Question on arithmetic overflow detection support in C2

[Rémi Forax]

On 06/27/2012 03:37 PM, Krystal Mok wrote:
> Hi all,
>
> Just FYI, I've posted an updated version of the patch here:
> https://gist.github.com/db03ab15ef8b76246b84#file_checked_add_prototype.ver3.patch
>
> It pretty much implements what John suggested in a previous email 
> (quoted below).
>
> This version still suffers from a couple of problem mentioned before:
> 1. It's emitting a jmpConU instead of a jmpCon during instruction 
> selection. Is there a way to force it use jmpCon here?

I'm may be wrong but the idea is to put 0 (or a very small value) to the 
frequency of the basic block
that follow the jump on overflow.

> 2. I had to use a fixed register for the sum projection of 
> CheckedAddI, otherwise I couldn't find a way to specify this 
> projection should use the same register as "dst".
>
> - Kris

Rémi