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| 1 : | pazsan | 1.1 | \ generic.fs implements generic assembler definitions 13aug97jaw |
| 2 : | |||
| 3 : | anton | 1.7 | \ Copyright (C) 1998,2000,2003,2007 Free Software Foundation, Inc. |
| 4 : | anton | 1.2 | |
| 5 : | \ This file is part of Gforth. | ||
| 6 : | |||
| 7 : | \ Gforth is free software; you can redistribute it and/or | ||
| 8 : | \ modify it under the terms of the GNU General Public License | ||
| 9 : | anton | 1.6 | \ as published by the Free Software Foundation, either version 3 |
| 10 : | anton | 1.2 | \ of the License, or (at your option) any later version. |
| 11 : | |||
| 12 : | \ This program 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 : | anton | 1.6 | \ along with this program. If not, see http://www.gnu.org/licenses/. |
| 19 : | pazsan | 1.1 | |
| 20 : | \ These are generic routines to build up a table-driven assembler | ||
| 21 : | \ fo any modern (RISC)-CPU | ||
| 22 : | |||
| 23 : | \ Revision Log: | ||
| 24 : | \ | ||
| 25 : | \ 13aug97jaw-14aug97 Initial Version -> V0.5 | ||
| 26 : | \ ToDo: operand count checking | ||
| 27 : | dvdkhlng | 1.8 | \ |
| 28 : | \ 24apr10dk Added documentation | ||
| 29 : | pazsan | 1.1 | |
| 30 : | \ general definitions | ||
| 31 : | |||
| 32 : | dvdkhlng | 1.8 | : clearstack ( k*x -- ) depth 0 ?DO drop LOOP ; |
| 33 : | pazsan | 1.1 | |
| 34 : | \ redefinitions to avoid conflicts | ||
| 35 : | |||
| 36 : | ' , ALIAS dic, | ||
| 37 : | ' NOOP ALIAS X | ||
| 38 : | |||
| 39 : | \ ------------ Modes | ||
| 40 : | |||
| 41 : | [IFUNDEF] modes# | ||
| 42 : | 4 Constant modes# | ||
| 43 : | [THEN] | ||
| 44 : | |||
| 45 : | Create modes modes# cells allot \ Modes for differend operands are stored here | ||
| 46 : | \ Example: | ||
| 47 : | \ Offset 0: general modifier ( .B, .W, .L) | ||
| 48 : | \ Offset 1: addressing mode operand 1 | ||
| 49 : | \ Offset 2: addressing mode operand 2 | ||
| 50 : | |||
| 51 : | : Mode-Compare ( adr1 adr2 -- flag ) | ||
| 52 : | modes# | ||
| 53 : | BEGIN dup WHILE >r 2dup @ swap @ <> IF rdrop 2drop false EXIT THEN | ||
| 54 : | cell+ swap cell+ r> 1- | ||
| 55 : | REPEAT drop 2drop true ; | ||
| 56 : | |||
| 57 : | Variable Start-Depth | ||
| 58 : | Variable Mode# | ||
| 59 : | |||
| 60 : | dvdkhlng | 1.8 | : reset ( -- ) |
| 61 : | \G End an opcode / star a new opcode. | ||
| 62 : | pazsan | 1.1 | modes modes# cells erase |
| 63 : | 1 Mode# ! | ||
| 64 : | depth Start-Depth ! ; | ||
| 65 : | |||
| 66 : | dvdkhlng | 1.8 | : Mode! ( x -- ) |
| 67 : | \G Set current operand's mode to X | ||
| 68 : | pazsan | 1.1 | Modes Mode# @ cells + ! ; |
| 69 : | |||
| 70 : | dvdkhlng | 1.8 | : +Mode! ( x -- ) |
| 71 : | \G Logically OR X to current operand's mode | ||
| 72 : | pazsan | 1.1 | Modes Mode# @ cells + tuck @ or swap ! ; |
| 73 : | |||
| 74 : | dvdkhlng | 1.8 | : 0Mode! ( x -- ) |
| 75 : | \G Set mode of operand #0. Use operand #0 for an (optional) operands that | ||
| 76 : | \G can be placed anywhere, e.g. condition codes or operand lengths .B .W .L | ||
| 77 : | \G etc. | ||
| 78 : | pazsan | 1.1 | Modes ! ; |
| 79 : | |||
| 80 : | dvdkhlng | 1.8 | : , ( -- ) |
| 81 : | \G Advance to next operand | ||
| 82 : | pazsan | 1.1 | 1 Mode# +! ; |
| 83 : | |||
| 84 : | dvdkhlng | 1.8 | : Mode ( x "name" -- ) |
