/*--------------------------------------------------------------------*/
/*--- Callgrind ---*/
/*--- bb.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Callgrind, a Valgrind tool for call tracing.
Copyright (C) 2002-2011, 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 "global.h"
/*------------------------------------------------------------*/
/*--- Basic block (BB) operations ---*/
/*------------------------------------------------------------*/
/* BB hash, resizable */
bb_hash bbs;
void CLG_(init_bb_hash)()
{
Int i;
bbs.size = 8437;
bbs.entries = 0;
bbs.table = (BB**) CLG_MALLOC("cl.bb.ibh.1",
bbs.size * sizeof(BB*));
for (i = 0; i < bbs.size; i++) bbs.table[i] = NULL;
}
bb_hash* CLG_(get_bb_hash)()
{
return &bbs;
}
/* The hash stores BBs according to
* - ELF object (is 0 for code in anonymous mapping)
* - BB base as object file offset
*/
static __inline__
UInt bb_hash_idx(obj_node* obj, PtrdiffT offset, UInt size)
{
return (((Addr)obj) + offset) % size;
}
/* double size of bb table */
static
void resize_bb_table(void)
{
Int i, new_size, conflicts1 = 0, conflicts2 = 0;
BB **new_table, *curr, *next;
UInt new_idx;
new_size = 2* bbs.size +3;
new_table = (BB**) CLG_MALLOC("cl.bb.rbt.1",
new_size * sizeof(BB*));
if (!new_table) return;
for (i = 0; i < new_size; i++)
new_table[i] = NULL;
for (i = 0; i < bbs.size; i++) {
if (bbs.table[i] == NULL) continue;
curr = bbs.table[i];
while (NULL != curr) {
next = curr->next;
new_idx = bb_hash_idx(curr->obj, curr->offset, new_size);
curr->next = new_table[new_idx];
new_table[new_idx] = curr;
if (curr->next) {
conflicts1++;
if (curr->next->next)
conflicts2++;
}
curr = next;
}
}
VG_(free)(bbs.table);
CLG_DEBUG(0, "Resize BB Hash: %d => %d (entries %d, conflicts %d/%d)\n",
bbs.size, new_size,
bbs.entries, conflicts1, conflicts2);
bbs.size = new_size;
bbs.table = new_table;
CLG_(stat).bb_hash_resizes++;
}
/**
* Allocate new BB structure (including space for event type list)
* Not initialized:
* - instr_len, cost_count, instr[]
*/
static BB* new_bb(obj_node* obj, PtrdiffT offset,
UInt instr_count, UInt cjmp_count, Bool cjmp_inverted)
{
BB* bb;
UInt idx, size;
/* check fill degree of bb hash table and resize if needed (>80%) */
bbs.entries++;
if (10 * bbs.entries / bbs.size > 8)
resize_bb_table();
size = sizeof(BB) + instr_count * sizeof(InstrInfo)
+ (cjmp_count+1) * sizeof(CJmpInfo);
bb = (BB*) CLG_MALLOC("cl.bb.nb.1", size);
VG_(memset)(bb, 0, size);
bb->obj = obj;
bb->offset = offset;
bb->instr_count = instr_count;
bb->cjmp_count = cjmp_count;
bb->cjmp_inverted = cjmp_inverted;
bb->jmp = (CJmpInfo*) &(bb->instr[instr_count]);
bb->instr_len = 0;
bb->cost_count = 0;
bb->sect_kind = VG_(DebugInfo_sect_kind)(NULL, 0, offset + obj->offset);
bb->fn = 0;
bb->line = 0;
bb->is_entry = 0;
bb->bbcc_list = 0;
bb->last_bbcc = 0;
/* insert into BB hash table */
idx = bb_hash_idx(obj, offset, bbs.size);
bb->next = bbs.table[idx];
bbs.table[idx] = bb;
CLG_(stat).distinct_bbs++;
#if CLG_ENABLE_DEBUG
CLG_DEBUGIF(3) {
VG_(printf)(" new_bb (instr %d, jmps %d, inv %s) [now %d]: ",
instr_count, cjmp_count,
cjmp_inverted ? "yes":"no",
CLG_(stat).distinct_bbs);
CLG_(print_bb)(0, bb);
VG_(printf)("\n");
}
#endif
CLG_(get_fn_node)(bb);
return bb;
}
/* get the BB structure for a BB start address */
static __inline__
BB* lookup_bb(obj_node* obj, PtrdiffT offset)
{
BB* bb;
Int idx;
idx = bb_hash_idx(obj, offset, bbs.size);
bb = bbs.table[idx];
while(bb) {
if ((bb->obj == obj) && (bb->offset == offset)) break;
bb = bb->next;
}
CLG_DEBUG(5, " lookup_bb (Obj %s, off %#lx): %p\n",
obj->name, offset, bb);
return bb;
}
static __inline__
obj_node* obj_of_address(Addr addr)
{
obj_node* obj;
DebugInfo* di;
PtrdiffT offset;
di = VG_(find_DebugInfo)(addr);
obj = CLG_(get_obj_node)( di );
/* Update symbol offset in object if remapped */
/* FIXME (or at least check this) 2008 Feb 19: 'offset' is
only correct for text symbols, not for data symbols */
offset = di ? VG_(DebugInfo_get_text_bias)(di):0;
if (obj->offset != offset) {
Addr start = di ? VG_(DebugInfo_get_text_avma)(di) : 0;
CLG_DEBUG(0, "Mapping changed for '%s': %#lx -> %#lx\n",
obj->name, obj->start, start);
/* Size should be the same, and offset diff == start diff */
CLG_ASSERT( obj->size == (di ? VG_(DebugInfo_get_text_size)(di) : 0) );
CLG_ASSERT( obj->start - start == obj->offset - offset );
obj->offset = offset;
obj->start = start;
}
return obj;
}
/* Get the BB structure for a BB start address.
