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, 2004, 2005, 4 2007 Free Software Foundation, Inc. 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING3. If not see 20<http://www.gnu.org/licenses/>. */ 21 22 23/* This file defines all the MACHINE MODES used by GCC. 24 25 A machine mode specifies a size and format of data 26 at the machine level. 27 28 Each RTL expression has a machine mode. 29 30 At the syntax tree level, each ..._TYPE and each ..._DECL node 31 has a machine mode which describes data of that type or the 32 data of the variable declared. */ 33 34/* This file is included by the genmodes program. Its text is the 35 body of a function. Do not rely on this, it will change in the 36 future. 37 38 The following statements can be used in this file -- all have 39 the form of a C macro call. In their arguments: 40 41 A CLASS argument must be one of the constants defined in 42 mode-classes.def, less the leading MODE_ prefix; some statements 43 that take CLASS arguments have restrictions on which classes are 44 acceptable. For instance, INT. 45 46 A MODE argument must be the printable name of a machine mode, 47 without quotation marks or trailing "mode". For instance, SI. 48 49 A PRECISION, BYTESIZE, or COUNT argument must be a positive integer 50 constant. 51 52 A FORMAT argument must be one of the real_mode_format structures 53 declared in real.h, or else a literal 0. Do not put a leading & 54 on the argument. 55 56 An EXPR argument must be a syntactically valid C expression. 57 If an EXPR contains commas, you may need to write an extra pair of 58 parentheses around it, so it appears to be a single argument to the 59 statement. 60 61 This file defines only those modes which are of use on almost all 62 machines. Other modes can be defined in the target-specific 63 mode definition file, config/ARCH/ARCH-modes.def. 64 65 Order matters in this file in so far as statements which refer to 66 other modes must appear after the modes they refer to. However, 67 statements which do not refer to other modes may appear in any 68 order. 69 70 RANDOM_MODE (MODE); 71 declares MODE to be of class RANDOM. 72 73 CC_MODE (MODE); 74 declares MODE to be of class CC. 75 76 INT_MODE (MODE, BYTESIZE); 77 declares MODE to be of class INT and BYTESIZE bytes wide. 78 All of the bits of its representation are significant. 79 80 FRACTIONAL_INT_MODE (MODE, PRECISION, BYTESIZE); 81 declares MODE to be of class INT, BYTESIZE bytes wide in 82 storage, but with only PRECISION significant bits. 83 84 FLOAT_MODE (MODE, BYTESIZE, FORMAT); 85 declares MODE to be of class FLOAT and BYTESIZE bytes wide, 86 using floating point format FORMAT. 87 All of the bits of its representation are significant. 88 89 DECIMAL FLOAT_MODE (MODE, BYTESIZE); 90 declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes 91 wide. All of the bits of its representation are significant. 92 93 FRACTIONAL_FLOAT_MODE (MODE, PRECISION, BYTESIZE, FORMAT); 94 declares MODE to be of class FLOAT, BYTESIZE bytes wide in 95 storage, but with only PRECISION significant bits, using 96 floating point format FORMAT. 97 98 FRACT_MODE (MODE, BYTESIZE, FBIT); 99 declares MODE to be of class FRACT and BYTESIZE bytes wide 100 with FBIT fractional bits. There may be padding bits. 101 102 UFRACT_MODE (MODE, BYTESIZE, FBIT); 103 declares MODE to be of class UFRACT and BYTESIZE bytes wide 104 with FBIT fractional bits. There may be padding bits. 105 106 ACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT); 107 declares MODE to be of class ACCUM and BYTESIZE bytes wide 108 with IBIT integral bits and FBIT fractional bits. 109 There may be padding bits. 110 111 UACCUM_MODE (MODE, BYTESIZE, FBIT); 112 declares MODE to be of class UACCUM and BYTESIZE bytes wide 113 with IBIT integral bits and FBIT fractional bits. 114 There may be padding bits. 115 116 RESET_FLOAT_FORMAT (MODE, FORMAT); 117 changes the format of MODE, which must be class FLOAT, 118 to FORMAT. Use in an ARCH-modes.def to reset the format 119 of one of the float modes defined in this file. 120 121 PARTIAL_INT_MODE (MODE); 122 declares a mode of class PARTIAL_INT with the same size as 123 MODE (which must be an INT mode). The name of the new mode 124 is made by prefixing a P to the name MODE. This statement 125 may grow a PRECISION argument in the future. 126 127 VECTOR_MODE (CLASS, MODE, COUNT); 128 Declare a vector mode whose component mode is MODE (of class 129 CLASS) with COUNT components. CLASS must be INT or FLOAT. 