1/* opc2c.c --- generate C simulator code from from .opc file
2
3Copyright (C) 2005-2020 Free Software Foundation, Inc.
4Contributed by Red Hat, Inc.
5
6This file is part of the GNU simulators.
7
8This program is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3 of the License, or
11(at your option) any later version.
12
13This program is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20
21
22#include <stdio.h>
23#include <string.h>
24#include <ctype.h>
25#include <stdlib.h>
26
27#include "safe-fgets.h"
28
29static int errors = 0;
30
31#define MAX_BYTES 10
32
33typedef struct
34{
35  int varyno:16;
36  int byte:8;
37  int shift:8;
38} VaryRef;
39
40typedef struct
41{
42  char nbytes;
43  char dbytes;
44  char id[MAX_BYTES * 8 + 1];
45  unsigned char var_start[MAX_BYTES * 8 + 1];
46  struct
47  {
48    unsigned char decodable_mask;
49    unsigned char decodable_bits;
50  } b[MAX_BYTES];
51  char *comment;
52  int lineno;
53  int nlines;
54  char **lines;
55  struct Indirect *last_ind;
56  int semantics_label;
57  int nvaries;
58  VaryRef *vary;
59} opcode;
60
61int n_opcodes;
62opcode **opcodes;
63opcode *op;
64
65typedef struct
66{
67  char *name;
68  int nlen;
69  unsigned char mask;
70  int n_patterns;
71  unsigned char *patterns;
72} Vary;
73
74Vary **vary = 0;
75int n_varies = 0;
76
77unsigned char cur_bits[MAX_BYTES + 1];
78
79char *orig_filename;
80
81FILE *sim_log = 0;
82#define lprintf if (sim_log) fprintf
83
84opcode prefix_text, suffix_text;
85
86typedef enum
87{
88  T_unused,
89  T_op,
90  T_indirect,
91  T_done
92} OpType;
93
94typedef struct Indirect
95{
96  OpType type;
97  union
98  {
99    struct Indirect *ind;
100    opcode *op;
101  } u;
102} Indirect;
103
104Indirect indirect[256];
105
106static int
107next_varybits (int bits, opcode * op, int byte)
108{
109  int mask = op->b[byte].decodable_mask;
110  int i;
111
112  for (i = 0; i < 8; i++)
113    if (!(mask & (1 << i)))
114      {
115	if (bits & (1 << i))
116	  {
117	    bits &= ~(1 << i);
118	  }
119	else
120	  {
121	    bits |= (1 << i);
122	    return bits;
123	  }
124      }
125  return 0;
126}
127
128static int
129valid_varybits (int bits, opcode * op, int byte)
130{
131  if (op->nvaries)
132    {
133      int vn;
134      for (vn = 0; vn < op->nvaries; vn++)
135	{
136	  int found = 0;
137	  int i;
138	  int ob;
139
140	  if (byte != op->vary[vn].byte)
141	    continue;
142	  Vary *v = vary[op->vary[vn].varyno];
143	  ob = (bits >> op->vary[vn].shift) & v->mask;
144	  lprintf (sim_log, "varybits: vary %s ob %x\n", v->name, ob);
145
146	  for (i = 0; i < v->n_patterns; i++)
147	    if (ob == v->patterns[i])
148	      {
149		lprintf (sim_log, "  found at %d\n", i);
150		found = 1;
151		break;
152	      }
153	  if (!found)
154	    return 0;
155	}
156    }
157  return 1;
158}
159
160char *
161prmb (int mask, int bits)
162{
163  static char buf[8][30];
164  static int bn = 0;
165  char *bp;
166
167  bn = (bn + 1) % 8;
168  bp = buf[bn];
169  int i;
170  for (i = 0; i < 8; i++)
171    {
172      int bit = 0x80 >> i;
173      if (!(mask & bit))
174	*bp++ = '-';
175      else if (bits & bit)
176	*bp++ = '1';
177      else
178	*bp++ = '0';
179      if (i % 4 == 3)
180	*bp++ = ' ';
181    }
182  *--bp = 0;
183  return buf[bn];
184}
185
186static int
187op_cmp (const void *va, const void *vb)
188{
189  const opcode *a = *(const opcode **) va;
190  const opcode *b = *(const opcode **) vb;
191
192  if (a->nbytes != b->nbytes)
