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1 | @c Copyright (C) 1999, 2000 Free Software Foundation, Inc. |
2 | @c This is part of the GAS manual. | |
3 | @c For copying conditions, see the file as.texinfo. | |
4 | @c TI TMS320C54X description by Timothy Wall, twall@cygnus.com | |
5 | @ifset GENERIC | |
6 | @page | |
7 | @node C54X-Dependent | |
8 | @chapter C54X Dependent Features | |
9 | @end ifset | |
10 | @ifclear GENERIC | |
11 | @node Machine Dependencies | |
12 | @chapter C54X Dependent Features | |
13 | @end ifclear | |
14 | ||
15 | @cindex C54X support | |
16 | @menu | |
17 | * C54X-Opts:: Command-line Options | |
18 | * C54X-Block:: Blocking | |
19 | * C54X-Env:: Environment Settings | |
20 | * C54X-Constants:: Constants Syntax | |
21 | * C54X-Subsyms:: String Substitution | |
22 | * C54X-Locals:: Local Label Syntax | |
23 | * C54X-Builtins:: Builtin Assembler Math Functions | |
24 | * C54X-Ext:: Extended Addressing Support | |
25 | * C54X-Directives:: Directives | |
26 | * C54X-Macros:: Macro Features | |
27 | * C54X-MMRegs:: Memory-mapped Registers | |
28 | @end menu | |
29 | ||
30 | @node C54X-Opts | |
31 | @section Options | |
32 | ||
33 | @cindex options, C54X | |
34 | @cindex C54X options | |
35 | The 'c54x version of @code{@value{AS}} has a few machine-dependent options. | |
36 | ||
37 | @cindex @samp{-mfar-mode} option, far-mode | |
38 | @cindex @samp{-mf} option, far-mode | |
39 | You can use the @samp{-mfar-mode} option to enable extended addressing mode. | |
40 | All addresses will be assumed to be > 16 bits, and the appropriate | |
41 | relocation types will be used. This option is equivalent to using the | |
42 | @samp{.far_mode} directive in the assembly code. If you do not use the | |
43 | @samp{-mfar-mode} option, all references will be assumed to be 16 bits. | |
44 | This option may be abbreviated to @samp{-mf}. | |
45 | ||
46 | @cindex @samp{-mcpu} option, cpu | |
47 | You can use the @samp{-mcpu} option to specify a particular CPU. | |
48 | This option is equivalent to using the @samp{.version} directive in the | |
49 | assembly code. For recognized CPU codes, see | |
50 | @xref{C54X-Directives,,@code{.version}}. The default CPU version is | |
51 | @samp{542}. | |
52 | ||
53 | @cindex @samp{-merrors-to-file} option, stderr redirect | |
54 | @cindex @samp{-me} option, stderr redirect | |
55 | You can use the @samp{-merrors-to-file} option to redirect error output | |
56 | to a file (this provided for those deficient environments which don't | |
57 | provide adequate output redirection). This option may be abbreviated to | |
58 | @samp{-me}. | |
59 | ||
60 | @node C54X-Block | |
61 | @section Blocking | |
62 | A blocked section or memory block is guaranteed not to cross the blocking | |
63 | boundary (usually a page, or 128 words) if it is smaller than the | |
64 | blocking size, or to start on a page boundary if it is larger than the | |
65 | blocking size. | |
66 | ||
67 | @node C54X-Env | |
68 | @section Environment Settings | |
69 | ||
70 | @cindex environment settings, C54X | |
71 | @cindex @samp{A_DIR} environment variable, C54X | |
72 | @cindex @samp{C54XDSP_DIR} environment variable, C54X | |
73 | @samp{C54XDSP_DIR} and @samp{A_DIR} are semicolon-separated | |
74 | paths which are added to the list of directories normally searched for | |
75 | source and include files. @samp{C54XDSP_DIR} will override @samp{A_DIR}. | |
76 | ||
77 | @node C54X-Constants | |
78 | @section Constants Syntax | |
79 | ||
80 | @cindex constants, C54X | |
81 | The C54X version of @code{@value{AS}} allows the following additional | |
82 | constant formats, using a suffix to indicate the radix: | |
83 | @smallexample | |
84 | @cindex binary constants, C54X | |
85 | ||
86 | Binary @code{000000B, 011000b} | |
87 | Octal @code{10Q, 224q} | |
88 | Hexadecimal @code{45h, 0FH} | |
89 | ||
90 | @end smallexample | |
91 | ||
92 | @node C54X-Subsyms | |
93 | @section String Substitution | |
94 | A subset of allowable symbols (which we'll call subsyms) may be assigned | |
95 | arbitrary string values. This is roughly equivalent to C preprocessor | |
96 | #define macros. When @code{@value{AS}} encounters one of these | |
97 | symbols, the symbol is replaced in the input stream by its string value. | |
98 | Subsym names @strong{must} begin with a letter. | |
99 | ||
100 | Subsyms may be defined using the @code{.asg} and @code{.eval} directives | |
