[llvm] r206228 - [ARM64][MC] Set the default CPU string to generic.

[Eric Christopher]

On Tue, Apr 22, 2014 at 11:22 AM, Filip Pizlo <fpizlo at apple.com> wrote:
>
>
> On April 22, 2014 at 11:09:40 AM, Tim Northover (t.p.northover at gmail.com)
> wrote:
>
>> No, I'm saying that the default CPU in the JIT should always be the CPU
>> we're actually running on. That's not insane, that's how any sensible JIT
>> would work.
>
> Possibly (though the lldb developers may quibble about their JIT not
> being sensible).
>
> Sure, but lldb already manually sets the CPU.
>
> The question here is what behavior to give to those who don't manually set
> the CPU.  I'm arguing that the API previously guaranteed that the JIT would
> target the CPU flavor that the process was running on, and that we should
> arrange for the JIT to continue to obey this in the case that the JIT's
> client doesn't manually set the CPU.
>

This is patently false except for the single cpu that changed.

> In the future, if someone does break one platform to fix another -
> especially when it involves stable API, and where it's clear what the right
> fix is - then we should revert to avoid a situation where clients have to
> blacklist a series of LLVM revisions.
>

It's only stable between releases. Anything else is anything goes. As
I don't believe it was in 3.4...

-eric