| 1 | @c Copyright (C) 1997-2016 Free Software Foundation, Inc. |
| 2 | @c This is part of the GAS manual. |
| 3 | @c For copying conditions, see the file as.texinfo. |
| 4 | @ifset GENERIC |
| 5 | @page |
| 6 | @node D30V-Dependent |
| 7 | @chapter D30V Dependent Features |
| 8 | @end ifset |
| 9 | @ifclear GENERIC |
| 10 | @node Machine Dependencies |
| 11 | @chapter D30V Dependent Features |
| 12 | @end ifclear |
| 13 | |
| 14 | @cindex D30V support |
| 15 | @menu |
| 16 | * D30V-Opts:: D30V Options |
| 17 | * D30V-Syntax:: Syntax |
| 18 | * D30V-Float:: Floating Point |
| 19 | * D30V-Opcodes:: Opcodes |
| 20 | @end menu |
| 21 | |
| 22 | @node D30V-Opts |
| 23 | @section D30V Options |
| 24 | @cindex options, D30V |
| 25 | @cindex D30V options |
| 26 | The Mitsubishi D30V version of @code{@value{AS}} has a few machine |
| 27 | dependent options. |
| 28 | |
| 29 | @table @samp |
| 30 | @item -O |
| 31 | The D30V can often execute two sub-instructions in parallel. When this option |
| 32 | is used, @code{@value{AS}} will attempt to optimize its output by detecting when |
| 33 | instructions can be executed in parallel. |
| 34 | |
| 35 | @item -n |
| 36 | When this option is used, @code{@value{AS}} will issue a warning every |
| 37 | time it adds a nop instruction. |
| 38 | |
| 39 | @item -N |
| 40 | When this option is used, @code{@value{AS}} will issue a warning if it |
| 41 | needs to insert a nop after a 32-bit multiply before a load or 16-bit |
| 42 | multiply instruction. |
| 43 | @end table |
| 44 | |
| 45 | @node D30V-Syntax |
| 46 | @section Syntax |
| 47 | @cindex D30V syntax |
| 48 | @cindex syntax, D30V |
| 49 | |
| 50 | The D30V syntax is based on the syntax in Mitsubishi's D30V architecture manual. |
| 51 | The differences are detailed below. |
| 52 | |
| 53 | @menu |
| 54 | * D30V-Size:: Size Modifiers |
| 55 | * D30V-Subs:: Sub-Instructions |
| 56 | * D30V-Chars:: Special Characters |
| 57 | * D30V-Guarded:: Guarded Execution |
| 58 | * D30V-Regs:: Register Names |
| 59 | * D30V-Addressing:: Addressing Modes |
| 60 | @end menu |
| 61 | |
| 62 | |
| 63 | @node D30V-Size |
| 64 | @subsection Size Modifiers |
| 65 | @cindex D30V size modifiers |
| 66 | @cindex size modifiers, D30V |
| 67 | The D30V version of @code{@value{AS}} uses the instruction names in the D30V |
| 68 | Architecture Manual. However, the names in the manual are sometimes ambiguous. |
| 69 | There are instruction names that can assemble to a short or long form opcode. |
| 70 | How does the assembler pick the correct form? @code{@value{AS}} will always pick the |
| 71 | smallest form if it can. When dealing with a symbol that is not defined yet when a |
| 72 | line is being assembled, it will always use the long form. If you need to force the |
| 73 | assembler to use either the short or long form of the instruction, you can append |
| 74 | either @samp{.s} (short) or @samp{.l} (long) to it. For example, if you are writing |
| 75 | an assembly program and you want to do a branch to a symbol that is defined later |
| 76 | in your program, you can write @samp{bra.s foo}. |
| 77 | Objdump and GDB will always append @samp{.s} or @samp{.l} to instructions which |
| 78 | have both short and long forms. |
| 79 | |
| 80 | @node D30V-Subs |
| 81 | @subsection Sub-Instructions |
| 82 | @cindex D30V sub-instructions |
| 83 | @cindex sub-instructions, D30V |
| 84 | The D30V assembler takes as input a series of instructions, either one-per-line, |
| 85 | or in the special two-per-line format described in the next section. Some of these |
| 86 | instructions will be short-form or sub-instructions. These sub-instructions can be packed |
| 87 | into a single instruction. The assembler will do this automatically. It will also detect |
| 88 | when it should not pack instructions. For example, when a label is defined, the next |
| 89 | instruction will never be packaged with the previous one. Whenever a branch and link |
| 90 | instruction is called, it will not be packaged with the next instruction so the return |
| 91 | address will be valid. Nops are automatically inserted when necessary. |
