1 /*--------------------------------------------------------------------*/
2 /*--- Callgrind ---*/
3 /*--- bbcc.c ---*/
4 /*--------------------------------------------------------------------*/
5
6 /*
7 This file is part of Callgrind, a Valgrind tool for call tracing.
8
9 Copyright (C) 2002-2013, Josef Weidendorfer (Josef.Weidendorfer@gmx.de)
10
11 This program is free software; you can redistribute it and/or
12 modify it under the terms of the GNU General Public License as
13 published by the Free Software Foundation; either version 2 of the
14 License, or (at your option) any later version.
15
16 This program is distributed in the hope that it will be useful, but
17 WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
24 02111-1307, USA.
25
26 The GNU General Public License is contained in the file COPYING.
27 */
28
29 #include "global.h"
30 #include "costs.h"
31
32 #include "pub_tool_threadstate.h"
33
34 /*------------------------------------------------------------*/
35 /*--- BBCC operations ---*/
36 /*------------------------------------------------------------*/
37
38 #define N_BBCC_INITIAL_ENTRIES 10437
39
40 /* BBCC table (key is BB/Context), per thread, resizable */
41 bbcc_hash current_bbccs;
42
CLG_(init_bbcc_hash)43 void CLG_(init_bbcc_hash)(bbcc_hash* bbccs)
44 {
45 Int i;
46
47 CLG_ASSERT(bbccs != 0);
48
49 bbccs->size = N_BBCC_INITIAL_ENTRIES;
50 bbccs->entries = 0;
51 bbccs->table = (BBCC**) CLG_MALLOC("cl.bbcc.ibh.1",
52 bbccs->size * sizeof(BBCC*));
53
54 for (i = 0; i < bbccs->size; i++) bbccs->table[i] = NULL;
55 }
56
CLG_(copy_current_bbcc_hash)57 void CLG_(copy_current_bbcc_hash)(bbcc_hash* dst)
58 {
59 CLG_ASSERT(dst != 0);
60
61 dst->size = current_bbccs.size;
62 dst->entries = current_bbccs.entries;
63 dst->table = current_bbccs.table;
64 }
65
CLG_(get_current_bbcc_hash)66 bbcc_hash* CLG_(get_current_bbcc_hash)()
67 {
68 return ¤t_bbccs;
69 }
70
CLG_(set_current_bbcc_hash)71 void CLG_(set_current_bbcc_hash)(bbcc_hash* h)
72 {
73 CLG_ASSERT(h != 0);
74
75 current_bbccs.size = h->size;
76 current_bbccs.entries = h->entries;
77 current_bbccs.table = h->table;
78 }
79
80 /*
81 * Zero all costs of a BBCC
82 */
CLG_(zero_bbcc)83 void CLG_(zero_bbcc)(BBCC* bbcc)
84 {
85 Int i;
86 jCC* jcc;
87
88 CLG_ASSERT(bbcc->cxt != 0);
89 CLG_DEBUG(1, " zero_bbcc: BB %#lx, Cxt %d "
90 "(fn '%s', rec %d)\n",
91 bb_addr(bbcc->bb),
92 bbcc->cxt->base_number + bbcc->rec_index,
93 bbcc->cxt->fn[0]->name,
94 bbcc->rec_index);
95
96 if ((bbcc->ecounter_sum ==0) &&
97 (bbcc->ret_counter ==0)) return;
98
99 for(i=0;i<bbcc->bb->cost_count;i++)
100 bbcc->cost[i] = 0;
101 for(i=0;i <= bbcc->bb->cjmp_count;i++) {
102 bbcc->jmp[i].ecounter = 0;
103 for(jcc=bbcc->jmp[i].jcc_list; jcc; jcc=jcc->next_from)
104 CLG_(init_cost)( CLG_(sets).full, jcc->cost );
105 }
106 bbcc->ecounter_sum = 0;
107 bbcc->ret_counter = 0;
108 }
109
110
111
CLG_(forall_bbccs)112 void CLG_(forall_bbccs)(void (*func)(BBCC*))
113 {
114 BBCC *bbcc, *bbcc2;
115 int i, j;
116
117 for (i = 0; i < current_bbccs.size; i++) {
118 if ((bbcc=current_bbccs.table[i]) == NULL) continue;
119 while (bbcc) {
120 /* every bbcc should have a rec_array */
121 CLG_ASSERT(bbcc->rec_array != 0);
122
123 for(j=0;j<bbcc->cxt->fn[0]->separate_recursions;j++) {
124 if ((bbcc2 = bbcc->rec_array[j]) == 0) continue;
125
126 (*func)(bbcc2);
127 }
128 bbcc = bbcc->next;
129 }
130 }
131 }
132
133
134 /* All BBCCs for recursion level 0 are inserted into a
135 * thread specific hash table with key
136 * - address of BB structure (unique, as never freed)
137 * - current context (includes caller chain)
138 * BBCCs for other recursion levels are in bbcc->rec_array.