193    return a->nbytes - b->nbytes;
194
195  return strcmp (a->id, b->id);
196}
197
198void
199dump_lines (opcode * op, int level, Indirect * ind)
200{
201  char *varnames[40];
202  int i, vn = 0;
203
204  if (op->semantics_label)
205    {
206      printf ("%*sgoto op_semantics_%d;\n", level, "", op->semantics_label);
207      return;
208    }
209
210  if (ind != op->last_ind)
211    {
212      static int labelno = 0;
213      labelno++;
214      printf ("%*sop_semantics_%d:\n", level, "", labelno);
215      op->semantics_label = labelno;
216    }
217
218  if (op->comment)
219    {
220      level += 2;
221      printf ("%*s{\n", level, "");
222      printf ("%*s  %s\n", level, "", op->comment);
223    }
224
225  for (i = 0; i < op->nbytes * 8;)
226    {
227      if (isalpha (op->id[i]))
228	{
229	  int byte = i >> 3;
230	  int mask = 0;
231	  int shift = 0;
232	  char name[33];
233	  char *np = name;
234	  while (op->id[i] && isalpha (op->id[i]))
235	    {
236	      mask = (mask << 1) | 1;
237	      shift = 7 - (i & 7);
238	      *np++ = op->id[i++];
239	      if (op->var_start[i])
240		break;
241	    }
242	  *np = 0;
243	  varnames[vn++] = strdup (name);
244	  printf ("#line %d \"%s\"\n", op->lineno, orig_filename);
245	  if (mask & ~0xff)
246	    {
247	      fprintf (stderr, "Error: variable %s spans bytes: %s\n",
248		       name, op->comment);
249	      errors++;
250	    }
251	  else if (shift && (mask != 0xff))
252	    printf ("%*s  int %s AU = (op[%d] >> %d) & 0x%02x;\n",
253		    level, "", name, byte, shift, mask);
254	  else if (mask != 0xff)
255	    printf ("%*s  int %s AU = op[%d] & 0x%02x;\n",
256		    level, "", name, byte, mask);
257	  else
258	    printf ("%*s  int %s AU = op[%d];\n", level, "", name, byte);
259	}
260      else
261	i++;
262    }
263  if (op->comment)
264    {
265      printf ("%*s  if (trace) {\n", level, "");
266      printf ("%*s      printf(\"\\033[33m%%s\\033[0m ", level, "");
267      for (i = 0; i < op->nbytes; i++)
268	printf (" %%02x");
269      printf ("\\n\"");
270      printf (",\n%*s             \"%s\"", level, "", op->comment);
271      for (i = 0; i < op->nbytes; i++)
272	{
273	  if (i == 0)
274	    printf (",\n%*s             op[%d]", level, "", i);
275	  else
276	    printf (", op[%d]", i);
277	}
278      printf (");\n");
279      for (i = 0; i < vn; i++)
280	printf ("%*s      printf(\"  %s = 0x%%x%s\", %s);\n", level, "",
281		varnames[i], (i < vn - 1) ? "," : "\\n", varnames[i]);
282      printf ("%*s    }\n", level, "");
283    }
284  printf ("#line %d \"%s\"\n", op->lineno + 1, orig_filename);
285  for (i = 0; i < op->nlines; i++)
286    printf ("%*s%s", level, "", op->lines[i]);
287  if (op->comment)
288    printf ("%*s}\n", level, "");
289}
290
291void
292store_opcode_bits (opcode * op, int byte, Indirect * ind)
293{
294  int bits = op->b[byte].decodable_bits;
295
296  do
297    {
298      if (!valid_varybits (bits, op, byte))
299	continue;
300
301      switch (ind[bits].type)
302	{
303	case T_unused:
304	  if (byte == op->dbytes - 1)
305	    {
306	      ind[bits].type = T_op;
307	      ind[bits].u.op = op;
308	      op->last_ind = ind;
309	      break;
310	    }
311	  else
312	    {
313	      int i2;
314	      ind[bits].type = T_indirect;
315	      ind[bits].u.ind = (Indirect *) malloc (256 * sizeof (Indirect));
316	      for (i2 = 0; i2 < 256; i2++)
317		ind[bits].u.ind[i2].type = T_unused;
318	      store_opcode_bits (op, byte + 1, ind[bits].u.ind);
