1 | /* This file contains the definitions and documentation for the |
2 | machine modes used in the GNU compiler. |
3 | Copyright (C) 1987-2023 Free Software Foundation, Inc. |
4 | |
5 | This file is part of GCC. |
6 | |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free |
9 | Software Foundation; either version 3, or (at your option) any later |
10 | version. |
11 | |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. |
16 | |
17 | You should have received a copy of the GNU General Public License |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ |
20 | |
21 | |
22 | /* This file defines all the MACHINE MODES used by GCC. |
23 | |
24 | A machine mode specifies a size and format of data |
25 | at the machine level. |
26 | |
27 | Each RTL expression has a machine mode. |
28 | |
29 | At the syntax tree level, each ..._TYPE and each ..._DECL node |
30 | has a machine mode which describes data of that type or the |
31 | data of the variable declared. */ |
32 | |
33 | /* This file is included by the genmodes program. Its text is the |
34 | body of a function. Do not rely on this, it will change in the |
35 | future. |
36 | |
37 | The following statements can be used in this file -- all have |
38 | the form of a C macro call. In their arguments: |
39 | |
40 | A CLASS argument must be one of the constants defined in |
41 | mode-classes.def, less the leading MODE_ prefix; some statements |
42 | that take CLASS arguments have restrictions on which classes are |
43 | acceptable. For instance, INT. |
44 | |
45 | A MODE argument must be the printable name of a machine mode, |
46 | without quotation marks or trailing "mode". For instance, SI. |
47 | |
48 | A PRECISION, BYTESIZE, or COUNT argument must be a positive integer |
49 | constant. |
50 | |
51 | A FORMAT argument must be one of the real_mode_format structures |
52 | declared in real.h, or else a literal 0. Do not put a leading & |
53 | on the argument. |
54 | |
55 | An EXPR argument must be a syntactically valid C expression. |
56 | If an EXPR contains commas, you may need to write an extra pair of |
57 | parentheses around it, so it appears to be a single argument to the |
58 | statement. |
59 | |
60 | This file defines only those modes which are of use on almost all |
61 | machines. Other modes can be defined in the target-specific |
62 | mode definition file, config/ARCH/ARCH-modes.def. |
63 | |
64 | Order matters in this file in so far as statements which refer to |
65 | other modes must appear after the modes they refer to. However, |
66 | statements which do not refer to other modes may appear in any |
67 | order. |
68 | |
69 | RANDOM_MODE (MODE); |
70 | declares MODE to be of class RANDOM. |
71 | |
72 | CC_MODE (MODE); |
73 | declares MODE to be of class CC. |
74 | |
75 | INT_MODE (MODE, BYTESIZE); |
76 | declares MODE to be of class INT and BYTESIZE bytes wide. |
77 | All of the bits of its representation are significant. |
78 | |
79 | FRACTIONAL_INT_MODE (MODE, PRECISION, BYTESIZE); |
80 | declares MODE to be of class INT, BYTESIZE bytes wide in |
81 | storage, but with only PRECISION significant bits. |
82 | |
83 | FLOAT_MODE (MODE, BYTESIZE, FORMAT); |
84 | declares MODE to be of class FLOAT and BYTESIZE bytes wide, |
85 | using floating point format FORMAT. |
86 | All of the bits of its representation are significant. |
87 | |
88 | FRACTIONAL_FLOAT_MODE (MODE, PRECISION, BYTESIZE, FORMAT); |
89 | declares MODE to be of class FLOAT, BYTESIZE bytes wide in |
90 | storage, but with only PRECISION significant bits, using |
91 | floating point format FORMAT. |
92 | |
93 | DECIMAL_FLOAT_MODE (MODE, BYTESIZE, FORMAT); |
94 | declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes |
95 | wide. All of the bits of its representation are significant. |
96 | |
97 | FRACTIONAL_DECIMAL_FLOAT_MODE (MODE, BYTESIZE, FORMAT); |
98 | declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes |
99 | wide. All of the bits of its representation are significant. |
100 | |
101 | FRACT_MODE (MODE, BYTESIZE, FBIT); |
