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Subject: Re: [PATCH] middle-end/95493 - bogus MEM_ATTRS for variable array
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To: Eric Botcazou <botcazou@adacore.com>
CC: gcc-patches@gcc.gnu.org
From: Richard Biener <rguenther@suse.de>
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On June 5, 2020 6:38:10 PM GMT+02:00, Eric Botcazou <botcazou@adacore=2Ecom=
> wrote:
>> I've installed it on trunk but will give it quite a while there
>before
>> backporting=2E  I'm still somewhat worried about the
>>=20
>>       /* ???  If we end up with a constant or a descriptor do not
>>          record a MEM_EXPR=2E  */
>>       else if (CONSTANT_CLASS_P (t)
>>=20
>>                || TREE_CODE (t) =3D=3D CONSTRUCTOR)
>>=20
>>         ;
>>=20
>> case, maybe we should assert that bitpos =3D=3D 0 here since we're
>> dropping it on the floor but eventually inherit offset_known_p =3D=3D
>true
>> from the already present MEM_ATTRs=2E
>
>It's hard to imagine without a testcase how you can end up inheriting
>anything=20
>for CONSTANT_CLASS_P or CONSTRUCTOR though: where do the MEM_ATTRs come
>from?=20

For constructor it was constant descriptors seen during ada bootstrap=2E I=
 can imagine constants are similar for constant pool entries=2E=20

Richard=2E=20