139 *
140 * The hash is used in setup_bb(), i.e. to find the cost
141 * counters to be changed in the execution of a BB.
142 */
143
144 static __inline__
bbcc_hash_idx(BB * bb,Context * cxt,UInt size)145 UInt bbcc_hash_idx(BB* bb, Context* cxt, UInt size)
146 {
147 CLG_ASSERT(bb != 0);
148 CLG_ASSERT(cxt != 0);
149
150 return ((Addr)bb + (Addr)cxt) % size;
151 }
152
153
154 /* Lookup for a BBCC in hash.
155 */
156 static
lookup_bbcc(BB * bb,Context * cxt)157 BBCC* lookup_bbcc(BB* bb, Context* cxt)
158 {
159 BBCC* bbcc = bb->last_bbcc;
160 UInt idx;
161
162 /* check LRU */
163 if (bbcc->cxt == cxt) {
164 if (!CLG_(clo).separate_threads) {
165 /* if we don't dump threads separate, tid doesn't have to match */
166 return bbcc;
167 }
168 if (bbcc->tid == CLG_(current_tid)) return bbcc;
169 }
170
171 CLG_(stat).bbcc_lru_misses++;
172
173 idx = bbcc_hash_idx(bb, cxt, current_bbccs.size);
174 bbcc = current_bbccs.table[idx];
175 while (bbcc &&
176 (bb != bbcc->bb ||
177 cxt != bbcc->cxt)) {
178 bbcc = bbcc->next;
179 }
180
181 CLG_DEBUG(2," lookup_bbcc(BB %#lx, Cxt %d, fn '%s'): %p (tid %d)\n",
182 bb_addr(bb), cxt->base_number, cxt->fn[0]->name,
183 bbcc, bbcc ? bbcc->tid : 0);
184
185 CLG_DEBUGIF(2)
186 if (bbcc) CLG_(print_bbcc)(-2,bbcc);
187
188 return bbcc;
189 }
190
191
192 /* double size of hash table 1 (addr->BBCC) */
resize_bbcc_hash(void)193 static void resize_bbcc_hash(void)
194 {
195 Int i, new_size, conflicts1 = 0, conflicts2 = 0;
196 BBCC** new_table;
197 UInt new_idx;
198 BBCC *curr_BBCC, *next_BBCC;
199
200 new_size = 2*current_bbccs.size+3;
201 new_table = (BBCC**) CLG_MALLOC("cl.bbcc.rbh.1",
202 new_size * sizeof(BBCC*));
203
204 if (!new_table) return;
205
206 for (i = 0; i < new_size; i++)
207 new_table[i] = NULL;
208
209 for (i = 0; i < current_bbccs.size; i++) {
210 if (current_bbccs.table[i] == NULL) continue;
211
212 curr_BBCC = current_bbccs.table[i];
213 while (NULL != curr_BBCC) {
214 next_BBCC = curr_BBCC->next;
215
216 new_idx = bbcc_hash_idx(curr_BBCC->bb,
217 curr_BBCC->cxt,
218 new_size);
219
220 curr_BBCC->next = new_table[new_idx];
221 new_table[new_idx] = curr_BBCC;
222 if (curr_BBCC->next) {
223 conflicts1++;
224 if (curr_BBCC->next->next)
225 conflicts2++;
226 }
227
228 curr_BBCC = next_BBCC;
229 }
230 }
231
232 VG_(free)(current_bbccs.table);
233
234
235 CLG_DEBUG(0,"Resize BBCC Hash: %d => %d (entries %d, conflicts %d/%d)\n",
236 current_bbccs.size, new_size,
237 current_bbccs.entries, conflicts1, conflicts2);
238
239 current_bbccs.size = new_size;
240 current_bbccs.table = new_table;
241 CLG_(stat).bbcc_hash_resizes++;
242 }
243
244
245 static __inline
new_recursion(int size)246 BBCC** new_recursion(int size)
247 {
248 BBCC** bbccs;
249 int i;
250
251 bbccs = (BBCC**) CLG_MALLOC("cl.bbcc.nr.1", sizeof(BBCC*) * size);
252 for(i=0;i<size;i++)
253 bbccs[i] = 0;
254