101 | (@xref{C54X-Directives,,@code{.asg}}, | |
102 | @xref{C54X-Directives,,@code{.eval}}. | |
103 | ||
104 | Expansion is recursive until a previously encountered symbol is seen, at | |
105 | which point substitution stops. | |
106 | ||
107 | In this example, x is replaced with SYM2; SYM2 is replaced with SYM1, and SYM1 | |
108 | is replaced with x. At this point, x has already been encountered | |
109 | and the substitution stops. | |
110 | ||
111 | @smallexample @code | |
112 | .asg "x",SYM1 | |
113 | .asg "SYM1",SYM2 | |
114 | .asg "SYM2",x | |
115 | add x,a ; final code assembled is "add x, a" | |
116 | @end smallexample | |
117 | ||
118 | Macro parameters are converted to subsyms; a side effect of this is the normal | |
119 | @code{@value{AS}} '\ARG' dereferencing syntax is unnecessary. Subsyms | |
120 | defined within a macro will have global scope, unless the @code{.var} | |
121 | directive is used to identify the subsym as a local macro variable | |
122 | @pxref{C54X-Directives,,@code{.var}}. | |
123 | ||
124 | Substitution may be forced in situations where replacement might be | |
125 | ambiguous by placing colons on either side of the subsym. The following | |
126 | code: | |
127 | ||
128 | @smallexample @code | |
129 | .eval "10",x | |
130 | LAB:X: add #x, a | |
131 | @end smallexample | |
132 | ||
133 | When assembled becomes: | |
134 | ||
135 | @smallexample @code | |
136 | LAB10 add #10, a | |
137 | @end smallexample | |
138 | ||
139 | Smaller parts of the string assigned to a subsym may be accessed with | |
140 | the following syntax: | |
141 | ||
142 | @table @code | |
143 | @item @code{:@var{symbol}(@var{char_index}):} | |
144 | Evaluates to a single-character string, the character at @var{char_index}. | |
145 | @item @code{:@var{symbol}(@var{start},@var{length}):} | |
146 | Evaluates to a substring of @var{symbol} beginning at @var{start} with | |
147 | length @var{length}. | |
148 | @end table | |
149 | ||
150 | @node C54X-Locals | |
151 | @section Local Labels | |
152 | Local labels may be defined in two ways: | |
153 | ||
154 | @itemize @bullet | |
155 | @item | |
156 | $N, where N is a decimal number between 0 and 9 | |
157 | @item | |
158 | LABEL?, where LABEL is any legal symbol name. | |
159 | @end itemize | |
160 | ||
161 | Local labels thus defined may be redefined or automatically generated. | |
162 | The scope of a local label is based on when it may be undefined or reset. | |
163 | This happens when one of the following situations is encountered: | |
164 | ||
165 | @itemize @bullet | |
166 | @item | |
167 | .newblock directive @pxref{C54X-Directives,,@code{.newblock}} | |
168 | @item | |
169 | The current section is changed (.sect, .text, or .data) | |
170 | @item | |
171 | Entering or leaving an included file | |
172 | @item | |
173 | The macro scope where the label was defined is exited | |
174 | @end itemize | |
175 | ||
176 | @node C54X-Builtins | |
177 | @section Math Builtins | |
178 | ||
179 | @cindex math builtins, C54X | |
180 | @cindex C54X builtin math functions | |
181 | @cindex builtin math functions, C54X | |
182 | ||
183 | The following built-in functions may be used to generate a | |
184 | floating-point value. All return a floating-point value except | |
185 | @samp{$cvi}, @samp{$int}, and @samp{$sgn}, which return an integer | |
186 | value. | |
187 | ||
188 | @table @code | |
189 | @cindex @code{$acos} math builtin, C54X | |
190 | @item @code{$acos(@var{expr})} | |
191 | Returns the floating point arccosine of @var{expr}. | |
192 | ||
193 | @cindex @code{$asin} math builtin, C54X | |
194 | @item @code{$asin(@var{expr})} | |
195 | Returns the floating point arcsine of @var{expr}. | |
196 | ||
197 | @cindex @code{$atan} math builtin, C54X | |
198 | @item @code{$atan(@var{expr})} | |
199 | Returns the floating point arctangent of @var{expr}. | |
200 | ||
201 | @cindex @code{$atan2} math builtin, C54X | |
202 | @item @code{$atan2(@var{expr1},@var{expr2})} | |
203 | Returns the floating point arctangent of @var{expr1} / @var{expr2}. | |
204 | ||
205 | @cindex @code{$ceil} math builtin, C54X | |
206 | @item @code{$ceil(@var{expr})} | |
207 | Returns the smallest integer not less than @var{expr} as floating point. | |
208 | ||
209 | @cindex @code{$cosh} math builtin, C54X | |
210 | @item @code{$cosh(@var{expr})} | |
211 | Returns the floating point hyperbolic cosine of @var{expr}. | |