* If the BB has to be created, the IRBB is needed to
* compute the event type list for costs, and seen_before is
* set to False. Otherwise, seen_before is set to True.
*
* BBs are never discarded. There are 2 cases where this function
* is called from CLG_(instrument)() and a BB already exists:
* - The instrumented version was removed from Valgrinds TT cache
* - The ELF object of the BB was unmapped and mapped again.
* This involves a possibly different address, but is handled by
* looking up a BB keyed by (obj_node, file offset).
*
* bbIn==0 is possible for artifical BB without real code.
* Such a BB is created when returning to an unknown function.
*/
BB* CLG_(get_bb)(Addr addr, IRSB* bbIn, /*OUT*/ Bool *seen_before)
{
BB* bb;
obj_node* obj;
UInt n_instrs, n_jmps;
Bool cjmp_inverted = False;
CLG_DEBUG(5, "+ get_bb(BB %#lx)\n", addr);
obj = obj_of_address(addr);
bb = lookup_bb(obj, addr - obj->offset);
n_instrs = 0;
n_jmps = 0;
CLG_(collectBlockInfo)(bbIn, &n_instrs, &n_jmps, &cjmp_inverted);
*seen_before = bb ? True : False;
if (*seen_before) {
if (bb->instr_count != n_instrs) {
VG_(message)(Vg_DebugMsg,
"ERROR: BB Retranslation Mismatch at BB %#lx\n", addr);
VG_(message)(Vg_DebugMsg,
" new: Obj %s, Off %#lx, BBOff %#lx, Instrs %u\n",
obj->name, obj->offset,
addr - obj->offset, n_instrs);
VG_(message)(Vg_DebugMsg,
" old: Obj %s, Off %#lx, BBOff %#lx, Instrs %u\n",
bb->obj->name, bb->obj->offset,
bb->offset, bb->instr_count);
CLG_ASSERT(bb->instr_count == n_instrs );
}
CLG_ASSERT(bb->cjmp_count == n_jmps );
CLG_(stat).bb_retranslations++;
CLG_DEBUG(5, "- get_bb(BB %#lx): seen before.\n", addr);
return bb;
}
bb = new_bb(obj, addr - obj->offset, n_instrs, n_jmps, cjmp_inverted);
CLG_DEBUG(5, "- get_bb(BB %#lx)\n", addr);
return bb;
}
/* Delete the BB info for the bb with unredirected entry-point
address 'addr'. */
void CLG_(delete_bb)(Addr addr)
{
BB *bb, *bp;
Int idx, size;
obj_node* obj = obj_of_address(addr);
PtrdiffT offset = addr - obj->offset;
idx = bb_hash_idx(obj, offset, bbs.size);
bb = bbs.table[idx];
/* bb points at the current bb under consideration, and bp is the
one before. */
bp = NULL;
while(bb) {
if ((bb->obj == obj) && (bb->offset == offset)) break;
bp = bb;
bb = bb->next;
}
if (bb == NULL) {
CLG_DEBUG(3, " delete_bb (Obj %s, off %#lx): NOT FOUND\n",
obj->name, offset);
/* we didn't find it.
* this happens when callgrinds instrumentation mode
* was off at BB translation time, ie. no BB was created.
*/
return;
}
/* unlink it from hash table */
if (bp == NULL) {
/* we found the first one in the list. */
tl_assert(bb == bbs.table[idx]);
bbs.table[idx] = bb->next;
} else {
tl_assert(bb != bbs.table[idx]);
bp->next = bb->next;
}
CLG_DEBUG(3, " delete_bb (Obj %s, off %#lx): %p, BBCC head: %p\n",
obj->name, offset, bb, bb->bbcc_list);
if (bb->bbcc_list == 0) {
/* can be safely deleted */
/* Fill the block up with junk and then free it, so we will
hopefully get a segfault if it is used again by mistake. */
size = sizeof(BB)
+ bb->instr_count * sizeof(InstrInfo)
+ (bb->cjmp_count+1) * sizeof(CJmpInfo);
VG_(memset)( bb, 0xAA, size );
CLG_FREE(bb);
return;
}
CLG_DEBUG(3, " delete_bb: BB in use, can not free!\n");
}