2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
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9 * packaging of this file.
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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,
31 #include "irgraph_t.h"
33 #include "iroptimize.h"
44 #include "iredges_t.h"
48 * A wrapper around optimize_inplace_2() to be called from a walker.
50 static void optimize_in_place_wrapper(ir_node *n, void *env)
52 ir_node *optimized = optimize_in_place_2(n);
56 exchange(n, optimized);
61 * Do local optimizations for a node.
63 * @param n the IR-node where to start. Typically the End node
66 * @note current_ir_graph must be set
68 static inline void do_local_optimize(ir_node *n)
70 ir_graph *irg = get_irn_irg(n);
72 /* Handle graph state */
73 assert(get_irg_phase_state(irg) != phase_building);
75 if (get_opt_global_cse())
76 set_irg_pinned(irg, op_pin_state_floats);
77 clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
79 /* Clean the value_table in irg for the CSE. */
82 /* walk over the graph */
83 irg_walk(n, firm_clear_link, optimize_in_place_wrapper, NULL);
86 void local_optimize_node(ir_node *n)
88 ir_graph *rem = current_ir_graph;
89 current_ir_graph = get_irn_irg(n);
93 current_ir_graph = rem;
96 static void enqueue_node(ir_node *node, pdeq *waitq)
98 if (get_irn_link(node) == waitq)
100 pdeq_putr(waitq, node);
101 set_irn_link(node, waitq);
105 * Enqueue all users of a node to a wait queue.
106 * Handles mode_T nodes.
108 static void enqueue_users(ir_node *n, pdeq *waitq)
110 const ir_edge_t *edge;
112 foreach_out_edge(n, edge) {
113 ir_node *succ = get_edge_src_irn(edge);
114 const ir_edge_t *edge2;
116 enqueue_node(succ, waitq);
118 /* Also enqueue Phis to prevent inconsistencies. */
119 if (is_Block(succ)) {
120 foreach_out_edge(succ, edge2) {
121 ir_node *succ2 = get_edge_src_irn(edge2);
124 enqueue_node(succ2, waitq);
127 } else if (get_irn_mode(succ) == mode_T) {
128 /* A mode_T node has Proj's. Because most optimizations
129 run on the Proj's we have to enqueue them also. */
130 enqueue_users(succ, waitq);
136 * Block-Walker: uses dominance depth to mark dead blocks.
138 static void find_unreachable_blocks(ir_node *block, void *env)
140 pdeq *waitq = (pdeq*) env;
142 if (get_Block_dom_depth(block) < 0) {
143 ir_graph *irg = get_irn_irg(block);
144 ir_node *end = get_irg_end(irg);
146 const ir_edge_t *edge;
147 foreach_block_succ(block, edge) {
148 const ir_edge_t *edge2;
149 ir_node *succ_block = get_edge_src_irn(edge);
150 enqueue_node(succ_block, waitq);
151 foreach_out_edge(succ_block, edge2) {
152 ir_node *succ = get_edge_src_irn(edge2);
154 enqueue_node(succ, waitq);
157 enqueue_node(end, waitq);
161 void local_optimize_graph(ir_graph *irg)
163 ir_graph *rem = current_ir_graph;
164 current_ir_graph = irg;
166 do_local_optimize(get_irg_end(irg));
168 current_ir_graph = rem;
172 * Data flow optimization walker.
173 * Optimizes all nodes and enqueue its users
176 static void opt_walker(ir_node *n, void *env)
178 pdeq *waitq = (pdeq*)env;
181 optimized = optimize_in_place_2(n);
182 set_irn_link(optimized, NULL);
184 if (optimized != n) {
185 enqueue_users(n, waitq);
186 exchange(n, optimized);
190 int optimize_graph_df(ir_graph *irg)
192 pdeq *waitq = new_pdeq();
193 ir_graph *rem = current_ir_graph;
196 current_ir_graph = irg;
198 if (get_opt_global_cse())
199 set_irg_pinned(irg, op_pin_state_floats);
201 /* enable unreachable code elimination */
202 assert(!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_OPTIMIZE_UNREACHABLE_CODE));
203 add_irg_constraints(irg, IR_GRAPH_CONSTRAINT_OPTIMIZE_UNREACHABLE_CODE);
210 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
211 irg_walk_graph(irg, NULL, opt_walker, waitq);
213 /* any optimized nodes are stored in the wait queue,
214 * so if it's not empty, the graph has been changed */
215 while (!pdeq_empty(waitq)) {
216 /* finish the wait queue */
217 while (! pdeq_empty(waitq)) {
218 ir_node *n = (ir_node*)pdeq_getl(waitq);
219 opt_walker(n, waitq);
221 /* Calculate dominance so we can kill unreachable code
222 * We want this intertwined with localopts for better optimization (phase coupling) */
224 irg_block_walk_graph(irg, NULL, find_unreachable_blocks, waitq);
227 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
229 /* disable unreachable code elimination */
230 clear_irg_constraints(irg, IR_GRAPH_CONSTRAINT_OPTIMIZE_UNREACHABLE_CODE);
231 add_irg_properties(irg, IR_GRAPH_PROPERTY_NO_UNREACHABLE_CODE);
233 /* invalidate infos */
234 clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
235 clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
236 edges_deactivate(irg);
238 /* Finally kill BAD and doublets from the keep alives.
239 * Doing this AFTER edges where deactivated saves cycles */
240 end = get_irg_end(irg);
241 remove_End_Bads_and_doublets(end);
243 current_ir_graph = rem;
245 /* Note we do not have a reliable way to detect changes, since some
246 * localopt rules change the inputs of a node and do not return a new
247 * node, so we conservatively say true here */
251 ir_graph_pass_t *optimize_graph_df_pass(const char *name)
253 return def_graph_pass_ret(name ? name : "optimize_graph_df", optimize_graph_df);