212 | ||
213 | @cindex @code{$cos} math builtin, C54X | |
214 | @item @code{$cos(@var{expr})} | |
215 | Returns the floating point cosine of @var{expr}. | |
216 | ||
217 | @cindex @code{$cvf} math builtin, C54X | |
218 | @item @code{$cvf(@var{expr})} | |
219 | Returns the integer value @var{expr} converted to floating-point. | |
220 | ||
221 | @cindex @code{$cvi} math builtin, C54X | |
222 | @item @code{$cvi(@var{expr})} | |
223 | Returns the floating point value @var{expr} converted to integer. | |
224 | ||
225 | @cindex @code{$exp} math builtin, C54X | |
226 | @item @code{$exp(@var{expr})} | |
227 | Returns the floating point value e ^ @var{expr}. | |
228 | ||
229 | @cindex @code{$fabs} math builtin, C54X | |
230 | @item @code{$fabs(@var{expr})} | |
231 | Returns the floating point absolute value of @var{expr}. | |
232 | ||
233 | @cindex @code{$floor} math builtin, C54X | |
234 | @item @code{$floor(@var{expr})} | |
235 | Returns the largest integer that is not greater than @var{expr} as | |
236 | floating point. | |
237 | ||
238 | @cindex @code{$fmod} math builtin, C54X | |
239 | @item @code{$fmod(@var{expr1},@var{expr2})} | |
240 | Returns the floating point remainder of @var{expr1} / @var{expr2}. | |
241 | ||
242 | @cindex @code{$int} math builtin, C54X | |
243 | @item @code{$int(@var{expr})} | |
244 | Returns 1 if @var{expr} evaluates to an integer, zero otherwise. | |
245 | ||
246 | @cindex @code{$ldexp} math builtin, C54X | |
247 | @item @code{$ldexp(@var{expr1},@var{expr2})} | |
248 | Returns the floating point value @var{expr1} * 2 ^ @var{expr2}. | |
249 | ||
250 | @cindex @code{$log10} math builtin, C54X | |
251 | @item @code{$log10(@var{expr})} | |
252 | Returns the base 10 logarithm of @var{expr}. | |
253 | ||
254 | @cindex @code{$log} math builtin, C54X | |
255 | @item @code{$log(@var{expr})} | |
256 | Returns the natural logarithm of @var{expr}. | |
257 | ||
258 | @cindex @code{$max} math builtin, C54X | |
259 | @item @code{$max(@var{expr1},@var{expr2})} | |
260 | Returns the floating point maximum of @var{expr1} and @var{expr2}. | |
261 | ||
262 | @cindex @code{$min} math builtin, C54X | |
263 | @item @code{$min(@var{expr1},@var{expr2})} | |
264 | Returns the floating point minimum of @var{expr1} and @var{expr2}. | |
265 | ||
266 | @cindex @code{$pow} math builtin, C54X | |
267 | @item @code{$pow(@var{expr1},@var{expr2})} | |
268 | Returns the floating point value @var{expr1} ^ @var{expr2}. | |
269 | ||
270 | @cindex @code{$round} math builtin, C54X | |
271 | @item @code{$round(@var{expr})} | |
272 | Returns the nearest integer to @var{expr} as a floating point number. | |
273 | ||
274 | @cindex @code{$sgn} math builtin, C54X | |
275 | @item @code{$sgn(@var{expr})} | |
276 | Returns -1, 0, or 1 based on the sign of @var{expr}. | |
277 | ||
278 | @cindex @code{$sin} math builtin, C54X | |
279 | @item @code{$sin(@var{expr})} | |
280 | Returns the floating point sine of @var{expr}. | |
281 | ||
282 | @cindex @code{$sinh} math builtin, C54X | |
283 | @item @code{$sinh(@var{expr})} | |
284 | Returns the floating point hyperbolic sine of @var{expr}. | |
285 | ||
286 | @cindex @code{$sqrt} math builtin, C54X | |
287 | @item @code{$sqrt(@var{expr})} | |
288 | Returns the floating point square root of @var{expr}. | |
289 | ||
290 | @cindex @code{$tan} math builtin, C54X | |
291 | @item @code{$tan(@var{expr})} | |
292 | Returns the floating point tangent of @var{expr}. | |
293 | ||
294 | @cindex @code{$tanh} math builtin, C54X | |
295 | @item @code{$tanh(@var{expr})} | |
296 | Returns the floating point hyperbolic tangent of @var{expr}. | |
297 | ||
298 | @cindex @code{$trunc} math builtin, C54X | |
299 | @item @code{$trunc(@var{expr})} | |
300 | Returns the integer value of @var{expr} truncated towards zero as | |
301 | floating point. | |
302 | ||
303 | @end table | |
304 | ||
305 | @node C54X-Ext | |
306 | @section Extended Addressing | |
307 | The @code{LDX} pseudo-op is provided for loading the extended addressing bits | |
308 | of a label or address. For example, if an address @code{_label} resides | |
309 | in extended program memory, the value of @code{_label} may be loaded as | |
310 | follows: | |
311 | @smallexample @code | |
312 | ldx #_label,16,a ; loads extended bits of _label | |
313 | or #_label,a ; loads lower 16 bits of _label | |
314 | bacc a ; full address is in accumulator A | |
315 | @end smallexample | |
