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
34 #include "irgraph_t.h"
39 #include "iredges_t.h"
44 * Turns a node into a "useless" Tuple. The Tuple just forms a tuple
45 * from several inputs.
46 * This is useful if a node returning a tuple is removed, but the Projs
47 * extracting values from the tuple are not available.
49 void turn_into_tuple(ir_node *node, int arity) {
51 set_irn_op(node, op_Tuple);
52 if (get_irn_arity(node) == arity) {
55 ir_graph *irg = get_irn_irg(node);
56 ir_node *block = get_nodes_block(node);
57 edges_node_deleted(node, irg);
58 /* Allocate new array, don't free old in_array, it's on the obstack. */
59 node->in = NEW_ARR_D(ir_node *, irg->obst, arity+1);
60 /* clear the new in array, else edge_notify tries to delete garbage */
61 memset(node->in, 0, (arity+1) * sizeof(node->in[0]));
62 /* set the block back */
63 set_nodes_block(node, block);
68 * Insert irnode `new' in place of irnode `old'
69 * Since `new' may be bigger than `old' replace `old'
70 * by an op_Id which is smaller than everything.
72 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 assert(get_irn_op(old)->opar != oparity_dynamic);
101 hook_turn_into_id(old);
105 block = is_Block(nw) ? nw : get_nodes_block(nw);
108 panic("cannot find legal block for id");
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(ir_node *n, void *env) {
133 ir_node *block = get_nodes_block(n);
134 set_Phi_next(n, get_Block_phis(block));
135 set_Block_phis(block, n);
136 } else if (is_Proj(n)) {
139 pred = get_Proj_pred(pred);
140 } while (is_Proj(pred));
142 set_irn_link(n, get_irn_link(pred));
143 set_irn_link(pred, n);
144 } else if (is_Block(n)) {
145 ir_node *mbh = get_Block_MacroBlock(n);
148 set_irn_link(n, get_irn_link(mbh));
149 set_irn_link(mbh, n);
155 * clear all links, including the Phi list of blocks and Phi nodes.
157 static void clear_links(ir_node *n, void *env) {
160 set_irn_link(n, NULL);
162 set_Block_phis(n, NULL);
164 set_Phi_next(n, NULL);
167 void collect_phiprojs(ir_graph *irg) {
168 irg_walk_graph(irg, clear_links, collect, NULL);
172 /*--------------------------------------------------------------------*/
173 /* Functionality for part_block */
174 /*--------------------------------------------------------------------*/
177 * Moves node and all predecessors of node from from_bl to to_bl.
178 * Does not move predecessors of Phi nodes (or block nodes).
180 static void move(ir_node *node, ir_node *from_bl, ir_node *to_bl) {
184 set_nodes_block(node, to_bl);
187 if (get_irn_mode(node) == mode_T) {
188 ir_node *proj = get_irn_link(node);
190 if (get_nodes_block(proj) == from_bl)
191 set_nodes_block(proj, to_bl);
192 proj = get_irn_link(proj);
200 arity = get_irn_arity(node);
201 for (i = 0; i < arity; i++) {
202 ir_node *pred = get_irn_n(node, i);
203 if (get_nodes_block(pred) == from_bl)
204 move(pred, from_bl, to_bl);
208 void part_block(ir_node *node) {
214 /* Turn off optimizations so that blocks are not merged again. */
215 int rem_opt = get_opt_optimize();
218 /* Transform the control flow */
219 old_block = get_nodes_block(node);
220 mbh = get_Block_MacroBlock(old_block);
221 new_block = new_Block(get_Block_n_cfgpreds(old_block),
222 get_Block_cfgpred_arr(old_block));
224 if (mbh != old_block) {
225 /* we splitting a partBlock */
226 set_Block_MacroBlock(new_block, mbh);
228 /* we are splitting a header: this creates a new header */
229 set_Block_MacroBlock(new_block, new_block);
231 set_irg_current_block(current_ir_graph, new_block);
233 ir_node *jmp = new_Jmp();
234 set_irn_in(old_block, 1, &jmp);
235 irn_vrfy_irg(old_block, current_ir_graph);
238 /* move node and its predecessors to new_block */
239 move(node, old_block, new_block);
241 /* move Phi nodes to new_block */
242 phi = get_Block_phis(old_block);
243 set_Block_phis(new_block, phi);
244 set_Block_phis(old_block, NULL);
246 set_nodes_block(phi, new_block);
247 phi = get_Phi_next(phi);
250 /* rewire partBlocks */
251 if (mbh != old_block) {
252 ir_node *next, *block = get_irn_link(mbh);
254 set_irn_link(mbh, NULL);
255 set_irn_link(old_block, NULL);
257 /* note that we must splice the list of partBlock here */
258 for (; block != NULL; block = next) {
259 ir_node *curr = block;
260 assert(is_Block(curr));
262 next = get_irn_link(block);
263 assert(get_Block_MacroBlock(curr) == mbh);
266 if (curr == old_block) {
267 /* old_block dominates the block, so old_block will be
268 the new macro block header */
269 set_Block_MacroBlock(block, old_block);
270 set_irn_link(block, get_irn_link(old_block));
271 set_irn_link(old_block, block);
275 /* leave it in the mbh */
276 set_irn_link(block, get_irn_link(mbh));
277 set_irn_link(mbh, block);
281 assert(get_Block_n_cfgpreds(curr) == 1);
282 curr = get_Block_cfgpred_block(curr, 0);
287 set_optimize(rem_opt);
290 /* kill a node by setting its predecessors to Bad and finally exchange the node by Bad itself. */
291 void kill_node(ir_node *node) {
292 ir_graph *irg = get_irn_irg(node);
293 ir_node *bad = get_irg_bad(irg);
296 for (i = get_irn_arity(node) - 1; i >= -1; --i) {
297 set_irn_n(node, i, bad);