Re: gcc feature request / RFC: extra clobbered regs

Jakub Jelinek
2015-07-01T17:43:47Z

On Wed, Jul 01, 2015 at 01:35:16PM -0400, Vladimir Makarov wrote:
> Actually it raise a question for me. If we describe that a function
> clobbers more than calling convention and then use it as a value (assigning
> a variable or passing as an argument) and loosing a track of it and than
> call it. How can RA know what the call clobbers actually. So for the
> function with the attributes we should prohibit use it as a value or make
> the attributes as a part of the function type, or at least say it is unsafe.
> So now I see this as a *bigger problem* with this extension. Although I
> guess it already exists as we have description of different ABI as an
> extension.

Unfortunately target attribute is function decl attribute rather than
function type. And having more attributes affect switchable targets will be
non-fun.

Jakub