Re: [PATCH] Add auto-resizing capability to irange's [PR109695]

[Aldy Hernandez via Gcc-patches]

On 5/15/23 12:42, Jakub Jelinek wrote:
On Mon, May 15, 2023 at 12:35:23PM +0200, Aldy Hernandez wrote:
gcc/ChangeLog:

        PR tree-optimization/109695
        * value-range.cc (irange::operator=): Resize range.
        (irange::union_): Same.
        (irange::intersect): Same.
        (irange::invert): Same.
        (int_range_max): Default to 3 sub-ranges and resize as needed.
        * value-range.h (irange::maybe_resize): New.
        (~int_range): New.
        (int_range::int_range): Adjust for resizing.
        (int_range::operator=): Same.

LGTM.

One question is if we shouldn't do it for GCC13/GCC12 as well, perhaps
changing it to some larger number than 3 when the members aren't wide_ints
in there but just trees.  Sure, in 13/12 the problem is 10x less severe
than in current trunk, but still we have some cases where we run out of
stack because of it on some hosts.

Sure, but that would require messing around with the gt_* GTY functions, 
and making sure we're allocating the trees from a sensible place, etc 
etc.  I'm less confident in my ability to mess with GTY stuff this late 
in the game.

Thoughts?
Aldy