[LLVMdev] Optimization passes organization and tradeoffs

[David Greene]

On Wednesday 21 May 2008 15:48, Chris Lattner wrote:

> > What's the difference between GVN and GCSE, if they both perform common
> > subexpression elimination?
>
> GVN does more, and is a better algorithm.  GCSE is basically deprecated
> and should be removed at some point.

Er...waitaminute.  Maybe there's something I don't fully grok about GVN,
but in general, value numbering and CSE are different and often complementary.
Neither is "more powerful" than the other.

                                       -Dave