Re: [PATCH] Remove legacy VRP (maybe?)

[Aldy Hernandez <aldyh@redhat.com>]

On 11/22/22 09:25, Richard Biener wrote:
> On Tue, Nov 22, 2022 at 9:24 AM Richard Biener
> <richard.guenther@gmail.com> wrote:
>>
>> On Mon, Nov 21, 2022 at 5:49 PM Jeff Law <jeffreyalaw@gmail.com> wrote:
>>>
>>>
>>> On 11/21/22 09:35, Aldy Hernandez via Gcc-patches wrote:
>>>> I've been playing around with removing the legacy VRP code for the
>>>> next release.  It's a layered onion to get this right, but the first
>>>> bit is pretty straightforward and may be useful for this release.
>>>> Basically, it entails removing the old VRP pass itself, along with
>>>> value_range_equiv which have no producers left.  The current users of
>>>> value_range_equiv don't put anything in the equivalence bitmaps, so
>>>> they're basically behaving like plain value_range.
>>>>
>>>> I removed as much as possible without having to change any behavior,
>>>> and this is what I came up with.  Is this something that would be
>>>> useful for this release?  Would it help release managers have less
>>>> unused cruft in the tree?
>>>>
>>>> Neither Andrew nor I have any strong feelings here.  We don't foresee
>>>> the legacy code changing at all in the offseason, so we can just
>>>> accumulate these patches in local trees.
>>>
>>> I'd lean towards removal after gcc-13 releases.
>>
>> I think removing the ability to switch to the old implementation easens
>> maintainance so I'd prefer to have this before the gcc-13 release.
>>
>> So please go ahead.
> 
> Btw, ASSERT_EXPR should also go away with this, no?

Ah yes, for everything except ipa-*.* which uses it internally (and sets 
it in its internal structures):

        - ASSERT_EXPR means that only the value in operand is allowed to 
pass
          through (without any change), for all other values the result is
          unknown.

I can remove all other uses, including any externally visible documentation.

Thanks.
Aldy