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[/] [ao486/] [trunk/] [bochs486/] [cpu/] [shift8.cc] - Blame information for rev 2

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1 2 alfik 
/////////////////////////////////////////////////////////////////////////
2 
// $Id: shift8.cc 11313 2012-08-05 13:52:40Z sshwarts $
3 
/////////////////////////////////////////////////////////////////////////
4 
//
5 
//  Copyright (C) 2001-2012  The Bochs Project
6 
//
7 
//  This library is free software; you can redistribute it and/or
8 
//  modify it under the terms of the GNU Lesser General Public
9 
//  License as published by the Free Software Foundation; either
10 
//  version 2 of the License, or (at your option) any later version.
11 
//
12 
//  This library 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 GNU
15 
//  Lesser General Public License for more details.
16 
//
17 
//  You should have received a copy of the GNU Lesser General Public
18 
//  License along with this library; if not, write to the Free Software
19 
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
20 
/////////////////////////////////////////////////////////////////////////
21 
 
22 
#define NEED_CPU_REG_SHORTCUTS 1
23 
#include "bochs.h"
24 
#include "cpu.h"
25 
#define LOG_THIS BX_CPU_THIS_PTR
26 
 
27 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROL_EbR(bxInstruction_c *i)
28 
{
29 
  unsigned count;
30 
  unsigned bit0, bit7;
31 
 
32 
  if (i->getIaOpcode() == BX_IA_ROL_Eb)
33 
    count = CL;
34 
  else
35 
    count = i->Ib();
36 
 
37 
  Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
38 
 
39 
  if ((count & 0x07) == 0) {
40 
    if (count & 0x18) {
41 
      bit0 = (op1_8 &  1);
42 
      bit7 = (op1_8 >> 7);
43 
      SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
44 
    }
45 
  }
46 
  else {
47 
    count &= 0x7; // use only lowest 3 bits
48 
 
49 
    Bit8u result_8 = (op1_8 << count) | (op1_8 >> (8 - count));
50 
 
51 
    BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
52 
 
53 
    /* set eflags:
54 
     * ROL count affects the following flags: C, O
55 
     */
56 
    bit0 = (result_8 &  1);
57 
    bit7 = (result_8 >> 7);
58 
 
59 
    SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
60 
  }
61 
 
62 
  BX_NEXT_INSTR(i);
63 
}
64 
 
65 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROL_EbM(bxInstruction_c *i)
66 
{
67 
  unsigned count;
68 
  unsigned bit0, bit7;
69 
 
70 
  if (i->getIaOpcode() == BX_IA_ROL_Eb)
71 
    count = CL;
72 
  else
73 
    count = i->Ib();
74 
 
75 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
76 
  /* pointer, segment address pair */
77 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
78 
 
79 
  if ((count & 0x07) == 0) {
80 
    if (count & 0x18) {
81 
      bit0 = (op1_8 &  1);
82 
      bit7 = (op1_8 >> 7);
83 
      SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
84 
    }
85 
  }
86 
  else {
87 
    count &= 0x7; // use only lowest 3 bits
88 
 
89 
    Bit8u result_8 = (op1_8 << count) | (op1_8 >> (8 - count));
90 
 
91 
    write_RMW_virtual_byte(result_8);
92 
 
93 
    /* set eflags:
94 
     * ROL count affects the following flags: C, O
95 
     */
96 
    bit0 = (result_8 &  1);
97 
    bit7 = (result_8 >> 7);
98 
 
99 
    SET_FLAGS_OxxxxC(bit0 ^ bit7, bit0);
100 
  }
101 
 
102 
  BX_NEXT_INSTR(i);
103 
}
104 
 
105 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROR_EbR(bxInstruction_c *i)
106 
{
107 
  unsigned count;
108 
  unsigned bit6, bit7;
109 
 
110 
  if (i->getIaOpcode() == BX_IA_ROR_Eb)
111 
    count = CL;
112 
  else
113 
    count = i->Ib();
114 
 
115 
  Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
116 
 
117 
  if ((count & 0x07) == 0) {
118 
    if (count & 0x18) {
119 
      bit6 = (op1_8 >> 6) & 1;
120 
      bit7 = (op1_8 >> 7) & 1;
121 
 
122 
      SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
123 
    }
124 
  }
125 
  else {
126 
    count &= 0x7; /* use only bottom 3 bits */
127 
 
