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,
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 /* Handle graph state */
75 assert(get_irg_phase_state(current_ir_graph) != phase_building);
77 if (get_opt_global_cse())
78 set_irg_pinned(current_ir_graph, op_pin_state_floats);
79 set_irg_outs_inconsistent(current_ir_graph);
80 set_irg_doms_inconsistent(current_ir_graph);
81 set_irg_loopinfo_inconsistent(current_ir_graph);
83 /* Clean the value_table in irg for the CSE. */
84 del_identities(current_ir_graph->value_table);
85 current_ir_graph->value_table = new_identities();
87 /* walk over the graph */
88 irg_walk(n, firm_clear_link, optimize_in_place_wrapper, NULL);
91 /* Applies local optimizations (see iropt.h) to all nodes reachable from node n */
92 void local_optimize_node(ir_node *n)
94 ir_graph *rem = current_ir_graph;
95 current_ir_graph = get_irn_irg(n);
99 current_ir_graph = rem;
103 * Block-Walker: uses dominance depth to mark dead blocks.
105 static void kill_dead_blocks(ir_node *block, void *env)
109 if (get_Block_dom_depth(block) < 0) {
111 * Note that the new dominance code correctly handles
112 * the End block, i.e. it is always reachable from Start
114 set_Block_dead(block);
118 /* Applies local optimizations (see iropt.h) to all nodes reachable from node n. */
119 void local_optimize_graph(ir_graph *irg)
121 ir_graph *rem = current_ir_graph;
122 current_ir_graph = irg;
124 if (get_irg_dom_state(irg) == dom_consistent)
125 irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
127 do_local_optimize(get_irg_end(irg));
129 current_ir_graph = rem;
133 * Enqueue all users of a node to a wait queue.
134 * Handles mode_T nodes.
136 static void enqueue_users(ir_node *n, pdeq *waitq)
138 const ir_edge_t *edge;
140 foreach_out_edge(n, edge) {
141 ir_node *succ = get_edge_src_irn(edge);
143 if (get_irn_link(succ) != waitq) {
144 pdeq_putr(waitq, succ);
145 set_irn_link(succ, waitq);
147 if (get_irn_mode(succ) == mode_T) {
148 /* A mode_T node has Proj's. Because most optimizations
149 run on the Proj's we have to enqueue them also. */
150 enqueue_users(succ, waitq);
156 * Data flow optimization walker.
157 * Optimizes all nodes and enqueue it's users
160 static void opt_walker(ir_node *n, void *env)
165 optimized = optimize_in_place_2(n);
166 set_irn_link(optimized, NULL);
168 if (optimized != n) {
169 enqueue_users(n, waitq);
170 exchange(n, optimized);
174 /* Applies local optimizations to all nodes in the graph until fixpoint. */
175 int optimize_graph_df(ir_graph *irg)
177 pdeq *waitq = new_pdeq();
178 ir_graph *rem = current_ir_graph;
182 current_ir_graph = irg;
184 state = edges_assure(irg);
186 if (get_opt_global_cse())
187 set_irg_pinned(current_ir_graph, op_pin_state_floats);
189 /* Clean the value_table in irg for the CSE. */
190 del_identities(irg->value_table);
191 irg->value_table = new_identities();
193 if (get_irg_dom_state(irg) == dom_consistent)
194 irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
196 /* invalidate info */
197 set_irg_outs_inconsistent(irg);
198 set_irg_doms_inconsistent(irg);
199 set_irg_loopinfo_inconsistent(irg);
201 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
203 /* walk over the graph, but don't touch keep-alives */
204 irg_walk_graph(irg, NULL, opt_walker, waitq);
206 /* any optimized nodes are stored in the wait queue,
207 * so if it's not empty, the graph has been changed */
208 changed = !pdeq_empty(waitq);
210 /* finish the wait queue */
211 while (! pdeq_empty(waitq)) {
212 ir_node *n = pdeq_getl(waitq);
214 opt_walker(n, waitq);
219 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
222 edges_deactivate(irg);
224 /* Finally kill BAD and doublets from the keep alives.
225 Doing this AFTER edges where deactivated saves cycles */
226 end = get_irg_end(irg);
227 remove_End_Bads_and_doublets(end);
229 current_ir_graph = rem;
233 /* Creates an ir_graph pass for optimize_graph_df. */
234 ir_graph_pass_t *optimize_graph_df_pass(const char *name)
236 return def_graph_pass_ret(name ? name : "optimize_graph_df", optimize_graph_df);
237 } /* optimize_graph_df_pass */