1/* Engine header for Cpu tools GENerated simulators.
2   Copyright (C) 1998-2020 Free Software Foundation, Inc.
3   Contributed by Cygnus Support.
4
5This file is part of GDB, the GNU debugger.
6
7This program is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3 of the License, or
10(at your option) any later version.
11
12This program is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20/* This file is included by ${cpu}.h.
21   It needs CGEN_INSN_WORD which is defined by ${cpu}.h.
22   ??? A lot of this could be moved to genmloop.sh to be put in eng.h
23   and thus remove some conditional compilation.  We'd still need
24   CGEN_INSN_WORD though.  */
25
26/* Semantic functions come in six versions on two axes:
27   fast/full-featured, and using one of the simple/scache/compilation engines.
28   A full featured simulator is always provided.  --enable-sim-fast includes
29   support for fast execution by duplicating the semantic code but leaving
30   out all features like tracing and profiling.
31   Using the scache is selected with --enable-sim-scache.  */
32/* FIXME: --enable-sim-fast not implemented yet.  */
33/* FIXME: undecided how to handle WITH_SCACHE_PBB.  */
34
35/* There are several styles of engines, all generally supported by the
36   same code:
37
38   WITH_SCACHE && WITH_SCACHE_PBB - pseudo-basic-block scaching
39   WITH_SCACHE && !WITH_SCACHE_PBB - scaching on an insn by insn basis
40   !WITH_SCACHE - simple engine: fetch an insn, execute an insn
41
42   The !WITH_SCACHE case can also be broken up into two flavours:
43   extract the fields of the insn into an ARGBUF struct, or defer the
44   extraction to the semantic handler.  The former can be viewed as the
45   WITH_SCACHE case with a cache size of 1 (thus there's no need for a
46   WITH_EXTRACTION macro).  The WITH_SCACHE case always extracts the fields
47   into an ARGBUF struct.  */
48
49#ifndef CGEN_ENGINE_H
50#define CGEN_ENGINE_H
51
52/* Instruction field support macros.  */
53
54#define EXTRACT_MSB0_SINT(val, total, start, length) \
55(((INT) (val) << ((sizeof (INT) * 8) - (total) + (start))) \
56 >> ((sizeof (INT) * 8) - (length)))
57#define EXTRACT_MSB0_UINT(val, total, start, length) \
58(((UINT) (val) << ((sizeof (UINT) * 8) - (total) + (start))) \
59 >> ((sizeof (UINT) * 8) - (length)))
60
61#define EXTRACT_LSB0_SINT(val, total, start, length) \
62(((INT) (val) << ((sizeof (INT) * 8) - (start) - 1)) \
63 >> ((sizeof (INT) * 8) - (length)))
64#define EXTRACT_LSB0_UINT(val, total, start, length) \
65(((UINT) (val) << ((sizeof (UINT) * 8) - (start) - 1)) \
66 >> ((sizeof (UINT) * 8) - (length)))
67
68#define EXTRACT_MSB0_LGSINT(val, total, start, length) \
69(((CGEN_INSN_LGSINT) (val) << ((sizeof (CGEN_INSN_LGSINT) * 8) - (total) + (start))) \
70 >> ((sizeof (CGEN_INSN_LGSINT) * 8) - (length)))
71#define EXTRACT_MSB0_LGUINT(val, total, start, length) \
72(((CGEN_INSN_UINT) (val) << ((sizeof (CGEN_INSN_LGUINT) * 8) - (total) + (start))) \
73 >> ((sizeof (CGEN_INSN_LGUINT) * 8) - (length)))
74
75#define EXTRACT_LSB0_LGSINT(val, total, start, length) \
76(((CGEN_INSN_LGSINT) (val) << ((sizeof (CGEN_INSN_LGSINT) * 8) - (start) - 1)) \
77 >> ((sizeof (CGEN_INSN_LGSINT) * 8) - (length)))
78#define EXTRACT_LSB0_LGUINT(val, total, start, length) \
79(((CGEN_INSN_LGUINT) (val) << ((sizeof (CGEN_INSN_LGUINT) * 8) - (start) - 1)) \
80 >> ((sizeof (CGEN_INSN_LGUINT) * 8) - (length)))
81
82/* Semantic routines.  */
83
84/* Type of the machine generated extraction fns.  */
85/* ??? No longer used.  */
86typedef void (EXTRACT_FN) (SIM_CPU *, IADDR, CGEN_INSN_WORD, ARGBUF *);
87
88/* Type of the machine generated semantic fns.  */
89
90#if WITH_SCACHE
91
92/* Instruction fields are extracted into ARGBUF before calling the
93   semantic routine.  */
94#if HAVE_PARALLEL_INSNS && ! WITH_PARALLEL_GENWRITE
95typedef SEM_PC (SEMANTIC_FN) (SIM_CPU *, SEM_ARG, PAREXEC *);
96#else
97typedef SEM_PC (SEMANTIC_FN) (SIM_CPU *, SEM_ARG);
98#endif
99
100#else
101
102/* Result of semantic routines is a status indicator (wip).  */
103typedef unsigned int SEM_STATUS;
104
105/* Instruction fields are extracted by the semantic routine.