128 
    Bit8u result_8 = (op1_8 >> count) | (op1_8 << (8 - count));
129 
 
130 
    BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
131 
 
132 
    /* set eflags:
133 
     * ROR count affects the following flags: C, O
134 
     */
135 
    bit6 = (result_8 >> 6) & 1;
136 
    bit7 = (result_8 >> 7) & 1;
137 
 
138 
    SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
139 
  }
140 
 
141 
  BX_NEXT_INSTR(i);
142 
}
143 
 
144 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::ROR_EbM(bxInstruction_c *i)
145 
{
146 
  unsigned count;
147 
  unsigned bit6, bit7;
148 
 
149 
  if (i->getIaOpcode() == BX_IA_ROR_Eb)
150 
    count = CL;
151 
  else
152 
    count = i->Ib();
153 
 
154 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
155 
  /* pointer, segment address pair */
156 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
157 
 
158 
  if ((count & 0x07) == 0) {
159 
    if (count & 0x18) {
160 
      bit6 = (op1_8 >> 6) & 1;
161 
      bit7 = (op1_8 >> 7) & 1;
162 
 
163 
      SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
164 
    }
165 
  }
166 
  else {
167 
    count &= 0x7; /* use only bottom 3 bits */
168 
 
169 
    Bit8u result_8 = (op1_8 >> count) | (op1_8 << (8 - count));
170 
 
171 
    write_RMW_virtual_byte(result_8);
172 
 
173 
    /* set eflags:
174 
     * ROR count affects the following flags: C, O
175 
     */
176 
    bit6 = (result_8 >> 6) & 1;
177 
    bit7 = (result_8 >> 7) & 1;
178 
 
179 
    SET_FLAGS_OxxxxC(bit6 ^ bit7, bit7);
180 
  }
181 
 
182 
  BX_NEXT_INSTR(i);
183 
}
184 
 
185 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCL_EbR(bxInstruction_c *i)
186 
{
187 
  Bit8u result_8;
188 
  unsigned count;
189 
  unsigned of, cf;
190 
 
191 
  if (i->getIaOpcode() == BX_IA_RCL_Eb)
192 
    count = CL;
193 
  else
194 
    count = i->Ib();
195 
 
196 
  count = (count & 0x1f) % 9;
197 
 
198 
  if (! count) {
199 
    BX_NEXT_INSTR(i);
200 
  }
201 
 
202 
  Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
203 
 
204 
  if (count==1) {
205 
    result_8 = (op1_8 << 1) | getB_CF();
206 
  }
207 
  else {
208 
    result_8 = (op1_8 << count) | (getB_CF() << (count - 1)) |
209 
               (op1_8 >> (9 - count));
210 
  }
211 
 
212 
  BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
213 
 
214 
  cf = (op1_8 >> (8 - count)) & 0x01;
215 
  of = cf ^ (result_8 >> 7);  // of = cf ^ result7
216 
  SET_FLAGS_OxxxxC(of, cf);
217 
 
218 
  BX_NEXT_INSTR(i);
219 
}
220 
 
221 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCL_EbM(bxInstruction_c *i)
222 
{
223 
  Bit8u result_8;
224 
  unsigned count;
225 
  unsigned of, cf;
226 
 
227 
  if (i->getIaOpcode() == BX_IA_RCL_Eb)
228 
    count = CL;
229 
  else
230 
    count = i->Ib();
231 
 
232 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
233 
  /* pointer, segment address pair */
234 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
235 
 
236 
  count = (count & 0x1f) % 9;
237 
 
238 
  if (! count) {
239 
    BX_NEXT_INSTR(i);
240 
  }
241 
 
242 
  if (count==1) {
243 
    result_8 = (op1_8 << 1) | getB_CF();
244 
  }
245 
  else {
246 
    result_8 = (op1_8 << count) | (getB_CF() << (count - 1)) |
247 
               (op1_8 >> (9 - count));
248 
  }
249 
 
250 
  write_RMW_virtual_byte(result_8);
251 
 
252 
  cf = (op1_8 >> (8 - count)) & 0x01;
253 
  of = cf ^ (result_8 >> 7);  // of = cf ^ result7
254 
  SET_FLAGS_OxxxxC(of, cf);
255 
 
256 
  BX_NEXT_INSTR(i);
257 
}
258 
 
259 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCR_EbR(bxInstruction_c *i)
260 
{
261 
  unsigned count;
262 
  unsigned cf, of;
263 
 