102 | declares MODE to be of class FRACT and BYTESIZE bytes wide |
103 | with FBIT fractional bits. There may be padding bits. |
104 | |
105 | UFRACT_MODE (MODE, BYTESIZE, FBIT); |
106 | declares MODE to be of class UFRACT and BYTESIZE bytes wide |
107 | with FBIT fractional bits. There may be padding bits. |
108 | |
109 | ACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT); |
110 | declares MODE to be of class ACCUM and BYTESIZE bytes wide |
111 | with IBIT integral bits and FBIT fractional bits. |
112 | There may be padding bits. |
113 | |
114 | UACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT); |
115 | declares MODE to be of class UACCUM and BYTESIZE bytes wide |
116 | with IBIT integral bits and FBIT fractional bits. |
117 | There may be padding bits. |
118 | |
119 | RESET_FLOAT_FORMAT (MODE, FORMAT); |
120 | changes the format of MODE, which must be class FLOAT, |
121 | to FORMAT. Use in an ARCH-modes.def to reset the format |
122 | of one of the float modes defined in this file. |
123 | |
124 | PARTIAL_INT_MODE (MODE, PRECISION, NAME); |
125 | declares a mode of class PARTIAL_INT with the same size as |
126 | MODE (which must be an INT mode) and precision PREC. |
127 | Optionally, NAME is the new name of the mode. NAME is the |
128 | name of the mode. |
129 | |
130 | VECTOR_MODE (CLASS, MODE, COUNT); |
131 | Declare a vector mode whose component mode is MODE (of class |
132 | CLASS) with COUNT components. CLASS must be INT or FLOAT. |
133 | The name of the vector mode takes the form VnX where n is |
134 | COUNT in decimal and X is MODE. |
135 | |
136 | VECTOR_MODES (CLASS, WIDTH); |
137 | For all modes presently declared in class CLASS, construct |
138 | corresponding vector modes having width WIDTH. Modes whose |
139 | byte sizes do not evenly divide WIDTH are ignored, as are |
140 | modes that would produce vector modes with only one component, |
141 | and modes smaller than one byte (if CLASS is INT) or smaller |
142 | than two bytes (if CLASS is FLOAT). CLASS must be INT or |
143 | FLOAT. The names follow the same rule as VECTOR_MODE uses. |
144 | |
145 | VECTOR_MODES_WITH_PREFIX (PREFIX, CLASS, WIDTH, ORDER); |
146 | Like VECTOR_MODES, but start the mode names with PREFIX instead |
147 | of the usual "V". ORDER is the top-level sorting order of the |
148 | mode, with smaller numbers indicating a higher priority. |
149 | |
150 | VECTOR_BOOL_MODE (NAME, COUNT, COMPONENT, BYTESIZE) |
151 | Create a vector mode called NAME that contains COUNT boolean |
152 | elements and occupies BYTESIZE bytes in total. Each boolean |
153 | element is of COMPONENT type and occupies (COUNT * BITS_PER_UNIT) / |
154 | BYTESIZE bits, with the element at index 0 occupying the lsb of the |
155 | first byte in memory. Only the lowest bit of each element is |
156 | significant. |
157 | |
158 | OPAQUE_MODE (NAME, BYTESIZE) |
159 | Create an opaque mode called NAME that is BYTESIZE bytes wide. |
160 | |
161 | COMPLEX_MODES (CLASS); |
162 | For all modes presently declared in class CLASS, construct |
163 | corresponding complex modes. Modes smaller than one byte |
164 | are ignored. For FLOAT modes, the names are derived by |
165 | replacing the 'F' in the mode name with a 'C'. (It is an |
166 | error if there is no 'F'. For INT modes, the names are |
167 | derived by prefixing a C to the name. |
168 | |
169 | ADJUST_BYTESIZE (MODE, EXPR); |
170 | ADJUST_ALIGNMENT (MODE, EXPR); |
171 | ADJUST_FLOAT_FORMAT (MODE, EXPR); |
172 | ADJUST_IBIT (MODE, EXPR); |
173 | ADJUST_FBIT (MODE, EXPR); |
174 | Arrange for the byte size, alignment, floating point format, ibit, |
175 | or fbit of MODE to be adjustable at run time. EXPR will be executed |
176 | once after processing all command line options, and should |
177 | evaluate to the desired byte size, alignment, format, ibit or fbit. |
178 | |
179 | Unlike a FORMAT argument, if you are adjusting a float format |
180 | you must put an & in front of the name of each format structure. |
181 | |
182 | ADJUST_NUNITS (MODE, EXPR); |
