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

On Fri, Aug 29, 2008 at 1:16 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> In theory the above implementation of newNode should be a clear win,
> so I'm thinking this result must be an artifact of some kind. I'm
> going to go try it on PPC and HPPA machines next; does anyone want to
> try it on something else?

Hrm, I tried it on my x86_64 (quad core 2.66ghz, sorry no exotic
machines here :)) and did not see any real noticeable difference
between the two...

Here is what I tried:
(all with ./configure --enable-debug and make clean in between)

CVS HEAD:
tps = 30.375794
tps = 31.138078
tps = 30.928565

#define newNode(size, tag) \
({ Node *newNodeMacroHolder; \
AssertMacro((size) >= sizeof(Node)); /* need the tag, at least */ \
newNodeMacroHolder = (Node *) palloc0fast(size); \
newNodeMacroHolder->type = (tag); \
newNodeMacroHolder; \
})

tps = 30.814628
tps = 30.706080
tps = 31.10788

static inline Node *newNode(Size size, NodeTag tag)
{
Node *newNode;
Assert(size >= sizeof(Node));
newNode = (Node *) palloc0(size);
newNode->type = tag;
return newNode;
}

tps = 30.317978
tps = 30.786187
tps = 30.747112