264 
  if (i->getIaOpcode() == BX_IA_RCR_Eb)
265 
    count = CL;
266 
  else
267 
    count = i->Ib();
268 
 
269 
  count = (count & 0x1f) % 9;
270 
 
271 
  if (count) {
272 
    Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
273 
 
274 
    Bit8u result_8 = (op1_8 >> count) | (getB_CF() << (8 - count)) |
275 
                     (op1_8 << (9 - count));
276 
 
277 
    BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
278 
 
279 
    cf = (op1_8 >> (count - 1)) & 0x1;
280 
    of = (((result_8 << 1) ^ result_8) >> 7) & 0x1; // of = result6 ^ result7
281 
    SET_FLAGS_OxxxxC(of, cf);
282 
  }
283 
 
284 
  BX_NEXT_INSTR(i);
285 
}
286 
 
287 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::RCR_EbM(bxInstruction_c *i)
288 
{
289 
  unsigned count;
290 
  unsigned cf, of;
291 
 
292 
  if (i->getIaOpcode() == BX_IA_RCR_Eb)
293 
    count = CL;
294 
  else
295 
    count = i->Ib();
296 
 
297 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
298 
  /* pointer, segment address pair */
299 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
300 
 
301 
  count = (count & 0x1f) % 9;
302 
 
303 
  if (count) {
304 
    Bit8u result_8 = (op1_8 >> count) | (getB_CF() << (8 - count)) |
305 
                     (op1_8 << (9 - count));
306 
 
307 
    write_RMW_virtual_byte(result_8);
308 
 
309 
    cf = (op1_8 >> (count - 1)) & 0x1;
310 
    of = (((result_8 << 1) ^ result_8) >> 7) & 0x1; // of = result6 ^ result7
311 
    SET_FLAGS_OxxxxC(of, cf);
312 
  }
313 
 
314 
  BX_NEXT_INSTR(i);
315 
}
316 
 
317 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHL_EbR(bxInstruction_c *i)
318 
{
319 
  Bit8u result_8;
320 
  unsigned count;
321 
  unsigned of = 0, cf = 0;
322 
 
323 
  if (i->getIaOpcode() == BX_IA_SHL_Eb)
324 
    count = CL;
325 
  else
326 
    count = i->Ib();
327 
 
328 
  count &= 0x1f;
329 
 
330 
  if (!count) {
331 
    BX_NEXT_INSTR(i);
332 
  }
333 
 
334 
  Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
335 
 
336 
  if (count <= 8) {
337 
    result_8 = (op1_8 << count);
338 
    cf = (op1_8 >> (8 - count)) & 0x1;
339 
    of = cf ^ (result_8 >> 7);
340 
  }
341 
  else {
342 
    result_8 = 0;
343 
  }
344 
 
345 
  BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
346 
 
347 
  SET_FLAGS_OSZAPC_LOGIC_8(result_8);
348 
  SET_FLAGS_OxxxxC(of, cf);
349 
 
350 
  BX_NEXT_INSTR(i);
351 
}
352 
 
353 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHL_EbM(bxInstruction_c *i)
354 
{
355 
  Bit8u result_8;
356 
  unsigned count;
357 
  unsigned of = 0, cf = 0;
358 
 
359 
  if (i->getIaOpcode() == BX_IA_SHL_Eb)
360 
    count = CL;
361 
  else
362 
    count = i->Ib();
363 
 
364 
  count &= 0x1f;
365 
 
366 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
367 
  /* pointer, segment address pair */
368 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
369 
 
370 
  if (!count) {
371 
    BX_NEXT_INSTR(i);
372 
  }
373 
 
374 
  if (count <= 8) {
375 
    result_8 = (op1_8 << count);
376 
    cf = (op1_8 >> (8 - count)) & 0x1;
377 
    of = cf ^ (result_8 >> 7);
378 
  }
379 
  else {
380 
    result_8 = 0;
381 
  }
382 
 
383 
  write_RMW_virtual_byte(result_8);
384 
 
385 
  SET_FLAGS_OSZAPC_LOGIC_8(result_8);
386 
  SET_FLAGS_OxxxxC(of, cf);
387 
 
388 
  BX_NEXT_INSTR(i);
389 
}
390 
 
391 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHR_EbR(bxInstruction_c *i)
392 
{
393 
  unsigned count;
394 
 
