1 /* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001, 2002 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 2, or (at your option) any
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 In other words, you are welcome to use, share and improve this program.
19 You are forbidden to forbid anyone else to use, share and improve
20 what you give them. Help stamp out software-hoarding! */
22 /* This file contains a data structure that describes a GCC target.
23 At present it is incomplete, but in future it should grow to
24 contain most or all target machine and target O/S specific
27 This structure has its initializer declared in target-def.h in the
28 form of large macro TARGET_INITIALIZER that expands to many smaller
31 The smaller macros each initialize one component of the structure,
32 and each has a default. Each target should have a file that
33 includes target.h and target-def.h, and overrides any inappropriate
34 defaults by undefining the relevant macro and defining a suitable
35 replacement. That file should then contain the definition of
38 struct gcc_target targetm = TARGET_INITIALIZER;
40 Doing things this way allows us to bring together everything that
41 defines a GCC target. By supplying a default that is appropriate
42 to most targets, we can easily add new items without needing to
43 edit dozens of target configuration files. It should also allow us
44 to gradually reduce the amount of conditional compilation that is
45 scattered throughout GCC. */
49 /* Functions that output assembler for the target. */
52 /* Opening and closing parentheses for asm expression grouping. */
53 const char *open_paren, *close_paren;
55 /* Assembler instructions for creating various kinds of integer object. */
63 } aligned_op, unaligned_op;
65 /* Try to output the assembler code for an integer object whose
66 value is given by X. SIZE is the size of the object in bytes and
67 ALIGNED_P indicates whether it is aligned. Return true if
68 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
69 and UNALIGNED_OP are NULL. */
70 bool (* integer) PARAMS ((rtx x, unsigned int size, int aligned_p));
72 /* Output the assembler code for entry to a function. */
73 void (* function_prologue) PARAMS ((FILE *, HOST_WIDE_INT));
75 /* Output the assembler code for end of prologue. */
76 void (* function_end_prologue) PARAMS ((FILE *));
78 /* Output the assembler code for start of epilogue. */
79 void (* function_begin_epilogue) PARAMS ((FILE *));
81 /* Output the assembler code for function exit. */
82 void (* function_epilogue) PARAMS ((FILE *, HOST_WIDE_INT));
84 /* Switch to an arbitrary section NAME with attributes as
85 specified by FLAGS. */
86 void (* named_section) PARAMS ((const char *, unsigned int));
88 /* Switch to the section that holds the exception table. */
89 void (* exception_section) PARAMS ((void));
91 /* Switch to the section that holds the exception frames. */
92 void (* eh_frame_section) PARAMS ((void));
94 /* Select and switch to a section for EXP. It may be a DECL or a
95 constant for which TREE_CST_RTL is valid. RELOC is non-zero if
96 runtime relocations must be applied; bit 1 will be set if the
97 runtime relocations require non-local name resolution. ALIGN is
98 the required alignment of the data. */
99 void (* select_section) PARAMS ((tree, int, unsigned HOST_WIDE_INT));
101 /* Select a unique section name for DECL. RELOC is the same as
102 for SELECT_SECTION. */
103 void (* unique_section) PARAMS ((tree, int));
105 /* Output a constructor for a symbol with a given priority. */
106 void (* constructor) PARAMS ((rtx, int));
108 /* Output a destructor for a symbol with a given priority. */
109 void (* destructor) PARAMS ((rtx, int));
112 /* Functions relating to instruction scheduling. */
115 /* Given the current cost, COST, of an insn, INSN, calculate and
116 return a new cost based on its relationship to DEP_INSN through
117 the dependence LINK. The default is to make no adjustment. */
118 int (* adjust_cost) PARAMS ((rtx insn, rtx link, rtx def_insn, int cost));
120 /* Adjust the priority of an insn as you see fit. Returns the new
122 int (* adjust_priority) PARAMS ((rtx, int));
124 /* Function which returns the maximum number of insns that can be
125 scheduled in the same machine cycle. This must be constant
126 over an entire compilation. The default is 1. */
127 int (* issue_rate) PARAMS ((void));
129 /* Calculate how much this insn affects how many more insns we
130 can emit this cycle. Default is they all cost the same. */
131 int (* variable_issue) PARAMS ((FILE *, int, rtx, int));
133 /* Initialize machine-dependent scheduling code. */
134 void (* md_init) PARAMS ((FILE *, int, int));
136 /* Finalize machine-dependent scheduling code. */
137 void (* md_finish) PARAMS ((FILE *, int));
139 /* Reorder insns in a machine-dependent fashion, in two different
140 places. Default does nothing. */
141 int (* reorder) PARAMS ((FILE *, int, rtx *, int *, int));
142 int (* reorder2) PARAMS ((FILE *, int, rtx *, int *, int));
144 /* The following member value is a pointer to a function returning
145 nonzero if we should use DFA based scheduling. The default is
146 to use the old pipeline scheduler. */
147 int (* use_dfa_pipeline_interface) PARAMS ((void));
148 /* The values of all the following members are used only for the
149 DFA based scheduler: */
150 /* The values of the following four members are pointers to
151 functions used to simplify the automaton descriptions.
