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).
78 * - remove Load that loads a value already loaded (RAR)
79 * - replace Load of constant values with constants (RC)
81 void set_opt_redundant_LoadStore(int value);
83 /** Enables/Disables constant subexpression elimination.
85 * If opt_cse == 1 perform constant subexpression elimination.
86 * Default: opt_cse == 1.
88 void set_opt_cse (int value);
90 /** Returns constant folding optimization setting. */
91 int get_opt_cse(void);
93 /** Enables/Disables global constant subexpression elimination.
95 * If opt_global_cse == 1 and opt_cse == 1 perform intra procedure
96 * constant subexpression elimination for floating nodes. Intra
97 * procedure cse gets the graph into state "floating". It is necessary
98 * to run pre/code motion to get the graph back into state "op_pin_state_pinned".
99 * right after a call to local_optimize with global cse turned on.
100 * Default: opt_global_cse == 0.
102 void set_opt_global_cse (int value);
104 /** Enables/Disables strength reduction.
106 * If opt_strength_red == 1 perform strength reduction.
109 * Default: opt_strength_red = 1;
111 void set_opt_strength_red (int value);
113 /** Enables/Disables output of information about strength reduction.
115 void set_opt_strength_red_verbose (int value);
117 /** Enables/Disables unreachable code elimination.
119 * If set, evaluate conditions of conditional branch and replace the
120 * branch with a Jmp/Bad Tuple.
122 * If opt_unreachable_code == 1 replace nodes (except Block,
123 * Phi and Tuple) with a Bad predecessor by the Bad node.
124 * Default: opt_unreachable_code == 1.
126 void set_opt_unreachable_code(int value);
128 /** Enables/Disables control flow optimizations.
130 * Performs Straightening, if simplifications and loop simplifications.
131 * Sets all separate control flow flags (control_flow_straightening,
132 * weak_simplification, strong_simplification and critical_edges).
134 void set_opt_control_flow(int value);
136 /** Enables/Disables Straightening. */
137 void set_opt_control_flow_straightening(int value);
139 /** Enables/Disables if simplifications in local optimizations. */
140 void set_opt_control_flow_weak_simplification(int value);
142 /** Enables/Disables strong if and loop simplification (in optimize_cf). */
143 void set_opt_control_flow_strong_simplification(int value);
145 /** Enables/Disables removal of critical control flow edges. */
146 void set_opt_critical_edges(int value);
148 /** Enables/Disables reassociation.
150 * If opt_reassociation == 1 reassociation is performed.
151 * Default: opt_reassociation == 1.
153 void set_opt_reassociation(int value);
155 /** Enables/Disables dead node elimination.
157 * If opt_dead_node_elimination == 1 deallocate all dead nodes
158 * by copying the firm graph.
159 * Default: opt_dead_node_elimination == 1. */
160 void set_opt_dead_node_elimination (int value);
162 /** Enables/Disables dead method elimination.
164 * If opt_dead_method_elimination == 1 methods never called are
166 * Default: opt_dead_method_elimination == 1. */
167 void set_opt_dead_method_elimination (int value);
168 void set_opt_dead_method_elimination_verbose (int value);
170 /** Enable/Disables inlining.
172 * If opt_inline == 1 the inlining transformation is performed.
174 void set_opt_inline (int value);
176 /** Enable/Disable optimization of dynamic method dispatch
178 * This flag enables/disables the optimization of dynamic method dispatch.
179 * If the flag is turned on Sel nodes can be replaced by Const nodes representing
180 * the address of a function.
182 void set_opt_dyn_meth_dispatch (int value);
184 /** Enable/Disable optimization of tail-recursion calls.
186 * This flag enables/disables the optimization tail-recursion call.
187 * If the flag is turned on tail-recursion calls are optimized into loops.
189 void set_opt_tail_recursion(int value);
190 void set_opt_tail_recursion_verbose(int value);
192 void set_opt_fragile_ops(int value);
195 /** Enable/Disable normalizations of the firm representation.
197 * This flag guards transformations that normalize the firm representation
198 * as removing Ids and Tuples, useless Phis, replacing SymConst(id) by
199 * Const(entity) and others.
200 * The transformations guarded by this flag are not guarded by flag
202 * Many algorithms operating on firm can not deal with constructs in
203 * the non-normalized representation.
205 * @@@ ATTENTION: not all such transformations are guarded by a flag.
207 void set_opt_normalize (int value);
210 /** Enable/Disable precise exception context. */
211 void set_opt_precise_exc_context(int value);
214 * Save the current optimization state.
216 void save_optimization_state(optimization_state_t *state);
219 * Restore the current optimization state.
221 void restore_optimization_state(const optimization_state_t *state);