106   ??? TODO: multi word insns.  */
107#if HAVE_PARALLEL_INSNS && ! WITH_PARALLEL_GENWRITE
108typedef SEM_STATUS (SEMANTIC_FN) (SIM_CPU *, SEM_ARG, PAREXEC *, CGEN_INSN_WORD);
109#else
110typedef SEM_STATUS (SEMANTIC_FN) (SIM_CPU *, SEM_ARG, CGEN_INSN_WORD);
111#endif
112
113#endif
114
115/* In the ARGBUF struct, a pointer to the semantic routine for the insn.  */
116
117union sem {
118#if ! WITH_SEM_SWITCH_FULL
119  SEMANTIC_FN *sem_full;
120#endif
121#if ! WITH_SEM_SWITCH_FAST
122  SEMANTIC_FN *sem_fast;
123#endif
124#if WITH_SEM_SWITCH_FULL || WITH_SEM_SWITCH_FAST
125#ifdef __GNUC__
126  void *sem_case;
127#else
128  int sem_case;
129#endif
130#endif
131};
132
133/* Set the appropriate semantic handler in ABUF.  */
134
135#if WITH_SEM_SWITCH_FULL
136#ifdef __GNUC__
137#define SEM_SET_FULL_CODE(abuf, idesc) \
138  do { (abuf)->semantic.sem_case = (idesc)->sem_full_lab; } while (0)
139#else
140#define SEM_SET_FULL_CODE(abuf, idesc) \
141  do { (abuf)->semantic.sem_case = (idesc)->num; } while (0)
142#endif
143#else
144#define SEM_SET_FULL_CODE(abuf, idesc) \
145  do { (abuf)->semantic.sem_full = (idesc)->sem_full; } while (0)
146#endif
147
148#if WITH_SEM_SWITCH_FAST
149#ifdef __GNUC__
150#define SEM_SET_FAST_CODE(abuf, idesc) \
151  do { (abuf)->semantic.sem_case = (idesc)->sem_fast_lab; } while (0)
152#else
153#define SEM_SET_FAST_CODE(abuf, idesc) \
154  do { (abuf)->semantic.sem_case = (idesc)->num; } while (0)
155#endif
156#else
157#define SEM_SET_FAST_CODE(abuf, idesc) \
158  do { (abuf)->semantic.sem_fast = (idesc)->sem_fast; } while (0)
159#endif
160
161#define SEM_SET_CODE(abuf, idesc, fast_p) \
162do { \
163  if (fast_p) \
164    SEM_SET_FAST_CODE ((abuf), (idesc)); \
165  else \
166    SEM_SET_FULL_CODE ((abuf), (idesc)); \
167} while (0)
168
169/* Return non-zero if IDESC is a conditional or unconditional CTI.  */
170
171#define IDESC_CTI_P(idesc) \
172     ((CGEN_ATTR_BOOLS (CGEN_INSN_ATTRS ((idesc)->idata)) \
173       & (CGEN_ATTR_MASK (CGEN_INSN_COND_CTI) \
174	  | CGEN_ATTR_MASK (CGEN_INSN_UNCOND_CTI))) \
175      != 0)
176
177/* Return non-zero if IDESC is a skip insn.  */
178
179#define IDESC_SKIP_P(idesc) \
180     ((CGEN_ATTR_BOOLS (CGEN_INSN_ATTRS ((idesc)->idata)) \
181       & CGEN_ATTR_MASK (CGEN_INSN_SKIP_CTI)) \
182      != 0)
183
184/* Return pointer to ARGBUF given ptr to SCACHE.  */
185#define SEM_ARGBUF(sem_arg) (& (sem_arg) -> argbuf)
186
187#if WITH_SCACHE
188
189#if WITH_SCACHE_PBB
190
191/* Return the scache pointer of the current insn.  */
192#define SEM_SEM_ARG(vpc, sc) (vpc)
193
194/* Return the virtual pc of the next insn to execute
195   (assuming this isn't a cti or the branch isn't taken).  */
196#define SEM_NEXT_VPC(sem_arg, pc, len) ((sem_arg) + 1)
197
198/* Update the instruction counter.  */
199#define PBB_UPDATE_INSN_COUNT(cpu,sc) \
200  (CPU_INSN_COUNT (cpu) += SEM_ARGBUF (sc) -> fields.chain.insn_count)
201
202/* Do not append a `;' to invocations of this.