255 CLG_DEBUG(3," new_recursion(size %d): %p\n", size, bbccs);
256
257 return bbccs;
258 }
259
260
261 /*
262 * Allocate a new BBCC
263 *
264 * Uninitialized:
265 * cxt, rec_index, rec_array, next_bbcc, next1, next2
266 */
267 static __inline__
new_bbcc(BB * bb)268 BBCC* new_bbcc(BB* bb)
269 {
270 BBCC* bbcc;
271 Int i;
272
273 /* We need cjmp_count+1 JmpData structs:
274 * the last is for the unconditional jump/call/ret at end of BB
275 */
276 bbcc = (BBCC*)CLG_MALLOC("cl.bbcc.nb.1",
277 sizeof(BBCC) +
278 (bb->cjmp_count+1) * sizeof(JmpData));
279 bbcc->bb = bb;
280 bbcc->tid = CLG_(current_tid);
281
282 bbcc->ret_counter = 0;
283 bbcc->skipped = 0;
284 bbcc->cost = CLG_(get_costarray)(bb->cost_count);
285 for(i=0;i<bb->cost_count;i++)
286 bbcc->cost[i] = 0;
287 for(i=0; i<=bb->cjmp_count; i++) {
288 bbcc->jmp[i].ecounter = 0;
289 bbcc->jmp[i].jcc_list = 0;
290 }
291 bbcc->ecounter_sum = 0;
292
293 /* Init pointer caches (LRU) */
294 bbcc->lru_next_bbcc = 0;
295 bbcc->lru_from_jcc = 0;
296 bbcc->lru_to_jcc = 0;
297
298 CLG_(stat).distinct_bbccs++;
299
300 CLG_DEBUG(3, " new_bbcc(BB %#lx): %p (now %d)\n",
301 bb_addr(bb), bbcc, CLG_(stat).distinct_bbccs);
302
303 return bbcc;
304 }
305
306
307 /**
308 * Inserts a new BBCC into hashes.
309 * BBCC specific items must be set as this is used for the hash
310 * keys:
311 * fn : current function
312 * tid : current thread ID
313 * from : position where current function is called from
314 *
315 * Recursion level doesn't need to be set as this is not included
316 * in the hash key: Only BBCCs with rec level 0 are in hashes.
317 */
318 static
insert_bbcc_into_hash(BBCC * bbcc)319 void insert_bbcc_into_hash(BBCC* bbcc)
320 {
321 UInt idx;
322
323 CLG_ASSERT(bbcc->cxt != 0);
324
325 CLG_DEBUG(3,"+ insert_bbcc_into_hash(BB %#lx, fn '%s')\n",
326 bb_addr(bbcc->bb), bbcc->cxt->fn[0]->name);
327
328 /* check fill degree of hash and resize if needed (>90%) */
329 current_bbccs.entries++;
330 if (100 * current_bbccs.entries / current_bbccs.size > 90)
331 resize_bbcc_hash();
332
333 idx = bbcc_hash_idx(bbcc->bb, bbcc->cxt, current_bbccs.size);
334 bbcc->next = current_bbccs.table[idx];
335 current_bbccs.table[idx] = bbcc;
336
337 CLG_DEBUG(3,"- insert_bbcc_into_hash: %d entries\n",
338 current_bbccs.entries);
339 }
340
mangled_cxt(Context * cxt,int rec_index)341 static const HChar* mangled_cxt(Context* cxt, int rec_index)
342 {
343 static HChar mangled[FN_NAME_LEN];
344 int i, p;
345
346 if (!cxt) return "(no context)";
347
348 p = VG_(sprintf)(mangled, "%s", cxt->fn[0]->name);
349 if (rec_index >0)
350 p += VG_(sprintf)(mangled+p, "'%d", rec_index +1);
351 for(i=1;i<cxt->size;i++)
352 p += VG_(sprintf)(mangled+p, "'%s", cxt->fn[i]->name);
353
354 return mangled;
355 }
356
357
358 /* Create a new BBCC as a copy of an existing one,
359 * but with costs set to 0 and jcc chains empty.
