File: /usr/src/linux/arch/m68k/math-emu/fp_decode.h
1 /*
2 * fp_decode.h
3 *
4 * Copyright Roman Zippel, 1997. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, and the entire permission notice in its entirety,
11 * including the disclaimer of warranties.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote
16 * products derived from this software without specific prior
17 * written permission.
18 *
19 * ALTERNATIVELY, this product may be distributed under the terms of
20 * the GNU General Public License, in which case the provisions of the GPL are
21 * required INSTEAD OF the above restrictions. (This clause is
22 * necessary due to a potential bad interaction between the GPL and
23 * the restrictions contained in a BSD-style copyright.)
24 *
25 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
28 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
33 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
35 * OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #ifndef _FP_DECODE_H
39 #define _FP_DECODE_H
40
41 /* These macros do the dirty work of the instr decoding, several variables
42 * can be defined in the source file to modify the work of these macros,
43 * currently the following variables are used:
44 * ...
45 * The register usage:
46 * d0 - will contain source operand for data direct mode,
47 * otherwise scratch register
48 * d1 - upper 16bit are reserved for caller
49 * lower 16bit may contain further arguments,
50 * is destroyed during decoding
51 * d2 - contains first two instruction words,
52 * first word will be used for extension word
53 * a0 - will point to source/dest operand for any indirect mode
54 * otherwise scratch register
55 * a1 - scratch register
56 * a2 - base addr to the task structure
57 *
58 * the current implementation doesn't check for every disallowed
59 * addressing mode (e.g. pc relative modes as destination), as long
60 * as it only means a new addressing mode, which should not appear
61 * in a program and that doesn't crash the emulation, I think it's
62 * not a problem to allow these modes.
63 */
64
65 do_fmovem=0
66 do_fmovem_cr=0
67 do_no_pc_mode=0
68 do_fscc=0
69
70 | first decoding of the instr type
71 | this seperates the conditional instr
72 .macro fp_decode_cond_instr_type
73 bfextu %d2{#8,#2},%d0
74 jmp ([0f:w,%pc,%d0*4])
75
76 .align 4
77 0:
78 | .long "f<op>","fscc/fdbcc"
79 | .long "fbccw","fbccl"
80 .endm
81
82 | second decoding of the instr type
83 | this seperates most move instr
84 .macro fp_decode_move_instr_type
85 bfextu %d2{#16,#3},%d0
86 jmp ([0f:w,%pc,%d0*4])
87
88 .align 4
89 0:
90 | .long "f<op> fpx,fpx","invalid instr"
91 | .long "f<op> <ea>,fpx","fmove fpx,<ea>"
92 | .long "fmovem <ea>,fpcr","fmovem <ea>,fpx"
93 | .long "fmovem fpcr,<ea>","fmovem fpx,<ea>"
94 .endm
95
96 | extract the source specifier, specifies
97 | either source fp register or data format
98 .macro fp_decode_sourcespec
99 bfextu %d2{#19,#3},%d0
100 .endm
101
102 | decode destination format for fmove reg,ea
103 .macro fp_decode_dest_format
104 bfextu %d2{#19,#3},%d0
105 .endm
106
107 | decode source register for fmove reg,ea
108 .macro fp_decode_src_reg
109 bfextu %d2{#22,#3},%d0
110 .endm
111
112 | extract the addressing mode
113 | it depends on the instr which of the modes is valid
114 .macro fp_decode_addr_mode
115 bfextu %d2{#10,#3},%d0
116 jmp ([0f:w,%pc,%d0*4])
117
118 .align 4
119 0:
120 | .long "data register direct","addr register direct"
121 | .long "addr register indirect"
122 | .long "addr register indirect postincrement"
123 | .long "addr register indirect predecrement"
124 | .long "addr register + index16"
125 | .long "extension mode1","extension mode2"
126 .endm
127
128 | extract the register for the addressing mode
129 .macro fp_decode_addr_reg
130 bfextu %d2{#13,#3},%d0
131 .endm
132
133 | decode the 8bit diplacement from the brief extension word
134 .macro fp_decode_disp8
135 move.b %d2,%d0
136 ext.w %d0
137 .endm
138
139 | decode the index of the brief/full extension word
140 .macro fp_decode_index
141 bfextu %d2{#17,#3},%d0 | get the register nr
142 btst #15,%d2 | test for data/addr register
143 jne 1\@f
144 printf PDECODE,"d%d",1,%d0
145 jsr fp_get_data_reg
146 jra 2\@f
147 1\@: printf PDECODE,"a%d",1,%d0
148 jsr fp_get_addr_reg
149 move.l %a0,%d0
150 2\@:
151 debug lea "'l'.w,%a0"
152 btst #11,%d2 | 16/32 bit size?
