unsigned int bitmap_find_zero_bit(const unsigned long *bitmap,
unsigned int nbits, unsigned int start) {
const unsigned long *p, *pend;
unsigned long tmp;
if (start >= nbits)
return nbits;
p = bitmap + BITMAP_OFFSET(start);
pend = bitmap + BITMAP_OFFSET(nbits);
tmp = *p | ((1 << BITMAP_SHIFT(start)) - 1);
while (p < pend) {
if (~tmp)
goto found;
tmp = *(++p);
}
tmp |= ~(1 << BITMAP_SHIFT(nbits)) + 1;
if (!~tmp)
return nbits;
found:
return LONG_BIT * (p - bitmap) + bit_ctz(~tmp);
}
unsigned int bitmap_find_bit(const unsigned long *bitmap,
unsigned int nbits, unsigned int start) {
const unsigned long *p = bitmap + BITMAP_OFFSET(start); /* start word */
unsigned int shift = BITMAP_SHIFT(start); /* within the start word */
unsigned int result = start - shift; /* LONG_BIT-aligned down start */
unsigned long tmp;
if (start >= nbits)
return nbits;
nbits -= result;
tmp = *(p++) & (~0x0ul << shift); /* mask out the beginning */
while (nbits > LONG_BIT) {
if (tmp)
goto found;
result += LONG_BIT;
nbits -= LONG_BIT;
tmp = *(p++);
}
tmp &= (~0x0ul >> (LONG_BIT - nbits)); /* ...and the ending */
if (!tmp)
return result + nbits;
found:
return result + bit_ctz(tmp);
}
static inline bool
bb_table_add(bb_table_t *table, bb_entry_t *entry)
{
byte *bm;
uint idx, offs, addr_end, idx_end, offs_end, i;
if (table == BB_TABLE_IGNORE)
return false;
if (table->size <= entry->start + entry->size) {
WARN(3, "Wrong range "PFX"-"PFX" or table size "PFX" for table "PFX"\n",
(ptr_uint_t)entry->start,
(ptr_uint_t)entry->start + entry->size,
(ptr_uint_t)table->size,
(ptr_uint_t)table);
return false;
}
bm = table->bm;
idx = BITMAP_INDEX(entry->start);
/* we assume that the whole bb is seen if its start addr is seen */
if (bm[idx] == BB_TABLE_RANGE_SET)
return false;
offs = BITMAP_OFFSET(entry->start);
if (TEST(BITMAP_MASK(offs), bm[idx]))
return false;
/* now we add a new bb */
PRINT(6, "Add "PFX"-"PFX" in table "PFX"\n",
(ptr_uint_t)entry->start,
(ptr_uint_t)entry->start + entry->size,
(ptr_uint_t)table);
addr_end = entry->start + entry->size - 1;
idx_end = BITMAP_INDEX(addr_end);
offs_end = (idx_end > idx) ? BITS_PER_BYTE-1 : BITMAP_OFFSET(addr_end);
/* first byte in the bitmap */
bm[idx] |= bitmap_set[offs][offs_end];
/* set all the middle byte */
for (i = idx + 1; i < idx_end; i++)
bm[i] = BB_TABLE_RANGE_SET;
/* last byte in the bitmap */
if (idx_end > idx) {
offs_end = BITMAP_OFFSET(addr_end);
bm[idx_end] |= bitmap_set[0][offs_end];
}
return true;
}
static inline int
bb_table_lookup(bb_table_t *table, uint addr)
{
byte *bm = table->bm;
PRINT(5, "lookup "PFX" in bb table "PFX"\n",
(ptr_uint_t)addr, (ptr_uint_t)table);
/* We see this and it seems to be erroneous data from the pdb,
* xref drsym_enumerate_lines() from drsyms.
*/
if (table->size <= addr)
return BB_TABLE_ENTRY_INVALID;
if (bm[BITMAP_INDEX(addr)] == 0xff ||
TEST(BITMAP_MASK(BITMAP_OFFSET(addr)), bm[BITMAP_INDEX(addr)]))
return BB_TABLE_ENTRY_SET;
return BB_TABLE_ENTRY_CLEAR;
}