| 92 | |
| 93 | If you do not want the assembler automatically making these decisions, you can control |
| 94 | the packaging and execution type (parallel or sequential) with the special execution |
| 95 | symbols described in the next section. |
| 96 | |
| 97 | @node D30V-Chars |
| 98 | @subsection Special Characters |
| 99 | @cindex line comment character, D30V |
| 100 | @cindex D30V line comment character |
| 101 | A semicolon (@samp{;}) can be used anywhere on a line to start a |
| 102 | comment that extends to the end of the line. |
| 103 | |
| 104 | If a @samp{#} appears as the first character of a line, the whole line |
| 105 | is treated as a comment, but in this case the line could also be a |
| 106 | logical line number directive (@pxref{Comments}) or a preprocessor |
| 107 | control command (@pxref{Preprocessing}). |
| 108 | |
| 109 | @cindex sub-instruction ordering, D30V |
| 110 | @cindex D30V sub-instruction ordering |
| 111 | Sub-instructions may be executed in order, in reverse-order, or in parallel. |
| 112 | Instructions listed in the standard one-per-line format will be executed |
| 113 | sequentially unless you use the @samp{-O} option. |
| 114 | |
| 115 | To specify the executing order, use the following symbols: |
| 116 | @table @samp |
| 117 | @item -> |
| 118 | Sequential with instruction on the left first. |
| 119 | |
| 120 | @item <- |
| 121 | Sequential with instruction on the right first. |
| 122 | |
| 123 | @item || |
| 124 | Parallel |
| 125 | @end table |
| 126 | |
| 127 | The D30V syntax allows either one instruction per line, one instruction per line with |
| 128 | the execution symbol, or two instructions per line. For example |
| 129 | @table @code |
| 130 | @item abs r2,r3 -> abs r4,r5 |
| 131 | Execute these sequentially. The instruction on the right is in the right |
| 132 | container and is executed second. |
| 133 | |
| 134 | @item abs r2,r3 <- abs r4,r5 |
| 135 | Execute these reverse-sequentially. The instruction on the right is in the right |
| 136 | container, and is executed first. |
| 137 | |
| 138 | @item abs r2,r3 || abs r4,r5 |
| 139 | Execute these in parallel. |
| 140 | |
| 141 | @item ldw r2,@@(r3,r4) || |
| 142 | @itemx mulx r6,r8,r9 |
| 143 | Two-line format. Execute these in parallel. |
| 144 | |
| 145 | @item mulx a0,r8,r9 |
| 146 | @itemx stw r2,@@(r3,r4) |
| 147 | Two-line format. Execute these sequentially unless @samp{-O} option is |
| 148 | used. If the @samp{-O} option is used, the assembler will determine if |
| 149 | the instructions could be done in parallel (the above two instructions |
| 150 | can be done in parallel), and if so, emit them as parallel instructions. |
| 151 | The assembler will put them in the proper containers. In the above |
| 152 | example, the assembler will put the @samp{stw} instruction in left |
| 153 | container and the @samp{mulx} instruction in the right container. |
| 154 | |
| 155 | @item stw r2,@@(r3,r4) -> |
| 156 | @itemx mulx a0,r8,r9 |
| 157 | Two-line format. Execute the @samp{stw} instruction followed by the |
| 158 | @samp{mulx} instruction sequentially. The first instruction goes in the |
| 159 | left container and the second instruction goes into right container. |
| 160 | The assembler will give an error if the machine ordering constraints are |
| 161 | violated. |
| 162 | |
| 163 | @item stw r2,@@(r3,r4) <- |
| 164 | @itemx mulx a0,r8,r9 |
| 165 | Same as previous example, except that the @samp{mulx} instruction is |
| 166 | executed before the @samp{stw} instruction. |
| 167 | @end table |
| 168 | |
| 169 | @cindex symbol names, @samp{$} in |
| 170 | @cindex @code{$} in symbol names |
| 171 | Since @samp{$} has no special meaning, you may use it in symbol names. |
| 172 | |
| 173 | @node D30V-Guarded |
| 174 | @subsection Guarded Execution |
| 175 | @cindex D30V Guarded Execution |
| 176 | @code{@value{AS}} supports the full range of guarded execution |
| 177 | directives for each instruction. Just append the directive after the |
| 178 | instruction proper. The directives are: |
| 179 | |
| 180 | @table @samp |
| 181 | @item /tx |