153 jne 3\@f
154 debug lea "'w'.w,%a0"
155 ext.l %d0
156 3\@: printf PDECODE,":%c",1,%a0
157 move.w %d2,%d1 | scale factor
158 rol.w #7,%d1
159 and.w #3,%d1
160 debug move.l "%d1,-(%sp)"
161 debug ext.l "%d1"
162 printf PDECODE,":%d",1,%d1
163 debug move.l "(%sp)+,%d1"
164 lsl.l %d1,%d0
165 .endm
166
167 | decode the base displacement size
168 .macro fp_decode_basedisp
169 bfextu %d2{#26,#2},%d0
170 jmp ([0f:w,%pc,%d0*4])
171
172 .align 4
173 0:
174 | .long "reserved","null displacement"
175 | .long "word displacement","long displacement"
176 .endm
177
178 .macro fp_decode_outerdisp
179 bfextu %d2{#30,#2},%d0
180 jmp ([0f:w,%pc,%d0*4])
181
182 .align 4
183 0:
184 | .long "no memory indirect action/reserved","null outer displacement"
185 | .long "word outer displacement","long outer displacement"
186 .endm
187
188 | get the extension word and test for brief or full extension type
189 .macro fp_get_test_extword label
190 fp_get_instr_word %d2,fp_err_ua1
191 btst #8,%d2
192 jne \label
193 .endm
194
195
196 | test if %pc is the base register for the indirect addr mode
197 .macro fp_test_basereg_d16 label
198 btst #20,%d2
199 jeq \label
200 .endm
201
202 | test if %pc is the base register for one of the extended modes
203 .macro fp_test_basereg_ext label
204 btst #19,%d2
205 jeq \label
206 .endm
207
208 .macro fp_test_suppr_index label
209 btst #6,%d2
210 jne \label
211 .endm
212
213
214 | addressing mode: data register direct
215 .macro fp_mode_data_direct
216 fp_decode_addr_reg
217 printf PDECODE,"d%d",1,%d0
218 .endm
219
220 | addressing mode: address register indirect
221 .macro fp_mode_addr_indirect
222 fp_decode_addr_reg
223 printf PDECODE,"(a%d)",1,%d0
224 jsr fp_get_addr_reg
225 .endm
226
227 | adjust stack for byte moves from/to stack
228 .macro fp_test_sp_byte_move
229 .if !do_fmovem
230 .if do_fscc
231 move.w #6,%d1
232 .endif
233 cmp.w #7,%d0
234 jne 1\@f
235 .if !do_fscc
236 cmp.w #6,%d1
237 jne 1\@f
238 .endif
239 move.w #4,%d1
240 1\@:
241 .endif
242 .endm
243
244 | addressing mode: address register indirect with postincrement
245 .macro fp_mode_addr_indirect_postinc
246 fp_decode_addr_reg
247 printf PDECODE,"(a%d)+",1,%d0
248 fp_test_sp_byte_move
249 jsr fp_get_addr_reg
250 move.l %a0,%a1 | save addr
251 .if do_fmovem
252 lea (%a0,%d1.w*4),%a0
253 .if !do_fmovem_cr
254 lea (%a0,%d1.w*8),%a0
255 .endif
256 .else
257 add.w (fp_datasize,%d1.w*2),%a0
258 .endif
259 jsr fp_put_addr_reg
260 move.l %a1,%a0
261 .endm
262
263 | addressing mode: address register indirect with predecrement
264 .macro fp_mode_addr_indirect_predec
265 fp_decode_addr_reg
266 printf PDECODE,"-(a%d)",1,%d0
267 fp_test_sp_byte_move
268 jsr fp_get_addr_reg
269 .if do_fmovem
270 .if !do_fmovem_cr
271 lea (-12,%a0),%a1 | setup to addr of 1st reg to move
272 neg.w %d1
273 lea (%a0,%d1.w*4),%a0
274 add.w %d1,%d1
275 lea (%a0,%d1.w*4),%a0
276 jsr fp_put_addr_reg
277 move.l %a1,%a0
278 .else
279 neg.w %d1
280 lea (%a0,%d1.w*4),%a0
281 jsr fp_put_addr_reg
282 .endif
283 .else
284 sub.w (fp_datasize,%d1.w*2),%a0
285 jsr fp_put_addr_reg
286 .endif
287 .endm
288
289 | addressing mode: address register/programm counter indirect
