Re: Is it really such a good thing for newNode() to be a macro?

["Heikki Linnakangas"]

Tom Lane wrote:
> "Heikki Linnakangas" <heikki@xxxxxxxxxxxxxxxx> writes:
> > Note that the MemSetLoop macro used in palloc0fast is supposed to be 
> > evaluated at compile time,
>
> Oooh, good point, I had forgotten about that little detail.  Yeah,
> we'll lose that optimization if we move the code out-of-line.

Well, we could still have the MemSetTest outside the function, and 
evaluated at compile-time, if we provided an aligned and unaligned 
version of newNode:

#define newNode(size, tag) \
( \
        AssertMacro((size) >= sizeof(Node)),         /* need the tag, at least 
*/ \
        ( MemSetTest(0, sz) ? \
                newNodeAligned(CurrentMemoryContext, sz, tag) : \
                newNodeNotAligned(CurrentMemoryContext, sz, tag))

And if you're worried about the function call overhead, 
newNode(Not)Aligned could have the contents of MemoryContextAllocZero 
inlined into it. Not sure how much optimization is worthwhile here..

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com

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