Re: [PATCH] powerpc/bug: Remove specific powerpc BUG_ON()

[Segher Boessenkool]

On Thu, Feb 11, 2021 at 08:04:55PM +1000, Nicholas Piggin wrote:
> Excerpts from Christophe Leroy's message of February 11, 2021 5:41 pm:
> > As modern powerpc implement branch folding, that's even more efficient.

Ah, it seems you mean what Arm calls branch folding.  Sure, power4
already did that, and this has not changed.

> I think POWER will speculate conditional traps as non faulting always
> so it should be just as good if not better than the branch.

Right, these are not branch instructions, so are not branch predicted;
all trap instructions are assumed to fall through, like all other
non-branch instructions.


Segher