| 85 : | \G Define a new mode that logically ors X to current mode when executed | ||
| 86 : | pazsan | 1.1 | Create dic, DOES> @ +Mode! ; |
| 87 : | |||
| 88 : | dvdkhlng | 1.8 | : 0Mode ( x "name" -- ) |
| 89 : | \G Define a new mode that sets operand #0 when executed | ||
| 90 : | pazsan | 1.1 | Create dic, DOES> @ 0Mode! ; |
| 91 : | |||
| 92 : | dvdkhlng | 1.8 | : Reg ( xt x "name" -- ) |
| 93 : | \G Define a parametrized mode, that executes mode XT, then puts X onto the | ||
| 94 : | \G stack | ||
| 95 : | pazsan | 1.1 | Create dic, dic, DOES> dup perform cell+ @ ; |
| 96 : | |||
| 97 : | \ --------- Instruction Latch | ||
| 98 : | |||
| 99 : | Create I-Latch 10 chars allot | ||
| 100 : | Variable I-Len | ||
| 101 : | |||
| 102 : | : opc! ( adr len -- ) | ||
| 103 : | dvdkhlng | 1.8 | \G Logically OR string of bytes into instruction latch |
| 104 : | pazsan | 1.1 | dup I-Len @ max I-Len ! |
| 105 : | dvdkhlng | 1.9 | I-Latch -rot bounds ?DO I c@ over c@ or over c! char+ LOOP drop ; |
| 106 : | pazsan | 1.1 | |
| 107 : | dvdkhlng | 1.8 | : I-Init ( -- ) 0 I-Len ! I-Latch 10 erase ; |
| 108 : | : I-Flush ( -- ) | ||
| 109 : | \G Append contents of instruction latch to dictionary | ||
| 110 : | I-Latch I-len @ bounds DO i c@ X c, LOOP reset ; | ||
| 111 : | pazsan | 1.1 | |
| 112 : | : (g!) ( val addr n -1/1 -- ) | ||
| 113 : | dup 0< IF rot 2 pick + 1- -rot THEN | ||
| 114 : | swap >r -rot r> 0 | ||
| 115 : | DO 2dup c! 2 pick + swap 8 rshift swap LOOP | ||
| 116 : | 2drop drop ; | ||
| 117 : | |||
| 118 : | : (g@) ( addr n -1/1 -- val ) | ||
| 119 : | negate dup 0< IF rot 2 pick + 1- -rot THEN | ||
| 120 : | swap >r swap 0 swap r> 0 | ||
| 121 : | DO swap 8 lshift over c@ or swap 2 pick + LOOP | ||
| 122 : | drop nip ; | ||
| 123 : | |||
| 124 : | Variable ByteDirection \ -1 = big endian; 1 = little endian | ||
| 125 : | |||
| 126 : | dvdkhlng | 1.8 | : g@ ( addr n -- val ) |
| 127 : | \G read n-byte integer from addr using current endianess | ||
| 128 : | ByteDirection @ (g@) ; | ||
| 129 : | : g! ( val addr n -- ) | ||
| 130 : | \G write n-byte integer to addr using current endianess | ||
| 131 : | ByteDirection @ (g!) ; | ||
| 132 : | pazsan | 1.1 | |
| 133 : | \ ---------------- Tables | ||
| 134 : | |||
| 135 : | : >modes ( addr -- addr ) 5 cells + ; | ||
| 136 : | : >data ( addr -- addr ) >modes modes# cells + ; | ||
| 137 : | |||
| 138 : | 0 Value Describ | ||
| 139 : | |||
| 140 : | : Table-Exec ( addr -- ) | ||
| 141 : | to Describ | ||
| 142 : | Describ 2 cells + perform \ to store the opcode | ||
| 143 : | Describ 3 cells + perform \ to store the operands | ||
| 144 : | Describ 4 cells + perform \ to flush the instruction | ||
| 145 : | ; | ||
| 146 : | |||
| 147 : | dvdkhlng | 1.8 | : 1st-mc ( addr -- flag ) |
| 148 : | \G mnemonic check? check for matching operands. if matching, execute code | ||
| 149 : | \G to encode mode and operands and return true, else return false | ||
| 150 : | pazsan | 1.1 | dup >modes modes Mode-Compare |
| 151 : | IF Table-Exec | ||
| 152 : | true | ||
| 153 : | ELSE false | ||
| 154 : | THEN ; | ||
| 155 : | |||
| 156 : | : 1st-always ( addr -- flag ) | ||
| 157 : | dvdkhlng | 1.8 | \G Undconditionally encode operands and/or instruction used for instructions |
