1 /* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001, 2002, 2003 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 /* Output an internal label. */
76 void (* internal_label
) PARAMS ((FILE *, const char *, unsigned long));
78 /* Emit an assembler directive to set visibility for the symbol
79 associated with the tree decl. */
80 void (* visibility
) PARAMS ((tree
, int));
82 /* Output the assembler code for entry to a function. */
83 void (* function_prologue
) PARAMS ((FILE *, HOST_WIDE_INT
));
85 /* Output the assembler code for end of prologue. */
86 void (* function_end_prologue
) PARAMS ((FILE *));
88 /* Output the assembler code for start of epilogue. */
89 void (* function_begin_epilogue
) PARAMS ((FILE *));
91 /* Output the assembler code for function exit. */
92 void (* function_epilogue
) PARAMS ((FILE *, HOST_WIDE_INT
));
94 /* Switch to an arbitrary section NAME with attributes as
95 specified by FLAGS. */
96 void (* named_section
) PARAMS ((const char *, unsigned int));
98 /* Switch to the section that holds the exception table. */
99 void (* exception_section
) PARAMS ((void));
101 /* Switch to the section that holds the exception frames. */
102 void (* eh_frame_section
) PARAMS ((void));
104 /* Select and switch to a section for EXP. It may be a DECL or a
105 constant for which TREE_CST_RTL is valid. RELOC is nonzero if
106 runtime relocations must be applied; bit 1 will be set if the
107 runtime relocations require non-local name resolution. ALIGN is
108 the required alignment of the data. */
109 void (* select_section
) PARAMS ((tree
, int, unsigned HOST_WIDE_INT
));
111 /* Select and switch to a section for X with MODE. ALIGN is
112 the desired alignment of the data. */
113 void (* select_rtx_section
) PARAMS ((enum machine_mode
, rtx
,
114 unsigned HOST_WIDE_INT
));
116 /* Select a unique section name for DECL. RELOC is the same as
117 for SELECT_SECTION. */
118 void (* unique_section
) PARAMS ((tree
, int));
120 /* Output a constructor for a symbol with a given priority. */
121 void (* constructor
) PARAMS ((rtx
, int));
123 /* Output a destructor for a symbol with a given priority. */
124 void (* destructor
) PARAMS ((rtx
, int));
126 /* Output the assembler code for a thunk function. THUNK_DECL is the
127 declaration for the thunk function itself, FUNCTION is the decl for
128 the target function. DELTA is an immediate constant offset to be
129 added to THIS. If VCALL_OFFSET is nonzero, the word at
130 *(*this + vcall_offset) should be added to THIS. */
131 void (* output_mi_thunk
) PARAMS ((FILE *file
, tree thunk_decl
,
133 HOST_WIDE_INT vcall_offset
,
134 tree function_decl
));
136 /* Determine whether output_mi_thunk would succeed. */
137 /* ??? Ideally, this hook would not exist, and success or failure
138 would be returned from output_mi_thunk directly. But there's
139 too much undo-able setup involved in invoking output_mi_thunk.
140 Could be fixed by making output_mi_thunk emit rtl instead of
141 text to the output file. */
142 bool (* can_output_mi_thunk
) PARAMS ((tree thunk_decl
,
144 HOST_WIDE_INT vcall_offset
,
145 tree function_decl
));
148 /* Functions relating to instruction scheduling. */
151 /* Given the current cost, COST, of an insn, INSN, calculate and
152 return a new cost based on its relationship to DEP_INSN through
153 the dependence LINK. The default is to make no adjustment. */
154 int (* adjust_cost
) PARAMS ((rtx insn
, rtx link
, rtx def_insn
, int cost
));
156 /* Adjust the priority of an insn as you see fit. Returns the new
158 int (* adjust_priority
) PARAMS ((rtx
, int));
160 /* Function which returns the maximum number of insns that can be
161 scheduled in the same machine cycle. This must be constant
162 over an entire compilation. The default is 1. */
163 int (* issue_rate
) PARAMS ((void));
165 /* Calculate how much this insn affects how many more insns we
166 can emit this cycle. Default is they all cost the same. */
167 int (* variable_issue
) PARAMS ((FILE *, int, rtx
, int));
169 /* Initialize machine-dependent scheduling code. */
170 void (* md_init
) PARAMS ((FILE *, int, int));
172 /* Finalize machine-dependent scheduling code. */
173 void (* md_finish
) PARAMS ((FILE *, int));
175 /* Reorder insns in a machine-dependent fashion, in two different
176 places. Default does nothing. */
177 int (* reorder
) PARAMS ((FILE *, int, rtx
*, int *, int));
178 int (* reorder2
) PARAMS ((FILE *, int, rtx
*, int *, int));
180 /* The following member value is a pointer to a function called
181 after evaluation forward dependencies of insns in chain given
182 by two parameter values (head and tail correspondingly). */
183 void (* dependencies_evaluation_hook
) PARAMS ((rtx
, rtx
));
185 /* The following member value is a pointer to a function returning
186 nonzero if we should use DFA based scheduling. The default is
187 to use the old pipeline scheduler. */
188 int (* use_dfa_pipeline_interface
) PARAMS ((void));
189 /* The values of all the following members are used only for the
190 DFA based scheduler: */
191 /* The values of the following four members are pointers to
192 functions used to simplify the automaton descriptions.