316 | ||
317 | @node C54X-Directives | |
318 | @section Directives | |
319 | ||
320 | @cindex machine directives, C54X | |
321 | @cindex C54X machine directives | |
322 | ||
323 | @table @code | |
324 | ||
325 | @cindex @code{align} directive, C54X | |
326 | @cindex @code{even} directive, C54X | |
327 | @item .align [@var{size}] | |
328 | @itemx .even | |
329 | Align the section program counter on the next boundary, based on | |
330 | @var{size}. @var{size} may be any power of 2. @code{.even} is | |
331 | equivalent to @code{.align} with a @var{size} of 2. | |
332 | @table @code | |
333 | @item 1 | |
334 | Align SPC to word boundary | |
335 | @item 2 | |
336 | Align SPC to longword boundary (same as .even) | |
337 | @item 128 | |
338 | Align SPC to page boundary | |
339 | @end table | |
340 | ||
341 | @cindex @code{asg} directive, C54X | |
342 | @item .asg @var{string}, @var{name} | |
343 | Assign @var{name} the string @var{string}. String replacement is | |
344 | performed on @var{string} before assignment. | |
345 | ||
346 | @cindex @code{eval} directive, C54X | |
347 | @itemx .eval @var{string}, @var{name} | |
348 | Evaluate the contents of string @var{string} and assign the result as a | |
349 | string to the subsym @var{name}. String replacement is performed on | |
350 | @var{string} before assignment. | |
351 | ||
352 | @cindex @code{bss} directive, C54X | |
353 | @item .bss @var{symbol}, @var{size} [, [@var{blocking_flag}] [,@var{alignment_flag}]] | |
354 | Reserve space for @var{symbol} in the .bss section. @var{size} is in | |
355 | words. If present, @var{blocking_flag} indicates the allocated space | |
356 | should be aligned on a page boundary if it would otherwise cross a page | |
357 | boundary. If present, @var{alignment_flag} causes the assembler to | |
358 | allocate @var{size} on a long word boundary. | |
359 | ||
360 | @cindex @code{byte} directive, C54X | |
361 | @cindex @code{ubyte} directive, C54X | |
362 | @cindex @code{char} directive, C54X | |
363 | @cindex @code{uchar} directive, C54X | |
364 | @item .byte @var{value} [,...,@var{value_n}] | |
365 | @itemx .ubyte @var{value} [,...,@var{value_n}] | |
366 | @itemx .char @var{value} [,...,@var{value_n}] | |
367 | @itemx .uchar @var{value} [,...,@var{value_n}] | |
368 | Place one or more bytes into consecutive words of the current section. | |
369 | The upper 8 bits of each word is zero-filled. If a label is used, it | |
370 | points to the word allocated for the first byte encountered. | |
371 | ||
372 | @cindex @code{clink} directive, C54X | |
373 | @item .clink ["@var{section_name}"] | |
374 | Set STYP_CLINK flag for this section, which indicates to the linker that | |
375 | if no symbols from this section are referenced, the section should not | |
376 | be included in the link. If @var{section_name} is omitted, the current | |
377 | section is used. | |
378 | ||
379 | @cindex @code{c_mode} directive, C54X | |
380 | @item .c_mode | |
381 | TBD. | |
382 | ||
383 | @cindex @code{copy} directive, C54X | |
384 | @item .copy "@var{filename}" | @var{filename} | |
385 | @itemx .include "@var{filename}" | @var{filename} | |
386 | Read source statements from @var{filename}. The normal include search | |
387 | path is used. Normally .copy will cause statements from the included | |
388 | file to be printed in the assembly listing and .include will not, but | |
389 | this distinction is not currently implemented. | |
390 | ||
391 | @cindex @code{data} directive, C54X | |
392 | @item .data | |
393 | Begin assembling code into the .data section. | |
394 | ||
395 | @cindex @code{double} directive, C54X | |
396 | @cindex @code{ldouble} directive, C54X | |
397 | @cindex @code{float} directive, C54X | |
398 | @cindex @code{xfloat} directive, C54X | |
399 | @item .double @var{value} [,...,@var{value_n}] | |
400 | @itemx .ldouble @var{value} [,...,@var{value_n}] | |
401 | @itemx .float @var{value} [,...,@var{value_n}] | |
402 | @itemx .xfloat @var{value} [,...,@var{value_n}] | |
403 | Place an IEEE single-precision floating-point representation of one or | |
404 | more floating-point values into the current section. All but | |
405 | @code{.xfloat} align the result on a longword boundary. Values are | |
406 | stored most-significant word first. | |
407 | ||
408 | @cindex @code{drlist} directive, C54X | |
409 | @cindex @code{drnolist} directive, C54X | |
410 | @item .drlist | |
