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4 * This file is part of libFirm.
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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 Optimizations for a whole ir graph, i.e., a procedure.
23 * @author Christian Schaefer, Goetz Lindenmaier, Sebastian Felis,
32 #include "irgraph_t.h"
34 #include "iroptimize.h"
44 #include "iredges_t.h"
47 /*------------------------------------------------------------------*/
48 /* apply optimizations of iropt to all nodes. */
49 /*------------------------------------------------------------------*/
52 * A wrapper around optimize_inplace_2() to be called from a walker.
54 static void optimize_in_place_wrapper(ir_node *n, void *env)
56 ir_node *optimized = optimize_in_place_2(n);
60 exchange(n, optimized);
65 * Do local optimizations for a node.
67 * @param n the IR-node where to start. Typically the End node
70 * @note current_ir_graph must be set
72 static inline void do_local_optimize(ir_node *n)
74 ir_graph *irg = get_irn_irg(n);
76 /* Handle graph state */
77 assert(get_irg_phase_state(irg) != phase_building);
79 if (get_opt_global_cse())
80 set_irg_pinned(irg, op_pin_state_floats);
81 clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE);
83 /* Clean the value_table in irg for the CSE. */
86 /* walk over the graph */
87 irg_walk(n, firm_clear_link, optimize_in_place_wrapper, NULL);
90 /* Applies local optimizations (see iropt.h) to all nodes reachable from node n */
91 void local_optimize_node(ir_node *n)
93 ir_graph *rem = current_ir_graph;
94 current_ir_graph = get_irn_irg(n);
98 current_ir_graph = rem;
101 static void enqueue_node(ir_node *node, pdeq *waitq)
103 if (get_irn_link(node) == waitq)
105 pdeq_putr(waitq, node);
106 set_irn_link(node, waitq);
110 * Enqueue all users of a node to a wait queue.
111 * Handles mode_T nodes.
113 static void enqueue_users(ir_node *n, pdeq *waitq)
115 const ir_edge_t *edge;
117 foreach_out_edge(n, edge) {
118 ir_node *succ = get_edge_src_irn(edge);
119 const ir_edge_t *edge2;
121 enqueue_node(succ, waitq);
123 /* Also enqueue Phis to prevent inconsistencies. */
124 if (is_Block(succ)) {
125 foreach_out_edge(succ, edge2) {
126 ir_node *succ2 = get_edge_src_irn(edge2);
129 enqueue_node(succ2, waitq);
132 } else if (get_irn_mode(succ) == mode_T) {
133 /* A mode_T node has Proj's. Because most optimizations
134 run on the Proj's we have to enqueue them also. */
135 enqueue_users(succ, waitq);
141 * Block-Walker: uses dominance depth to mark dead blocks.
143 static void find_unreachable_blocks(ir_node *block, void *env)
145 pdeq *waitq = (pdeq*) env;
147 if (get_Block_dom_depth(block) < 0) {
148 ir_graph *irg = get_irn_irg(block);
149 ir_node *end = get_irg_end(irg);
151 const ir_edge_t *edge;
152 foreach_block_succ(block, edge) {
153 const ir_edge_t *edge2;
154 ir_node *succ_block = get_edge_src_irn(edge);
155 enqueue_node(succ_block, waitq);
156 foreach_out_edge(succ_block, edge2) {
157 ir_node *succ = get_edge_src_irn(edge2);
159 enqueue_node(succ, waitq);
162 enqueue_node(end, waitq);
166 /* Applies local optimizations (see iropt.h) to all nodes reachable from node n. */
167 void local_optimize_graph(ir_graph *irg)
169 ir_graph *rem = current_ir_graph;
170 current_ir_graph = irg;
172 do_local_optimize(get_irg_end(irg));
174 current_ir_graph = rem;
178 * Data flow optimization walker.
179 * Optimizes all nodes and enqueue its users
182 static void opt_walker(ir_node *n, void *env)
184 pdeq *waitq = (pdeq*)env;
187 optimized = optimize_in_place_2(n);
188 set_irn_link(optimized, NULL);
190 if (optimized != n) {
191 enqueue_users(n, waitq);
192 exchange(n, optimized);
196 int optimize_graph_df(ir_graph *irg)
198 pdeq *waitq = new_pdeq();
199 ir_graph *rem = current_ir_graph;
202 current_ir_graph = irg;
204 if (get_opt_global_cse())
205 set_irg_pinned(irg, op_pin_state_floats);
207 /* enable unreachable code elimination */
208 assert(!is_irg_state(irg, IR_GRAPH_STATE_OPTIMIZE_UNREACHABLE_CODE));
209 set_irg_state(irg, IR_GRAPH_STATE_OPTIMIZE_UNREACHABLE_CODE);
216 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
217 irg_walk_graph(irg, NULL, opt_walker, waitq);
219 /* any optimized nodes are stored in the wait queue,
220 * so if it's not empty, the graph has been changed */
221 while (!pdeq_empty(waitq)) {
222 /* finish the wait queue */
223 while (! pdeq_empty(waitq)) {
224 ir_node *n = (ir_node*)pdeq_getl(waitq);
225 opt_walker(n, waitq);
227 /* Calculate dominance so we can kill unreachable code
228 * We want this intertwined with localopts for better optimization (phase coupling) */
230 irg_block_walk_graph(irg, NULL, find_unreachable_blocks, waitq);
233 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
235 /* disable unreachable code elimination */
236 clear_irg_state(irg, IR_GRAPH_STATE_OPTIMIZE_UNREACHABLE_CODE);
237 set_irg_state(irg, IR_GRAPH_STATE_NO_UNREACHABLE_CODE);
239 /* invalidate infos */
240 clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE);
241 clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_LOOPINFO);
242 clear_irg_state(irg, IR_GRAPH_STATE_VALID_EXTENDED_BLOCKS);
243 edges_deactivate(irg);
245 /* Finally kill BAD and doublets from the keep alives.
246 * Doing this AFTER edges where deactivated saves cycles */
247 end = get_irg_end(irg);
248 remove_End_Bads_and_doublets(end);
250 current_ir_graph = rem;
252 /* Note we do not have a reliable way to detect changes, since some
253 * localopt rules change the inputs of a node and do not return a new
254 * node, so we conservatively say true here */
258 ir_graph_pass_t *optimize_graph_df_pass(const char *name)
260 return def_graph_pass_ret(name ? name : "optimize_graph_df", optimize_graph_df);