193 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
194 returning insns which are used to change the pipeline hazard
195 recognizer state when the new simulated processor cycle
196 correspondingly starts and finishes. The function defined by
197 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
198 to initialize the corresponding insns. The default values of
199 the memebers result in not changing the automaton state when
200 the new simulated processor cycle correspondingly starts and
202 void (* init_dfa_pre_cycle_insn
) PARAMS ((void));
203 rtx (* dfa_pre_cycle_insn
) PARAMS ((void));
204 void (* init_dfa_post_cycle_insn
) PARAMS ((void));
205 rtx (* dfa_post_cycle_insn
) PARAMS ((void));
206 /* The following member value is a pointer to a function returning value
207 which defines how many insns in queue `ready' will we try for
208 multi-pass scheduling. if the member value is nonzero and the
209 function returns positive value, the DFA based scheduler will make
210 multi-pass scheduling for the first cycle. In other words, we will
211 try to choose ready insn which permits to start maximum number of
212 insns on the same cycle. */
213 int (* first_cycle_multipass_dfa_lookahead
) PARAMS ((void));
214 /* The following member value is pointer to a function controlling
215 what insns from the ready insn queue will be considered for the
216 multipass insn scheduling. If the hook returns zero for insn
217 passed as the parameter, the insn will be not chosen to be
219 int (* first_cycle_multipass_dfa_lookahead_guard
) PARAMS ((rtx
));
220 /* The following member value is pointer to a function called by
221 the insn scheduler before issuing insn passed as the third
222 parameter on given cycle. If the hook returns nonzero, the
223 insn is not issued on given processors cycle. Instead of that,
224 the processor cycle is advanced. If the value passed through
225 the last parameter is zero, the insn ready queue is not sorted
226 on the new cycle start as usually. The first parameter passes
227 file for debugging output. The second one passes the scheduler
228 verbose level of the debugging output. The forth and the fifth
229 parameter values are correspondingly processor cycle on which
230 the previous insn has been issued and the current processor
232 int (* dfa_new_cycle
) PARAMS ((FILE *, int, rtx
, int, int, int *));
233 /* The values of the following members are pointers to functions
234 used to improve the first cycle multipass scheduling by
235 inserting nop insns. dfa_scheduler_bubble gives a function
236 returning a nop insn with given index. The indexes start with
237 zero. The function should return NULL if there are no more nop
238 insns with indexes greater than given index. To initialize the
239 nop insn the function given by member
240 init_dfa_scheduler_bubbles is used. The default values of the
241 members result in not inserting nop insns during the multipass
243 void (* init_dfa_bubbles
) PARAMS ((void));
244 rtx (* dfa_bubble
) PARAMS ((int));
247 /* Given two decls, merge their attributes and return the result. */
248 tree (* merge_decl_attributes
) PARAMS ((tree
, tree
));
250 /* Given two types, merge their attributes and return the result. */
251 tree (* merge_type_attributes
) PARAMS ((tree
, tree
));
253 /* Table of machine attributes and functions to handle them.
