Re: make check error in native compiler resulting from commit 1cd188799f86bcb13ad76e82e3436b1b7e9f9e9f on 2021-12-30.

[Andrea Corallo <akrl@sdf.org>]

Andrea Corallo <akrl@sdf.org> writes:

> Alan Mackenzie <acm@muc.de> writes:
>
>> Hello, Andrea.
>>
>> In that patch, I made the following change so that a comparison
>> involving Qnil would not go through the (newly) expensive emit_EQ:
>>
>> diff --git a/lisp/emacs-lisp/comp.el b/lisp/emacs-lisp/comp.el
>> index 0a10505257..8581fe8066 100644
>> --- a/lisp/emacs-lisp/comp.el
>> +++ b/lisp/emacs-lisp/comp.el
>> @@ -1829,9 +1829,7 @@ comp-limplify-lap-inst
>>        (byte-listp auto)
>>        (byte-eq auto)
>>        (byte-memq auto)
>> -      (byte-not
>> -       (comp-emit-set-call (comp-call 'eq (comp-slot-n (comp-sp))
>> -                                      (make-comp-mvar :constant nil))))
>> +      (byte-not null)
>>        (byte-car auto)
>>        (byte-cdr auto)
>>        (byte-cons auto)

Yeah, I think reverting this hunk and keeping the `eq' explicit in
LIMPLE is the right thing to do, it solves this specific issue and we
get back null and not inlined for free.

The explicit `eq' gets already nicely handled by the logic you have
added in comp.c:2244 so we emit libgccjit IR using emit_BASE_EQ in this
case.

I've pushed dcf30f14f9 to do that as it works here.

Thanks

  Andrea