| 158 : | \G that do not have any operands. Return true i.e. make the assembler stop | ||
| 159 : | \G looking for more instruction variants | ||
| 160 : | pazsan | 1.1 | Table-Exec true ; |
| 161 : | |||
| 162 : | : 1st-thru | ||
| 163 : | dvdkhlng | 1.8 | \G Unconditionally encode, but return false to make assembler execute next |
| 164 : | \G table rows also. | ||
| 165 : | pazsan | 1.1 | dup Table-Exec false ; |
| 166 : | |||
| 167 : | dvdkhlng | 1.8 | : 2nd-opc! ( -- ) |
| 168 : | \G encode opcode by ORing data column of current instruction row into | ||
| 169 : | \G instruction latch | ||
| 170 : | pazsan | 1.1 | Describ >data count opc! ; |
| 171 : | |||
| 172 : | dvdkhlng | 1.8 | : opcode, ( "<NNN> ..." -- ) |
| 173 : | \G Append a counted string to dictionary, reading in every character as | ||
| 174 : | \G space-terminated numbers form the parser until the end of line is | ||
| 175 : | \G reached. | ||
| 176 : | pazsan | 1.1 | here 0 c, |
| 177 : | BEGIN bl word count dup WHILE s>number drop c, | ||
| 178 : | REPEAT 2drop here over - 1- swap c! ; | ||
| 179 : | |||
| 180 : | dvdkhlng | 1.8 | : modes, ( -- ) |
| 181 : | \G append contents of MODES to dictionary | ||
| 182 : | pazsan | 1.1 | modes# 0 DO I cells modes + @ dic, LOOP ; |
| 183 : | |||
| 184 : | 0 Value Table-Link | ||
| 185 : | |||
| 186 : | dvdkhlng | 1.8 | : Table ( "name" -- ) |
| 187 : | \G create table that lists allowed operand/mode combinations for opcode | ||
| 188 : | \G "name" | ||
| 189 : | pazsan | 1.1 | Reset |
| 190 : | Create here to Table-Link 0 dic, | ||
| 191 : | DOES> I-Init | ||
| 192 : | BEGIN @ dup WHILE dup | ||
| 193 : | cell+ perform \ first element is executed always | ||
| 194 : | \ makes check | ||
| 195 : | ?EXIT | ||
| 196 : | REPEAT -1 ABORT" no valid mode!" | ||
| 197 : | ; | ||
| 198 : | dvdkhlng | 1.8 | |
| 199 : | : Follows ( "name" -- ) | ||
| 200 : | \G Link current instruction's table to execute all rows of table "name" | ||
| 201 : | \G (after executing all rows already defined). Do not add any more rows to | ||
| 202 : | \G current table, after executing Follows. Else you're going to modify | ||
| 203 : | \G "name"'s table! | ||
| 204 : | pazsan | 1.1 | ' >body @ Table-Link @ ! ; |
| 205 : | |||
| 206 : | dvdkhlng | 1.8 | : opc, ( k*x "<NNN> ..." -- ) |
| 207 : | \G Append current modes and opcode given byte-wise on current input line to | ||
| 208 : | \G dictionary. Clear forth stack to remove any data provided by the | ||
| 209 : | \G otherwise unused operands that wer used to set up the modes array. | ||
| 210 : | pazsan | 1.1 | modes, opcode, clearstack reset ; |
| 211 : | |||
| 212 : | dvdkhlng | 1.8 | : (Opc() ( k*x xt "<NNN> ..." -- ) |
| 213 : | \G Fill table row for opcode with Operands. XT will be executed by the | ||
| 214 : | \G assembler for encoding the operands using data from the stack. | ||
| 215 : | pazsan | 1.1 | ['] 1st-mc dic, |
| 216 : | ['] 2nd-opc! dic, | ||
| 217 : | dic, | ||
| 218 : | ['] I-Flush dic, | ||
| 219 : | opc, ; | ||
| 220 : | |||
| 221 : | dvdkhlng | 1.8 | : (Opc) ( k*x xt "<NNN> ..." -- ) |
| 222 : | pazsan | 1.1 | \ Opcode without Operands |
| 223 : | ['] 1st-always dic, | ||
| 224 : | ['] 2nd-opc! dic, | ||
| 225 : | ['] Noop dic, | ||
| 226 : | ['] I-Flush dic, | ||
| 227 : | opc, ; | ||
| 228 : | |||
