1 /* This file contains the definitions and documentation for the
2 machine modes used in the GNU compiler.
3 Copyright (C) 1987, 1992, 1994, 1997, 1998, 2000, 2003
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 /* This file defines all the MACHINE MODES used by GCC.
26 A machine mode specifies a size and format of data
29 Each RTL expression has a machine mode.
31 At the syntax tree level, each ..._TYPE and each ..._DECL node
32 has a machine mode which describes data of that type or the
33 data of the variable declared. */
35 /* This file is included by the genmodes program. Its text is the
36 body of a function. Do not rely on this, it will change in the
39 The following statements can be used in this file -- all have
40 the form of a C macro call. In their arguments:
42 A CLASS argument must be one of the constants defined in
43 mode-classes.def, less the leading MODE_ prefix; some statements
44 that take CLASS arguments have restructions on which classes are
45 acceptable. For instance, INT.
47 A MODE argument must be the printable name of a machine mode,
48 without quotation marks or trailing "mode". For instance, SI.
50 A BITSIZE, BYTESIZE, or COUNT argument must be a positive integer
53 Order matters in this file in so far as statements which refer to
54 other modes must appear after the modes they refer to. However,
55 statements which do not refer to other modes may appear in any
59 declares MODE to be of class RANDOM.
62 declares MODE to be of class CC.
64 INT_MODE (MODE, BYTESIZE);
65 declares MODE to be of class INT and BYTESIZE bytes wide.
66 All of the bits of its representation are significant.
68 FRACTIONAL_INT_MODE (MODE, BITSIZE, BYTESIZE);
69 declares MODE to be of class INT, BYTESIZE bytes wide in
70 storage, but with only BITSIZE significant bits.
72 FLOAT_MODE (MODE, BYTESIZE);
73 declares MODE to be of class FLOAT and BYTESIZE bytes wide.
74 All of the bits of its representation are significant.
76 FRACTIONAL_FLOAT_MODE (MODE, BITSIZE, BYTESIZE);
77 declares MODE to be of class FLOAT, BYTESIZE bytes wide in
78 storage, but with only BITSIZE significant bits.
80 PARTIAL_INT_MODE (MODE);
81 declares a mode of class PARTIAL_INT with the same size as
82 MODE (which must be an INT mode). The name of the new mode
83 is made by prefixing a P to the name MODE. This statement
84 may grow a BITSIZE argument in the future.
86 VECTOR_MODE (CLASS, MODE, COUNT);
87 Declare a vector mode whose component mode is MODE (of class
88 CLASS) with COUNT components. CLASS must be INT or FLOAT.
89 The name of the vector mode takes the form VnX where n is
90 COUNT in decimal and X is MODE.
92 VECTOR_MODES (CLASS, WIDTH);
93 For all modes presently declared in class CLASS, construct
94 corresponding vector modes having width WIDTH. Modes whose
95 byte sizes do not evenly divide WIDTH are ignored, as are
96 modes that would produce vector modes with only one component,
97 and modes smaller than one byte (if CLASS is INT) or smaller
98 than two bytes (if CLASS is FLOAT). CLASS must be INT or
99 FLOAT. The names follow the same rule as VECTOR_MODE uses.
101 COMPLEX_MODES (CLASS);
102 For all modes presently declared in class CLASS, construct
103 corresponding complex modes. Modes smaller than one byte
104 are ignored. For FLOAT modes, the names are derived by
105 replacing the 'F' in the mode name with a 'C'. (It is an
106 error if there is no 'F'. For INT modes, the names are
107 derived by prefixing a C to the name.
109 BITS_PER_UNIT (COUNT);
110 Sets the number of bits in a machine byte (least addressable
111 unit). If this statement does not appear, the default is 8.
113 Note: If a mode is ever made which is more than 255 bytes wide,
114 machmode.h and genmodes.c will have to be changed to allocate
115 more space for the mode_size and mode_alignment arrays. */
117 /* VOIDmode is used when no mode needs to be specified,
118 as for example on CONST_INT RTL expressions. */
121 /* BLKmode is used for structures, arrays, etc.
122 that fit no more specific mode. */
125 /* Single bit mode used for booleans. */
126 FRACTIONAL_INT_MODE (BI, 1, 1);
128 /* Basic integer modes. */
136 /* Pointers on some machines use these types to distinguish them from
137 ints. Useful if a pointer is 4 bytes but has some bits that are
138 not significant, so it is really not quite as wide as an integer. */
139 PARTIAL_INT_MODE (QI);
140 PARTIAL_INT_MODE (HI);
141 PARTIAL_INT_MODE (SI);
142 PARTIAL_INT_MODE (DI);
144 /* Basic floating point modes. */
145 FLOAT_MODE (QF, 1); /* C4x single precision */
146 FLOAT_MODE (HF, 2); /* C4x double precision */
147 FLOAT_MODE (TQF, 3); /* MIL-STD-1750a */
150 FLOAT_MODE (XF, 12); /* IEEE extended (80-bit) */
153 /* Basic CC modes. */
156 /* Allow the target to specify additional modes of various kinds. */
158 # define CC(X) CC_MODE(X); /* backward compatibility, temporary */
159 # include EXTRA_MODES_FILE
165 COMPLEX_MODES (FLOAT);
168 VECTOR_MODES (INT, 2); /* V2QI */
169 VECTOR_MODES (INT, 4); /* V4QI V2HI */
170 VECTOR_MODES (INT, 8); /* V8QI V4HI V2SI */
171 VECTOR_MODES (INT, 16); /* V16QI V8HI V4SI V2DI */
172 /* VECTOR_MODES (INT, 32); V8SI V4DI */
173 /* VECTOR_MODES (INT, 64); V8DI */
175 VECTOR_MODE (INT, SI, 8)
176 VECTOR_MODE (INT, DI, 4);
177 VECTOR_MODE (INT, DI, 8);
179 VECTOR_MODE (INT, DI, 1); /* PPC uses this. Why not plain DI? */
181 VECTOR_MODES (FLOAT, 4); /* V2HF */
182 VECTOR_MODES (FLOAT, 8); /* V4HF V2SF */
183 VECTOR_MODES (FLOAT, 16); /* V8HF V4SF V2DF */
184 /* VECTOR_MODES (FLOAT, 32); V8SF V4DF */
185 /* VECTOR_MODES (FLOAT, 64); V16SF V8DF */
187 VECTOR_MODE (FLOAT, SF, 8);
188 VECTOR_MODE (FLOAT, SF, 16);
189 VECTOR_MODE (FLOAT, DF, 4);
190 VECTOR_MODE (FLOAT, DF, 8);
192 /* The symbol Pmode stands for one of the above machine modes (usually SImode).
193 The tm.h file specifies which one. It is not a distinct mode. */