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 Flags to control optimizations.
23 * @author Christian Schaefer, Goetz Lindenmaier, Michael Beck
25 * Flags to customize the behavior of libfirm.
27 * There are the following groups of flags:
28 * 1. Optimization flags.
29 * a) There is a flag, 'optimize' to turn on/off all optimizations.
30 * b) There are flags for each individual optimization. Some flags turns
31 * transformations in several algorithms on/off.
32 * 2. Normalization flags.
33 * These flags steer transformations of the ir that improve it, as removing
34 * dump Phi nodes (one predecessor, all predecessors are equal ...), Ids, Tuples ...
36 * a) Flags to steer the level of the information.
37 * b) Flags to steer in which phase information should be dumped.
38 * 4. Verification flag
39 * This one controls the behavior of node and type verifications
41 #ifndef FIRM_IR_IRFLAG_H
42 #define FIRM_IR_IRFLAG_H
44 #include "firm_types.h"
48 * A container type to load/restore all optimizations
50 typedef unsigned optimization_state_t;
53 * This function enables/disables optimizations globally.
55 * If optimize == 0 no optimizations are performed at all.
56 * Default: optimize == 1.
58 FIRM_API void set_optimize(int value);
59 FIRM_API int get_optimize(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 * Default: opt_constant_folding == 1.
67 FIRM_API void set_opt_constant_folding(int value);
69 /** Enables/Disables algebraic simplifications.
71 * If opt_algebraic_simplification == 1 perform
72 * - algebraic simplification (a * 0 ==> 0, a or a ==> a)
73 * - simplification of tests ( !(a < b) ==> (a >= b))
74 * Default: opt_algebraic_simplification == 1.
76 FIRM_API void set_opt_algebraic_simplification(int value);
78 /** Enables/Disables common subexpression elimination.
80 * If opt_cse == 1 perform common subexpression elimination.
81 * Default: opt_cse == 1.
83 FIRM_API void set_opt_cse(int value);
85 /** Returns constant folding optimization setting. */
86 FIRM_API int get_opt_cse(void);
88 /** Enables/Disables global constant subexpression elimination.
90 * If opt_global_cse == 1 and opt_cse == 1 perform intra procedure
91 * constant subexpression elimination for floating nodes. Intra
92 * procedure cse gets the graph into state "floating". It is necessary
93 * to run pre/code motion to get the graph back into state "op_pin_state_pinned".
94 * right after a call to local_optimize with global cse turned on.
95 * Default: opt_global_cse == 0.
97 FIRM_API void set_opt_global_cse(int value);
99 /** Restricts the behavior of cast optimization.
101 * If set, downcast are not optimized if they might be
102 * illegal as in (Super)(Sub) (new Super()). Default:
103 * 0 == not suppressed.
105 FIRM_API void set_opt_suppress_downcast_optimization(int value);
106 FIRM_API int get_opt_suppress_downcast_optimization(void);
109 * Enable/Disable Null exception in Load and Store nodes only.
111 * If enabled, only Null pointer exception can occur at Load and
112 * store nodes. If it can be proved that the address input of these
113 * nodes is non-null, the exception edge can safely be removed.
114 * If disabled, other exceptions (like unaligned access, read-only memory,
117 * This flag is enabled by default.
119 FIRM_API void set_opt_ldst_only_null_ptr_exceptions(int value);
122 * Enable/Disable Global Null Pointer Test Elimination.
124 * In languages where it is illegal to dereference NULL pointer, doing
125 * so makes the pointer "valid non-null", else the program will stop
128 * This flag should be set for C style languages.
130 FIRM_API void set_opt_global_null_ptr_elimination(int value);
133 * Enable/Disable Automatic construction of Sync nodes during
136 * If this flags is set, sequential non-volatile Loads are automatically
137 * rearranged so that they can be executed in parallel by creating Sync nodes.
139 * This flag should be set for Java style languages.
141 FIRM_API void set_opt_auto_create_sync(int value);
143 /** Enable/Disable Alias analysis.
145 * If enabled, memory disambiguation by alias analysis is used.
147 FIRM_API void set_opt_alias_analysis(int value);
149 /** Enable/Disable closed world assumption.
151 * If enabled, optimizations expect to know the "whole world", i.e. no
152 * external types or callers exist.
153 * This enables some powerful optimizations.
155 FIRM_API void set_opt_closed_world(int value);
158 * Save the current optimization state.
160 FIRM_API void save_optimization_state(optimization_state_t *state);
163 * Restore the current optimization state.
165 FIRM_API void restore_optimization_state(const optimization_state_t *state);
168 * Switches ALL optimizations off.
170 FIRM_API void all_optimizations_off(void);
173 * Possible verification modes.
175 typedef enum firm_verification_t {
176 FIRM_VERIFICATION_OFF = 0, /**< do not verify nodes at all */
177 FIRM_VERIFICATION_ON = 1, /**< do node verification and assert on error in debug version */
178 FIRM_VERIFICATION_REPORT = 2, /**< do node verification, but report to stderr only */
179 FIRM_VERIFICATION_ERROR_ONLY = 3 /**< do node verification, but NEVER do assert nor report */
180 } firm_verification_t;
183 * Select verification of IR nodes and types.
185 * Per default the verification is in mode NODE_VERIFICATION_ASSERT.
186 * Turn the verification off during development to check partial
189 FIRM_API void do_node_verification(firm_verification_t mode);