395 
  if (i->getIaOpcode() == BX_IA_SHR_Eb)
396 
    count = CL;
397 
  else
398 
    count = i->Ib();
399 
 
400 
  count &= 0x1f;
401 
 
402 
  if (count) {
403 
    Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
404 
    Bit8u result_8 = (op1_8 >> count);
405 
    BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
406 
 
407 
    unsigned cf = (op1_8 >> (count - 1)) & 0x1;
408 
    // note, that of == result7 if count == 1 and
409 
    //            of == 0       if count >= 2
410 
    unsigned of = (((result_8 << 1) ^ result_8) >> 7) & 0x1;
411 
 
412 
    SET_FLAGS_OSZAPC_LOGIC_8(result_8);
413 
    SET_FLAGS_OxxxxC(of, cf);
414 
  }
415 
 
416 
  BX_NEXT_INSTR(i);
417 
}
418 
 
419 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SHR_EbM(bxInstruction_c *i)
420 
{
421 
  unsigned count;
422 
 
423 
  if (i->getIaOpcode() == BX_IA_SHR_Eb)
424 
    count = CL;
425 
  else
426 
    count = i->Ib();
427 
 
428 
  count &= 0x1f;
429 
 
430 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
431 
  /* pointer, segment address pair */
432 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
433 
 
434 
  if (count) {
435 
    Bit8u result_8 = (op1_8 >> count);
436 
 
437 
    write_RMW_virtual_byte(result_8);
438 
 
439 
    unsigned cf = (op1_8 >> (count - 1)) & 0x1;
440 
    // note, that of == result7 if count == 1 and
441 
    //            of == 0       if count >= 2
442 
    unsigned of = (((result_8 << 1) ^ result_8) >> 7) & 0x1;
443 
 
444 
    SET_FLAGS_OSZAPC_LOGIC_8(result_8);
445 
    SET_FLAGS_OxxxxC(of, cf);
446 
  }
447 
 
448 
  BX_NEXT_INSTR(i);
449 
}
450 
 
451 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SAR_EbR(bxInstruction_c *i)
452 
{
453 
  unsigned count;
454 
 
455 
  if (i->getIaOpcode() == BX_IA_SAR_Eb)
456 
    count = CL;
457 
  else
458 
    count = i->Ib();
459 
 
460 
  count &= 0x1f;
461 
 
462 
  if (count) {
463 
    Bit8u op1_8 = BX_READ_8BIT_REGx(i->dst(), i->extend8bitL());
464 
    Bit8u result_8 = ((Bit8s) op1_8) >> count;
465 
    BX_WRITE_8BIT_REGx(i->dst(), i->extend8bitL(), result_8);
466 
 
467 
    unsigned cf = (((Bit8s) op1_8) >> (count - 1)) & 0x1;
468 
 
469 
    SET_FLAGS_OSZAPC_LOGIC_8(result_8);
470 
    /* signed overflow cannot happen in SAR instruction */
471 
    SET_FLAGS_OxxxxC(0, cf);
472 
  }
473 
 
474 
  BX_NEXT_INSTR(i);
475 
}
476 
 
477 
BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::SAR_EbM(bxInstruction_c *i)
478 
{
479 
  unsigned count;
480 
 
481 
  if (i->getIaOpcode() == BX_IA_SAR_Eb)
482 
    count = CL;
483 
  else
484 
    count = i->Ib();
485 
 
486 
  count &= 0x1f;
487 
 
488 
  bx_address eaddr = BX_CPU_CALL_METHODR(i->ResolveModrm, (i));
489 
  /* pointer, segment address pair */
490 
  Bit8u op1_8 = read_RMW_virtual_byte(i->seg(), eaddr);
491 
 
492 
  if (count) {
493 
    Bit8u result_8 = ((Bit8s) op1_8) >> count;
494 
 
495 
    write_RMW_virtual_byte(result_8);
496 
 
497 
    unsigned cf = (((Bit8s) op1_8) >> (count - 1)) & 0x1;
498 
 
499 
    SET_FLAGS_OSZAPC_LOGIC_8(result_8);
500 
    /* signed overflow cannot happen in SAR instruction */
501 
    SET_FLAGS_OxxxxC(0, cf);
502 
  }
503 
 
504 
  BX_NEXT_INSTR(i);
505 
}

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