0005-Search-all-dominated-blocks-for-expressions-to-hoist.patch

[Steven Bosscher]

On Wed, Jun 16, 2010 at 5:58 PM, Maxim Kuvyrkov <maxim@codesourcery.com> wrote:
> Currently, code hoisting only checks immediately-dominated blocks for
> expressions to hoist.  I wonder if limiting the search for expressions is
> intentional.
>
> This patch makes code hoisting search through all dominated blocks for
> expressions to hoist.

And makes the algorithm quadratic in the size of the CFG. You should
limit the depth not only to avoid excessive live range lengths but
also for corner cases of strangely-formed CFGs.

Ciao!
Steven