/*--------------------------------------------------------------------*/ /*--- Callgrind ---*/ /*--- ct_bbcc.c ---*/ /*--------------------------------------------------------------------*/ /* This file is part of Callgrind, a Valgrind tool for call tracing. Copyright (C) 2002-2004, Josef Weidendorfer (Josef.Weidendorfer@gmx.de) This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. The GNU General Public License is contained in the file COPYING. */ #include "ct_include.h" #include "ct_costs.h" Addr SK_(bb_base); ULong* SK_(cost_base); /*------------------------------------------------------------*/ /*--- BBCC operations ---*/ /*------------------------------------------------------------*/ #define N_BBCC_INITIAL_ENTRIES 10437 /* BBCC table (key is BB/Context), per thread, resizable */ bbcc_hash current_bbccs; void SK_(init_bbcc_hash)(bbcc_hash* bbccs) { Int i; CT_ASSERT(bbccs != 0); bbccs->size = N_BBCC_INITIAL_ENTRIES; bbccs->entries = 0; bbccs->table = (BBCC**) VG_(malloc)(bbccs->size * sizeof(BBCC*)); for (i = 0; i < bbccs->size; i++) bbccs->table[i] = NULL; } void SK_(copy_current_bbcc_hash)(bbcc_hash* dst) { CT_ASSERT(dst != 0); dst->size = current_bbccs.size; dst->entries = current_bbccs.entries; dst->table = current_bbccs.table; } bbcc_hash* SK_(get_current_bbcc_hash)() { return ¤t_bbccs; } void SK_(set_current_bbcc_hash)(bbcc_hash* h) { CT_ASSERT(h != 0); current_bbccs.size = h->size; current_bbccs.entries = h->entries; current_bbccs.table = h->table; } /* * Zero all costs of a BBCC */ void SK_(zero_bbcc)(BBCC* bbcc) { Int i; jCC* jcc; CT_ASSERT(bbcc->cxt != 0); CT_DEBUG(1, " zero_bbcc: BB 0x%x, Cxt %d " "(fn '%s', rec %d)\n", bb_addr(bbcc->bb), bbcc->cxt->base_number + bbcc->rec_index, bbcc->cxt->fn[0]->name, bbcc->rec_index); if ((bbcc->exe_counter ==0) && (bbcc->ret_counter ==0)) return; for(i=0;ibb->cost_count;i++) bbcc->cost[i] = 0; for(jcc=bbcc->jcc_list; jcc; jcc=jcc->next_from) SK_(init_cost)( SK_(sets).full, jcc->cost ); bbcc->exe_counter = 0; bbcc->ret_counter = 0; } void SK_(forall_bbccs)(void (*func)(BBCC*)) { BBCC *bbcc, *bbcc2; int i, j; for (i = 0; i < current_bbccs.size; i++) { if ((bbcc=current_bbccs.table[i]) == NULL) continue; while (bbcc) { /* every bbcc should have a rec_array */ CT_ASSERT(bbcc->rec_array != 0); for(j=0;jcxt->fn[0]->separate_recursions;j++) { if ((bbcc2 = bbcc->rec_array[j]) == 0) continue; (*func)(bbcc2); } bbcc = bbcc->next; } } } /* All BBCCs for recursion level 0 are inserted into a * thread specific hash table with key * - address of BB structure (unique, as never freed) * - current context (includes caller chain) * BBCCs for other recursion levels are in bbcc->rec_array. * * The hash is used in setup_bb(), i.e. to find the cost * counters to be changed in the execution of a BB. */ static __inline__ UInt hash_bbcc(BB* bb, Context* cxt, UInt size) { CT_ASSERT(bb != 0); CT_ASSERT(cxt != 0); return ((Addr)bb + (Addr)cxt) % size; } /* Lookup for a BBCC in hash. */ static BBCC* lookup_bbcc(BB* bb, Context* cxt) { BBCC* bbcc = bb->last_bbcc; UInt hash; /* check LRU */ if (bbcc->cxt == cxt) { if (!SK_(clo).separate_threads) { /* if we don't dump threads separate, tid doesn't have to match */ return bbcc; } if (bbcc->tid == SK_(current_tid)) return bbcc; } SK_(stat).bbcc_lru_misses++; hash = hash_bbcc(bb, cxt, current_bbccs.size); bbcc = current_bbccs.table[hash]; while (bbcc && (bb != bbcc->bb || cxt != bbcc->cxt)) { bbcc = bbcc->next; } CT_DEBUG(2," lookup_bbcc(BB 0x%x, Cxt %d, fn '%s'): 0x%p (tid %d)\n", bb_addr(bb), cxt->base_number, cxt->fn[0]->name, bbcc, bbcc ? bbcc->tid : 0); CT_DEBUGIF(2) if (bbcc) SK_(print_bbcc)(-2,bbcc,False); return bbcc; } /* double size of hash table 1 (addr->BBCC) */ static void resize_bbcc_hash() { Int i, new_size, conflicts1 = 0, conflicts2 = 0; BBCC** new_table; UInt new_hash; BBCC *curr_BBCC, *next_BBCC; new_size = 2*current_bbccs.size+3; new_table = (BBCC**) VG_(malloc)(new_size * sizeof(BBCC*)); if (!new_table) return; for (i = 0; i < new_size; i++) new_table[i] = NULL; for (i = 0; i < current_bbccs.size; i++) { if (current_bbccs.table[i] == NULL) continue; curr_BBCC = current_bbccs.table[i]; while (NULL != curr_BBCC) { next_BBCC = curr_BBCC->next; new_hash = hash_bbcc(curr_BBCC->bb, curr_BBCC->cxt, new_size); curr_BBCC->next = new_table[new_hash]; new_table[new_hash] = curr_BBCC; if (curr_BBCC->next) { conflicts1++; if (curr_BBCC->next->next) conflicts2++; } curr_BBCC = next_BBCC; } } VG_(free)(current_bbccs.table); CT_DEBUG(0,"Resize BBCC Hash: %d => %d (entries %d, conflicts %d/%d)\n", current_bbccs.size, new_size, current_bbccs.entries, conflicts1, conflicts2); current_bbccs.size = new_size; current_bbccs.table = new_table; SK_(stat).bbcc_hash_resizes++; } static __inline BBCC** new_recursion(int size) { BBCC** bbccs; int i; bbccs = (BBCC**) VG_(malloc)(sizeof(BBCC*) * size); for(i=0;ibb = bb; new->tid = SK_(current_tid); new->exe_counter = 0; new->ret_counter = 0; new->skipped = 0; new->cost = SK_(get_costarray)(bb->cost_count); for(i=0;icost_count;i++) new->cost[i] = 0; /* Init pointer caches (LRU) */ new->lru_next_bbcc = 0; new->lru_from_jcc = 0; new->lru_to_jcc = 0; new->jcc_list = 0; SK_(stat).distinct_bbccs++; CT_DEBUG(3, " new_bbcc(BB 0x%x): %p (now %d)\n", bb_addr(bb), new, SK_(stat).distinct_bbccs); return new; } /** * Inserts a new BBCC into hashes. * BBCC specific items must be set as this is used for the hash * keys: * fn : current function * tid : current thread ID * from : position where current function is called from * * Recursion level doesn't need to be set as this is not included * in the hash key: Only BBCCs with rec level 0 are in hashes. */ static void insert_bbcc_into_hash(BBCC* bbcc) { UInt hash; CT_ASSERT(bbcc->cxt != 0); CT_DEBUG(3,"+ insert_bbcc_into_hash(BB 0x%x, fn '%s')\n", bb_addr(bbcc->bb), bbcc->cxt->fn[0]->name); /* check fill degree of hash and resize if needed (>90%) */ current_bbccs.entries++; if (100 * current_bbccs.entries / current_bbccs.size > 90) resize_bbcc_hash(); hash = hash_bbcc(bbcc->bb, bbcc->cxt, current_bbccs.size); bbcc->next = current_bbccs.table[hash]; current_bbccs.table[hash] = bbcc; CT_DEBUG(3,"- insert_bbcc_into_hash: %d entries\n", current_bbccs.entries); } static Char* mangled_cxt(Context* cxt, int rec_index) { static Char mangled[FN_NAME_LEN]; int i, p; if (!cxt) return "(no context)"; p = VG_(sprintf)(mangled, "%s", cxt->fn[0]->name); if (rec_index >0) p += VG_(sprintf)(mangled+p, "'%d", rec_index +1); for(i=1;isize;i++) p += VG_(sprintf)(mangled+p, "'%s", cxt->fn[i]->name); return mangled; } /* Create a new BBCC as a copy of an existing one, * but with costs set to 0 and jcc chains empty. * * This is needed when a BB is executed in another context than * the one at instrumentation time of the BB. * * Use cases: * rec_index == 0: clone from a BBCC with differing tid/cxt * and insert into hashes * rec_index >0 : clone from a BBCC with same tid/cxt and rec_index 0 * don't insert into hashes */ static BBCC* clone_bbcc(BBCC* orig, Context* cxt, Int rec_index) { BBCC* new; CT_DEBUG(3,"+ clone_bbcc(BB 0x%x, rec %d, fn %s)\n", bb_addr(orig->bb), rec_index, cxt->fn[0]->name); new = new_bbcc(orig->bb); if (rec_index == 0) { /* hash insertion is only allowed if tid or cxt is different */ CT_ASSERT((orig->tid != SK_(current_tid)) || (orig->cxt != cxt)); new->rec_index = 0; new->cxt = cxt; new->rec_array = new_recursion(cxt->fn[0]->separate_recursions); new->rec_array[0] = new; insert_bbcc_into_hash(new); } else { if (SK_(clo).separate_threads) CT_ASSERT(orig->tid == SK_(current_tid)); CT_ASSERT(orig->cxt == cxt); CT_ASSERT(orig->rec_array); CT_ASSERT(cxt->fn[0]->separate_recursions > rec_index); CT_ASSERT(orig->rec_array[rec_index] ==0); /* new BBCC will only have differing recursion level */ new->rec_index = rec_index; new->cxt = cxt; new->rec_array = orig->rec_array; new->rec_array[rec_index] = new; } /* update list of BBCCs for same BB */ new->next_bbcc = orig->bb->bbcc_list; orig->bb->bbcc_list = new; CT_DEBUGIF(3) SK_(print_bbcc)(-2, new, False); CT_DEBUG(2,"- clone_BBCC(0x%p, %d) for BB 0x%x\n" " orig %s\n" " new %s\n", orig, rec_index, bb_addr(orig->bb), mangled_cxt(orig->cxt, orig->rec_index), mangled_cxt(new->cxt, new->rec_index)); SK_(stat).bbcc_clones++; return new; }; /* Get a pointer to the cost centre structure for given basic block * address. If created, the BBCC is inserted into the BBCC hash. * Also sets BB_seen_before by reference. * */ BBCC* SK_(get_bbcc)(BB* bb) { BBCC* bbcc; VGP_PUSHCC(VgpCacheGetBBCC); CT_DEBUG(3, "+ get_bbcc(BB 0x%x)\n", bb_addr(bb)); bbcc = bb->bbcc_list; if (!bbcc) { bbcc = new_bbcc(bb); /* initialize BBCC */ bbcc->cxt = 0; bbcc->rec_array = 0; bbcc->rec_index = 0; bbcc->next_bbcc = bb->bbcc_list; bb->bbcc_list = bbcc; bb->last_bbcc = bbcc; CT_DEBUGIF(3) SK_(print_bbcc)(-2, bbcc, False); } CT_DEBUG(3, "- get_bbcc(BB 0x%x): BBCC 0x%p\n", bb_addr(bb), bbcc); VGP_POPCC(VgpCacheGetBBCC); return bbcc; } /* Callgrind manages its own call stack for each thread. * When leaving a function, a underflow can happen when * Callgrind's tracing was switched on in the middle of * a run, i.e. when Callgrind was not able to trace the * Call. * This function tries to reconstruct the original call. * As we know the return address (the address following * the CALL instruction), we can detect the function * we return back to, but the original call site is unknown. * We suppose a call site at return address - 1. * (TODO: other heuristic: lookup info of instrumented BBs). */ static void handleUnderflow(BB* bb) { /* RET at top of call stack */ BBCC* source_bbcc; BB* source_bb; jCC* jcc; Bool seen_before; fn_node* caller; int fn_number, *pactive; call_entry* call_entry_up; CT_DEBUG(1," Callstack underflow !\n"); /* we emulate an old call from the function we return to * by using ( -1) */ source_bb = SK_(get_bb)(bb_addr(bb)-1, 0, &seen_before); source_bbcc = SK_(get_bbcc)(source_bb); /* seen_before can be true if RET from a signal handler */ if (!seen_before) { source_bbcc->exe_counter = SK_(current_state).collect ? 1 : 0; } else if (SK_(current_state).collect) source_bbcc->exe_counter++; /* Force a new top context, will be set active by push_cxt() */ SK_(current_fn_stack).top--; SK_(current_state).cxt = 0; caller = SK_(get_fn_node)(bb); SK_(push_cxt)( caller ); if (!seen_before) { /* set rec array for source BBCC: this is at rec level 1 */ source_bbcc->rec_array = new_recursion(caller->separate_recursions); source_bbcc->rec_array[0] = source_bbcc; CT_ASSERT(source_bbcc->cxt == 0); source_bbcc->cxt = SK_(current_state).cxt; insert_bbcc_into_hash(source_bbcc); } CT_ASSERT(SK_(current_state).bbcc); /* correct active counts */ fn_number = SK_(current_state).bbcc->cxt->fn[0]->number; pactive = SK_(get_fn_entry)(fn_number); (*pactive)--; /* This assertion is not correct for reentrant * signal handlers */ /* CT_ASSERT(*pactive == 0); */ SK_(current_state).nonskipped = 0; /* we didn't skip this function */ /* back to current context */ SK_(push_cxt)( SK_(current_state).bbcc->cxt->fn[0] ); SK_(push_call_stack)(source_bbcc, SK_(current_state).bbcc, (Addr)-1, False); call_entry_up = &(SK_(current_call_stack).entry[SK_(current_call_stack).sp -1]); jcc = call_entry_up->jcc; /* assume this call is lasting since last dump or * for a signal handler since it's call */ if (SK_(current_state).sig == 0) SK_(copy_cost)( SK_(sets).full, call_entry_up->enter_cost, SK_(get_current_thread)()->lastdump_cost ); else SK_(zero_cost)( SK_(sets).full, call_entry_up->enter_cost ); } /* * Helper function called at start of each instrumented BB to setup * pointer to costs for current thread/context/recursion level */ __attribute__ ((regparm (1))) void SK_(setup_bbcc)(BB* bb) { BBCC *bbcc, *last_bbcc; Bool call_emulation = False, delayed_push = False, skip = False; Addr esp; BB* last_bb; VGP_PUSHCC(VgpCacheSetup); CT_DEBUG(3,"+ setup_bbcc(BB 0x%x)\n", bb_addr(bb)); esp = VG_(get_stack_pointer)(); last_bbcc = SK_(current_state).bbcc; last_bb = last_bbcc ? last_bbcc->bb : 0; /* Manipulate JmpKind if needed, only using BB specific info */ if (( SK_(current_state).jmpkind != JmpRet) && ( SK_(current_state).jmpkind != JmpCall) && last_bb) { /* We simulate a JMP/Cont to be a CALL if * - jump is in another ELF object or section kind * - jump is to first instruction of a function (tail recursion) */ if (bb->is_entry || (last_bb->sect_kind != bb->sect_kind) || (last_bb->obj->number != bb->obj->number)) { SK_(current_state).jmpkind = JmpCall; call_emulation = True; CT_DEBUG(1," JMP: %s to %s!\n", last_bb->obj->name, bb->obj->name); } } if (SK_(current_state).jmpkind == JmpCall) skip = SK_(get_fn_node)(bb)->skip; CT_DEBUGIF(1) { VG_(printf)("%s %08x -> %08x, ESP %08x\n", (SK_(current_state).jmpkind == JmpNone) ? "CONT" : (SK_(current_state).jmpkind == JmpCond) ? "JCND" : (SK_(current_state).jmpkind == JmpRet) ? "RET " : (SK_(current_state).jmpkind == JmpCall) ? "CALL" : (SK_(current_state).jmpkind == JmpBoring)? "JMP " : (SK_(current_state).jmpkind == JmpSyscall)? "SYSC" : "CREQ", last_bb ? bb_jmpaddr(last_bb) : 0, bb_addr(bb), esp); } /* Handle CALL/RET and update context to get correct BBCC */ if (SK_(current_state).jmpkind == JmpRet) { if ((SK_(current_call_stack).sp == 0) || ((SK_(current_fn_stack).top > SK_(current_fn_stack).bottom) && ( *(SK_(current_fn_stack).top-1)==0)) ) { /* On an empty call stack or at a signal separation marker, * a RETURN generates an call stack underflow. */ handleUnderflow(bb); SK_(pop_call_stack)(); } else { if (SK_(unwind_call_stack)(esp)==0) { call_entry* call_entry_up = &(SK_(current_call_stack).entry[SK_(current_call_stack).sp-1]); /* Return without Call, i.e. a Jump. * If this is a jump into another function, * pretend a Return and a Call happening. * TODO: Check for jump to same function */ CT_DEBUG(1," RET without call!