On Tue, 12 Nov 2013, Jeff Law wrote:
On 11/12/13 10:14, Marc Glisse wrote:
You didn't like Jakub's comment about __builtin_unreachable?
No, it's certainly not appropriate for this optimization. The problem with
using builtin_unreachable is if you do reach that point, you fall into an
unrelated blob of code in the executable. That is a huge security issue.
I guess this will end up as a flag and the debate will only be about the
default value of the flag?
(-fsanitize=Idontrememberwhat would already be such a flag ;-) but you may
prefer a more specific one)
Note that security is a concern for some applications, but for others it
is irrelevant and performance trumps it. I would even consider a flag that
turns abort, trap, etc into __builtin_unreachable.
Anyway, thanks for the optimization, I am only discussing the details
because I like it.
--
Marc Glisse