319	    }
320	  break;
321
322	case T_indirect:
323	  if (byte < op->dbytes - 1)
324	    store_opcode_bits (op, byte + 1, ind[bits].u.ind);
325	  break;
326
327	case T_op:
328	  break;
329
330	case T_done:
331	  break;
332	}
333    }
334  while ((bits = next_varybits (bits, op, byte)) != 0);
335}
336
337void
338emit_indirect (Indirect * ind, int byte)
339{
340  int unsup = 0;
341  int j, n, mask;
342
343  mask = 0;
344  for (j = 0; j < 256; j++)
345    {
346      switch (ind[j].type)
347	{
348	case T_indirect:
349	  mask = 0xff;
350	  break;
351	case T_op:
352	  mask |= ind[j].u.op->b[byte].decodable_mask;
353	  break;
354	case T_done:
355	case T_unused:
356	  break;
357	}
358    }
359
360  printf ("%*s  GETBYTE();\n", byte * 6, "");
361  printf ("%*s  switch (op[%d] & 0x%02x) {\n", byte * 6, "", byte, mask);
362  for (j = 0; j < 256; j++)
363    if ((j & ~mask) == 0)
364      {
365	switch (ind[j].type)
366	  {
367	  case T_done:
368	    break;
369	  case T_unused:
370	    unsup = 1;
371	    break;
372	  case T_op:
373	    for (n = j; n < 256; n++)
374	      if ((n & ~mask) == 0
375		  && ind[n].type == T_op && ind[n].u.op == ind[j].u.op)
376		{
377		  ind[n].type = T_done;
378		  printf ("%*s    case 0x%02x:\n", byte * 6, "", n);
379		}
380	    for (n = byte; n < ind[j].u.op->nbytes - 1; n++)
381	      printf ("%*s      GETBYTE();\n", byte * 6, "");
382	    dump_lines (ind[j].u.op, byte * 6 + 6, ind);
383	    printf ("%*s      break;\n", byte * 6, "");
384	    break;
385	  case T_indirect:
386	    printf ("%*s    case 0x%02x:\n", byte * 6, "", j);
387	    emit_indirect (ind[j].u.ind, byte + 1);
388	    printf ("%*s      break;\n", byte * 6, "");
389	    break;
390	  }
391      }
392  if (unsup)
393    printf ("%*s    default: UNSUPPORTED(); break;\n", byte * 6, "");
394  printf ("%*s  }\n", byte * 6, "");
395}
396
397static char *
398pv_dup (char *p, char *ep)
399{
400  int n = ep - p;
401  char *rv = (char *) malloc (n + 1);
402  memcpy (rv, p, n);
403  rv[n] = 0;
404  return rv;
405}
406
407static unsigned char
408str2mask (char *str, char *ep)
409{
410  unsigned char rv = 0;
411  while (str < ep)
412    {
413      rv *= 2;
414      if (*str == '1')
415	rv += 1;
416      str++;
417    }
418  return rv;
419}
420
421static void
422process_vary (char *line)
423{
424  char *cp, *ep;
425  Vary *v = (Vary *) malloc (sizeof (Vary));
426
427  n_varies++;
428  if (vary)
429    vary = (Vary **) realloc (vary, n_varies * sizeof (Vary *));
430  else
431    vary = (Vary **) malloc (n_varies * sizeof (Vary *));
432  vary[n_varies - 1] = v;
433
434  cp = line;
435
436  for (cp = line; isspace (*cp); cp++);
437  for (ep = cp; *ep && !isspace (*ep); ep++);
438
439  v->name = pv_dup (cp, ep);
440  v->nlen = strlen (v->name);
441  v->mask = (1 << v->nlen) - 1;
442
443  v->n_patterns = 0;
444  v->patterns = (unsigned char *) malloc (1);
445  while (1)
446    {
447      for (cp = ep; isspace (*cp); cp++);
448      if (!isdigit (*cp))
449	break;
450      for (ep = cp; *ep && !isspace (*ep); ep++);
451      v->n_patterns++;
452      v->patterns = (unsigned char *) realloc (v->patterns, v->n_patterns);
453      v->patterns[v->n_patterns - 1] = str2mask (cp, ep);
454    }
455}
456
457static int
458fieldcmp (opcode * op, int bit, char *name)
459{
460  int n = strlen (name);
461  if (memcmp (op->id + bit, name, n) == 0
462      && (!isalpha (op->id[bit + n]) || op->var_start[bit + n]))
463    return 1;
464  return 0;
465}
