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 code that will globalize a label. */
73 void (* globalize_label
) PARAMS ((FILE *, const char *));
75 /* Emit an assembler directive to set visibility for the symbol
76 associated with the tree decl. */
77 void (* visibility
) PARAMS ((tree
, const char *));
79 /* Output the assembler code for entry to a function. */
80 void (* function_prologue
) PARAMS ((FILE *, HOST_WIDE_INT
));
82 /* Output the assembler code for end of prologue. */
83 void (* function_end_prologue
) PARAMS ((FILE *));
85 /* Output the assembler code for start of epilogue. */
86 void (* function_begin_epilogue
) PARAMS ((FILE *));
88 /* Output the assembler code for function exit. */
89 void (* function_epilogue
) PARAMS ((FILE *, HOST_WIDE_INT
));
91 /* Switch to an arbitrary section NAME with attributes as
92 specified by FLAGS. */
93 void (* named_section
) PARAMS ((const char *, unsigned int));
95 /* Switch to the section that holds the exception table. */
96 void (* exception_section
) PARAMS ((void));
98 /* Switch to the section that holds the exception frames. */
99 void (* eh_frame_section
) PARAMS ((void));
101 /* Select and switch to a section for EXP. It may be a DECL or a
102 constant for which TREE_CST_RTL is valid. RELOC is nonzero if
103 runtime relocations must be applied; bit 1 will be set if the
104 runtime relocations require non-local name resolution. ALIGN is
105 the required alignment of the data. */
106 void (* select_section
) PARAMS ((tree
, int, unsigned HOST_WIDE_INT
));
108 /* Select and switch to a section for X with MODE. ALIGN is
109 the desired alignment of the data. */
110 void (* select_rtx_section
) PARAMS ((enum machine_mode
, rtx
,
111 unsigned HOST_WIDE_INT
));
113 /* Select a unique section name for DECL. RELOC is the same as
114 for SELECT_SECTION. */
115 void (* unique_section
) PARAMS ((tree
, int));
117 /* Output a constructor for a symbol with a given priority. */
118 void (* constructor
) PARAMS ((rtx
, int));
120 /* Output a destructor for a symbol with a given priority. */
121 void (* destructor
) PARAMS ((rtx
, int));
123 /* Output the assembler code for a thunk function. THUNK_DECL is the
124 declaration for the thunk function itself, FUNCTION is the decl for
125 the target function. DELTA is an immediate constant offset to be
126 added to THIS. If VCALL_OFFSET is nonzero, the word at
127 *(*this + vcall_offset) should be added to THIS. */
128 void (* output_mi_thunk
) PARAMS ((FILE *file
, tree thunk_decl
,
130 HOST_WIDE_INT vcall_offset
,
131 tree function_decl
));
133 /* Determine whether output_mi_thunk would succeed. */
134 /* ??? Ideally, this hook would not exist, and success or failure
135 would be returned from output_mi_thunk directly. But there's
136 too much undo-able setup involved in invoking output_mi_thunk.
137 Could be fixed by making output_mi_thunk emit rtl instead of
138 text to the output file. */
139 bool (* can_output_mi_thunk
) PARAMS ((tree thunk_decl
,
141 HOST_WIDE_INT vcall_offset
,
142 tree function_decl
));
145 /* Functions relating to instruction scheduling. */
148 /* Given the current cost, COST, of an insn, INSN, calculate and
149 return a new cost based on its relationship to DEP_INSN through
150 the dependence LINK. The default is to make no adjustment. */
151 int (* adjust_cost
) PARAMS ((rtx insn
, rtx link
, rtx def_insn
, int cost
));
153 /* Adjust the priority of an insn as you see fit. Returns the new
155 int (* adjust_priority
) PARAMS ((rtx
, int));
157 /* Function which returns the maximum number of insns that can be
158 scheduled in the same machine cycle. This must be constant
159 over an entire compilation. The default is 1. */
160 int (* issue_rate
) PARAMS ((void));
162 /* Calculate how much this insn affects how many more insns we
163 can emit this cycle. Default is they all cost the same. */
164 int (* variable_issue
) PARAMS ((FILE *, int, rtx
, int));
166 /* Initialize machine-dependent scheduling code. */
167 void (* md_init
) PARAMS ((FILE *, int, int));
169 /* Finalize machine-dependent scheduling code. */
170 void (* md_finish
) PARAMS ((FILE *, int));
172 /* Reorder insns in a machine-dependent fashion, in two different
173 places. Default does nothing. */
174 int (* reorder
) PARAMS ((FILE *, int, rtx
*, int *, int));
175 int (* reorder2
) PARAMS ((FILE *, int, rtx
*, int *, int));
177 /* The following member value is a pointer to a function returning
178 nonzero if we should use DFA based scheduling. The default is
179 to use the old pipeline scheduler. */
180 int (* use_dfa_pipeline_interface
) PARAMS ((void));
181 /* The values of all the following members are used only for the
182 DFA based scheduler: */
183 /* The values of the following four members are pointers to
184 functions used to simplify the automaton descriptions.
