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 set_irn_op(node, op_Tuple);
50 if (get_irn_arity(node) == arity) {
53 ir_graph *irg = get_irn_irg(node);
54 ir_node *block = get_nodes_block(node);
55 edges_node_deleted(node, irg);
56 /* Allocate new array, don't free old in_array, it's on the obstack. */
57 node->in = NEW_ARR_D(ir_node *, irg->obst, arity+1);
58 /* clear the new in array, else edge_notify tries to delete garbage */
59 memset(node->in, 0, (arity+1) * sizeof(node->in[0]));
60 /* set the block back */
61 set_nodes_block(node, block);
66 * Insert irnode `new' in place of irnode `old'
67 * Since `new' may be bigger than `old' replace `old'
68 * by an op_Id which is smaller than everything.
70 void exchange(ir_node *old, ir_node *nw) {
74 assert(old != nw && "Exchanging node with itself is not allowed");
76 irg = get_irn_irg(old);
77 assert(irg == get_irn_irg(nw) && "New node must be in same irg as old node");
79 hook_replace(old, nw);
82 * If new outs are on, we can skip the id node creation and reroute
83 * the edges from the old node to the new directly.
85 if (edges_activated(irg)) {
86 /* copy all dependencies from old to new */
87 add_irn_deps(nw, old);
89 edges_reroute(old, nw, irg);
90 edges_reroute_kind(old, nw, EDGE_KIND_DEP, irg);
91 edges_node_deleted(old, irg);
94 /* Else, do it the old-fashioned way. */
97 hook_turn_into_id(old);
101 block = is_Block(nw) ? nw : get_nodes_block(nw);
104 panic("cannot find legal block for id");
108 if (get_irn_op(old)->opar == oparity_dynamic) {
109 DEL_ARR_F(get_irn_in(old));
113 old->in = NEW_ARR_D (ir_node *, irg->obst, 2);
119 /*--------------------------------------------------------------------*/
120 /* Functionality for collect_phis */
121 /*--------------------------------------------------------------------*/
124 * Walker: links all Phi nodes to their Blocks lists,
125 * all Proj nodes to there predecessors and all
126 * partBlocks to there MacroBlock header.
128 static void collect_phiprojs_walker(ir_node *n, void *env) {
133 ir_node *block = get_nodes_block(n);
134 add_Block_phi(block, n);
135 } else if (is_Proj(n)) {
138 pred = get_Proj_pred(pred);
139 } while (is_Proj(pred));
141 set_irn_link(n, get_irn_link(pred));
142 set_irn_link(pred, n);
143 } else if (is_Block(n)) {
144 ir_node *mbh = get_Block_MacroBlock(n);
147 set_irn_link(n, get_irn_link(mbh));
148 set_irn_link(mbh, n);
153 void collect_phiprojs(ir_graph *irg) {
154 assert((ir_resources_reserved(irg) & (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST)) ==
155 (IR_RESOURCE_IRN_LINK|IR_RESOURCE_PHI_LIST));
156 irg_walk_graph(irg, firm_clear_node_and_phi_links, collect_phiprojs_walker, NULL);
159 /*--------------------------------------------------------------------*/
160 /* Functionality for part_block */
161 /*--------------------------------------------------------------------*/
164 * Moves node and all predecessors of node from from_bl to to_bl.
165 * Does not move predecessors of Phi nodes (or block nodes).
167 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) {
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) {
301 ir_graph *irg = get_irn_irg(node);
302 ir_node *bad = get_irg_bad(irg);
305 for (i = get_irn_arity(node) - 1; i >= -1; --i) {
306 set_irn_n(node, i, bad);