On 03/29/2012 01:16 PM, Jan Hubicka wrote: >> Of course, there's still the problem of getting the unwind data correct at >> the point of the asm. I commented about that in the PR you filed. > > I think i386 still has the problem that it is small register class target and > if you > set rdi/rax and friends as hard registers, you risk reload failures.
True, and if this were i386 code I would certainly recommend using the [acd] constraints instead (for suitible regparm signature). But this is explicitly x86_64 code and the compiler has 8 registers otherwise available. > Do we prevent code motion of hard registers sets i.e. at GIMPLE level? I don't know for positive, but I'd certainly consider it a bug if we don't. There are plenty of targets which have no alternative but to use this style of programming for inline syscalls. r~