360 *
361 * This is needed when a BB is executed in another context than
362 * the one at instrumentation time of the BB.
363 *
364 * Use cases:
365 * rec_index == 0: clone from a BBCC with differing tid/cxt
366 * and insert into hashes
367 * rec_index >0 : clone from a BBCC with same tid/cxt and rec_index 0
368 * don't insert into hashes
369 */
clone_bbcc(BBCC * orig,Context * cxt,Int rec_index)370 static BBCC* clone_bbcc(BBCC* orig, Context* cxt, Int rec_index)
371 {
372 BBCC* bbcc;
373
374 CLG_DEBUG(3,"+ clone_bbcc(BB %#lx, rec %d, fn %s)\n",
375 bb_addr(orig->bb), rec_index, cxt->fn[0]->name);
376
377 bbcc = new_bbcc(orig->bb);
378
379 if (rec_index == 0) {
380
381 /* hash insertion is only allowed if tid or cxt is different */
382 CLG_ASSERT((orig->tid != CLG_(current_tid)) ||
383 (orig->cxt != cxt));
384
385 bbcc->rec_index = 0;
386 bbcc->cxt = cxt;
387 bbcc->rec_array = new_recursion(cxt->fn[0]->separate_recursions);
388 bbcc->rec_array[0] = bbcc;
389
390 insert_bbcc_into_hash(bbcc);
391 }
392 else {
393 if (CLG_(clo).separate_threads)
394 CLG_ASSERT(orig->tid == CLG_(current_tid));
395
396 CLG_ASSERT(orig->cxt == cxt);
397 CLG_ASSERT(orig->rec_array);
398 CLG_ASSERT(cxt->fn[0]->separate_recursions > rec_index);
399 CLG_ASSERT(orig->rec_array[rec_index] ==0);
400
401 /* new BBCC will only have differing recursion level */
402 bbcc->rec_index = rec_index;
403 bbcc->cxt = cxt;
404 bbcc->rec_array = orig->rec_array;
405 bbcc->rec_array[rec_index] = bbcc;
406 }
407
408 /* update list of BBCCs for same BB */
409 bbcc->next_bbcc = orig->bb->bbcc_list;
410 orig->bb->bbcc_list = bbcc;
411
412
413 CLG_DEBUGIF(3)
414 CLG_(print_bbcc)(-2, bbcc);
415
416 // FIXME: mangled_cxt returns a pointer to a static buffer that
417 // gets overwritten with each invocation.
418 CLG_DEBUG(2,"- clone_BBCC(%p, %d) for BB %#lx\n"
419 " orig %s\n"
420 " new %s\n",
421 orig, rec_index, bb_addr(orig->bb),
422 mangled_cxt(orig->cxt, orig->rec_index),
423 mangled_cxt(bbcc->cxt, bbcc->rec_index));
424
425 CLG_(stat).bbcc_clones++;
426
427 return bbcc;
428 };
429
430
431
432 /* Get a pointer to the cost centre structure for given basic block
433 * address. If created, the BBCC is inserted into the BBCC hash.
434 * Also sets BB_seen_before by reference.
435 *
436 */
CLG_(get_bbcc)437 BBCC* CLG_(get_bbcc)(BB* bb)
438 {
439 BBCC* bbcc;
440
441 CLG_DEBUG(3, "+ get_bbcc(BB %#lx)\n", bb_addr(bb));
442
443 bbcc = bb->bbcc_list;
444
445 if (!bbcc) {
446 bbcc = new_bbcc(bb);
447
448 /* initialize BBCC */
449 bbcc->cxt = 0;
450 bbcc->rec_array = 0;
451 bbcc->rec_index = 0;
452
453 bbcc->next_bbcc = bb->bbcc_list;
454 bb->bbcc_list = bbcc;
455 bb->last_bbcc = bbcc;
456
457 CLG_DEBUGIF(3)
458 CLG_(print_bbcc)(-2, bbcc);
459 }
460
461 CLG_DEBUG(3, "- get_bbcc(BB %#lx): BBCC %p\n",
462 bb_addr(bb), bbcc);
463
464 return bbcc;
465 }
466
467
468 /* Callgrind manages its own call stack for each thread.
469 * When leaving a function, a underflow can happen when
470 * Callgrind's tracing was switched on in the middle of
471 * a run, i.e. when Callgrind was not able to trace the
472 * call instruction.
