3 * File name: ir/ir/irflag.h
4 * Purpose: Flags to control optimizations.
5 * Author: Christian Schaefer, Goetz Lindenmaier
6 * Modified by: Michael Beck
9 * Copyright: (c) 1999-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
16 * Flags to customize the behaviour of libfirm.
18 * @author Christian Schaefer
20 * There are the following groups of flags:
21 * 1. Optimization flags.
22 * a) There is a flag, 'optimize' to turn on/off all optimizations.
23 * b) There are flags for each individual optimization. Some flags turns
24 * transformations in several algorithms on/off.
25 * 2. Normalization flags.
26 * These flags steer transformations of the ir that improve it, as removing
27 * dump Phi nodes (one predecessor, all preds are equal ...), Ids, Tuples ...
29 * a) Flags to steer the level of the information.
30 * b) Flags to steer in which phase information should be dumped.
38 * A container type to load/restore all optimizations
40 typedef unsigned optimization_state_t;
43 * This function enables/disables optimizations globally.
45 * If optimize == 0 no optimizations are performed at all.
46 * Default: optimize == 1.
48 void set_optimize (int value);
49 int get_optimize(void);
51 /** This function enables/disables output of information about phases and
52 * controls the verbosity level.
54 * 0: no output at all.
55 * 1: very short output
56 * >>1: very verbose output.
58 void set_firm_verbosity (int value);
59 int get_firm_verbosity (void);
61 /** Enables/Disables constant folding optimization.
63 * If opt_constant_folding == 1 perform
64 * - constant expression evaluation (2 + 5 ==> 7, 3 < 2 ==> false)
65 * - algebraic simplification (a * 0 ==> 0, a or a ==> a)
66 * - simplification of tests ( !(a < b) ==> (a >= b))
67 * - refining the memory representation
68 * - remove store after load
69 * Default: opt_constant_folding == 1.
71 void set_opt_constant_folding (int value);
73 /** Enables/Disables removal of redundant Loads and Stores.
75 * - Remove Store that overwrites a just stored value (WAW).
76 * - Remove Store if it stores a value just loaded (WAR with the same value).
77 * - Remove Load that loads a value just saved (RAW with the same value).
79 void set_opt_redundant_LoadStore(int value);
81 /** Enables/Disables constant subexpression elimination.
83 * If opt_cse == 1 perform constant subexpression elimination.
84 * Default: opt_cse == 1.
86 void set_opt_cse (int value);
88 /** Returns constant folding optimization setting. */
89 int get_opt_cse(void);
91 /** Enables/Disables global constant subexpression elimination.
93 * If opt_global_cse == 1 and opt_cse == 1 perform intra procedure
94 * constant subexpression elimination for floating nodes. Intra
95 * procedure cse gets the graph into state "floating". It is necessary
96 * to run pre/code motion to get the graph back into state "op_pin_state_pinned".
97 * right after a call to local_optimize with global cse turned on.
98 * Default: opt_global_cse == 0.
100 void set_opt_global_cse (int value);
102 /** Enables/Disables strength reduction.
104 * If opt_strength_red == 1 perform strength reduction.
107 * Default: opt_strength_red = 1;
109 void set_opt_strength_red (int value);
111 /** Enables/Disables output of information about strength reduction.
113 void set_opt_strength_red_verbose (int value);
115 /** Enables/Disables unreachable code elimination.
117 * If set, evaluate conditions of conditional branch and replace the
118 * branch with a Jmp/Bad Tuple.
120 * If opt_unreachable_code == 1 replace nodes (except Block,
121 * Phi and Tuple) with a Bad predecessor by the Bad node.
122 * Default: opt_unreachable_code == 1.
124 void set_opt_unreachable_code(int value);
126 /** Enables/Disables control flow optimizations.
128 * Performs Straightening, if simplifications and loop simplifications.
129 * Sets all separate control flow flags (control_flow_straightening,
130 * weak_simplification, strong_simplification and critical_edges).
132 void set_opt_control_flow(int value);
134 /** Enables/Disables Straightening. */
135 void set_opt_control_flow_straightening(int value);
137 /** Enables/Disables if simplifications in local optimizations. */
138 void set_opt_control_flow_weak_simplification(int value);
140 /** Enables/Disables strong if and loop simplification (in optimize_cf). */
141 void set_opt_control_flow_strong_simplification(int value);
143 /** Enables/Disables removal of critical control flow edges. */
144 void set_opt_critical_edges(int value);
146 /** Enables/Disables reassociation.
148 * If opt_reassociation == 1 reassociation is performed.
149 * Default: opt_reassociation == 1.
151 void set_opt_reassociation(int value);
153 /** Enables/Disables dead node elimination.
155 * If opt_dead_node_elimination == 1 deallocate all dead nodes
156 * by copying the firm graph.
157 * Default: opt_dead_node_elimination == 1. */
158 void set_opt_dead_node_elimination (int value);
160 /** Enables/Disables dead method elimination.
162 * If opt_dead_method_elimination == 1 methods never called are
164 * Default: opt_dead_method_elimination == 1. */
165 void set_opt_dead_method_elimination (int value);
166 void set_opt_dead_method_elimination_verbose (int value);
168 /** Enable/Disables inlining.
170 * If opt_inline == 1 the inlining transformation is performed.
172 void set_opt_inline (int value);
174 /** Enable/Disable optimization of dynamic method dispatch
176 * This flag enables/disables the optimization of dynamic method dispatch.
177 * If the flag is turned on Sel nodes can be replaced by Const nodes representing
178 * the address of a function.
180 void set_opt_dyn_meth_dispatch (int value);
182 /** Enable/Disable optimization of tail-recursion calls.
184 * This flag enables/disables the optimization tail-recursion call.
185 * If the flag is turned on tail-recursion calls are optimized into loops.
187 void set_opt_tail_recursion(int value);
188 void set_opt_tail_recursion_verbose(int value);
190 void set_opt_fragile_ops(int value);
193 /** Enable/Disable normalizations of the firm representation.
195 * This flag guards transformations that normalize the firm representation
196 * as removing Ids and Tuples, useless Phis, replacing SymConst(id) by
197 * Const(entity) and others.
198 * The transformations guarded by this flag are not guarded by flag
200 * Many algorithms operating on firm can not deal with constructs in
201 * the non-normalized representation.
203 * @@@ ATTENTION: not all such transformations are guarded by a flag.
205 void set_opt_normalize (int value);
208 /** Enable/Disable precise exception context. */
209 void set_opt_precise_exc_context(int value);
212 * Save the current optimization state.
214 void save_optimization_state(optimization_state_t *state);
217 * Restore the current optimization state.
219 void restore_optimization_state(const optimization_state_t *state);