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count_bits() moved to mysys/

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unknown 2003-05-04 18:43:07 +02:00
parent 981a2b742b
commit 97946e16b3
3 changed files with 45 additions and 43 deletions
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1
include/my_sys.h
View file

@ -749,6 +749,7 @@ extern my_bool my_uncompress(byte *, ulong *, ulong *);
extern byte *my_compress_alloc(const byte *packet, ulong *len, ulong *complen);
extern ulong checksum(const byte *mem, uint count);
extern uint my_bit_log2(ulong value);
uint my_count_bits(ulonglong v);
extern void my_sleep(ulong m_seconds);
#ifdef __WIN__

42
mysys/my_bit.c
View file

@ -29,3 +29,45 @@ uint my_bit_log2(ulong value)
for (bit=0 ; value > 1 ; value>>=1, bit++) ;
return bit;
}
static char nbits[256] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
};
uint my_count_bits(ulonglong v)
{
#if SIZEOF_LONG_LONG > 4
/* The following code is a bit faster on 16 bit machines than if we would
only shift v */
ulong v2=(ulong) (v >> 32);
return (uint) (uchar) (nbits[(uchar) v] +
nbits[(uchar) (v >> 8)] +
nbits[(uchar) (v >> 16)] +
nbits[(uchar) (v >> 24)] +
nbits[(uchar) (v2)] +
nbits[(uchar) (v2 >> 8)] +
nbits[(uchar) (v2 >> 16)] +
nbits[(uchar) (v2 >> 24)]);
#else
return (uint) (uchar) (nbits[(uchar) v] +
nbits[(uchar) (v >> 8)] +
nbits[(uchar) (v >> 16)] +
nbits[(uchar) (v >> 24)]);
#endif
}

45
sql/item_func.cc
View file

@ -1110,47 +1110,6 @@ longlong Item_func_find_in_set::val_int()
return 0;
}
static char nbits[256] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
};
uint count_bits(ulonglong v)
{
#if SIZEOF_LONG_LONG > 4
/* The following code is a bit faster on 16 bit machines than if we would
only shift v */
ulong v2=(ulong) (v >> 32);
return (uint) (uchar) (nbits[(uchar) v] +
nbits[(uchar) (v >> 8)] +
nbits[(uchar) (v >> 16)] +
nbits[(uchar) (v >> 24)] +
nbits[(uchar) (v2)] +
nbits[(uchar) (v2 >> 8)] +
nbits[(uchar) (v2 >> 16)] +
nbits[(uchar) (v2 >> 24)]);
#else
return (uint) (uchar) (nbits[(uchar) v] +
nbits[(uchar) (v >> 8)] +
nbits[(uchar) (v >> 16)] +
nbits[(uchar) (v >> 24)]);
#endif
}
longlong Item_func_bit_count::val_int()
{
ulonglong value= (ulonglong) args[0]->val_int();
@ -1159,7 +1118,7 @@ longlong Item_func_bit_count::val_int()
null_value=1; /* purecov: inspected */
return 0; /* purecov: inspected */
}
return (longlong) count_bits(value);
return (longlong) my_count_bits(value);
}
@ -2221,7 +2180,7 @@ bool Item_func_match::fix_fields(THD *thd,struct st_table_list *tlist)
used_tables_cache|=item->used_tables();
}
/* check that all columns come from the same table */
if (count_bits(used_tables_cache) != 1)
if (my_count_bits(used_tables_cache) != 1)
key=NO_SUCH_KEY;
const_item_cache=0;
table=((Item_field *)fields.head())->field->table;