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, 2010 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 FRACTIONAL_FLOAT_MODE (MODE, PRECISION, BYTESIZE, FORMAT); 90 declares MODE to be of class FLOAT, BYTESIZE bytes wide in 91 storage, but with only PRECISION significant bits, using 92 floating point format FORMAT. 93 94 DECIMAL_FLOAT_MODE (MODE, BYTESIZE, FORMAT); 95 declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes 96 wide. All of the bits of its representation are significant. 97 98 FRACTIONAL_DECIMAL_FLOAT_MODE (MODE, BYTESIZE, FORMAT); 99 declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes 100 wide. All of the bits of its representation are significant. 101 102 FRACT_MODE (MODE, BYTESIZE, FBIT); 103 declares MODE to be of class FRACT and BYTESIZE bytes wide 104 with FBIT fractional bits. There may be padding bits. 105 106 UFRACT_MODE (MODE, BYTESIZE, FBIT); 107 declares MODE to be of class UFRACT and BYTESIZE bytes wide 108 with FBIT fractional bits. There may be padding bits. 109 110 ACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT); 111 declares MODE to be of class ACCUM and BYTESIZE bytes wide 112 with IBIT integral bits and FBIT fractional bits. 113 There may be padding bits. 114 115 UACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT); 116 declares MODE to be of class UACCUM and BYTESIZE bytes wide 117 with IBIT integral bits and FBIT fractional bits. 118 There may be padding bits. 119 120 RESET_FLOAT_FORMAT (MODE, FORMAT); 121 changes the format of MODE, which must be class FLOAT, 122 to FORMAT. Use in an ARCH-modes.def to reset the format 123 of one of the float modes defined in this file. 124 125 PARTIAL_INT_MODE (MODE); 126 declares a mode of class PARTIAL_INT with the same size as 127 MODE (which must be an INT mode). The name of the new mode 128 is made by prefixing a P to the name MODE. This statement 129 may grow a PRECISION argument in the future. 130 131 VECTOR_MODE (CLASS, MODE, COUNT); 132 Declare a vector mode whose component mode is MODE (of class 133 CLASS) with COUNT components. CLASS must be INT or FLOAT. 134 The name of the vector mode takes the form VnX where n is 135 COUNT in decimal and X is MODE. 136 137 VECTOR_MODES (CLASS, WIDTH); 138 For all modes presently declared in class CLASS, construct 139 corresponding vector modes having width WIDTH. Modes whose 140 byte sizes do not evenly divide WIDTH are ignored, as are 141 modes that would produce vector modes with only one component, 142 and modes smaller than one byte (if CLASS is INT) or smaller 143 than two bytes (if CLASS is FLOAT). CLASS must be INT or 144 FLOAT. The names follow the same rule as VECTOR_MODE uses. 145 146 COMPLEX_MODES (CLASS); 147 For all modes presently declared in class CLASS, construct 148 corresponding complex modes. Modes smaller than one byte 149 are ignored. For FLOAT modes, the names are derived by 150 replacing the 'F' in the mode name with a 'C'. (It is an 151 error if there is no 'F'. For INT modes, the names are 152 derived by prefixing a C to the name. 153 154 ADJUST_BYTESIZE (MODE, EXPR); 155 ADJUST_ALIGNMENT (MODE, EXPR); 156 ADJUST_FLOAT_FORMAT (MODE, EXPR); 157 ADJUST_IBIT (MODE, EXPR); 158 ADJUST_FBIT (MODE, EXPR); 159 Arrange for the byte size, alignment, floating point format, ibit, 160 or fbit of MODE to be adjustable at run time. EXPR will be executed 161 once after processing all command line options, and should 162 evaluate to the desired byte size, alignment, format, ibit or fbit. 163 164 Unlike a FORMAT argument, if you are adjusting a float format 165 you must put an & in front of the name of each format structure. 