[PATCH] consider MIN_EXPR in get_size_range() (PR 85888)

[Jeff Law]

On 05/30/2018 03:37 AM, Richard Biener wrote:
> On Tue, May 29, 2018 at 4:58 PM Martin Sebor <msebor@gmail.com> wrote:
> 
>> On 05/28/2018 03:11 AM, Richard Biener wrote:
>>> On Fri, May 25, 2018 at 10:15 PM Martin Sebor <msebor@gmail.com> wrote:
>>>
>>>> Attached is revision 3 of the patch incorporating your
>>>> determine_value_range function with the requested changes.
>>>
>>> I'm somewhat torn about removing the "basic" interface on SSA names
>>> so can you please not change get_range_info for now and instead
>>> use determine_value_range in get_size_range for now?
> 
>> I can do that.  Can you explain why you're having second thoughts
>> about going this route?
> 
> I've seen you recurse between both APIs, thus they call each other.
> That's ugly which is why I prefer to keep one of them a simple accessor
> to the range-info associated with an SSA name.
> 
> A future enhancement for the new API would be to walk def stmts
> but then the API should stop at SSA names that do have range-info
> associated and record range-info it computed into SSA names it
> walked so the IL itself serves as a cache.  That requires a way
> to see whether an SSA name has range-info rather than having
> get_range_info recurse into the walking machinery again.
There's a lot of similarities between what you're suggesting here and
the ranger API that Andrew has been working on.


Jeff