473 * This function tries to reconstruct the original call.
474 * As we know the return address (the address following
475 * the CALL instruction), we can detect the function
476 * we return back to, but the original call site is unknown.
477 * We suppose a call site at return address - 1.
478 * (TODO: other heuristic: lookup info of instrumented BBs).
479 */
handleUnderflow(BB * bb)480 static void handleUnderflow(BB* bb)
481 {
482 /* RET at top of call stack */
483 BBCC* source_bbcc;
484 BB* source_bb;
485 Bool seen_before;
486 fn_node* caller;
487 int fn_number;
488 unsigned *pactive;
489 call_entry* call_entry_up;
490
491 CLG_DEBUG(1," Callstack underflow !\n");
492
493 /* we emulate an old call from the function we return to
494 * by using (<return address> -1) */
495 source_bb = CLG_(get_bb)(bb_addr(bb)-1, 0, &seen_before);
496 source_bbcc = CLG_(get_bbcc)(source_bb);
497
498 /* seen_before can be true if RET from a signal handler */
499 if (!seen_before) {
500 source_bbcc->ecounter_sum = CLG_(current_state).collect ? 1 : 0;
501 }
502 else if (CLG_(current_state).collect)
503 source_bbcc->ecounter_sum++;
504
505 /* Force a new top context, will be set active by push_cxt() */
506 CLG_(current_fn_stack).top--;
507 CLG_(current_state).cxt = 0;
508 caller = CLG_(get_fn_node)(bb);
509 CLG_(push_cxt)( caller );
510
511 if (!seen_before) {
512 /* set rec array for source BBCC: this is at rec level 1 */
513 source_bbcc->rec_array = new_recursion(caller->separate_recursions);
514 source_bbcc->rec_array[0] = source_bbcc;
515
516 CLG_ASSERT(source_bbcc->cxt == 0);
517 source_bbcc->cxt = CLG_(current_state).cxt;
518 insert_bbcc_into_hash(source_bbcc);
519 }
520 CLG_ASSERT(CLG_(current_state).bbcc);
521
522 /* correct active counts */
523 fn_number = CLG_(current_state).bbcc->cxt->fn[0]->number;
524 pactive = CLG_(get_fn_entry)(fn_number);
525 (*pactive)--;
526
527 /* This assertion is not correct for reentrant
528 * signal handlers */
529 /* CLG_ASSERT(*pactive == 0); */
530
531 CLG_(current_state).nonskipped = 0; /* we didn't skip this function */
532 /* back to current context */
533 CLG_(push_cxt)( CLG_(current_state).bbcc->cxt->fn[0] );
534 CLG_(push_call_stack)(source_bbcc, 0, CLG_(current_state).bbcc,
535 (Addr)-1, False);
536 call_entry_up =
537 &(CLG_(current_call_stack).entry[CLG_(current_call_stack).sp -1]);
538 /* assume this call is lasting since last dump or
539 * for a signal handler since it's call */
540 if (CLG_(current_state).sig == 0)
541 CLG_(copy_cost)( CLG_(sets).full, call_entry_up->enter_cost,
542 CLG_(get_current_thread)()->lastdump_cost );
543 else
544 CLG_(zero_cost)( CLG_(sets).full, call_entry_up->enter_cost );
545 }
546
547
548 /*
549 * Helper function called at start of each instrumented BB to setup
550 * pointer to costs for current thread/context/recursion level
551 */
552
553 VG_REGPARM(1)
CLG_(setup_bbcc)554 void CLG_(setup_bbcc)(BB* bb)
555 {
556 BBCC *bbcc, *last_bbcc;
557 Bool call_emulation = False, delayed_push = False, skip = False;
558 Addr sp;
559 BB* last_bb;
560 ThreadId tid;
561 ClgJumpKind jmpkind;
562 Bool isConditionalJump;
563 Int passed = 0, csp;
564 Bool ret_without_call = False;
565 Int popcount_on_return = 1;
566
567 CLG_DEBUG(3,"+ setup_bbcc(BB %#lx)\n", bb_addr(bb));
568
569 /* This is needed because thread switches can not reliable be tracked
570 * with callback CLG_(run_thread) only: we have otherwise no way to get
571 * the thread ID after a signal handler returns.
572 * This could be removed again if that bug is fixed in Valgrind.
573 * This is in the hot path but hopefully not to costly.