411 | @itemx .drnolist | |
412 | Control printing of directives to the listing file. Ignored. | |
413 | ||
414 | @cindex @code{emsg} directive, C54X | |
415 | @cindex @code{mmsg} directive, C54X | |
416 | @cindex @code{wmsg} directive, C54X | |
417 | @item .emsg @var{string} | |
418 | @itemx .mmsg @var{string} | |
419 | @itemx .wmsg @var{string} | |
420 | Emit a user-defined error, message, or warning, respectively. | |
421 | ||
422 | @cindex @code{far_mode} directive, C54X | |
423 | @item .far_mode | |
424 | Use extended addressing when assembling statements. This should appear | |
425 | only once per file, and is equivalent to the -mfar-mode option @pxref{C54X-Opts,,@code{-mfar-mode}}. | |
426 | ||
427 | @cindex @code{fclist} directive, C54X | |
428 | @cindex @code{fcnolist} directive, C54X | |
429 | @item .fclist | |
430 | @itemx .fcnolist | |
431 | Control printing of false conditional blocks to the listing file. | |
432 | ||
433 | @cindex @code{field} directive, C54X | |
434 | @item .field @var{value} [,@var{size}] | |
435 | Initialize a bitfield of @var{size} bits in the current section. If | |
436 | @var{value} is relocatable, then @var{size} must be 16. @var{size} | |
437 | defaults to 16 bits. If @var{value} does not fit into @var{size} bits, | |
438 | the value will be truncated. Successive @code{.field} directives will | |
439 | pack starting at the current word, filling the most significant bits | |
440 | first, and aligning to the start of the next word if the field size does | |
441 | not fit into the space remaining in the current word. A @code{.align} | |
442 | directive with an operand of 1 will force the next @code{.field} | |
443 | directive to begin packing into a new word. If a label is used, it | |
444 | points to the word that contains the specified field. | |
445 | ||
446 | @cindex @code{global} directive, C54X | |
447 | @cindex @code{def} directive, C54X | |
448 | @cindex @code{ref} directive, C54X | |
449 | @item .global @var{symbol} [,...,@var{symbol_n}] | |
450 | @itemx .def @var{symbol} [,...,@var{symbol_n}] | |
451 | @itemx .ref @var{symbol} [,...,@var{symbol_n}] | |
452 | @code{.def} nominally identifies a symbol defined in the current file | |
453 | and availalbe to other files. @code{.ref} identifies a symbol used in | |
454 | the current file but defined elsewhere. Both map to the standard | |
455 | @code{.global} directive. | |
456 | ||
457 | @cindex @code{half} directive, C54X | |
458 | @cindex @code{uhalf} directive, C54X | |
459 | @cindex @code{short} directive, C54X | |
460 | @cindex @code{ushort} directive, C54X | |
461 | @cindex @code{int} directive, C54X | |
462 | @cindex @code{uint} directive, C54X | |
463 | @cindex @code{word} directive, C54X | |
464 | @cindex @code{uword} directive, C54X | |
465 | @item .half @var{value} [,...,@var{value_n}] | |
466 | @itemx .uhalf @var{value} [,...,@var{value_n}] | |
467 | @itemx .short @var{value} [,...,@var{value_n}] | |
468 | @itemx .ushort @var{value} [,...,@var{value_n}] | |
469 | @itemx .int @var{value} [,...,@var{value_n}] | |
470 | @itemx .uint @var{value} [,...,@var{value_n}] | |
471 | @itemx .word @var{value} [,...,@var{value_n}] | |
472 | @itemx .uword @var{value} [,...,@var{value_n}] | |
473 | Place one or more values into consecutive words of the current section. | |
474 | If a label is used, it points to the word allocated for the first value | |
475 | encountered. | |
476 | ||
477 | @cindex @code{label} directive, C54X | |
478 | @item .label @var{symbol} | |
479 | Define a special @var{symbol} to refer to the load time address of the | |
480 | current section program counter. | |
481 | ||
482 | @cindex @code{length} directive, C54X | |
483 | @cindex @code{width} directive, C54X | |
484 | @item .length | |
485 | @itemx .width | |
486 | Set the page length and width of the output listing file. Ignored. | |
487 | ||
488 | @cindex @code{list} directive, C54X | |
489 | @cindex @code{nolist} directive, C54X | |
490 | @item .list | |
491 | @itemx .nolist | |
492 | Control whether the source listing is printed. Ignored. | |
493 | ||
494 | @cindex @code{long} directive, C54X | |
495 | @cindex @code{ulong} directive, C54X | |
496 | @cindex @code{xlong} directive, C54X | |
497 | @item .long @var{value} [,...,@var{value_n}] | |
498 | @itemx .ulong @var{value} [,...,@var{value_n}] | |
499 | @itemx .xlong @var{value} [,...,@var{value_n}] | |