183 | Like the above, but set the number of nunits of MODE to EXPR. |
184 | This changes the size and precision of the mode in proportion |
185 | to the change in the number of units; for example, doubling |
186 | the number of units doubles the size and precision as well. |
187 | |
188 | Note: If a mode is ever made which is more than 255 bytes wide, |
189 | machmode.h and genmodes.cc will have to be changed to allocate |
190 | more space for the mode_size and mode_alignment arrays. */ |
191 | |
192 | /* VOIDmode is used when no mode needs to be specified, |
193 | as for example on CONST_INT RTL expressions. */ |
194 | RANDOM_MODE (VOID); |
195 | |
196 | /* BLKmode is used for structures, arrays, etc. |
197 | that fit no more specific mode. */ |
198 | RANDOM_MODE (BLK); |
199 | |
200 | /* Single bit mode used for booleans. */ |
201 | BOOL_MODE (BI, 1, 1); |
202 | |
203 | /* Basic integer modes. We go up to TI in generic code (128 bits). |
204 | TImode is needed here because the some front ends now genericly |
205 | support __int128. If the front ends decide to generically support |
206 | larger types, then corresponding modes must be added here. The |
207 | name OI is reserved for a 256-bit type (needed by some back ends). |
208 | */ |
209 | INT_MODE (QI, 1); |
210 | INT_MODE (HI, 2); |
211 | INT_MODE (SI, 4); |
212 | INT_MODE (DI, 8); |
213 | INT_MODE (TI, 16); |
214 | |
215 | /* No partial integer modes are defined by default. */ |
216 | |
217 | /* The target normally defines any target-specific __intN types and |
218 | their modes, but __int128 for TImode is fairly common so define it |
219 | here. The type will not be created unless the target supports |
220 | TImode. */ |
221 | |
222 | INT_N (TI, 128); |
223 | |
224 | /* Basic floating point modes. SF and DF are the only modes provided |
225 | by default. The names QF, HF, XF, and TF are reserved for targets |
226 | that need 1-word, 2-word, 80-bit, or 128-bit float types respectively. |
227 | |
228 | These are the IEEE mappings. They can be overridden with |
229 | RESET_FLOAT_FORMAT or at runtime (in TARGET_OPTION_OVERRIDE). */ |
230 | |
231 | FLOAT_MODE (SF, 4, ieee_single_format); |
232 | FLOAT_MODE (DF, 8, ieee_double_format); |
233 | |
234 | /* Basic CC modes. |
235 | FIXME define this only for targets that need it. */ |
236 | CC_MODE (CC); |
237 | |
238 | /* Fixed-point modes. */ |
239 | FRACT_MODE (QQ, 1, 7); /* s.7 */ |
240 | FRACT_MODE (HQ, 2, 15); /* s.15 */ |
241 | FRACT_MODE (SQ, 4, 31); /* s.31 */ |
242 | FRACT_MODE (DQ, 8, 63); /* s.63 */ |
243 | FRACT_MODE (TQ, 16, 127); /* s.127 */ |
244 | |
245 | UFRACT_MODE (UQQ, 1, 8); /* .8 */ |
246 | UFRACT_MODE (UHQ, 2, 16); /* .16 */ |
247 | UFRACT_MODE (USQ, 4, 32); /* .32 */ |
248 | UFRACT_MODE (UDQ, 8, 64); /* .64 */ |
249 | UFRACT_MODE (UTQ, 16, 128); /* .128 */ |
250 | |
251 | ACCUM_MODE (HA, 2, 8, 7); /* s8.7 */ |
252 | ACCUM_MODE (SA, 4, 16, 15); /* s16.15 */ |
253 | ACCUM_MODE (DA, 8, 32, 31); /* s32.31 */ |
254 | ACCUM_MODE (TA, 16, 64, 63); /* s64.63 */ |
255 | |
256 | UACCUM_MODE (UHA, 2, 8, 8); /* 8.8 */ |
257 | UACCUM_MODE (USA, 4, 16, 16); /* 16.16 */ |
258 | UACCUM_MODE (UDA, 8, 32, 32); /* 32.32 */ |
259 | UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */ |
260 | |
261 | /* Allow the target to specify additional modes of various kinds. */ |
262 | #if HAVE_EXTRA_MODES |
263 | # include EXTRA_MODES_FILE |
264 | #endif |
265 | |
266 | /* Complex modes. */ |
267 | COMPLEX_MODES (INT); |
268 | COMPLEX_MODES (PARTIAL_INT); |
269 | COMPLEX_MODES (FLOAT); |
270 | |
271 | /* Decimal floating point modes. */ |
272 | DECIMAL_FLOAT_MODE (SD, 4, decimal_single_format); |
273 | DECIMAL_FLOAT_MODE (DD, 8, decimal_double_format); |
274 | DECIMAL_FLOAT_MODE (TD, 16, decimal_quad_format); |
275 | |
276 | /* The symbol Pmode stands for one of the above machine modes (usually SImode). |
277 | The tm.h file specifies which one. It is not a distinct mode. */ |
278 | |
279 | /* |
280 | Local variables: |
281 | mode:c |
282 | version-control: t |
283 | End: |
284 | */ |
285 | |