Functionality for part_block */
165 /*--------------------------------------------------------------------*/
168 * Moves node and all predecessors of node from from_bl to to_bl.
169 * Does not move predecessors of Phi nodes (or block nodes).
171 static void move(ir_node *node, ir_node *from_bl, ir_node *to_bl)
176 set_nodes_block(node, to_bl);
179 if (get_irn_mode(node) == mode_T) {
180 ir_node *proj = get_irn_link(node);
182 if (get_nodes_block(proj) == from_bl)
183 set_nodes_block(proj, to_bl);
184 proj = get_irn_link(proj);
192 arity = get_irn_arity(node);
193 for (i = 0; i < arity; i++) {
194 ir_node *pred = get_irn_n(node, i);
195 if (get_nodes_block(pred) == from_bl)
196 move(pred, from_bl, to_bl);
200 void part_block(ir_node *node)
202 ir_node *new_block, *old_block, *mbh;
203 ir_node *phi, *jmp, *next, *block;
204 ir_graph *rem = current_ir_graph;
206 /* Turn off optimizations so that blocks are not merged again. */
207 int rem_opt = get_opt_optimize();
210 current_ir_graph = get_irn_irg(node);
212 /* Transform the control flow */
213 old_block = get_nodes_block(node);
214 mbh = get_Block_MacroBlock(old_block);
215 new_block = new_Block(get_Block_n_cfgpreds(old_block),
216 get_Block_cfgpred_arr(old_block));
218 if (mbh != old_block) {
219 /* we splitting a partBlock */
220 set_Block_MacroBlock(new_block, mbh);
222 /* we are splitting a header: this creates a new header */
223 set_Block_MacroBlock(new_block, new_block);
226 /* create a jump from new_block to old_block, which is now the lower one */
227 jmp = new_r_Jmp(new_block);
228 set_irn_in(old_block, 1, &jmp);
230 /* move node and its predecessors to new_block */
231 move(node, old_block, new_block);
233 /* move Phi nodes to new_block */
234 phi = get_Block_phis(old_block);
235 set_Block_phis(new_block, phi);
236 set_Block_phis(old_block, NULL);
238 set_nodes_block(phi, new_block);
239 phi = get_Phi_next(phi);
242 /* rewire partBlocks: This is necessary, because old_block is a new MacroBlock
244 if (mbh != old_block) {
245 ir_node *list = NULL;
247 /* move blocks from mbh to old_block if old_block dominates them */
248 block = get_irn_link(mbh);
250 /* mbh's list will be rebuild */
251 set_irn_link(mbh, NULL);
252 /* old_block is a new mbh */
253 set_Block_MacroBlock(old_block, old_block);
255 /* note that we must splice the list of partBlock here */
256 for (; block != NULL; block = next) {
257 ir_node *curr = block;
258 assert(is_Block(curr));
260 next = get_irn_link(block);
262 if (block == old_block) {
263 /* this effectively removed old_block from mbh's list */
267 assert(get_Block_MacroBlock(curr) == mbh);
270 if (curr == old_block) {
271 /* old_block dominates the block, so old_block will be
272 the new macro block header */
273 set_Block_MacroBlock(block, old_block);
274 set_irn_link(block, list);
279 /* leave it in the mbh */
280 set_irn_link(block, get_irn_link(mbh));
281 set_irn_link(mbh, block);
285 assert(get_Block_n_cfgpreds(curr) == 1);
286 curr = get_Block_cfgpred_block(curr, 0);
289 /* beware: do NOT directly manipulate old_block's list, as old_block is
290 in mbh's list and this would destroy the list! */
291 set_irn_link(old_block, list);
293 /* finally add new_block to mbh's list */
294 set_irn_link(new_block, get_irn_link(mbh));
295 set_irn_link(mbh, new_block);
297 /* old_block is the mbh, as well as new_block */
298 set_Block_MacroBlock(new_block, new_block);
301 set_optimize(rem_opt);
302 current_ir_graph = rem;
305 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
306 void kill_node(ir_node *node)
308 ir_graph *irg = get_irn_irg(node);
309 ir_node *bad = get_irg_bad(irg);
312 for (i = get_irn_arity(node) - 1; i >= -1; --i) {
313 set_irn_n(node, i, bad);