500 | Place one or more 32-bit values into consecutive words in the current | |
501 | section. The most significant word is stored first. @code{.long} and | |
502 | @code{.ulong} align the result on a longword boundary; @code{xlong} does | |
503 | not. | |
504 | ||
505 | @cindex @code{loop} directive, C54X | |
506 | @cindex @code{break} directive, C54X | |
507 | @cindex @code{endloop} directive, C54X | |
508 | @item .loop [@var{count}] | |
509 | @itemx .break [@var{condition}] | |
510 | @itemx .endloop | |
511 | Repeatedly assemble a block of code. @code{.loop} begins the block, and | |
512 | @code{.endloop} marks its termination. @var{count} defaults to 1024, | |
513 | and indicates the number of times the block should be repeated. | |
514 | @code{.break} terminates the loop so that assembly begins after the | |
515 | @code{.endloop} directive. The optional @var{condition} will cause the | |
516 | loop to terminate only if it evaluates to zero. | |
517 | ||
518 | @cindex @code{macro} directive, C54X | |
519 | @cindex @code{endm} directive, C54X | |
520 | @item @var{macro_name} .macro [@var{param1}][,...@var{param_n}] | |
521 | @itemx [.mexit] | |
522 | @itemx .endm | |
523 | See the section on macros for more explanation (@xref{C54X-Macros}. | |
524 | ||
525 | @cindex @code{mlib} directive, C54X | |
526 | @item .mlib "@var{filename}" | @var{filename} | |
527 | Load the macro library @var{filename}. @var{filename} must be an | |
528 | archived library (BFD ar-compatible) of text files, expected to contain | |
529 | only macro definitions. The standard include search path is used. | |
530 | ||
531 | @cindex @code{mlist} directive, C54X | |
532 | @cindex @code{mnolist} directive, C54X | |
533 | @item .mlist | |
534 | @item .mnolist | |
535 | Control whether to include macro and loop block expansions in the | |
536 | listing output. Ignored. | |
537 | ||
538 | @cindex @code{mmregs} directive, C54X | |
539 | @item .mmregs | |
540 | Define global symbolic names for the 'c54x registers. Supposedly | |
541 | equivalent to executing @code{.set} directives for each register with | |
542 | its memory-mapped value, but in reality is provided only for | |
543 | compatibility and does nothing. | |
544 | ||
545 | @cindex @code{newblock} directive, C54X | |
546 | @item .newblock | |
547 | This directive resets any C54X local labels currently defined. Normal | |
548 | @code{@value{AS}} local labels are unaffected. | |
549 | ||
550 | @cindex @code{option} directive, C54X | |
551 | @item .option @var{option_list} | |
552 | Set listing options. Ignored. | |
553 | ||
554 | @cindex @code{sblock} directive, C54X | |
555 | @item .sblock "@var{section_name}" | @var{section_name} [,"@var{name_n}" | @var{name_n}] | |
556 | Designate @var{section_name} for blocking. Blocking guarantees that a | |
557 | section will start on a page boundary (128 words) if it would otherwise | |
558 | cross a page boundary. Only initialized sections may be designated with | |
559 | this directive. See also @xref{C54X-Block}. | |
560 | ||
561 | @cindex @code{sect} directive, C54X | |
562 | @item .sect "@var{section_name}" | |
563 | Define a named initialized section and make it the current section. | |
564 | ||
565 | @cindex @code{set} directive, C54X | |
566 | @cindex @code{equ} directive, C54X | |
567 | @item @var{symbol} .set "@var{value}" | |
568 | @itemx @var{symbol} .equ "@var{value}" | |
569 | Equate a constant @var{value} to a @var{symbol}, which is placed in the | |
570 | symbol table. @var{symbol} may not be previously defined. | |
571 | ||
572 | @cindex @code{space} directive, C54X | |
573 | @cindex @code{bes} directive, C54X | |
574 | @item .space @var{size_in_bits} | |
575 | @itemx .bes @var{size_in_bits} | |
576 | Reserve the given number of bits in the current section and zero-fill | |
577 | them. If a label is used with @code{.space}, it points to the | |
578 | @strong{first} word reserved. With @code{.bes}, the label points to the | |
579 | @strong{last} word reserved. | |
580 | ||
581 | @cindex @code{sslist} directive, C54X | |
582 | @cindex @code{ssnolist} directive, C54X | |
583 | @item .sslist | |
584 | @itemx .ssnolist | |
585 | Controls the inclusion of subsym replacement in the listing output. Ignored. | |
586 | ||
587 | @cindex @code{string} directive, C54X | |
588 | @cindex @code{pstring} directive, C54X | |
589 | @item .string "@var{string}" [,...,"@var{string_n}"] | |