290 | with 16bit displacement
291 .macro fp_mode_addr_indirect_disp16
292 .if !do_no_pc_mode
293 fp_test_basereg_d16 1f
294 printf PDECODE,"pc"
295 fp_get_pc %a0
296 jra 2f
297 .endif
298 1: fp_decode_addr_reg
299 printf PDECODE,"a%d",1,%d0
300 jsr fp_get_addr_reg
301 2: fp_get_instr_word %a1,fp_err_ua1
302 printf PDECODE,"@(%x)",1,%a1
303 add.l %a1,%a0
304 .endm
305
306 | perform preindex (if I/IS == 0xx and xx != 00)
307 .macro fp_do_preindex
308 moveq #3,%d0
309 and.w %d2,%d0
310 jeq 1f
311 btst #2,%d2
312 jne 1f
313 printf PDECODE,")@("
314 getuser.l (%a1),%a1,fp_err_ua1,%a1
315 debug jra "2f"
316 1: printf PDECODE,","
317 2:
318 .endm
319
320 | perform postindex (if I/IS == 1xx)
321 .macro fp_do_postindex
322 btst #2,%d2
323 jeq 1f
324 printf PDECODE,")@("
325 getuser.l (%a1),%a1,fp_err_ua1,%a1
326 debug jra "2f"
327 1: printf PDECODE,","
328 2:
329 .endm
330
331 | all other indirect addressing modes will finally end up here
332 .macro fp_mode_addr_indirect_extmode0
333 .if !do_no_pc_mode
334 fp_test_basereg_ext 1f
335 printf PDECODE,"pc"
336 fp_get_pc %a0
337 jra 2f
338 .endif
339 1: fp_decode_addr_reg
340 printf PDECODE,"a%d",1,%d0
341 jsr fp_get_addr_reg
342 2: move.l %a0,%a1
343 swap %d2
344 fp_get_test_extword 3f
345 | addressing mode: address register/programm counter indirect
346 | with index and 8bit displacement
347 fp_decode_disp8
348 debug ext.l "%d0"
349 printf PDECODE,"@(%x,",1,%d0
350 add.w %d0,%a1
351 fp_decode_index
352 add.l %d0,%a1
353 printf PDECODE,")"
354 jra 9f
355 3: | addressing mode: address register/programm counter memory indirect
356 | with base and/or outer displacement
357 btst #7,%d2 | base register suppressed?
358 jeq 1f
359 printf PDECODE,"!"
360 sub.l %a1,%a1
361 1: printf PDECODE,"@("
362 fp_decode_basedisp
363
364 .long fp_ill,1f
365 .long 2f,3f
366
367 #ifdef FPU_EMU_DEBUG
368 1: printf PDECODE,"0" | null base displacement
369 jra 1f
370 #endif
371 2: fp_get_instr_word %a0,fp_err_ua1 | 16bit base displacement
372 printf PDECODE,"%x:w",1,%a0
373 jra 4f
374 3: fp_get_instr_long %a0,fp_err_ua1 | 32bit base displacement
375 printf PDECODE,"%x:l",1,%a0
376 4: add.l %a0,%a1
377 1:
378 fp_do_postindex
379 fp_test_suppr_index 1f
380 fp_decode_index
381 add.l %d0,%a1
382 1: fp_do_preindex
383
384 fp_decode_outerdisp
385
386 .long 5f,1f
387 .long 2f,3f
388
389 #ifdef FPU_EMU_DEBUG
390 1: printf PDECODE,"0" | null outer displacement
391 jra 1f
392 #endif
393 2: fp_get_instr_word %a0,fp_err_ua1 | 16bit outer displacement
394 printf PDECODE,"%x:w",1,%a0
395 jra 4f
396 3: fp_get_instr_long %a0,fp_err_ua1 | 32bit outer displacement
397 printf PDECODE,"%x:l",1,%a0
398 4: add.l %a0,%a1
399 1:
400 5: printf PDECODE,")"
401 9: move.l %a1,%a0
402 swap %d2
403 .endm
404
405 | get the absolute short address from user space
406 .macro fp_mode_abs_short
407 fp_get_instr_word %a0,fp_err_ua1
408 printf PDECODE,"%x.w",1,%a0
409 .endm
410
411 | get the absolute long address from user space
412 .macro fp_mode_abs_long
413 fp_get_instr_long %a0,fp_err_ua1
414 printf PDECODE,"%x.l",1,%a0
415 .endm
416
417 #endif /* _FP_DECODE_H */
418