Re: [PATCH GIT 0.6] make use of register variables & size_t
- From
Linus Torvalds <torvalds@osdl.org>
- Date
- Apr 25, 2005, 18:50 UTC
- Message-ID
- <Pine.LNX.4.58.0504251147290.18901@ppc970.osdl.org>
- In-Reply-To
- <426D33BA.8040604@tiscali.de>
On Mon, 25 Apr 2005, Matthias-Christian Ott wrote:
> > But this makes, like "register", direct use of processor registers (it > stores int arguments in eax, ebx, etc.).
No. It make _unlike_ "register", direct use of processor registers.
The "register" keyword does _not_ use processor registers. It's just syntactic fluff, and tells the compiler exactly one thing:
- that the compiler should warn if you take the address of such a thing.
In addition, the compiler may generate code that takes it into account, which most likely means _worse_ code than if it didn't take it into account.
In contrast regparm() actually says something very relevant: it says that the function uses a totally different calling convention.
Linus