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) {
55 ir_node *optimized = optimize_in_place_2(n);
59 exchange(n, optimized);
64 * Do local optimizations for a node.
66 * @param n the IR-node where to start. Typically the End node
69 * @note current_ir_graph must be set
71 static inline void do_local_optimize(ir_node *n) {
72 /* Handle graph state */
73 assert(get_irg_phase_state(current_ir_graph) != phase_building);
75 if (get_opt_global_cse())
76 set_irg_pinned(current_ir_graph, op_pin_state_floats);
77 set_irg_outs_inconsistent(current_ir_graph);
78 set_irg_doms_inconsistent(current_ir_graph);
79 set_irg_loopinfo_inconsistent(current_ir_graph);
81 /* Clean the value_table in irg for the CSE. */
82 del_identities(current_ir_graph->value_table);
83 current_ir_graph->value_table = new_identities();
85 /* walk over the graph */
86 irg_walk(n, firm_clear_link, optimize_in_place_wrapper, NULL);
89 /* Applies local optimizations (see iropt.h) to all nodes reachable from node n */
90 void local_optimize_node(ir_node *n) {
91 ir_graph *rem = current_ir_graph;
92 current_ir_graph = get_irn_irg(n);
96 current_ir_graph = rem;
100 * Block-Walker: uses dominance depth to mark dead blocks.
102 static void kill_dead_blocks(ir_node *block, void *env) {
105 if (get_Block_dom_depth(block) < 0) {
107 * Note that the new dominance code correctly handles
108 * the End block, i.e. it is always reachable from Start
110 set_Block_dead(block);
114 /* Applies local optimizations (see iropt.h) to all nodes reachable from node n. */
115 void local_optimize_graph(ir_graph *irg) {
116 ir_graph *rem = current_ir_graph;
117 current_ir_graph = irg;
119 if (get_irg_dom_state(irg) == dom_consistent)
120 irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
122 do_local_optimize(get_irg_end(irg));
124 current_ir_graph = rem;
128 * Enqueue all users of a node to a wait queue.
129 * Handles mode_T nodes.
131 static void enqueue_users(ir_node *n, pdeq *waitq) {
132 const ir_edge_t *edge;
134 foreach_out_edge(n, edge) {
135 ir_node *succ = get_edge_src_irn(edge);
137 if (get_irn_link(succ) != waitq) {
138 pdeq_putr(waitq, succ);
139 set_irn_link(succ, waitq);
141 if (get_irn_mode(succ) == mode_T) {
142 /* A mode_T node has Proj's. Because most optimizations
143 run on the Proj's we have to enqueue them also. */
144 enqueue_users(succ, waitq);
150 * Data flow optimization walker.
151 * Optimizes all nodes and enqueue it's users
154 static void opt_walker(ir_node *n, void *env) {
158 optimized = optimize_in_place_2(n);
159 set_irn_link(optimized, NULL);
161 if (optimized != n) {
162 enqueue_users(n, waitq);
163 exchange(n, optimized);
167 /* Applies local optimizations to all nodes in the graph until fixpoint. */
168 int optimize_graph_df(ir_graph *irg) {
169 pdeq *waitq = new_pdeq();
170 ir_graph *rem = current_ir_graph;
174 current_ir_graph = irg;
176 state = edges_assure(irg);
178 if (get_opt_global_cse())
179 set_irg_pinned(current_ir_graph, op_pin_state_floats);
181 /* Clean the value_table in irg for the CSE. */
182 del_identities(irg->value_table);
183 irg->value_table = new_identities();
185 if (get_irg_dom_state(irg) == dom_consistent)
186 irg_block_walk_graph(irg, NULL, kill_dead_blocks, NULL);
188 /* invalidate info */
189 set_irg_outs_inconsistent(irg);
190 set_irg_doms_inconsistent(irg);
191 set_irg_loopinfo_inconsistent(irg);
193 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
195 /* walk over the graph, but don't touch keep-alives */
196 irg_walk_graph(irg, NULL, opt_walker, waitq);
198 /* any optimized nodes are stored in the wait queue,
199 * so if it's not empty, the graph has been changed */
200 changed = !pdeq_empty(waitq);
202 /* finish the wait queue */
203 while (! pdeq_empty(waitq)) {
204 ir_node *n = pdeq_getl(waitq);
206 opt_walker(n, waitq);
211 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
214 edges_deactivate(irg);
216 /* Finally kill BAD and doublets from the keep alives.
217 Doing this AFTER edges where deactivated saves cycles */
218 end = get_irg_end(irg);
219 remove_End_Bads_and_doublets(end);
221 current_ir_graph = rem;
225 /* Creates an ir_graph pass for optimize_graph_df. */
226 ir_graph_pass_t *optimize_graph_df_pass(const char *name, int verify, int dump)
228 return def_graph_pass_ret(name ? name : "optimize_graph_df", verify, dump, optimize_graph_df);
229 } /* optimize_graph_df_pass */