[PATCH] Allow blocks to be merged when one has an undef input to a phi.

[Mark Lacey]

On Jun 28, 2013, at 7:09 PM, Mark Lacey <mark.lacey at apple.com> wrote:
> I like your idea, so I went ahead and implemented it, as well as keeping track of which undef values were found in the phi (and then only walking those again to update them).

I meant to revise this line before hitting send - this was an earlier draft. Although it might be possible to keep track of the undef values and only walk those again to update, it added complexity and did not seem to be worthwhile, so instead the phi operands are walked again and updated after selecting a value for the undef inputs.

Mark