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1 | /* This file contains the definitions and documentation for the |
2 | machine modes used in the the GNU compiler. | |
3 | Copyright (C) 1987 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 1, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | ||
22 | /* This file defines all the MACHINE MODES used by GNU CC. | |
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 | /* The first argument is the internal name of the machine mode | |
34 | used in the C source. | |
35 | By convention these are in UPPER_CASE, except for the word "mode". | |
36 | ||
37 | The second argument is the name of the machine mode in the | |
38 | external ASCII format used for reading and printing RTL and trees. | |
39 | By convention these names in UPPER_CASE. | |
40 | ||
41 | Third argument states the kind of representation: | |
42 | MODE_INT - integer | |
43 | MODE_FLOAT - floating | |
44 | MODE_COMPLEX_INT - pair of integers | |
45 | MODE_COMPLEX_FLOAT - pair of floats | |
46 | MODE_FUNCTION - Algol or Pascal function-variable incl. static chain | |
47 | MODE_RANDOM - anything else | |
48 | ||
49 | Fourth argument is the relative size of the object. | |
50 | It is zero when the size is meaningless or not determined. | |
51 | On most machines, this is also the actual size in bytes. | |
52 | However, the general rule is that the size of SImode in bytes | |
53 | is UNITS_PER_WORD and the other sizes are proportional to that. | |
54 | (If UNITS_PER_WORD is less than 4, some modes would be less than | |
55 | one byte. Their sizes are rounded up to 1.) | |
56 | ||
57 | Fifth arg is the relative size of subunits of the object. | |
58 | It is same as the fourth argument except for complexes and EPmode, | |
59 | since they are really made of two equal size subunits. | |
60 | ||
61 | Sixth arg is next wider natural mode of the same class, | |
62 | for widening multiply and narrowing divide. 0 if there is none. */ | |
63 | ||
64 | /* The compiler assumes that a mode may be widened to another | |
65 | HIGHER NUMBERED mode if both those modes AND ALL MODES IN BETWEEN | |
66 | are in the same mode class. Thus, you must should assign all | |
67 | MODE_INT and MODE_FLOAT modes in separate contiguous blocks. */ | |
68 | ||
69 | /* VOIDmode is used when no mode needs to be specified, | |
70 | as for example on CONST_INT RTL expressions. */ | |
71 | DEF_MACHMODE (VOIDmode, "VOID", MODE_RANDOM, 0, 0, 0) | |
72 | ||
73 | DEF_MACHMODE (QImode, "QI", MODE_INT, 1, 1, HImode) /* int types */ | |
74 | DEF_MACHMODE (HImode, "HI", MODE_INT, 2, 2, SImode) | |
75 | /* Pointers on some machines use this type to distinguish them from ints. | |
76 | Useful if a pointer is 4 bytes but has some bits that are not significant, | |
77 | so it is really not quite as wide as an integer. */ | |
78 | DEF_MACHMODE (PSImode, "PSI", MODE_INT, 4, 4, 0) | |
79 | DEF_MACHMODE (SImode, "SI", MODE_INT, 4, 4, DImode) | |
80 | DEF_MACHMODE (PDImode, "PDI", MODE_INT, 8, 8, 0) | |
81 | DEF_MACHMODE (DImode, "DI", MODE_INT, 8, 8, TImode) | |
82 | DEF_MACHMODE (TImode, "TI", MODE_INT, 16, 16, 0) | |
83 | DEF_MACHMODE (QFmode, "QF", MODE_FLOAT, 1, 1, 0) | |
84 | DEF_MACHMODE (HFmode, "HF", MODE_FLOAT, 2, 2, 0) /* floating types */ | |
85 | DEF_MACHMODE (SFmode, "SF", MODE_FLOAT, 4, 4, 0) | |
86 | DEF_MACHMODE (DFmode, "DF", MODE_FLOAT, 8, 8, 0) | |
87 | DEF_MACHMODE (XFmode, "XF", MODE_FLOAT, 12, 12, 0) /* IEEE extended float */ | |
88 | DEF_MACHMODE (TFmode, "TF", MODE_FLOAT, 16, 16, 0) | |
89 | DEF_MACHMODE (CQImode, "CQI", MODE_COMPLEX_INT, 2, 1, 0) | |
90 | DEF_MACHMODE (CHImode, "CHI", MODE_COMPLEX_INT, 4, 2, 0) /* complex ints */ | |
91 | DEF_MACHMODE (CSImode, "CSI", MODE_COMPLEX_INT, 8, 4, 0) | |
92 | DEF_MACHMODE (CDImode, "CDI", MODE_COMPLEX_INT, 16, 8, 0) | |
93 | DEF_MACHMODE (CTImode, "CTI", MODE_COMPLEX_INT, 32, 16, 0) | |
94 | DEF_MACHMODE (CQFmode, "CQF", MODE_COMPLEX_FLOAT, 2, 1, 0) | |
95 | DEF_MACHMODE (CHFmode, "CHF", MODE_COMPLEX_FLOAT, 4, 2, 0) /* complex floats */ | |
96 | DEF_MACHMODE (CSFmode, "CSF", MODE_COMPLEX_FLOAT, 8, 4, 0) | |
97 | DEF_MACHMODE (CDFmode, "CDF", MODE_COMPLEX_FLOAT, 16, 8, 0) | |
98 | DEF_MACHMODE (CXFmode, "CXF", MODE_COMPLEX_FLOAT, 24, 12, 0) | |
99 | DEF_MACHMODE (CTFmode, "CTF", MODE_COMPLEX_FLOAT, 32, 16, 0) | |
100 | ||
101 | /* BImode is used only in FIELD_DECL nodes for bit fields | |
102 | whose size and alignment are not such as to fit any other mode. */ | |
103 | DEF_MACHMODE (BImode, "BI", MODE_INT, 0, 0, 0) /* signed bit field */ | |
104 | ||
105 | /* BLKmode is used for structures, arrays, etc. | |
106 | that fit no more specific mode. */ | |
107 | DEF_MACHMODE (BLKmode, "BLK", MODE_RANDOM, 0, 0, 0) | |
108 | ||
109 | /* Function-variable that includes a static chain. */ | |
110 | DEF_MACHMODE (EPmode, "EP", MODE_RANDOM, 8, 4, 0) | |
111 | ||
112 | /* The symbol Pmode stands for one of the above machine modes (usually SImode). | |
113 | The tm file specifies which one. It is not a distinct mode. */ | |
114 | ||
115 | /* | |
116 | Local variables: | |
117 | mode:c | |
118 | version-control: t | |
119 | End: | |
120 | */ |