590 | @itemx .pstring "@var{string}" [,...,"@var{string_n}"] | |
591 | Place 8-bit characters from @var{string} into the current section. | |
592 | @code{.string} zero-fills the upper 8 bits of each word, while | |
593 | @code{.pstring} puts two characters into each word, filling the | |
594 | most-significant bits first. Unused space is zero-filled. If a label | |
595 | is used, it points to the first word initialized. | |
596 | ||
597 | @cindex @code{struct} directive, C54X | |
598 | @cindex @code{tag} directive, C54X | |
599 | @cindex @code{endstruct} directive, C54X | |
600 | @item [@var{stag}] .struct [@var{offset}] | |
601 | @itemx [@var{name_1}] element [@var{count_1}] | |
602 | @itemx [@var{name_2}] element [@var{count_2}] | |
603 | @itemx [@var{tname}] .tag @var{stagx} [@var{tcount}] | |
604 | @itemx ... | |
605 | @itemx [@var{name_n}] element [@var{count_n}] | |
606 | @itemx [@var{ssize}] .endstruct | |
607 | @itemx @var{label} .tag [@var{stag}] | |
608 | Assign symbolic offsets to the elements of a structure. @var{stag} | |
609 | defines a symbol to use to reference the structure. @var{offset} | |
610 | indicates a starting value to use for the first element encountered; | |
611 | otherwise it defaults to zero. Each element can have a named offset, | |
612 | @var{name}, which is a symbol assigned the value of the element's offset | |
613 | into the structure. If @var{stag} is missing, these become global | |
614 | symbols. @var{count} adjusts the offset that many times, as if | |
615 | @code{element} were an array. @code{element} may be one of | |
616 | @code{.byte}, @code{.word}, @code{.long}, @code{.float}, or any | |
617 | equivalent of those, and the structure offset is adjusted accordingly. | |
618 | @code{.field} and @code{.string} are also allowed; the size of | |
619 | @code{.field} is one bit, and @code{.string} is considered to be one | |
620 | word in size. Only element descriptors, structure/union tags, | |
621 | @code{.align} and conditioanl assembly directies are allowed within | |
622 | @code{.struct}/@code{.endstruct}. @code{.align} aligns member offsets | |
623 | to word boundaries only. @var{ssize}, if provided, will always be | |
624 | assigned the size of the structure. | |
625 | ||
626 | The @code{.tag} directive, in addition to being used to define a | |
627 | structure/union element within a structure, may be used to apply a | |
628 | structure to a symbol. Once applied to @var{label}, the individual | |
629 | structure elements may be applied to @var{label} to produce the desired | |
630 | offsets using @var{label} as the structure base. | |
631 | ||
632 | @cindex @code{tab} directive, C54X | |
633 | @item .tab | |
634 | Set the tab size in the output listing. Ignored. | |
635 | ||
636 | @cindex @code{union} directive, C54X | |
637 | @cindex @code{tag} directive, C54X | |
638 | @cindex @code{endunion} directive, C54X | |
639 | @item [@var{utag}] .union | |
640 | @itemx [@var{name_1}] element [@var{count_1}] | |
641 | @itemx [@var{name_2}] element [@var{count_2}] | |
642 | @itemx [@var{tname}] .tag @var{utagx}[,@var{tcount}] | |
643 | @itemx ... | |
644 | @itemx [@var{name_n}] element [@var{count_n}] | |
645 | @itemx [@var{usize}] .endstruct | |
646 | @itemx @var{label} .tag [@var{utag}] | |
647 | Similar to @code{.struct}, but the offset after each element is reset to | |
648 | zero, and the @var{usize} is set to the maximum of all defined elements. | |
649 | Starting offset for the union is always zero. | |
650 | ||
651 | @cindex @code{usect} directive, C54X | |
652 | @item [@var{symbol}] .usect "@var{section_name}", @var{size}, [,[@var{blocking_flag}] [,@var{alignment_flag}]] | |
653 | Reserve space for variables in a named, uninitialzed section (similar to | |
654 | .bss). @code{.usect} allows definitions sections independent of .bss. | |
655 | @var{symbol} points to the first location reserved by this allocation. | |
656 | The symbol may be used as a variable name. @var{size} is the allocated | |
657 | size in words. @var{blocking_flag} indicates whether to block this | |
658 | section on a page boundary (128 words) (@pxref{C54X-Block}). | |
659 | @var{alignment flag} indicates whether the section should be | |
660 | longword-aligned. | |
661 | ||
662 | @cindex @code{var} directive, C54X | |
663 | @item .var @var{sym}[,..., @var{sym_n}] | |
664 | Define a subsym to be a local variable within a macro. See | |
