Re: [PATCH] Support bitmap_copy across representations

[Jeff Law <jeffreyalaw@gmail.com>]

On 8/17/2022 5:11 AM, Richard Biener via Gcc-patches wrote:
> The following started as making the backward threader m_imports
> use the tree representation.  Since that interfaces to a list
> representation bitmap in ranger by copying rewriting the tree
> to list to perform the copy is inefficient in that it loses
> balancing.  The following adds bitmap_copy_tree_to_list and
> integrates it with the generic bitmap_copy routine.  For symmetry
> I also added list to tree copy, relying on auto-balancing, and
> tree to tree copy which I didn't optimize to preserve the
> source balancing but instead use bitmap_copy_tree_to_list and
> have the result auto-balanced again.
>
> I've only exercised the tree to list path and I won't actually
> end up using it but it's at least worth posting.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu.
>
> Worth pushing?
>
> 	* bitmap.h: Document set_copy aka bitmap_copy as usable
> 	for tree representation.
> 	* bitmap.cc (bitmap_copy_tree_to_list): New helper.
> 	(bitmap_copy): Support copying all bitmap representation
> 	combinations.
I'd lean against unless you expect to be using it.   But it's not a 
strongly held opinion.

jeff