466
467static void
468log_indirect (Indirect * ind, int byte)
469{
470  int i, j;
471  char *last_c = 0;
472
473  for (i = 0; i < 256; i++)
474    {
475
476      for (j = 0; j < byte; j++)
477	fprintf (sim_log, "%s ", prmb (255, cur_bits[j]));
478      fprintf (sim_log, "%s ", prmb (255, i));
479
480      switch (ind[i].type)
481	{
482	case T_op:
483	case T_done:
484	  if (last_c && (ind[i].u.op->comment == last_c))
485	    fprintf (sim_log, "''\n");
486	  else
487	    fprintf (sim_log, "%s\n", ind[i].u.op->comment);
488	  last_c = ind[i].u.op->comment;
489	  break;
490	case T_unused:
491	  fprintf (sim_log, "unused\n");
492	  break;
493	case T_indirect:
494	  fprintf (sim_log, "indirect\n");
495	  cur_bits[byte] = i;
496	  log_indirect (ind[i].u.ind, byte + 1);
497	  last_c = 0;
498	  break;
499	}
500    }
501}
502
503int
504main (int argc, char **argv)
505{
506  char *line;
507  FILE *in;
508  int lineno = 0;
509  int i;
510  VaryRef *vlist;
511
512  if (argc > 2 && strcmp (argv[1], "-l") == 0)
513    {
514      sim_log = fopen (argv[2], "w");
515      fprintf (stderr, "sim_log: %s\n", argv[2]);
516      argc -= 2;
517      argv += 2;
518    }
519
520  if (argc < 2)
521    {
522      fprintf (stderr, "usage: opc2c infile.opc > outfile.opc\n");
523      exit (1);
524    }
525
526  orig_filename = argv[1];
527  in = fopen (argv[1], "r");
528  if (!in)
529    {
530      fprintf (stderr, "Unable to open file %s for reading\n", argv[1]);
531      perror ("The error was");
532      exit (1);
533    }
534
535  n_opcodes = 0;
536  opcodes = (opcode **) malloc (sizeof (opcode *));
537  op = &prefix_text;
538  op->lineno = 1;
539  while ((line = safe_fgets (in)) != 0)
540    {
541      lineno++;
542      if (strncmp (line, "  /** ", 6) == 0
543	  && (isdigit (line[6]) || memcmp (line + 6, "VARY", 4) == 0))
544	line += 2;
545      if (line[0] == '/' && line[1] == '*' && line[2] == '*')
546	{
547	  if (strncmp (line, "/** */", 6) == 0)
548	    {
549	      op = &suffix_text;
550	      op->lineno = lineno;
551	    }
552	  else if (strncmp (line, "/** VARY ", 9) == 0)
553	    process_vary (line + 9);
554	  else
555	    {
556	      char *lp;
557	      int i, bit, byte;
558	      int var_start = 1;
559
560	      n_opcodes++;
561	      opcodes =
562		(opcode **) realloc (opcodes, n_opcodes * sizeof (opcode *));
563	      op = (opcode *) malloc (sizeof (opcode));
564	      opcodes[n_opcodes - 1] = op;
565
566	      op->nbytes = op->dbytes = 0;
567	      memset (op->id, 0, sizeof (op->id));
568	      memset (op->var_start, 0, sizeof (op->var_start));
569	      for (i = 0; i < MAX_BYTES; i++)
570		{
571		  op->b[i].decodable_mask = 0;
572		  op->b[i].decodable_bits = 0;
573		}
574	      op->comment = strdup (line);
575	      op->comment[strlen (op->comment) - 1] = 0;
576	      while (op->comment[0] && isspace (op->comment[0]))
577		op->comment++;
578	      op->lineno = lineno;
579	      op->nlines = 0;
580	      op->lines = 0;
581	      op->last_ind = 0;
582	      op->semantics_label = 0;
583	      op->nvaries = 0;
584	      op->vary = 0;
585
586	      i = 0;
587	      for (lp = line + 4; *lp; lp++)
588		{
589		  bit = 7 - (i & 7);
590		  byte = i >> 3;
591
592		  if (strncmp (lp, "*/", 2) == 0)
593		    break;
594		  else if ((lp[0] == ' ' && lp[1] == ' ') || (lp[0] == '\t'))
595		    break;
596		  else if (*lp == ' ')
597		    var_start = 1;
598		  else
599		    {
600		      if (*lp == '0' || *lp == '1')
601			{