130 The name of the vector mode takes the form VnX where n is 131 COUNT in decimal and X is MODE. 132 133 VECTOR_MODES (CLASS, WIDTH); 134 For all modes presently declared in class CLASS, construct 135 corresponding vector modes having width WIDTH. Modes whose 136 byte sizes do not evenly divide WIDTH are ignored, as are 137 modes that would produce vector modes with only one component, 138 and modes smaller than one byte (if CLASS is INT) or smaller 139 than two bytes (if CLASS is FLOAT). CLASS must be INT or 140 FLOAT. The names follow the same rule as VECTOR_MODE uses. 141 142 COMPLEX_MODES (CLASS); 143 For all modes presently declared in class CLASS, construct 144 corresponding complex modes. Modes smaller than one byte 145 are ignored. For FLOAT modes, the names are derived by 146 replacing the 'F' in the mode name with a 'C'. (It is an 147 error if there is no 'F'. For INT modes, the names are 148 derived by prefixing a C to the name. 149 150 ADJUST_BYTESIZE (MODE, EXPR); 151 ADJUST_ALIGNMENT (MODE, EXPR); 152 ADJUST_FLOAT_FORMAT (MODE, EXPR); 153 ADJUST_IBIT (MODE, EXPR); 154 ADJUST_FBIT (MODE, EXPR); 155 Arrange for the byte size, alignment, floating point format, ibit, 156 or fbit of MODE to be adjustable at run time. EXPR will be executed 157 once after processing all command line options, and should 158 evaluate to the desired byte size, alignment, format, ibit or fbit. 159 160 Unlike a FORMAT argument, if you are adjusting a float format 161 you must put an & in front of the name of each format structure. 162 163 Note: If a mode is ever made which is more than 255 bytes wide, 164 machmode.h and genmodes.c will have to be changed to allocate 165 more space for the mode_size and mode_alignment arrays. */ 166 167/* VOIDmode is used when no mode needs to be specified, 168 as for example on CONST_INT RTL expressions. */ 169RANDOM_MODE (VOID); 170 171/* BLKmode is used for structures, arrays, etc. 172 that fit no more specific mode. */ 173RANDOM_MODE (BLK); 174 175/* Single bit mode used for booleans. */ 176FRACTIONAL_INT_MODE (BI, 1, 1); 177 178/* Basic integer modes. We go up to TI in generic code (128 bits). 179 The name OI is reserved for a 256-bit type (needed by some back ends). 180 FIXME TI shouldn't be generically available either. */ 181INT_MODE (QI, 1); 182INT_MODE (HI, 2); 183INT_MODE (SI, 4); 184INT_MODE (DI, 8); 185INT_MODE (TI, 16); 186 187/* No partial integer modes are defined by default. */ 188 189/* Basic floating point modes. SF and DF are the only modes provided 190 by default. The names QF, HF, XF, and TF are reserved for targets 191 that need 1-word, 2-word, 80-bit, or 128-bit float types respectively. 192 193 These are the IEEE mappings. They can be overridden with 194 RESET_FLOAT_FORMAT or at runtime (in OVERRIDE_OPTIONS). */ 195 196FLOAT_MODE (SF, 4, ieee_single_format); 197FLOAT_MODE (DF, 8, ieee_double_format); 198 199/* Basic CC modes. 200 FIXME define this only for targets that need it. */ 201CC_MODE (CC); 202 203/* Fixed-point modes. */ 204FRACT_MODE (QQ, 1, 7); /* s.7 */ 205FRACT_MODE (HQ, 2, 15); /* s.15 */ 206FRACT_MODE (SQ, 4, 31); /* s.31 */ 207FRACT_MODE (DQ, 8, 63); /* s.63 */ 208FRACT_MODE (TQ, 16, 127); /* s.127 */ 209 210UFRACT_MODE (UQQ, 1, 8); /* .8 */ 211UFRACT_MODE (UHQ, 2, 16); /* .16 */ 212UFRACT_MODE (USQ, 4, 32); /* .32 */ 213UFRACT_MODE (UDQ, 8, 64); /* .64 */ 214UFRACT_MODE (UTQ, 16, 128); /* .128 */ 215 216ACCUM_MODE (HA, 2, 8, 7); /* s8.7 */ 217ACCUM_MODE (SA, 4, 16, 15); /* s16.15 */ 218ACCUM_MODE (DA, 8, 32, 31); /* s32.31 */ 219ACCUM_MODE (TA, 16, 64, 63); /* s64.63 */ 220 221UACCUM_MODE (UHA, 2, 8, 8); /* 8.8 */ 222UACCUM_MODE (USA, 4, 16, 16); /* 16.16 */ 223UACCUM_MODE (UDA, 8, 32, 32); /* 32.32 */ 224UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */ 225 226/* Allow the target to specify additional modes of various kinds. */ 227#if HAVE_EXTRA_MODES 228# include EXTRA_MODES_FILE 229#endif 230 231/* Complex modes. */ 232COMPLEX_MODES (INT); 233COMPLEX_MODES (FLOAT); 234 235/* Decimal floating point modes. */ 236DECIMAL_FLOAT_MODE (SD, 4, decimal_single_format); 237DECIMAL_FLOAT_MODE (DD, 8, decimal_double_format); 238DECIMAL_FLOAT_MODE (TD, 16, decimal_quad_format); 239 240/* The symbol Pmode stands for one of the above machine modes (usually SImode). 241 The tm.h file specifies which one. It is not a distinct mode. */ 242 243/* 244Local variables: 245mode:c 246version-control: t 247End: 248*/ 249