[llvm-commits] mips commit regarding RA register problem

[Kotler, Reed]

Okay. We will make the changes you request.
________________________________________
From: Bill Wendling [wendling at apple.com]
Sent: Monday, September 17, 2012 9:24 PM
To: Kotler, Reed
Cc: llvm-commits at cs.uiuc.edu
Subject: Re: [llvm-commits] mips commit regarding RA register problem

On Sep 17, 2012, at 5:05 PM, "Kotler, Reed" <rkotler at mips.com> wrote:

> I have the whole rest of the mips 16 port sitting in our local repository.
>
> I can't check it in all at once because it's too big.
>
> So I need to check in all the pieces and then I can do more  work. This is what I'm trying to do right now.
>
> What part of this check in is bothering you?
>
> This code will work forever. It's correct.
>
> What you complained about is the test for a 0 stack size, which  cannot happen right now because
> I am forcing it to have a non zero stack size.
>
> I don't want to delete that code because it will become allowable once again when I do the optimization which makes it possible to not save RA at all.
>
> We CANNOT revert this patch right now and continue our work.
>
> The code we are checking in works. Why is it a horrible hack? It is correct. it will work until the Sun runs out of fuel and stops heating the planet.
>
Excellent! Fine. Please keep that patch in there and remove any comments that say otherwise.

> You want us to delete two lines of code that test that stack size is 0?
>
> What problem can this cause?
>
Dead code is dead code is dead code. Remove it immediately. Also place the addition by the arbitrary number 16 into the initialization of the variable.

> There are NO bugs caused by this checkin.
>
Great!

> The horrible bug is what happens without this checkin.

You say it's bug free. Then it's bug free. I expect you to never change this in the future.

-bw