\n"); /* change source for delayed push */ if (call_entry_up->jcc) { SK_(current_state).bbcc = call_entry_up->jcc->from; esp = call_entry_up->esp; SK_(pop_call_stack)(); } else { CT_ASSERT(SK_(current_state).nonskipped != 0); } skip = SK_(get_fn_node)(bb)->skip; delayed_push = True; } } } else { SK_(unwind_call_stack)(esp); if (SK_(current_state).jmpkind == JmpCall) { delayed_push = True; if (call_emulation && SK_(current_call_stack).sp>0) { call_entry* call_entry_up = &(SK_(current_call_stack).entry[SK_(current_call_stack).sp-1]); esp = call_entry_up->esp; } } } /* Change new context if needed, taking delayed_push into account */ if ((delayed_push && !skip) || (SK_(current_state).cxt == 0)) { SK_(push_cxt)(SK_(get_fn_node)(bb)); } CT_ASSERT(SK_(current_fn_stack).top > SK_(current_fn_stack).bottom); /* If there is a fresh instrumented BBCC, assign current context */ bbcc = SK_(get_bbcc)(bb); if (bbcc->cxt == 0) { CT_ASSERT(bbcc->rec_array == 0); bbcc->cxt = SK_(current_state).cxt; bbcc->rec_array = new_recursion((*SK_(current_fn_stack).top)->separate_recursions); bbcc->rec_array[0] = bbcc; insert_bbcc_into_hash(bbcc); } else { /* get BBCC with current context */ /* first check LRU of last bbcc executed */ if (last_bbcc) { bbcc = last_bbcc->lru_next_bbcc; if (bbcc && ((bbcc->bb != bb) || (bbcc->cxt != SK_(current_state).cxt))) bbcc = 0; } else bbcc = 0; if (!bbcc) bbcc = lookup_bbcc(bb, SK_(current_state).cxt); if (!bbcc) bbcc = clone_bbcc(bb->bbcc_list, SK_(current_state).cxt, 0); bb->last_bbcc = bbcc; } /* save for fast lookup */ if (last_bbcc) last_bbcc->lru_next_bbcc = bbcc; if ((*SK_(current_fn_stack).top)->separate_recursions >1) { UInt level, idx; fn_node* top = *(SK_(current_fn_stack).top); level = *SK_(get_fn_entry)(top->number); if (delayed_push && !skip) { if (SK_(clo).skip_direct_recursion) { /* do not increment rec. level if called from * same function */ if (!SK_(current_state).bbcc || (SK_(current_state).bbcc->cxt->fn[0] != bbcc->cxt->fn[0])) level++; } else level++; } if (level> top->separate_recursions) level = top->separate_recursions; if (level == 0) { /* can only happen if instrumentation just was switched on */ level = 1; *SK_(get_fn_entry)(top->number) = 1; } idx = level -1; if (bbcc->rec_array[idx]) bbcc = bbcc->rec_array[idx]; else bbcc = clone_bbcc(bbcc, SK_(current_state).cxt, idx); CT_ASSERT(bbcc->rec_array[bbcc->rec_index] == bbcc); } if (delayed_push) { if (!skip && SK_(current_state).nonskipped) { /* a call from skipped to nonskipped */ SK_(current_state).bbcc = SK_(current_state).nonskipped; } SK_(push_call_stack)(SK_(current_state).bbcc, bbcc, esp, skip); } if (SK_(current_state).jmpkind == JmpCond || SK_(current_state).jmpkind == JmpBoring) { /* Handle conditional jumps followed, i.e. trace arcs * This uses JCC structures, too */ jCC* jcc = SK_(get_jcc)(last_bbcc, bbcc); CT_ASSERT(jcc != 0); // Change from default, and check if already changed if (jcc->jmpkind == JmpCall) jcc->jmpkind = SK_(current_state).jmpkind; else CT_ASSERT(jcc->jmpkind == SK_(current_state).jmpkind); jcc->call_counter++; if (SK_(current_state).jmpkind == JmpCond) SK_(stat).jcnd_counter++; else SK_(stat).jump_counter++; } SK_(current_state).jmpkind = JmpNone; SK_(current_state).bbcc = bbcc; SK_(bb_base) = bb->obj->offset + bb->offset; SK_(cost_base) = bbcc->cost; CT_DEBUGIF(1) { VG_(printf)(" "); SK_(print_bbcc_fn)(bbcc); VG_(printf)("\n"); } CT_DEBUG(3,"- setup_bbcc (BB %p): Cost %p (Len %d), Instrs %d (Len %d)\n", bb_addr(bb), bbcc->cost, bb->cost_count, bb->instr_count, bb->instr_len); CT_DEBUGIF(3) SK_(print_cxt)(-8, SK_(current_state).cxt, bbcc->rec_index); CT_DEBUG(3,"\n"); if (SK_(current_state).collect) { if (!SK_(current_state).nonskipped) bbcc->exe_counter++; if (!SK_(clo).simulate_cache) /* even with skipping the log_ calls, we have to increment * the global counter */ SK_(current_state).cost[SK_(sets).off_sim_Ir] += bbcc->bb->instr_count; } SK_(stat).bb_executions++; VGP_POPCC(VgpCacheSetup); }