mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-11-21 03:13:05 +08:00
MemSet() must not cast its pointer argument to int32* until after it has
checked that the pointer is actually word-aligned. Casting a non-aligned pointer to int32* is technically illegal per the C spec, and some recent versions of gcc actually generate bad code for the memset() when given such a pointer. Per report from Andrew Morrow.
This commit is contained in:
parent
84e5ce7eb9
commit
a55a75f02d
@ -12,7 +12,7 @@
|
||||
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: c.h,v 1.114 2002/01/22 19:02:39 tgl Exp $
|
||||
* $Id: c.h,v 1.114.2.1 2005/07/18 15:55:01 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -560,21 +560,22 @@ typedef NameData *Name;
|
||||
#define MemSet(start, val, len) \
|
||||
do \
|
||||
{ \
|
||||
int32 * _start = (int32 *) (start); \
|
||||
void *_vstart = (void *) (start); \
|
||||
int _val = (val); \
|
||||
Size _len = (len); \
|
||||
\
|
||||
if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
|
||||
if ((((long) _vstart) & INT_ALIGN_MASK) == 0 && \
|
||||
(_len & INT_ALIGN_MASK) == 0 && \
|
||||
_val == 0 && \
|
||||
_len <= MEMSET_LOOP_LIMIT) \
|
||||
{ \
|
||||
int32 * _stop = (int32 *) ((char *) _start + _len); \
|
||||
int32 *_start = (int32 *) _vstart; \
|
||||
int32 *_stop = (int32 *) ((char *) _start + _len); \
|
||||
while (_start < _stop) \
|
||||
*_start++ = 0; \
|
||||
} \
|
||||
else \
|
||||
memset((char *) _start, _val, _len); \
|
||||
memset(_vstart, _val, _len); \
|
||||
} while (0)
|
||||
|
||||
#define MEMSET_LOOP_LIMIT 64
|
||||
|
Loading…
Reference in New Issue
Block a user