1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/* Data structure definitions for a generic GCC target.
Copyright (C) 2001 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
In other words, you are welcome to use, share and improve this program.
You are forbidden to forbid anyone else to use, share and improve
what you give them. Help stamp out software-hoarding! */
/* This file contains a data structure that describes a GCC target.
At present it is incomplete, but in future it should grow to
contain most or all target machine and target O/S specific
information.
This structure has its initializer declared in target-def.h in the
form of large macro TARGET_INITIALIZER that expands to many smaller
macros.
The smaller macros each initialize one component of the structure,
and each has a default. Each target should have a file that
includes target.h and target-def.h, and overrides any inappropriate
defaults by undefining the relevant macro and defining a suitable
replacement. That file should then contain the definition of
"targetm" like so:
struct gcc_target targetm = TARGET_INITIALIZER;
Doing things this way allows us to bring together everything that
defines a GCC target. By supplying a default that is appropriate
to most targets, we can easily add new items without needing to
edit dozens of target configuration files. It should also allow us
to gradually reduce the amount of conditional compilation that is
scattered throughout GCC. */
struct gcc_target
{
/* Functions that output assembler for the target. */
struct asm_out
{
/* Opening and closing parentheses for asm expression grouping. */
const char *open_paren, *close_paren;
/* Output the assembler code for entry to a function. */
void (* function_prologue) PARAMS ((FILE *, HOST_WIDE_INT));
/* Output the assembler code for end of prologue. */
void (* function_end_prologue) PARAMS ((FILE *));
/* Output the assembler code for start of epilogue. */
void (* function_begin_epilogue) PARAMS ((FILE *));
/* Output the assembler code for function exit. */
void (* function_epilogue) PARAMS ((FILE *, HOST_WIDE_INT));
/* Switch to an arbitrary section NAME with attributes as
specified by FLAGS. */
void (* named_section) PARAMS ((const char *, unsigned int));
/* Output a constructor for a symbol with a given priority. */
void (* constructor) PARAMS ((rtx, int));
/* Output a destructor for a symbol with a given priority. */
void (* destructor) PARAMS ((rtx, int));
} asm_out;
/* Functions relating to instruction scheduling. */
struct sched
{
/* Given the current cost, COST, of an insn, INSN, calculate and
return a new cost based on its relationship to DEP_INSN through
the dependence LINK. The default is to make no adjustment. */
int (* adjust_cost) PARAMS ((rtx insn, rtx link, rtx def_insn, int cost));
/* Adjust the priority of an insn as you see fit. Returns the new
priority. */
int (* adjust_priority) PARAMS ((rtx, int));
/* Function which returns the maximum number of insns that can be
scheduled in the same machine cycle. This must be constant
over an entire compilation. The default is 1. */
int (* issue_rate) PARAMS ((void));
/* Calculate how much this insn affects how many more insns we
can emit this cycle. Default is they all cost the same. */
int (* variable_issue) PARAMS ((FILE *, int, rtx, int));
/* Initialize machine-dependent scheduling code. */
void (* md_init) PARAMS ((FILE *, int, int));
/* Finalize machine-dependent scheduling code. */
void (* md_finish) PARAMS ((FILE *, int));
/* Reorder insns in a machine-dependent fashion, in two different
places. Default does nothing. */
int (* reorder) PARAMS ((FILE *, int, rtx *, int *, int));
int (* reorder2) PARAMS ((FILE *, int, rtx *, int *, int));
/* cycle_display is a pointer to a function which can emit
data into the assembly stream about the current cycle.
Arguments are CLOCK, the data to emit, and LAST, the last
insn in the new chain we're building. Returns a new LAST.
The default is to do nothing. */
rtx (* cycle_display) PARAMS ((int clock, rtx last));
} sched;
/* Given two decls, merge their attributes and return the result. */
tree (* merge_decl_attributes) PARAMS ((tree, tree));
/* Given two types, merge their attributes and return the result. */
tree (* merge_type_attributes) PARAMS ((tree, tree));
/* Return nonzero if IDENTIFIER with arguments ARGS is a valid machine
specific attribute for DECL. The attributes in ATTRIBUTES have
previously been assigned to DECL. */
int (* valid_decl_attribute) PARAMS ((tree decl, tree attributes,
tree identifier, tree args));
/* Return nonzero if IDENTIFIER with arguments ARGS is a valid machine
specific attribute for TYPE. The attributes in ATTRIBUTES have
previously been assigned to TYPE. */
int (* valid_type_attribute) PARAMS ((tree type, tree attributes,
tree identifier, tree args));
/* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
one if they are compatible and two if they are nearly compatible
(which causes a warning to be generated). */
int (* comp_type_attributes) PARAMS ((tree type1, tree type2));
/* Assign default attributes to the newly defined TYPE. */
void (* set_default_type_attributes) PARAMS ((tree type));
/* Insert attributes on the newly created DECL. */
void (* insert_attributes) PARAMS ((tree decl, tree *attributes));
/* Set up target-specific built-in functions. */
void (* init_builtins) PARAMS ((void));
/* Expand a target-specific builtin. */
rtx (* expand_builtin) PARAMS ((tree exp, rtx target, rtx subtarget,
enum machine_mode mode, int ignore));
/* Given a decl, a section name, and whether the decl initializer
has relocs, choose attributes for the section. */
/* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
unsigned int (* section_type_flags) PARAMS ((tree, const char *, int));
/* True if arbitrary sections are supported. */
bool have_named_sections;
/* True if "native" constructors and destructors are supported,
false if we're using collect2 for the job. */
bool have_ctors_dtors;
};
extern struct gcc_target targetm;
|
