[PATCH] D39483: [CVP] Remove some {s|u}{add|sub}.with.overflow checks.

[Joel Galenson via Phabricator via llvm-commits]

jgalenson added a comment.

> If you think the previous name was better I'm ok with that.

I don't have a strong preference, so I'll keep yours.

> I'm not suggesting you change ConstantRange in this commit (that indeed is not a great idea).  I'm suggesting that instead of adding a bunch of logic here only to move it to ConstantRange in a later commit, how about:
> 
> - Commit0: Only process uadd and sadd in CVP with ConstantRange::makeGuaranteedNoWrapRegion.
> - Commit1: Teach makeGuaranteedNoWrapRegion about usub and ssub
> - Commit2: Use Commit1 to process ssub and usub in CVP
> - ...
> 
>   If anything, the sequence above will make the commits even more focussed.  I hope I made sense.

Ah, sorry, I misunderstood you.  Looks like we agree. :)  I'll do that.

By the way, I would also like to get this code to handle non-constant arithmetic for cases such as:

if (x >= y)

  .. x - y ...

But that's even harder, so I'll leave it for later.


https://reviews.llvm.org/D39483