Re: gcc inlining heuristics was Re: [PATCH -v7][RFC]: mutex: implement adaptive spinning

Linus Torvalds
2009-01-11T20:52:28Z

On Sun, 11 Jan 2009, Andi Kleen wrote:
>
> Was -- i think that got fixed in gcc. But again only in newer versions.

I doubt it. People have said that about a million times, it has never
gotten fixed, and I've never seen any actual proof.

I think that what got fixed was that gcc now at least re-uses stack slots
for temporary spills. But only for things that fit in registers - not if
you actually had variables that are big enough to be of type MEM. And the
latter is what tends to eat stack-space (ie structures etc on stack).

But hey, maybe it really did get fixed. But the last big stack user wasn't
that long ago, and I saw it and I have a pretty recent gcc (gcc-4.3.2
right now, it could obviously have been slightly older back a few months
ago).

Linus