185 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
186 returning insns which are used to change the pipeline hazard
187 recognizer state when the new simulated processor cycle
188 correspondingly starts and finishes. The function defined by
189 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
190 to initialize the corresponding insns. The default values of
191 the memebers result in not changing the automaton state when
192 the new simulated processor cycle correspondingly starts and
194 void (* init_dfa_pre_cycle_insn
) PARAMS ((void));
195 rtx (* dfa_pre_cycle_insn
) PARAMS ((void));
196 void (* init_dfa_post_cycle_insn
) PARAMS ((void));
197 rtx (* dfa_post_cycle_insn
) PARAMS ((void));
198 /* The following member value is a pointer to a function returning value
199 which defines how many insns in queue `ready' will we try for
200 multi-pass scheduling. if the member value is nonzero and the
201 function returns positive value, the DFA based scheduler will make
202 multi-pass scheduling for the first cycle. In other words, we will
203 try to choose ready insn which permits to start maximum number of
204 insns on the same cycle. */
205 int (* first_cycle_multipass_dfa_lookahead
) PARAMS ((void));
206 /* The values of the following members are pointers to functions
207 used to improve the first cycle multipass scheduling by
208 inserting nop insns. dfa_scheduler_bubble gives a function
209 returning a nop insn with given index. The indexes start with
210 zero. The function should return NULL if there are no more nop
211 insns with indexes greater than given index. To initialize the
212 nop insn the function given by member
213 init_dfa_scheduler_bubbles is used. The default values of the
214 members result in not inserting nop insns during the multipass
216 void (* init_dfa_bubbles
) PARAMS ((void));
217 rtx (* dfa_bubble
) PARAMS ((int));
220 /* Given two decls, merge their attributes and return the result. */
221 tree (* merge_decl_attributes
) PARAMS ((tree
, tree
));
223 /* Given two types, merge their attributes and return the result. */
224 tree (* merge_type_attributes
) PARAMS ((tree
, tree
));
226 /* Table of machine attributes and functions to handle them.
228 const struct attribute_spec
*attribute_table
;
230 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
231 one if they are compatible and two if they are nearly compatible
232 (which causes a warning to be generated). */
233 int (* comp_type_attributes
) PARAMS ((tree type1
, tree type2
));
235 /* Assign default attributes to the newly defined TYPE. */
236 void (* set_default_type_attributes
) PARAMS ((tree type
));
238 /* Insert attributes on the newly created DECL. */
239 void (* insert_attributes
) PARAMS ((tree decl
, tree
*attributes
));
241 /* Return true if FNDECL (which has at least one machine attribute)
242 can be inlined despite its machine attributes, false otherwise. */
243 bool (* function_attribute_inlinable_p
) PARAMS ((tree fndecl
));
245 /* Return true if bitfields in RECORD_TYPE should follow the
246 Microsoft Visual C++ bitfield layout rules. */
247 bool (* ms_bitfield_layout_p
) PARAMS ((tree record_type
));
249 /* Set up target-specific built-in functions. */
250 void (* init_builtins
) PARAMS ((void));
252 /* Expand a target-specific builtin. */
253 rtx (* expand_builtin
) PARAMS ((tree exp
, rtx target
, rtx subtarget
,
254 enum machine_mode mode
, int ignore
));
256 /* Given a decl, a section name, and whether the decl initializer
257 has relocs, choose attributes for the section. */
258 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
259 unsigned int (* section_type_flags
) PARAMS ((tree
, const char *, int));
261 /* True if new jumps cannot be created, to replace existing ones or
262 not, at the current point in the compilation. */
263 bool (* cannot_modify_jumps_p
) PARAMS ((void));
265 /* True if EXP should be placed in a "small data" section. */
266 bool (* in_small_data_p
) PARAMS ((tree
));
268 /* True if EXP names an object for which name resolution must resolve
269 to the current module. */
270 bool (* binds_local_p
) PARAMS ((tree
));
272 /* Do something target-specific to record properties of the DECL into
273 the associated SYMBOL_REF. */
274 void (* encode_section_info
) PARAMS ((tree
, int));
276 /* Undo the effects of encode_section_info on the symbol string. */
277 const char * (* strip_name_encoding
) PARAMS ((const char *));
279 /* Leave the boolean fields at the end. */
281 /* True if arbitrary sections are supported. */
282 bool have_named_sections
;
284 /* True if "native" constructors and destructors are supported,
285 false if we're using collect2 for the job. */
286 bool have_ctors_dtors
;
288 /* True if thread-local storage is supported. */
291 /* True if a small readonly data section is supported. */
292 bool have_srodata_section
;
294 /* True if EH frame info sections should be zero-terminated. */
295 bool terminate_dw2_eh_frame_info
;
298 extern struct gcc_target targetm
;