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 Optimizations for a whole ir graph, i.e., a procedure.
23 * @author Christian Schaefer, Goetz Lindenmaier, Sebastian Felis
26 #ifndef FIRM_IR_IRGOPT_H
27 #define FIRM_IR_IRGOPT_H
29 #include "firm_types.h"
31 /** Applies local optimizations (see iropt.h) to all nodes reachable from node n.
33 * @param n The node to be optimized.
35 void local_optimize_node(ir_node *n);
37 /** Applies local optimizations (see iropt.h) to all nodes in the graph.
39 * @param irg The graph to be optimized.
41 * After applying local_optimize_graph() to a IR-graph, Bad nodes
42 * only occur as predecessor of Block and Phi nodes.
44 void local_optimize_graph(ir_graph *irg);
46 /** Applies local optimizations (see iropt.h) to all nodes in the graph.
48 * After applying optimize_graph_df() to a IR-graph, Bad nodes
49 * only occur as predecessor of Block and Phi nodes.
51 * This version uses fixpoint iteration.
53 * @param irg The graph to be optimized.
55 * @return non-zero if the optimization could be applied, 0 else
57 int optimize_graph_df(ir_graph *irg);
60 * Creates an ir_graph pass for optimize_graph_df().
62 * @param name the name of this pass or NULL
64 * @return the newly created ir_graph pass
66 ir_graph_pass_t *optimize_graph_df_pass(const char *name);
68 /** Performs dead node elimination by copying the ir graph to a new obstack.
70 * The major intention of this pass is to free memory occupied by
71 * dead nodes and outdated analyzes information. Further this
72 * function removes Bad predecessors from Blocks and the corresponding
73 * inputs to Phi nodes. This opens optimization potential for other
74 * optimizations. Further this phase reduces dead Block<->Jmp
75 * self-cycles to Bad nodes.
77 * Dead_node_elimination is only performed if options `optimize' and
78 * `opt_dead_node_elimination' are set. The graph may
79 * not be in state phase_building. The outs datasturcture is freed,
80 * the outs state set to outs_none. Backedge information is conserved.
81 * Removes old attributes of nodes. Sets link field to NULL.
82 * Callee information must be freed (irg_callee_info_none).
84 * @param irg The graph to be optimized.
86 void dead_node_elimination(ir_graph *irg);
89 * Creates an ir_graph pass for dead_node_elimination().
91 * @param name the name of this pass or NULL
93 * @return the newly created ir_graph pass
95 ir_graph_pass_t *dead_node_elimination_pass(const char *name);
97 typedef struct _survive_dce_t survive_dce_t;
100 * Make a new Survive DCE environment.
102 survive_dce_t *new_survive_dce(void);
105 * Free a Survive DCE environment.
107 void free_survive_dce(survive_dce_t *sd);
110 * Register a node pointer to be patched upon DCE.
111 * When DCE occurs, the node pointer specified by @p place will be
112 * patched to the new address of the node it is pointing to.
114 * @param sd The Survive DCE environment.
115 * @param place The address of the node pointer.
117 void survive_dce_register_irn(survive_dce_t *sd, ir_node **place);
119 /** Cleans the control flow from Bad predecessors.
121 * Removes Bad predecessors from Blocks and the corresponding
122 * inputs to Phi nodes as in dead_node_elimination but without
125 * Conserves loop information.
127 * @param irg The graph to be optimized.
129 void remove_bad_predecessors(ir_graph *irg);
131 /** Inlines a method at the given call site.
133 * Removes the call node and splits the basic block the call node
134 * belongs to. Inserts a copy of the called graph between these nodes.
135 * Assumes that call is a Call node in current_ir_graph and that
136 * the type in the Call nodes type attribute is the same as the
137 * type of the called graph.
138 * Further it assumes that all Phi nodes in a block of current_ir_graph
139 * are assembled in a "link" list in the link field of the corresponding
140 * block nodes. Further assumes that all Proj nodes are in a "link" list
141 * in the nodes producing the tuple. (This is only an optical feature
142 * for the graph.) Conserves this feature for the old
143 * nodes of the graph. This precondition can be established by a call to
144 * collect_phisprojs(), see irgmod.h.
145 * As dead_node_elimination this function reduces dead Block<->Jmp
146 * self-cycles to Bad nodes.
148 * Called_graph must be unequal to current_ir_graph. Will not inline
150 * Sets visited masterflag in current_ir_graph to the max of the flag in
151 * current and called graph.
152 * Assumes that both, the called and the calling graph are in state
153 * "op_pin_state_pinned".
154 * It is recommended to call local_optimize_graph() after inlining as this
155 * function leaves a set of obscure Tuple nodes, e.g. a Proj-Tuple-Jmp
156 * combination as control flow operation.
158 * @param call the call node that should be inlined
159 * @param called_graph the IR-graph that is called at call
161 * @return zero if method could not be inlined (recursion for instance),
162 * non-zero if all went ok
164 int inline_method(ir_node *call, ir_graph *called_graph);
168 * Pins all floating nodes to a block where they
169 * will be executed only if needed. Depends on the flag opt_global_cse.
170 * Graph may not be in phase_building. Does not schedule control dead
171 * code. Uses dominator information which it computes if the irg is not
172 * in state dom_consistent. Destroys the out information as it moves nodes
173 * to other blocks. Optimizes Tuples in Control edges.
174 * @todo This is not tested!
176 * Call remove_critical_cf_edges() before place_code(). This normalizes
177 * the control flow graph so that for all operations a basic block exists
178 * where they can be optimally placed.
180 * @todo A more powerful code placement would move operations past Phi nodes
183 void place_code(ir_graph *irg);
186 * Creates an ir_graph pass for place_code().
187 * This pass enables GCSE, runs optimize_graph_df() and finally
190 * @param name the name of this pass or NULL
192 * @return the newly created ir_graph pass
194 ir_graph_pass_t *place_code_pass(const char *name);
196 /** Places an empty basic block on critical control flow edges thereby
199 * A critical control flow edge is an edge from a block with several
200 * control exits to a block with several control entries (See Muchnic
201 * p. 407). Exception edges are always ignored.
203 * @param irg IR Graph
205 void remove_critical_cf_edges(ir_graph *irg);
207 /** Places an empty basic block on critical control flow edges thereby
210 * A critical control flow edge is an edge from a block with several
211 * control exits to a block with several control entries (See Muchnic
214 * @param irg IR Graph
215 * @param ignore_exception_edges if non-zero, exception edges will be ignored
217 void remove_critical_cf_edges_ex(ir_graph *irg, int ignore_exception_edges);