[llvm-commits] Adding add.with.overflow intrinsic support to CBackend.

[Chris Lattner]

On Jun 20, 2011, at 11:32 AM, Anna Zaks wrote:

> Hi,
> 
> Attached is a CBackend patch for review. It adds support for sadd.with.overflow and uadd.with.overflow intrinsics. Essentially, we emit implementation for each add.with.overflow intrinsic that occurs in the module. 
> 
> Issues are lack of support for arbitrary size integers and assumption about the two's compliment representation for integers (casts from signed to unsigned and backwards). However, it seems that these are the limitations of the current CBackend implementation as well.  
> 
> We know that the CBackend is no longer supported and might get completely rewritten, but this patch removes the known blockers for us and might be useful for someone else as well.

Sure, seems reasonable.  Please commit, thanks!

-Chris