574 */
575 tid = VG_(get_running_tid)();
576 #if 1
577 /* CLG_(switch_thread) is a no-op when tid is equal to CLG_(current_tid).
578 * As this is on the hot path, we only call CLG_(switch_thread)(tid)
579 * if tid differs from the CLG_(current_tid).
580 */
581 if (UNLIKELY(tid != CLG_(current_tid)))
582 CLG_(switch_thread)(tid);
583 #else
584 CLG_ASSERT(VG_(get_running_tid)() == CLG_(current_tid));
585 #endif
586
587 sp = VG_(get_SP)(tid);
588 last_bbcc = CLG_(current_state).bbcc;
589 last_bb = last_bbcc ? last_bbcc->bb : 0;
590
591 if (last_bb) {
592 passed = CLG_(current_state).jmps_passed;
593 CLG_ASSERT(passed <= last_bb->cjmp_count);
594 jmpkind = last_bb->jmp[passed].jmpkind;
595 isConditionalJump = (passed < last_bb->cjmp_count);
596
597 if (CLG_(current_state).collect) {
598 if (!CLG_(current_state).nonskipped) {
599 last_bbcc->ecounter_sum++;
600 last_bbcc->jmp[passed].ecounter++;
601 if (!CLG_(clo).simulate_cache) {
602 /* update Ir cost */
603 UInt instr_count = last_bb->jmp[passed].instr+1;
604 CLG_(current_state).cost[ fullOffset(EG_IR) ] += instr_count;
605 }
606 }
607 else {
608 /* do not increment exe counter of BBs in skipped functions, as it
609 * would fool dumping code */
610 if (!CLG_(clo).simulate_cache) {
611 /* update Ir cost */
612 UInt instr_count = last_bb->jmp[passed].instr+1;
613 CLG_(current_state).cost[ fullOffset(EG_IR) ] += instr_count;
614 CLG_(current_state).nonskipped->skipped[ fullOffset(EG_IR) ]
615 += instr_count;
616 }
617 }
618 }
619
620 CLG_DEBUGIF(4) {
621 CLG_(print_execstate)(-2, &CLG_(current_state) );
622 CLG_(print_bbcc_cost)(-2, last_bbcc);
623 }
624 }
625 else {
626 jmpkind = jk_None;
627 isConditionalJump = False;
628 }
629
630 /* Manipulate JmpKind if needed, only using BB specific info */
631
632 csp = CLG_(current_call_stack).sp;
633
634 /* A return not matching the top call in our callstack is a jump */
635 if ( (jmpkind == jk_Return) && (csp >0)) {
636 Int csp_up = csp-1;
637 call_entry* top_ce = &(CLG_(current_call_stack).entry[csp_up]);
638
639 /* We have a real return if
640 * - the stack pointer (SP) left the current stack frame, or
641 * - SP has the same value as when reaching the current function
642 * and the address of this BB is the return address of last call
643 * (we even allow to leave multiple frames if the SP stays the
644 * same and we find a matching return address)
645 * The latter condition is needed because on PPC, SP can stay
646 * the same over CALL=b(c)l / RET=b(c)lr boundaries
647 */
648 if (sp < top_ce->sp) popcount_on_return = 0;
649 else if (top_ce->sp == sp) {
650 while(1) {
651 if (top_ce->ret_addr == bb_addr(bb)) break;
652 if (csp_up>0) {
653 csp_up--;
654 top_ce = &(CLG_(current_call_stack).entry[csp_up]);
655 if (top_ce->sp == sp) {
656 popcount_on_return++;
657 continue;
658 }
659 }
660 popcount_on_return = 0;
661 break;
662 }
663 }
664 if (popcount_on_return == 0) {
665 jmpkind = jk_Jump;
666 ret_without_call = True;
667 }
668 }
669
670 /* Should this jump be converted to call or pop/call ? */
671 if (( jmpkind != jk_Return) &&
672 ( jmpkind != jk_Call) && last_bb) {
673
674 /* We simulate a JMP/Cont to be a CALL if
675 * - jump is in another ELF object or section kind
676 * - jump is to first instruction of a function (tail recursion)
677 */
678 if (ret_without_call ||
679 /* This is for detection of optimized tail recursion.