602			  op->b[byte].decodable_mask |= 1 << bit;
603			  var_start = 1;
604			  if (op->dbytes < byte + 1)
605			    op->dbytes = byte + 1;
606			}
607		      else if (var_start)
608			{
609			  op->var_start[i] = 1;
610			  var_start = 0;
611			}
612		      if (*lp == '1')
613			op->b[byte].decodable_bits |= 1 << bit;
614
615		      op->nbytes = byte + 1;
616		      op->id[i++] = *lp;
617		    }
618		}
619	    }
620	}
621      else
622	{
623	  op->nlines++;
624	  if (op->lines)
625	    op->lines =
626	      (char **) realloc (op->lines, op->nlines * sizeof (char *));
627	  else
628	    op->lines = (char **) malloc (op->nlines * sizeof (char *));
629	  op->lines[op->nlines - 1] = strdup (line);
630	}
631    }
632
633  {
634    int i, j;
635    for (i = 0; i < n_varies; i++)
636      {
637	Vary *v = vary[i];
638	lprintf (sim_log, "V[%s] %d\n", v->name, v->nlen);
639	for (j = 0; j < v->n_patterns; j++)
640	  lprintf (sim_log, "  P %02x\n", v->patterns[j]);
641      }
642  }
643
644  for (i = n_opcodes - 2; i >= 0; i--)
645    {
646      if (opcodes[i]->nlines == 0)
647	{
648	  opcodes[i]->nlines = opcodes[i + 1]->nlines;
649	  opcodes[i]->lines = opcodes[i + 1]->lines;
650	}
651    }
652
653  for (i = 0; i < 256; i++)
654    indirect[i].type = T_unused;
655
656  qsort (opcodes, n_opcodes, sizeof (opcodes[0]), op_cmp);
657
658  vlist = (VaryRef *) malloc (n_varies * sizeof (VaryRef));
659
660  for (i = 0; i < n_opcodes; i++)
661    {
662      int j, b, v;
663
664      for (j = 0; j < opcodes[i]->nbytes; j++)
665	lprintf (sim_log, "%s ",
666		 prmb (opcodes[i]->b[j].decodable_mask,
667		       opcodes[i]->b[j].decodable_bits));
668      lprintf (sim_log, " %s\n", opcodes[i]->comment);
669
670      for (j = 0; j < opcodes[i]->nbytes; j++)
671	{
672	  for (b = 0; b < 8; b++)
673	    if (isalpha (opcodes[i]->id[j * 8 + b]))
674	      for (v = 0; v < n_varies; v++)
675		if (fieldcmp (opcodes[i], j * 8 + b, vary[v]->name))
676		  {
677		    int nv = opcodes[i]->nvaries++;
678		    if (nv)
679		      opcodes[i]->vary =
680			(VaryRef *) realloc (opcodes[i]->vary,
681					     (nv + 1) * sizeof (VaryRef));
682		    else
683		      opcodes[i]->vary =
684			(VaryRef *) malloc ((nv + 1) * sizeof (VaryRef));
685
686		    opcodes[i]->vary[nv].varyno = v;
687		    opcodes[i]->vary[nv].byte = j;
688		    opcodes[i]->vary[nv].shift = 8 - b - vary[v]->nlen;
689		    lprintf (sim_log, "[vary %s shift %d]\n",
690			     vary[v]->name, opcodes[i]->vary[nv].shift);
691		  }
692
693	}
694    }
695
696  for (i = 0; i < n_opcodes; i++)
697    {
698      int i2;
699      int bytes = opcodes[i]->dbytes;
700
701      lprintf (sim_log, "\nmask:");
702      for (i2 = 0; i2 < opcodes[i]->nbytes; i2++)
703	lprintf (sim_log, " %02x", opcodes[i]->b[i2].decodable_mask);
704      lprintf (sim_log, "%*s%s\n", 13 - 3 * opcodes[i]->nbytes, "",
705	       opcodes[i]->comment);
706
707      lprintf (sim_log, "bits:");
708      for (i2 = 0; i2 < opcodes[i]->nbytes; i2++)
709	lprintf (sim_log, " %02x", opcodes[i]->b[i2].decodable_bits);
710      lprintf (sim_log, "%*s(%s) %d byte%s\n", 13 - 3 * opcodes[i]->nbytes,
711	       "", opcodes[i]->id, bytes, bytes == 1 ? "" : "s");
712
713      store_opcode_bits (opcodes[i], 0, indirect);
714    }
715
716  dump_lines (&prefix_text, 0, 0);
717
718  emit_indirect (indirect, 0);
719
720  dump_lines (&suffix_text, 0, 0);
721
722  if (sim_log)
723    log_indirect (indirect, 0);
724
725  return errors;
726}
727