203   npc,br_type are for communication between the cti insn and cti-chain.  */
204#define SEM_BRANCH_INIT \
205  IADDR npc = 0; /* assign a value for -Wall */ \
206  SEM_BRANCH_TYPE br_type = SEM_BRANCH_UNTAKEN;
207
208/* SEM_IN_SWITCH is defined at the top of the mainloop.c files
209   generated by genmloop.sh.  It exists so generated semantic code needn't
210   care whether it's being put in a switch or in a function.  */
211#ifdef SEM_IN_SWITCH
212#define SEM_BRANCH_FINI(pcvar) \
213do { \
214  pbb_br_npc = npc; \
215  pbb_br_type = br_type; \
216} while (0)
217#else /* 1 semantic function per instruction */
218#define SEM_BRANCH_FINI(pcvar) \
219do { \
220  CPU_PBB_BR_NPC (current_cpu) = npc; \
221  CPU_PBB_BR_TYPE (current_cpu) = br_type; \
222} while (0)
223#endif
224
225#define SEM_BRANCH_VIA_CACHE(cpu, sc, newval, pcvar) \
226do { \
227  npc = (newval); \
228  br_type = SEM_BRANCH_CACHEABLE; \
229} while (0)
230
231#define SEM_BRANCH_VIA_ADDR(cpu, sc, newval, pcvar) \
232do { \
233  npc = (newval); \
234  br_type = SEM_BRANCH_UNCACHEABLE; \
235} while (0)
236
237#define SEM_SKIP_COMPILE(cpu, sc, skip) \
238do { \
239  SEM_ARGBUF (sc) -> skip_count = (skip); \
240} while (0)
241
242#define SEM_SKIP_INSN(cpu, sc, vpcvar) \
243do { \
244  (vpcvar) += SEM_ARGBUF (sc) -> skip_count; \
245} while (0)
246
247#else /* ! WITH_SCACHE_PBB */
248
249#define SEM_SEM_ARG(vpc, sc) (sc)
250
251#define SEM_NEXT_VPC(sem_arg, pc, len) ((pc) + (len))
252
253/* ??? May wish to move taken_p out of here and make it explicit.  */
254#define SEM_BRANCH_INIT \
255  int taken_p = 0;
256
257#ifndef TARGET_SEM_BRANCH_FINI
258#define TARGET_SEM_BRANCH_FINI(pcvar, taken_p)
259#endif
260#define SEM_BRANCH_FINI(pcvar) \
261  do { TARGET_SEM_BRANCH_FINI (pcvar, taken_p); } while (0)
262
263#define SEM_BRANCH_VIA_CACHE(cpu, sc, newval, pcvar) \
264do { \
265  (pcvar) = (newval); \
266  taken_p = 1; \
267} while (0)
268
269#define SEM_BRANCH_VIA_ADDR(cpu, sc, newval, pcvar) \
270do { \
271  (pcvar) = (newval); \
272  taken_p = 1; \
273} while (0)
274
275#endif /* ! WITH_SCACHE_PBB */
276
277#else /* ! WITH_SCACHE */
278
279/* This is the "simple" engine case.  */
280
281#define SEM_SEM_ARG(vpc, sc) (sc)
282
283#define SEM_NEXT_VPC(sem_arg, pc, len) ((pc) + (len))
284
285#define SEM_BRANCH_INIT \
286  int taken_p = 0;
287
288#define SEM_BRANCH_VIA_CACHE(cpu, abuf, newval, pcvar) \
289do { \
290  (pcvar) = (newval); \
291  taken_p = 1; \
292} while (0)
293
294#define SEM_BRANCH_VIA_ADDR(cpu, abuf, newval, pcvar) \
295do { \
296  (pcvar) = (newval); \
297  taken_p = 1; \
298} while (0)
299
300/* Finish off branch insns.
301   The target must define TARGET_SEM_BRANCH_FINI.
302   ??? This can probably go away when define-execute is finished.  */
303#define SEM_BRANCH_FINI(pcvar, bool_attrs) \
304  do { TARGET_SEM_BRANCH_FINI ((pcvar), (bool_attrs), taken_p); } while (0)
305
306/* Finish off non-branch insns.