| 182 | Execute the instruction if flag f0 is true. |
| 183 | @item /fx |
| 184 | Execute the instruction if flag f0 is false. |
| 185 | @item /xt |
| 186 | Execute the instruction if flag f1 is true. |
| 187 | @item /xf |
| 188 | Execute the instruction if flag f1 is false. |
| 189 | @item /tt |
| 190 | Execute the instruction if both flags f0 and f1 are true. |
| 191 | @item /tf |
| 192 | Execute the instruction if flag f0 is true and flag f1 is false. |
| 193 | @end table |
| 194 | |
| 195 | @node D30V-Regs |
| 196 | @subsection Register Names |
| 197 | @cindex D30V registers |
| 198 | @cindex registers, D30V |
| 199 | You can use the predefined symbols @samp{r0} through @samp{r63} to refer |
| 200 | to the D30V registers. You can also use @samp{sp} as an alias for |
| 201 | @samp{r63} and @samp{link} as an alias for @samp{r62}. The accumulators |
| 202 | are @samp{a0} and @samp{a1}. |
| 203 | |
| 204 | The D30V also has predefined symbols for these control registers and status bits: |
| 205 | @table @code |
| 206 | @item psw |
| 207 | Processor Status Word |
| 208 | @item bpsw |
| 209 | Backup Processor Status Word |
| 210 | @item pc |
| 211 | Program Counter |
| 212 | @item bpc |
| 213 | Backup Program Counter |
| 214 | @item rpt_c |
| 215 | Repeat Count |
| 216 | @item rpt_s |
| 217 | Repeat Start address |
| 218 | @item rpt_e |
| 219 | Repeat End address |
| 220 | @item mod_s |
| 221 | Modulo Start address |
| 222 | @item mod_e |
| 223 | Modulo End address |
| 224 | @item iba |
| 225 | Instruction Break Address |
| 226 | @item f0 |
| 227 | Flag 0 |
| 228 | @item f1 |
| 229 | Flag 1 |
| 230 | @item f2 |
| 231 | Flag 2 |
| 232 | @item f3 |
| 233 | Flag 3 |
| 234 | @item f4 |
| 235 | Flag 4 |
| 236 | @item f5 |
| 237 | Flag 5 |
| 238 | @item f6 |
| 239 | Flag 6 |
| 240 | @item f7 |
| 241 | Flag 7 |
| 242 | @item s |
| 243 | Same as flag 4 (saturation flag) |
| 244 | @item v |
| 245 | Same as flag 5 (overflow flag) |
| 246 | @item va |
| 247 | Same as flag 6 (sticky overflow flag) |
| 248 | @item c |
| 249 | Same as flag 7 (carry/borrow flag) |
| 250 | @item b |
| 251 | Same as flag 7 (carry/borrow flag) |
| 252 | @end table |
| 253 | |
| 254 | @node D30V-Addressing |
| 255 | @subsection Addressing Modes |
| 256 | @cindex addressing modes, D30V |
| 257 | @cindex D30V addressing modes |
| 258 | @code{@value{AS}} understands the following addressing modes for the D30V. |
| 259 | @code{R@var{n}} in the following refers to any of the numbered |
| 260 | registers, but @emph{not} the control registers. |
| 261 | @table @code |
| 262 | @item R@var{n} |
| 263 | Register direct |
| 264 | @item @@R@var{n} |
| 265 | Register indirect |
| 266 | @item @@R@var{n}+ |
| 267 | Register indirect with post-increment |
| 268 | @item @@R@var{n}- |
| 269 | Register indirect with post-decrement |
| 270 | @item @@-SP |
| 271 | Register indirect with pre-decrement |
| 272 | @item @@(@var{disp}, R@var{n}) |
| 273 | Register indirect with displacement |
| 274 | @item @var{addr} |
| 275 | PC relative address (for branch or rep). |
| 276 | @item #@var{imm} |
| 277 | Immediate data (the @samp{#} is optional and ignored) |
| 278 | @end table |
| 279 | |
| 280 | @node D30V-Float |
| 281 | @section Floating Point |
| 282 | @cindex floating point, D30V |
| 283 | @cindex D30V floating point |
| 284 | The D30V has no hardware floating point, but the @code{.float} and @code{.double} |
| 285 | directives generates @sc{ieee} floating-point numbers for compatibility |
| 286 | with other development tools. |
| 287 | |
| 288 | @node D30V-Opcodes |
| 289 | @section Opcodes |
| 290 | @cindex D30V opcode summary |
| 291 | @cindex opcode summary, D30V |
| 292 | @cindex mnemonics, D30V |
| 293 | @cindex instruction summary, D30V |
| 294 | For detailed information on the D30V machine instruction set, see |
| 295 | @cite{D30V Architecture: A VLIW Microprocessor for Multimedia Applications} |
| 296 | (Mitsubishi Electric Corp.). |
| 297 | @code{@value{AS}} implements all the standard D30V opcodes. The only changes are those |
| 298 | described in the section on size modifiers |
| 299 | |