166 167 Note: If a mode is ever made which is more than 255 bytes wide, 168 machmode.h and genmodes.c will have to be changed to allocate 169 more space for the mode_size and mode_alignment arrays. */ 170 171/* VOIDmode is used when no mode needs to be specified, 172 as for example on CONST_INT RTL expressions. */ 173RANDOM_MODE (VOID); 174 175/* BLKmode is used for structures, arrays, etc. 176 that fit no more specific mode. */ 177RANDOM_MODE (BLK); 178 179/* Single bit mode used for booleans. */ 180FRACTIONAL_INT_MODE (BI, 1, 1); 181 182/* Basic integer modes. We go up to TI in generic code (128 bits). 183 The name OI is reserved for a 256-bit type (needed by some back ends). 184 FIXME TI shouldn't be generically available either. */ 185INT_MODE (QI, 1); 186INT_MODE (HI, 2); 187INT_MODE (SI, 4); 188INT_MODE (DI, 8); 189INT_MODE (TI, 16); 190 191/* No partial integer modes are defined by default. */ 192 193/* Basic floating point modes. SF and DF are the only modes provided 194 by default. The names QF, HF, XF, and TF are reserved for targets 195 that need 1-word, 2-word, 80-bit, or 128-bit float types respectively. 196 197 These are the IEEE mappings. They can be overridden with 198 RESET_FLOAT_FORMAT or at runtime (in TARGET_OPTION_OVERRIDE). */ 199 200FLOAT_MODE (SF, 4, ieee_single_format); 201FLOAT_MODE (DF, 8, ieee_double_format); 202 203/* Basic CC modes. 204 FIXME define this only for targets that need it. */ 205CC_MODE (CC); 206 207/* Fixed-point modes. */ 208FRACT_MODE (QQ, 1, 7); /* s.7 */ 209FRACT_MODE (HQ, 2, 15); /* s.15 */ 210FRACT_MODE (SQ, 4, 31); /* s.31 */ 211FRACT_MODE (DQ, 8, 63); /* s.63 */ 212FRACT_MODE (TQ, 16, 127); /* s.127 */ 213 214UFRACT_MODE (UQQ, 1, 8); /* .8 */ 215UFRACT_MODE (UHQ, 2, 16); /* .16 */ 216UFRACT_MODE (USQ, 4, 32); /* .32 */ 217UFRACT_MODE (UDQ, 8, 64); /* .64 */ 218UFRACT_MODE (UTQ, 16, 128); /* .128 */ 219 220ACCUM_MODE (HA, 2, 8, 7); /* s8.7 */ 221ACCUM_MODE (SA, 4, 16, 15); /* s16.15 */ 222ACCUM_MODE (DA, 8, 32, 31); /* s32.31 */ 223ACCUM_MODE (TA, 16, 64, 63); /* s64.63 */ 224 225UACCUM_MODE (UHA, 2, 8, 8); /* 8.8 */ 226UACCUM_MODE (USA, 4, 16, 16); /* 16.16 */ 227UACCUM_MODE (UDA, 8, 32, 32); /* 32.32 */ 228UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */ 229 230/* Allow the target to specify additional modes of various kinds. */ 231#if HAVE_EXTRA_MODES 232# include EXTRA_MODES_FILE 233#endif 234 235/* Complex modes. */ 236COMPLEX_MODES (INT); 237COMPLEX_MODES (FLOAT); 238 239/* Decimal floating point modes. */ 240DECIMAL_FLOAT_MODE (SD, 4, decimal_single_format); 241DECIMAL_FLOAT_MODE (DD, 8, decimal_double_format); 242DECIMAL_FLOAT_MODE (TD, 16, decimal_quad_format); 243 244/* The symbol Pmode stands for one of the above machine modes (usually SImode). 245 The tm.h file specifies which one. It is not a distinct mode. */ 246 247/* 248Local variables: 249mode:c 250version-control: t 251End: 252*/ 253