152 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
153 returning insns which are used to change the pipeline hazard
154 recognizer state when the new simulated processor cycle
155 correspondingly starts and finishes. The function defined by
156 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
157 to initialize the corresponding insns. The default values of
158 the memebers result in not changing the automaton state when
159 the new simulated processor cycle correspondingly starts and
161 void (* init_dfa_pre_cycle_insn) PARAMS ((void));
162 rtx (* dfa_pre_cycle_insn) PARAMS ((void));
163 void (* init_dfa_post_cycle_insn) PARAMS ((void));
164 rtx (* dfa_post_cycle_insn) PARAMS ((void));
165 /* The following member value is a pointer to a function returning value
166 which defines how many insns in queue `ready' will we try for
167 multi-pass scheduling. if the member value is nonzero and the
168 function returns positive value, the DFA based scheduler will make
169 multi-pass scheduling for the first cycle. In other words, we will
170 try to choose ready insn which permits to start maximum number of
171 insns on the same cycle. */
172 int (* first_cycle_multipass_dfa_lookahead) PARAMS ((void));
173 /* The values of the following members are pointers to functions
174 used to improve the first cycle multipass scheduling by
175 inserting nop insns. dfa_scheduler_bubble gives a function
176 returning a nop insn with given index. The indexes start with
177 zero. The function should return NULL if there are no more nop
178 insns with indexes greater than given index. To initialize the
179 nop insn the function given by member
180 init_dfa_scheduler_bubbles is used. The default values of the
181 members result in not inserting nop insns during the multipass
183 void (* init_dfa_bubbles) PARAMS ((void));
184 rtx (* dfa_bubble) PARAMS ((int));
187 /* Given two decls, merge their attributes and return the result. */
188 tree (* merge_decl_attributes) PARAMS ((tree, tree));
190 /* Given two types, merge their attributes and return the result. */
191 tree (* merge_type_attributes) PARAMS ((tree, tree));
193 /* Table of machine attributes and functions to handle them.
195 const struct attribute_spec *attribute_table;
197 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
198 one if they are compatible and two if they are nearly compatible
199 (which causes a warning to be generated). */
200 int (* comp_type_attributes) PARAMS ((tree type1, tree type2));
202 /* Assign default attributes to the newly defined TYPE. */
203 void (* set_default_type_attributes) PARAMS ((tree type));
205 /* Insert attributes on the newly created DECL. */
206 void (* insert_attributes) PARAMS ((tree decl, tree *attributes));
208 /* Return true if FNDECL (which has at least one machine attribute)
209 can be inlined despite its machine attributes, false otherwise. */
210 bool (* function_attribute_inlinable_p) PARAMS ((tree fndecl));
212 /* Return true if bitfields in RECORD_TYPE should follow the
213 Microsoft Visual C++ bitfield layout rules. */
214 bool (* ms_bitfield_layout_p) PARAMS ((tree record_type));
216 /* Set up target-specific built-in functions. */
217 void (* init_builtins) PARAMS ((void));
219 /* Expand a target-specific builtin. */
220 rtx (* expand_builtin) PARAMS ((tree exp, rtx target, rtx subtarget,
221 enum machine_mode mode, int ignore));
223 /* Given a decl, a section name, and whether the decl initializer
224 has relocs, choose attributes for the section. */
225 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
226 unsigned int (* section_type_flags) PARAMS ((tree, const char *, int));
228 /* True if arbitrary sections are supported. */
229 bool have_named_sections;
231 /* True if "native" constructors and destructors are supported,
232 false if we're using collect2 for the job. */
233 bool have_ctors_dtors;
235 /* True if new jumps cannot be created, to replace existing ones or
236 not, at the current point in the compilation. */
237 bool (* cannot_modify_jumps_p) PARAMS ((void));
239 /* True if EXP should be placed in a "small data" section. */
240 bool (* in_small_data_p) PARAMS ((tree));
243 extern struct gcc_target targetm;