255 const struct attribute_spec
*attribute_table
;
257 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
258 one if they are compatible and two if they are nearly compatible
259 (which causes a warning to be generated). */
260 int (* comp_type_attributes
) PARAMS ((tree type1
, tree type2
));
262 /* Assign default attributes to the newly defined TYPE. */
263 void (* set_default_type_attributes
) PARAMS ((tree type
));
265 /* Insert attributes on the newly created DECL. */
266 void (* insert_attributes
) PARAMS ((tree decl
, tree
*attributes
));
268 /* Return true if FNDECL (which has at least one machine attribute)
269 can be inlined despite its machine attributes, false otherwise. */
270 bool (* function_attribute_inlinable_p
) PARAMS ((tree fndecl
));
272 /* Return true if bitfields in RECORD_TYPE should follow the
273 Microsoft Visual C++ bitfield layout rules. */
274 bool (* ms_bitfield_layout_p
) PARAMS ((tree record_type
));
276 /* Set up target-specific built-in functions. */
277 void (* init_builtins
) PARAMS ((void));
279 /* Expand a target-specific builtin. */
280 rtx (* expand_builtin
) PARAMS ((tree exp
, rtx target
, rtx subtarget
,
281 enum machine_mode mode
, int ignore
));
283 /* Given a decl, a section name, and whether the decl initializer
284 has relocs, choose attributes for the section. */
285 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
286 unsigned int (* section_type_flags
) PARAMS ((tree
, const char *, int));
288 /* True if new jumps cannot be created, to replace existing ones or
289 not, at the current point in the compilation. */
290 bool (* cannot_modify_jumps_p
) PARAMS ((void));
292 /* True if the constant X cannot be placed in the constant pool. */
293 bool (* cannot_force_const_mem
) PARAMS ((rtx
));
295 /* True if the insn X cannot be duplicated. */
296 bool (* cannot_copy_insn_p
) PARAMS ((rtx
));
298 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
299 rtx (* delegitimize_address
) PARAMS ((rtx
));
301 /* True if it is OK to do sibling call optimization for the specified
302 call expression EXP. DECL will be the called function, or NULL if
303 this is an indirect call. */
304 bool (*function_ok_for_sibcall
) PARAMS ((tree decl
, tree exp
));
306 /* True if EXP should be placed in a "small data" section. */
307 bool (* in_small_data_p
) PARAMS ((tree
));
309 /* True if EXP names an object for which name resolution must resolve
310 to the current module. */
311 bool (* binds_local_p
) PARAMS ((tree
));
313 /* Do something target-specific to record properties of the DECL into
314 the associated SYMBOL_REF. */
315 void (* encode_section_info
) PARAMS ((tree
, rtx
, int));
317 /* Undo the effects of encode_section_info on the symbol string. */
318 const char * (* strip_name_encoding
) PARAMS ((const char *));
320 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
321 bool (* valid_pointer_mode
) PARAMS ((enum machine_mode mode
));
323 /* True if a vector is opaque. */
324 bool (* vector_opaque_p
) PARAMS ((tree
));
326 /* Compute a (partial) cost for rtx X. Return true if the complete
327 cost has been computed, and false if subexpressions should be
328 scanned. In either case, *TOTAL contains the cost result. */
329 /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
330 not necessarily defined at this point. */
331 bool (* rtx_costs
) PARAMS ((rtx x
, int code
, int outer_code
, int *total
));
333 /* Compute the cost of X, used as an address. Never called with
334 invalid addresses. */
335 int (* address_cost
) PARAMS ((rtx x
));
337 /* Given a register, this hook should return a parallel of registers
338 to represent where to find the register pieces. Define this hook
339 if the register and its mode are represented in Dwarf in
340 non-contiguous locations, or if the register should be
341 represented in more than one register in Dwarf. Otherwise, this
342 hook should return NULL_RTX. */
343 rtx (* dwarf_register_span
) PARAMS ((rtx
));
345 /* Leave the boolean fields at the end. */
347 /* True if arbitrary sections are supported. */
348 bool have_named_sections
;
350 /* True if "native" constructors and destructors are supported,
351 false if we're using collect2 for the job. */
352 bool have_ctors_dtors
;
354 /* True if thread-local storage is supported. */
357 /* True if a small readonly data section is supported. */
358 bool have_srodata_section
;
360 /* True if EH frame info sections should be zero-terminated. */
361 bool terminate_dw2_eh_frame_info
;
364 extern struct gcc_target targetm
;