Index: src/backend/utils/mmgr/mcxt.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/utils/mmgr/mcxt.c,v
retrieving revision 1.35
diff -c -c -r1.35 mcxt.c
*** src/backend/utils/mmgr/mcxt.c	10 Nov 2002 02:17:25 -0000	1.35
--- src/backend/utils/mmgr/mcxt.c	11 Nov 2002 19:11:05 -0000
***************
*** 453,466 ****
  }
  
  /*
!  * MemoryContextAllocZero
   *		Like MemoryContextAlloc, but clears allocated memory
   *
   *	We could just call MemoryContextAlloc then clear the memory, but this
   *	function is called too many times, so we have a separate version.
   */
  void *
! MemoryContextAllocZero(MemoryContext context, Size size)
  {
  	void *ret;
  
--- 453,466 ----
  }
  
  /*
!  * MemoryContextAllocPalloc0
   *		Like MemoryContextAlloc, but clears allocated memory
   *
   *	We could just call MemoryContextAlloc then clear the memory, but this
   *	function is called too many times, so we have a separate version.
   */
  void *
! MemoryContextAllocPalloc0(MemoryContext context, Size size)
  {
  	void *ret;
  
***************
*** 471,477 ****
  			 (unsigned long) size);
  
  	ret = (*context->methods->alloc) (context, size);
! 	MemSet(ret, 0, size);
  	return ret;
  }
  
--- 471,477 ----
  			 (unsigned long) size);
  
  	ret = (*context->methods->alloc) (context, size);
! 	MemSetLoop(ret, 0, size);
  	return ret;
  }
  
Index: src/include/c.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/c.h,v
retrieving revision 1.131
diff -c -c -r1.131 c.h
*** src/include/c.h	11 Nov 2002 03:02:19 -0000	1.131
--- src/include/c.h	11 Nov 2002 19:11:08 -0000
***************
*** 577,602 ****
   *	memset() functions.  More research needs to be done, perhaps with
   *	platform-specific MEMSET_LOOP_LIMIT values or tests in configure.
   *
   *	bjm 2002-10-08
   */
! #define MemSet(start, val, len) \
! 	do \
! 	{ \
! 		int32 * _start = (int32 *) (start); \
! 		int		_val = (val); \
! 		Size	_len = (len); \
  \
! 		if ((( ((long) _start) | _len) & INT_ALIGN_MASK) == 0 && \
! 			_val == 0 && \
! 			_len <= MEMSET_LOOP_LIMIT) \
! 		{ \
! 			int32 * _stop = (int32 *) ((char *) _start + _len); \
! 			while (_start < _stop) \
! 				*_start++ = 0; \
! 		} \
! 		else \
! 			memset((char *) _start, _val, _len); \
! 	} while (0)
  
  #define MEMSET_LOOP_LIMIT  1024
  
--- 577,612 ----
   *	memset() functions.  More research needs to be done, perhaps with
   *	platform-specific MEMSET_LOOP_LIMIT values or tests in configure.
   *
+  *	MemSet has been split into two parts so MemSetTest can be optimized
+  *	away for constant 'val' and 'len'.  This is used by palloc0().
+  *
+  *	Note, arguments are evaluated more than once.
+  *
   *	bjm 2002-10-08
   */
! #define MemSetTest(val, len) \
! 	( ((len) & INT_ALIGN_MASK) == 0 && \
! 	(len) <= MEMSET_LOOP_LIMIT && \
! 	(val) == 0 )
! 
! #define MemSetLoop(start, val, len) \
! do \
! { \
! 	int32 * _start = (int32 *) (start); \
! 	int32 * _stop = (int32 *) ((char *) _start + (len)); \
  \
! 	while (_start < _stop) \
! 		*_start++ = 0; \
! } while (0)
! 
! #define MemSet(start, val, len) \
! do \
! { \
! 	if (MemSetTest(val, len) && ((long)(start) & INT_ALIGN_MASK) == 0 ) \
! 		MemSetLoop(start, val, len); \
! 	else \
! 		memset((char *)(start), (val), (len)); \
! } while (0)
  
  #define MEMSET_LOOP_LIMIT  1024
  
Index: src/include/utils/palloc.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/utils/palloc.h,v
retrieving revision 1.22
diff -c -c -r1.22 palloc.h
*** src/include/utils/palloc.h	10 Nov 2002 02:17:25 -0000	1.22
--- src/include/utils/palloc.h	11 Nov 2002 19:11:10 -0000
***************
*** 46,56 ****
   * Fundamental memory-allocation operations (more are in utils/memutils.h)
   */
  extern void *MemoryContextAlloc(MemoryContext context, Size size);
! extern void *MemoryContextAllocZero(MemoryContext context, Size size);
  
  #define palloc(sz)	MemoryContextAlloc(CurrentMemoryContext, (sz))
  
! #define palloc0(sz)	MemoryContextAllocZero(CurrentMemoryContext, (sz))
  
  extern void pfree(void *pointer);
  
--- 46,59 ----
   * Fundamental memory-allocation operations (more are in utils/memutils.h)
   */
  extern void *MemoryContextAlloc(MemoryContext context, Size size);
! extern void *MemoryContextAllocPalloc0(MemoryContext context, Size size);
  
  #define palloc(sz)	MemoryContextAlloc(CurrentMemoryContext, (sz))
  
! #define palloc0(sz)	\
! 	( MemSetTest(0, (sz)) ? \
! 		MemoryContextAllocPalloc0(CurrentMemoryContext, (sz)) : \
! 		memset(palloc(sz), 0, (sz)))
  
  extern void pfree(void *pointer);