1/* This file contains the definitions and documentation for the 2 machine modes used in the GNU compiler. 3 Copyright (C) 1987-2018 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along 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); 146 Like VECTOR_MODES, but start the mode names with PREFIX instead 147 of the usual "V". 148 149 VECTOR_BOOL_MODE (NAME, COUNT, BYTESIZE) 150 Create a vector mode called NAME that contains COUNT boolean 151 elements and occupies BYTESIZE bytes in total. Each boolean 152 element occupies (COUNT * BITS_PER_UNIT) / BYTESIZE bits, with 153 the element at index 0 occupying the lsb of the first byte in 154 memory. Only the lowest bit of each element is significant. 155 156 COMPLEX_MODES (CLASS); 157 For all modes presently declared in class CLASS, construct 158 corresponding complex modes. Modes smaller than one byte 159 are ignored. For FLOAT modes, the names are derived by 160 replacing the 'F' in the mode name with a 'C'. (It is an 161 error if there is no 'F'. For INT modes, the names are 162 derived by prefixing a C to the name. 163 164 ADJUST_BYTESIZE (MODE, EXPR); 165 ADJUST_ALIGNMENT (MODE, EXPR); 166 ADJUST_FLOAT_FORMAT (MODE, EXPR); 167 ADJUST_IBIT (MODE, EXPR); 168 ADJUST_FBIT (MODE, EXPR); 169 Arrange for the byte size, alignment, floating point format, ibit, 170 or fbit of MODE to be adjustable at run time. EXPR will be executed 171 once after processing all command line options, and should 172 evaluate to the desired byte size, alignment, format, ibit or fbit. 173 174 Unlike a FORMAT argument, if you are adjusting a float format 175 you must put an & in front of the name of each format structure. 176 177 ADJUST_NUNITS (MODE, EXPR); 178 Like the above, but set the number of nunits of MODE to EXPR. 179 This changes the size and precision of the mode in proportion 180 to the change in the number of units; for example, doubling 181 the number of units doubles the size and precision as well. 182 183 Note: If a mode is ever made which is more than 255 bytes wide, 184 machmode.h and genmodes.c will have to be changed to allocate 185 more space for the mode_size and mode_alignment arrays. */ 186 187/* VOIDmode is used when no mode needs to be specified, 188 as for example on CONST_INT RTL expressions. */ 189RANDOM_MODE (VOID); 190 191/* BLKmode is used for structures, arrays, etc. 192 that fit no more specific mode. */ 193RANDOM_MODE (BLK); 194 195/* Single bit mode used for booleans. */ 196FRACTIONAL_INT_MODE (BI, 1, 1); 197 198/* Basic integer modes. We go up to TI in generic code (128 bits). 199 TImode is needed here because the some front ends now genericly 200 support __int128. If the front ends decide to generically support 201 larger types, then corresponding modes must be added here. The 202 name OI is reserved for a 256-bit type (needed by some back ends). 203 */ 204INT_MODE (QI, 1); 205INT_MODE (HI, 2); 206INT_MODE (SI, 4); 207INT_MODE (DI, 8); 208INT_MODE (TI, 16); 209 210/* No partial integer modes are defined by default. */ 211 212/* The target normally defines any target-specific __intN types and 213 their modes, but __int128 for TImode is fairly common so define it 214 here. The type will not be created unless the target supports 215 TImode. */ 216 217INT_N (TI, 128); 218 219/* Basic floating point modes. SF and DF are the only modes provided 220 by default. The names QF, HF, XF, and TF are reserved for targets 221 that need 1-word, 2-word, 80-bit, or 128-bit float types respectively. 222 223 These are the IEEE mappings. They can be overridden with 224 RESET_FLOAT_FORMAT or at runtime (in TARGET_OPTION_OVERRIDE). */ 225 226FLOAT_MODE (SF, 4, ieee_single_format); 227FLOAT_MODE (DF, 8, ieee_double_format); 228 229/* Basic CC modes. 230 FIXME define this only for targets that need it. */ 231CC_MODE (CC); 232 233/* Fixed-point modes. */ 234FRACT_MODE (QQ, 1, 7); /* s.7 */ 235FRACT_MODE (HQ, 2, 15); /* s.15 */ 236FRACT_MODE (SQ, 4, 31); /* s.31 */ 237FRACT_MODE (DQ, 8, 63); /* s.63 */ 238FRACT_MODE (TQ, 16, 127); /* s.127 */ 239 240UFRACT_MODE (UQQ, 1, 8); /* .8 */ 241UFRACT_MODE (UHQ, 2, 16); /* .16 */ 242UFRACT_MODE (USQ, 4, 32); /* .32 */ 243UFRACT_MODE (UDQ, 8, 64); /* .64 */ 244UFRACT_MODE (UTQ, 16, 128); /* .128 */ 245 246ACCUM_MODE (HA, 2, 8, 7); /* s8.7 */ 247ACCUM_MODE (SA, 4, 16, 15); /* s16.15 */ 248ACCUM_MODE (DA, 8, 32, 31); /* s32.31 */ 249ACCUM_MODE (TA, 16, 64, 63); /* s64.63 */ 250 251UACCUM_MODE (UHA, 2, 8, 8); /* 8.8 */ 252UACCUM_MODE (USA, 4, 16, 16); /* 16.16 */ 253UACCUM_MODE (UDA, 8, 32, 32); /* 32.32 */ 254UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */ 255 256/* Allow the target to specify additional modes of various kinds. */ 257#if HAVE_EXTRA_MODES 258# include EXTRA_MODES_FILE 259#endif 260 261/* Complex modes. */ 262COMPLEX_MODES (INT); 263COMPLEX_MODES (PARTIAL_INT); 264COMPLEX_MODES (FLOAT); 265 266/* Decimal floating point modes. */ 267DECIMAL_FLOAT_MODE (SD, 4, decimal_single_format); 268DECIMAL_FLOAT_MODE (DD, 8, decimal_double_format); 269DECIMAL_FLOAT_MODE (TD, 16, decimal_quad_format); 270 271/* The symbol Pmode stands for one of the above machine modes (usually SImode). 272 The tm.h file specifies which one. It is not a distinct mode. */ 273 274/* 275Local variables: 276mode:c 277version-control: t 278End: 279*/ 280