680 * On PPC, this is only detected as call when going to another
681 * function. The problem is that on PPC it can go wrong
682 * more easily (no stack frame setup needed)
683 */
684 #if defined(VGA_ppc32)
685 (bb->is_entry && (last_bb->fn != bb->fn)) ||
686 #else
687 bb->is_entry ||
688 #endif
689 (last_bb->sect_kind != bb->sect_kind) ||
690 (last_bb->obj->number != bb->obj->number)) {
691
692 CLG_DEBUG(1," JMP: %s[%s] to %s[%s]%s!\n",
693 last_bb->fn->name, last_bb->obj->name,
694 bb->fn->name, bb->obj->name,
695 ret_without_call?" (RET w/o CALL)":"");
696
697 if (CLG_(get_fn_node)(last_bb)->pop_on_jump && (csp>0)) {
698
699 call_entry* top_ce = &(CLG_(current_call_stack).entry[csp-1]);
700
701 if (top_ce->jcc) {
702
703 CLG_DEBUG(1," Pop on Jump!\n");
704
705 /* change source for delayed push */
706 CLG_(current_state).bbcc = top_ce->jcc->from;
707 sp = top_ce->sp;
708 passed = top_ce->jcc->jmp;
709 CLG_(pop_call_stack)();
710 }
711 else {
712 CLG_ASSERT(CLG_(current_state).nonskipped != 0);
713 }
714 }
715
716 jmpkind = jk_Call;
717 call_emulation = True;
718 }
719 }
720
721 if (jmpkind == jk_Call)
722 skip = CLG_(get_fn_node)(bb)->skip;
723
724 CLG_DEBUGIF(1) {
725 if (isConditionalJump)
726 VG_(printf)("Cond-");
727 switch(jmpkind) {
728 case jk_None: VG_(printf)("Fall-through"); break;
729 case jk_Jump: VG_(printf)("Jump"); break;
730 case jk_Call: VG_(printf)("Call"); break;
731 case jk_Return: VG_(printf)("Return"); break;
732 default: tl_assert(0);
733 }
734 VG_(printf)(" %08lx -> %08lx, SP %08lx\n",
735 last_bb ? bb_jmpaddr(last_bb) : 0,
736 bb_addr(bb), sp);
737 }
738
739 /* Handle CALL/RET and update context to get correct BBCC */
740
741 if (jmpkind == jk_Return) {
742
743 if ((csp == 0) ||
744 ((CLG_(current_fn_stack).top > CLG_(current_fn_stack).bottom) &&
745 ( *(CLG_(current_fn_stack).top-1)==0)) ) {
746
747 /* On an empty call stack or at a signal separation marker,
748 * a RETURN generates an call stack underflow.
749 */
750 handleUnderflow(bb);
751 CLG_(pop_call_stack)();
752 }
753 else {
754 CLG_ASSERT(popcount_on_return >0);
755 CLG_(unwind_call_stack)(sp, popcount_on_return);
756 }
757 }
758 else {
759 Int unwind_count = CLG_(unwind_call_stack)(sp, 0);
760 if (unwind_count > 0) {
761 /* if unwinding was done, this actually is a return */
762 jmpkind = jk_Return;
763 }
764
765 if (jmpkind == jk_Call) {
766 delayed_push = True;
767
768 csp = CLG_(current_call_stack).sp;
769 if (call_emulation && csp>0)
770 sp = CLG_(current_call_stack).entry[csp-1].sp;
771
772 }
773 }
774
775 /* Change new context if needed, taking delayed_push into account */
776 if ((delayed_push && !skip) || (CLG_(current_state).cxt == 0)) {
777 CLG_(push_cxt)(CLG_(get_fn_node)(bb));
778 }
779 CLG_ASSERT(CLG_(current_fn_stack).top > CLG_(current_fn_stack).bottom);
780
781 /* If there is a fresh instrumented BBCC, assign current context */
782 bbcc = CLG_(get_bbcc)(bb);
783 if (bbcc->cxt == 0) {
784 CLG_ASSERT(bbcc->rec_array == 0);
785
786 bbcc->cxt = CLG_(current_state).cxt;
787 bbcc->rec_array =
788 new_recursion((*CLG_(current_fn_stack).top)->separate_recursions);
789 bbcc->rec_array[0] = bbcc;
790
791 insert_bbcc_into_hash(bbcc);
792 }
793 else {
794 /* get BBCC with current context */
795
796 /* first check LRU of last bbcc executed */
797
798 if (last_bbcc) {
