Re: [PATCH 3/4] Add Visium support to gcc

[Jeff Law <law at redhat dot com>]

On 01/03/15 08:16, Eric Botcazou wrote:
> > I'm a little concerned about the MODES_TIEABLE_P definition, but if it's
> > working, I wouldn't mess with it.
>
> Could you elaborate?  Do you find it too restrictive?
I'm a little concerned it's too loose.  Basically it says that if both 
modes are integer modes, then they're tieable.  However, 
HARD_REGNO_MODE_OK may return different values for MODE1 and MODE2, even 
if both are integer modes.

My recollection is if MODES_TIEABLE_P returns true for mode1 and mode2, 
then HARD_REGNO_MODE_OK must return the same value when passed mode1 and 
mode2 regardless of the hard register and it's not obvious if 
HARD_REGNO_MODE_OK fits that criteria for this port.

Looking at the current docs, the language has been watered down from my 
recollection.  So.....

If it's working, then I'd leave it as-is.


> > Any thoughts on using LRA for this port?  Ideally we want to be moving
> > away from reload as much as we can.
>
> I can only promise to start experimenting with it and report issues, if any.
> The port is quite mature and the performances are closely monitored so bold
> changes need to be made with extra caution.
Understood.

FWIW, I suspect this is the last port I'll approve that doesn't use LRA 
instead of reload.


> Yes, I'm going to be the maintainer for now.
Given you're already maintaining other parts of GCC, I really just 
consider appointing you as the maintainer for the port a formality. 
I'll start that process, but go ahead and list yourself as the 
maintainer in the MAINTAINERS file.

jeff