307   The target must define TARGET_SEM_NBRANCH_FINI.
308   ??? This can probably go away when define-execute is finished.  */
309#define SEM_NBRANCH_FINI(pcvar, bool_attrs) \
310  do { TARGET_SEM_NBRANCH_FINI ((pcvar), (bool_attrs)); } while (0)
311
312#endif /* ! WITH_SCACHE */
313
314/* Instruction information.  */
315
316/* Sanity check, at most one of these may be true.  */
317#if WITH_PARALLEL_READ + WITH_PARALLEL_WRITE + WITH_PARALLEL_GENWRITE > 1
318#error "At most one of WITH_PARALLEL_{READ,WRITE,GENWRITE} can be true."
319#endif
320
321/* Compile time computable instruction data.  */
322
323struct insn_sem {
324  /* The instruction type (a number that identifies each insn over the
325     entire architecture).  */
326  CGEN_INSN_TYPE type;
327
328  /* Index in IDESC table.  */
329  int index;
330
331  /* Semantic format number.  */
332  int sfmt;
333
334#if HAVE_PARALLEL_INSNS && ! WITH_PARALLEL_ONLY
335  /* Index in IDESC table of parallel handler.  */
336  int par_index;
337#endif
338
339#if WITH_PARALLEL_READ
340  /* Index in IDESC table of read handler.  */
341  int read_index;
342#endif
343
344#if WITH_PARALLEL_WRITE
345  /* Index in IDESC table of writeback handler.  */
346  int write_index;
347#endif
348};
349
350/* Entry in semantic function table.
351   This information is copied to the insn descriptor table at run-time.  */
352
353struct sem_fn_desc {
354  /* Index in IDESC table.  */
355  int index;
356
357  /* Function to perform the semantics of the insn.  */
358  SEMANTIC_FN *fn;
359};
360
361/* Run-time computed instruction descriptor.  */
362
363struct idesc {
364#if WITH_SEM_SWITCH_FAST
365#ifdef __GNUC__
366  void *sem_fast_lab;
367#else
368  /* nothing needed, switch's on `num' member */
369#endif
370#else
371  SEMANTIC_FN *sem_fast;
372#endif
373
374#if WITH_SEM_SWITCH_FULL
375#ifdef __GNUC__
376  void *sem_full_lab;
377#else
378  /* nothing needed, switch's on `num' member */
379#endif
380#else
381  SEMANTIC_FN *sem_full;
382#endif
383
384  /* Parallel support.  */
385#if HAVE_PARALLEL_INSNS && (! WITH_PARALLEL_ONLY || (WITH_PARALLEL_ONLY && ! WITH_PARALLEL_GENWRITE))
386  /* Pointer to parallel handler if serial insn.
387     Pointer to readahead/writeback handler if parallel insn.  */
388  struct idesc *par_idesc;
389#endif
390
391  /* Instruction number (index in IDESC table, profile table).
392     Also used to switch on in non-gcc semantic switches.  */
393  int num;
394
395  /* Semantic format id.  */
396  int sfmt;
397
398  /* instruction data (name, attributes, size, etc.) */
399  const CGEN_INSN *idata;
400
401  /* instruction attributes, copied from `idata' for speed */
402  const CGEN_INSN_ATTR_TYPE *attrs;
403
404  /* instruction length in bytes, copied from `idata' for speed */
405  int length;
406
407  /* profiling/modelling support */
408  const INSN_TIMING *timing;
409};
410
411/* Tracing/profiling.  */
412
413/* Return non-zero if a before/after handler is needed.
414   When tracing/profiling a selected range there's no need to slow
415   down simulation of the other insns (except to get more accurate data!).
416
417   ??? May wish to profile all insns if doing insn tracing, or to
418   get more accurate cycle data.
419
420   First test ANY_P so we avoid a potentially expensive HIT_P call
421   [if there are lots of address ranges].  */
422
423#define PC_IN_TRACE_RANGE_P(cpu, pc) \
424  (TRACE_ANY_P (cpu) \
425   && ADDR_RANGE_HIT_P (TRACE_RANGE (CPU_TRACE_DATA (cpu)), (pc)))
426#define PC_IN_PROFILE_RANGE_P(cpu, pc) \
427  (PROFILE_ANY_P (cpu) \
428   && ADDR_RANGE_HIT_P (PROFILE_RANGE (CPU_PROFILE_DATA (cpu)), (pc)))
429
430#endif /* CGEN_ENGINE_H */
431