665 | @xref{C54X-Macros}. | |
666 | ||
667 | @cindex @code{version} directive, C54X | |
668 | @item .version @var{version} | |
669 | Set which processor to build instructions for. Though the following | |
670 | values are accepted, the op is ignored. | |
671 | @table @code | |
672 | @item 541 | |
673 | @itemx 542 | |
674 | @itemx 543 | |
675 | @itemx 545 | |
676 | @itemx 545LP | |
677 | @itemx 546LP | |
678 | @itemx 548 | |
679 | @itemx 549 | |
680 | @end table | |
681 | @end table | |
682 | ||
683 | @node C54X-Macros | |
684 | @section Macros | |
685 | ||
686 | @cindex C54X-specific macros | |
687 | @cindex macros, C54X | |
688 | Macros do not require explicit dereferencing of arguments (i.e. \ARG). | |
689 | ||
690 | During macro expansion, the macro parameters are converted to subsyms. | |
691 | If the number of arguments passed the macro invocation exceeds the | |
692 | number of parameters defined, the last parameter is assigned the string | |
693 | equivalent of all remaining arguments. If fewer arguments are given | |
694 | than parameters, the missing parameters are assigned empty strings. To | |
695 | include a comma in an argument, you must enclose the agument in quotes. | |
696 | ||
697 | @cindex subsym builtins, C54X | |
698 | @cindex C54X subsym builtins | |
699 | @cindex builtin subsym functions, C54X | |
700 | The following built-in subsym functions allow examination of the string | |
701 | value of subsyms (or ordinary strings). The arguments are strings | |
702 | unless otherwise indicated (subsyms passed as args will be replaced by | |
703 | the strings they represent). | |
704 | @table @code | |
705 | @cindex @code{$symlen} subsym builtin, C54X | |
706 | @item @code{$symlen(@var{str})} | |
707 | Returns the length of @var{str}. | |
708 | ||
709 | @cindex @code{$symcmp} subsym builtin, C54X | |
710 | @item @code{$symcmp(@var{str1},@var{str2})} | |
711 | Returns 0 if @var{str1} == @var{str2}, non-zero otherwise. | |
712 | ||
713 | @cindex @code{$firstch} subsym builtin, C54X | |
714 | @item @code{$firstch(@var{str},@var{ch})} | |
715 | Returns index of the first occurrence of character constant @var{ch} in | |
716 | @var{str}. | |
717 | ||
718 | @cindex @code{$lastch} subsym builtin, C54X | |
719 | @item @code{$lastch(@var{str},@var{ch})} | |
720 | Returns index of the last occurrence of character constant @var{ch} in | |
721 | @var{str}. | |
722 | ||
723 | @cindex @code{$isdefed} subsym builtin, C54X | |
724 | @item @code{$isdefed(@var{symbol})} | |
725 | Returns zero if the symbol @var{symbol} is not in the symbol table, | |
726 | non-zero otherwise. | |
727 | ||
728 | @cindex @code{$ismember} subsym builtin, C54X | |
729 | @item @code{$ismember(@var{symbol},@var{list})} | |
730 | Assign the first member of comma-separated string @var{list} to | |
731 | @var{symbol}; @var{list} is reassigned the remainder of the list. Returns | |
732 | zero if @var{list} is a null string. Both arguments must be subsyms. | |
733 | ||
734 | @cindex @code{$iscons} subsym builtin, C54X | |
735 | @item @code{$iscons(@var{expr})} | |
736 | Returns 1 if string @var{expr} is binary, 2 if octal, 3 if hexadecimal, | |
737 | 4 if a character, 5 if decimal, and zero if not an integer. | |
738 | ||
739 | @cindex @code{$isname} subsym builtin, C54X | |
740 | @item @code{$isname(@var{name})} | |
741 | Returns 1 if @var{name} is a valid symbol name, zero otherwise. | |
742 | ||
743 | @cindex @code{$isreg} subsym builtin, C54X | |
744 | @item @code{$isreg(@var{reg})} | |
745 | Returns 1 if @var{reg} is a valid predefined register name (AR0-AR7 only). | |
746 | ||
747 | @cindex @code{$structsz} subsym builtin, C54X | |
748 | @item @code{$structsz(@var{stag})} | |
749 | Returns the size of the structure or union represented by @var{stag}. | |
750 | ||
751 | @cindex @code{$structacc} subsym builtin, C54X | |
752 | @item @code{$structacc(@var{stag})} | |
753 | Returns the reference point of the structure or union represented by | |
754 | @var{stag}. Always returns zero. | |
755 | ||
756 | @end table | |
757 | ||
758 | @node C54X-MMRegs | |
759 | @section Memory-mapped Registers | |
760 | ||
761 | @cindex C54X memory-mapped registers | |
762 | @cindex registers, C54X memory-mapped | |
763 | @cindex memory-mapped registers, C54X | |
764 | The following symbols are recognized as memory-mapped registers: | |
765 | ||
766 | @table @code | |
767 | @end table |