799 bbcc = last_bbcc->lru_next_bbcc;
800 if (bbcc &&
801 ((bbcc->bb != bb) ||
802 (bbcc->cxt != CLG_(current_state).cxt)))
803 bbcc = 0;
804 }
805 else
806 bbcc = 0;
807
808 if (!bbcc)
809 bbcc = lookup_bbcc(bb, CLG_(current_state).cxt);
810 if (!bbcc)
811 bbcc = clone_bbcc(bb->bbcc_list, CLG_(current_state).cxt, 0);
812
813 bb->last_bbcc = bbcc;
814 }
815
816 /* save for fast lookup */
817 if (last_bbcc)
818 last_bbcc->lru_next_bbcc = bbcc;
819
820 if ((*CLG_(current_fn_stack).top)->separate_recursions >1) {
821 UInt level, idx;
822 fn_node* top = *(CLG_(current_fn_stack).top);
823
824 level = *CLG_(get_fn_entry)(top->number);
825
826 if (delayed_push && !skip) {
827 if (CLG_(clo).skip_direct_recursion) {
828 /* a call was detected, which means that the source BB != 0 */
829 CLG_ASSERT(CLG_(current_state).bbcc != 0);
830 /* only increment rec. level if called from different function */
831 if (CLG_(current_state).bbcc->cxt->fn[0] != bbcc->cxt->fn[0])
832 level++;
833 }
834 else level++;
835 }
836 if (level> top->separate_recursions)
837 level = top->separate_recursions;
838
839 if (level == 0) {
840 /* can only happen if instrumentation just was switched on */
841 level = 1;
842 *CLG_(get_fn_entry)(top->number) = 1;
843 }
844
845 idx = level -1;
846 if (bbcc->rec_array[idx])
847 bbcc = bbcc->rec_array[idx];
848 else
849 bbcc = clone_bbcc(bbcc, CLG_(current_state).cxt, idx);
850
851 CLG_ASSERT(bbcc->rec_array[bbcc->rec_index] == bbcc);
852 }
853
854 if (delayed_push) {
855 if (!skip && CLG_(current_state).nonskipped) {
856 /* a call from skipped to nonskipped */
857 CLG_(current_state).bbcc = CLG_(current_state).nonskipped;
858 /* FIXME: take the real passed count from shadow stack */
859 passed = CLG_(current_state).bbcc->bb->cjmp_count;
860 }
861 CLG_(push_call_stack)(CLG_(current_state).bbcc, passed,
862 bbcc, sp, skip);
863 }
864
865 if (CLG_(clo).collect_jumps && (jmpkind == jk_Jump)) {
866
867 /* Handle conditional jumps followed, i.e. trace arcs
868 * This uses JCC structures, too */
869
870 jCC* jcc = CLG_(get_jcc)(last_bbcc, passed, bbcc);
871 CLG_ASSERT(jcc != 0);
872 // Change from default, and check if already changed
873 if (jcc->jmpkind == jk_Call)
874 jcc->jmpkind = isConditionalJump ? jk_CondJump : jk_Jump;
875 else {
876 // FIXME: Why can this fail?
877 // CLG_ASSERT(jcc->jmpkind == jmpkind);
878 }
879
880 jcc->call_counter++;
881 if (isConditionalJump)
882 CLG_(stat).jcnd_counter++;
883 else
884 CLG_(stat).jump_counter++;
885 }
886
887 CLG_(current_state).bbcc = bbcc;
888 /* Even though this will be set in instrumented code directly before
889 * side exits, it needs to be set to 0 here in case an exception
890 * happens in first instructions of the BB */
891 CLG_(current_state).jmps_passed = 0;
892 // needed for log_* handlers called in this BB
893 CLG_(bb_base) = bb->obj->offset + bb->offset;
894 CLG_(cost_base) = bbcc->cost;
895
896 CLG_DEBUGIF(1) {
897 VG_(printf)(" ");
898 CLG_(print_bbcc_fn)(bbcc);
899 VG_(printf)("\n");
900 }
901
902 CLG_DEBUG(3,"- setup_bbcc (BB %#lx): Cost %p (Len %d), Instrs %d (Len %d)\n",
903 bb_addr(bb), bbcc->cost, bb->cost_count,
904 bb->instr_count, bb->instr_len);
905 CLG_DEBUGIF(3)
906 CLG_(print_cxt)(-8, CLG_(current_state).cxt, bbcc->rec_index);
907 CLG_DEBUG(3,"\n");
908
909 CLG_(stat).bb_executions++;
910 }
911