Re: optimize several list functions with SIMD intrinsics - Mailing list pgsql-hackers

On Wed, Mar 15, 2023 at 07:31:46PM +0530, Ankit Kumar Pandey wrote:
>> On 14/03/23 03:10, Nathan Bossart wrote:
>> On Sat, Mar 11, 2023 at 09:41:18AM +0000, Ankit Kumar Pandey wrote:
>> > 1. In list_member_ptr, will it be okay to bring `const ListCell
>> > *cell` from #ifdef USE_NO_SIMD
>> >     const ListCell *cell;
>> > #endif
>> > to #else like as mentioned below? This will make visual separation between #if cases more cleaner
>> I would expect to see -Wdeclaration-after-statement warnings if we did
>> this.
> 
> This worked fine for me, no warnings on gcc 12.2.0. Not a concern though.

Did you try building without SIMD support?  This is what I see:

    list.c: In function ‘list_member_ptr’:
    list.c:697:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
      697 |  const ListCell *cell;
          |  ^~~~~

If your build doesn't have USE_NO_SIMD defined, this warning won't appear
because the code in question will be compiled out.

-- 
Nathan Bossart
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