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Re: [PATCH] Fix hash_operand for fields of a CONSTRUCTOR.
On 11/5/19 1:35 AM, Martin Liška wrote:
> On 11/4/19 4:24 PM, Jeff Law wrote:
>> On 11/4/19 6:36 AM, Richard Biener wrote:
>>> On Mon, Nov 4, 2019 at 2:35 PM Richard Biener
>>> <richard.guenther@gmail.com> wrote:
>>>>
>>>> On Mon, Nov 4, 2019 at 10:09 AM Martin Liška <mliska@suse.cz> wrote:
>>>>>
>>>>> On 11/1/19 10:51 PM, Jeff Law wrote:
>>>>>> On 10/31/19 10:01 AM, Martin Liška wrote:
>>>>>>> Hi.
>>>>>>>
>>>>>>> operand_equal_p can properly handle situation where we have a CONSTRUCTOR
>>>>>>>
>>>>>>> where indices are NULL:
>>>>>>>
>>>>>>> if (!operand_equal_p (c0->value, c1->value, flags)
>>>>>>> /* In GIMPLE the indexes can be either NULL or matching i.
>>>>>>>
>>>>>>> Double check this so we won't get false
>>>>>>> positives for GENERIC. */
>>>>>>> || (c0->index
>>>>>>> && (TREE_CODE (c0->index) != INTEGER_CST
>>>>>>> || compare_tree_int (c0->index, i)))
>>>>>>> || (c1->index
>>>>>>> && (TREE_CODE (c1->index) != INTEGER_CST
>>>>>>> || compare_tree_int (c1->index, i))))
>>>>>>> return false;
>>>>>>>
>>>>>>> but the corresponding hash function always hashes field (which
>>>>>>> can be NULL_TREE or equal to ctor index).
>>>>>>>
>>>>>>> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>>>>>>>
>>>>>>>
>>>>>>> Ready to be installed?
>>>>>>> Thanks,
>>>>>>> Martin
>>>>>>>
>>>>>>> gcc/ChangeLog:
>>>>>>>
>>>>>>> 2019-10-31 Martin Liska <mliska@suse.cz>
>>>>>>>
>>>>>>> PR ipa/92304
>>>>>>> * fold-const.c (operand_compare::hash_operand): Fix field
>>>>>>> hashing of CONSTRUCTOR.
>>>>>> OK. One question though, do these routines need to handle
>>>>>> CONSTRUCTOR_NO_CLEARING?
>>>>>
>>>>> Good point, but I bet it's just a flag used in GENERIC, right?
>>>>
>>>> Yes. It matters for gimplification only. I don't think we can
>>>> optimistically make use of it in operand_equal_p.
>>>
>>> OTOH for GENERIC and sth like ICF the flags have to match.
>> Precisely my concern. I'm not immediately aware of any case where it
>> matters, but it'd be nice to future proof this if we can.
>>
>> jeff
>>
>
> Sure, I've got the following tested patch.
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
> Thanks,
> Martin
>
> 0001-Add-CONSTRUCTOR_NO_CLEARING-to-operand_equal_p.patch
>
> From 2302c15cb2568bc71b4b7bc3abbfd66aafc7c06c Mon Sep 17 00:00:00 2001
> From: Martin Liska <mliska@suse.cz>
> Date: Mon, 4 Nov 2019 15:39:40 +0100
> Subject: [PATCH] Add CONSTRUCTOR_NO_CLEARING to operand_equal_p.
>
> gcc/ChangeLog:
>
> 2019-11-04 Martin Liska <mliska@suse.cz>
>
> * fold-const.c (operand_compare::operand_equal_p): Add comparison
> of CONSTRUCTOR_NO_CLEARING.
> (operand_compare::hash_operand): Likewise.
OK
jeff