1 /* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001 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 /* Output the assembler code for entry to a function. */
56 void (* function_prologue
) PARAMS ((FILE *, HOST_WIDE_INT
));
58 /* Output the assembler code for end of prologue. */
59 void (* function_end_prologue
) PARAMS ((FILE *));
61 /* Output the assembler code for start of epilogue. */
62 void (* function_begin_epilogue
) PARAMS ((FILE *));
64 /* Output the assembler code for function exit. */
65 void (* function_epilogue
) PARAMS ((FILE *, HOST_WIDE_INT
));
67 /* Switch to an arbitrary section NAME with attributes as
68 specified by FLAGS. */
69 void (* named_section
) PARAMS ((const char *, unsigned int));
71 /* Output a constructor for a symbol with a given priority. */
72 void (* constructor
) PARAMS ((rtx
, int));
74 /* Output a destructor for a symbol with a given priority. */
75 void (* destructor
) PARAMS ((rtx
, int));
78 /* Functions relating to instruction scheduling. */
81 /* Given the current cost, COST, of an insn, INSN, calculate and
82 return a new cost based on its relationship to DEP_INSN through
83 the dependence LINK. The default is to make no adjustment. */
84 int (* adjust_cost
) PARAMS ((rtx insn
, rtx link
, rtx def_insn
, int cost
));
86 /* Adjust the priority of an insn as you see fit. Returns the new
88 int (* adjust_priority
) PARAMS ((rtx
, int));
90 /* Function which returns the maximum number of insns that can be
91 scheduled in the same machine cycle. This must be constant
92 over an entire compilation. The default is 1. */
93 int (* issue_rate
) PARAMS ((void));
95 /* Calculate how much this insn affects how many more insns we
96 can emit this cycle. Default is they all cost the same. */
97 int (* variable_issue
) PARAMS ((FILE *, int, rtx
, int));
99 /* Initialize machine-dependent scheduling code. */
100 void (* md_init
) PARAMS ((FILE *, int, int));
102 /* Finalize machine-dependent scheduling code. */
103 void (* md_finish
) PARAMS ((FILE *, int));
105 /* Reorder insns in a machine-dependent fashion, in two different
106 places. Default does nothing. */
107 int (* reorder
) PARAMS ((FILE *, int, rtx
*, int *, int));
108 int (* reorder2
) PARAMS ((FILE *, int, rtx
*, int *, int));
110 /* cycle_display is a pointer to a function which can emit
111 data into the assembly stream about the current cycle.
112 Arguments are CLOCK, the data to emit, and LAST, the last
113 insn in the new chain we're building. Returns a new LAST.
114 The default is to do nothing. */
115 rtx (* cycle_display
) PARAMS ((int clock
, rtx last
));
116 /* The following member value is a pointer to a function returning
117 nonzero if we should use DFA based scheduling. The default is
118 to use the old pipeline scheduler. */
119 int (* use_dfa_pipeline_interface
) PARAMS ((void));
120 /* The values of all the following members are used only for the
121 DFA based scheduler: */
122 /* The values of the following four members are pointers to
123 functions used to simplify the automaton descriptions.
124 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
125 returning insns which are used to change the pipeline hazard
126 recognizer state when the new simulated processor cycle
127 correspondingly starts and finishes. The function defined by
128 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
129 to initialize the corresponding insns. The default values of
130 the memebers result in not changing the automaton state when
131 the new simulated processor cycle correspondingly starts and
133 void (* init_dfa_pre_cycle_insn
) PARAMS ((void));
134 rtx (* dfa_pre_cycle_insn
) PARAMS ((void));
135 void (* init_dfa_post_cycle_insn
) PARAMS ((void));
136 rtx (* dfa_post_cycle_insn
) PARAMS ((void));
137 /* The following member value is a pointer to a function returning value
138 which defines how many insns in queue `ready' will we try for
139 multi-pass scheduling. if the member value is nonzero and the
140 function returns positive value, the DFA based scheduler will make
141 multi-pass scheduling for the first cycle. In other words, we will
142 try to choose ready insn which permits to start maximum number of
143 insns on the same cycle. */
144 int (* first_cycle_multipass_dfa_lookahead
) PARAMS ((void));
145 /* The values of the following members are pointers to functions
146 used to improve the first cycle multipass scheduling by
147 inserting nop insns. dfa_scheduler_bubble gives a function
148 returning a nop insn with given index. The indexes start with
149 zero. The function should return NULL if there are no more nop
150 insns with indexes greater than given index. To initialize the
151 nop insn the function given by member
152 init_dfa_scheduler_bubbles is used. The default values of the
153 members result in not inserting nop insns during the multipass
155 void (* init_dfa_bubbles
) PARAMS ((void));
156 rtx (* dfa_bubble
) PARAMS ((int));
159 /* Given two decls, merge their attributes and return the result. */
160 tree (* merge_decl_attributes
) PARAMS ((tree
, tree
));
162 /* Given two types, merge their attributes and return the result. */
163 tree (* merge_type_attributes
) PARAMS ((tree
, tree
));
165 /* Return nonzero if IDENTIFIER with arguments ARGS is a valid machine
166 specific attribute for DECL. The attributes in ATTRIBUTES have
167 previously been assigned to DECL. */
168 int (* valid_decl_attribute
) PARAMS ((tree decl
, tree attributes
,
169 tree identifier
, tree args
));
171 /* Return nonzero if IDENTIFIER with arguments ARGS is a valid machine
172 specific attribute for TYPE. The attributes in ATTRIBUTES have
173 previously been assigned to TYPE. */
174 int (* valid_type_attribute
) PARAMS ((tree type
, tree attributes
,
175 tree identifier
, tree args
));
177 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
178 one if they are compatible and two if they are nearly compatible
179 (which causes a warning to be generated). */
180 int (* comp_type_attributes
) PARAMS ((tree type1
, tree type2
));
182 /* Assign default attributes to the newly defined TYPE. */
183 void (* set_default_type_attributes
) PARAMS ((tree type
));
185 /* Insert attributes on the newly created DECL. */
186 void (* insert_attributes
) PARAMS ((tree decl
, tree
*attributes
));
188 /* Set up target-specific built-in functions. */
189 void (* init_builtins
) PARAMS ((void));
191 /* Expand a target-specific builtin. */
192 rtx (* expand_builtin
) PARAMS ((tree exp
, rtx target
, rtx subtarget
,
193 enum machine_mode mode
, int ignore
));
195 /* Given a decl, a section name, and whether the decl initializer
196 has relocs, choose attributes for the section. */
197 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
198 unsigned int (* section_type_flags
) PARAMS ((tree
, const char *, int));
200 /* True if arbitrary sections are supported. */
201 bool have_named_sections
;
203 /* True if "native" constructors and destructors are supported,
204 false if we're using collect2 for the job. */
205 bool have_ctors_dtors
;
208 extern struct gcc_target targetm
;