| 229 : | dvdkhlng | 1.8 | : Opc( ( k*x xt "<NNN> ..." -- ) |
| 230 : | \G Append a new table row for an opcode with Operands. Use your assembler | ||
| 231 : | \G operands to fill the MODES array with data showing how the opcode is | ||
| 232 : | \G used. Only the types of operands are recorded, any operand parameters | ||
| 233 : | \G passed on the stack are dropped. The opcode's instruction code is read | ||
| 234 : | \G as 8-bit numbers from the current input line and stored as counted string | ||
| 235 : | \G in the table's opcode column | ||
| 236 : | \G | ||
| 237 : | \G When assembling an instruction, the assembler checks for matching | ||
| 238 : | \G operands. If this row matches, first XT is called to consume operands | ||
| 239 : | \G parameters from the stack and encode them into the instruction latch. | ||
| 240 : | \G Then the opcode column is ORed to the instruction latch and the assembler | ||
| 241 : | \G quits assembly of the current instruction. | ||
| 242 : | pazsan | 1.1 | Table-Link linked |
| 243 : | (Opc() ; | ||
| 244 : | |||
| 245 : | dvdkhlng | 1.8 | : Opc ( k*x "<NNN> ..." -- ) |
| 246 : | \G Append a new table row for an opcode without operand parameters. | ||
| 247 : | \G | ||
| 248 : | \G When assembling an instruction, and the assembler reaches this row, it | ||
| 249 : | \G will assume the opcode is fully assembled and quits assembly of the | ||
| 250 : | \G instruction, after endcoding the opcode. | ||
| 251 : | pazsan | 1.1 | Table-Link linked |
| 252 : | (Opc) ; | ||
| 253 : | |||
| 254 : | dvdkhlng | 1.8 | : Opc+ ( k*x "<NNN> ..." -- ) |
| 255 : | \G Append a new table row that encodes part of an opcode, but falls through | ||
| 256 : | \G to following lines. | ||
| 257 : | pazsan | 1.1 | Table-Link linked |
| 258 : | ['] 1st-thru dic, | ||
| 259 : | ['] 2nd-opc! dic, | ||
| 260 : | ['] Noop dic, | ||
| 261 : | ['] Noop dic, | ||
| 262 : | opc, ; | ||
| 263 : | |||
| 264 : | dvdkhlng | 1.8 | : Opc(+ ( k*x xt "<NNN> ..." -- ) |
| 265 : | \G Like OPC+ but for a table row that has operands | ||
| 266 : | pazsan | 1.1 | Table-Link linked |
| 267 : | ['] 1st-thru dic, | ||
| 268 : | ['] 2nd-opc! dic, | ||
| 269 : | dic, | ||
| 270 : | ['] Noop dic, | ||
| 271 : | opc, ; | ||
| 272 : | |||
| 273 : | : End-Table ; | ||
| 274 : | |||
| 275 : | dvdkhlng | 1.8 | : alone ( k*x "<NNN> ..." -- ) |
| 276 : | \G Create a single-row instruction table for an instruction without operands. | ||
| 277 : | pazsan | 1.1 | Create 0 dic, ( Dummy Linkfield ) (opc) |
| 278 : | DOES> dup cell+ perform 0= ABORT" must work always!" ; | ||
| 279 : | dvdkhlng | 1.8 | |
| 280 : | : alone( ( k*x xt "<NNN> ..." -- ) | ||
| 281 : | \G Create a single-row instruction table for an instruction with operands. | ||
| 282 : | pazsan | 1.1 | Create 0 dic, ( Dummy Linkfield ) (opc() |
| 283 : | DOES> dup cell+ perform 0= ABORT" must work always!" ; | ||
| 284 : | dvdkhlng | 1.8 | |
| 285 : | |||
| 286 : | \ Configure Emacs forth-mode to keep this file's formatting | ||
| 287 : | 0 [IF] | ||
| 288 : | Local Variables: | ||
| 289 : | forth-indent-level: 2 | ||
| 290 : | forth-local-indent-words: | ||
| 291 : | (((";") (0 . -2) (0 . -2)) | ||
| 292 : | (("does>") (0 . 0) (0 . 0))) | ||
| 293 : | End: | ||
| 294 : | [THEN] |
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