> -----Original Message-----
> From: Eelco Chaudron <[email protected]>
> Sent: Friday, April 22, 2022 9:48 AM
> To: David Marchand <[email protected]>
> Cc: Van Haaren, Harry <[email protected]>; [email protected];
> Ilya Maximets <[email protected]>
> Subject: Re: [ovs-dev] [PATCH] dpif-netdev-avx512: fix ubsan shift error in 
> bitmasks
> 
> 
> 
> On 22 Apr 2022, at 10:29, David Marchand wrote:
> 
> > On Wed, Apr 20, 2022 at 10:19 AM Eelco Chaudron <[email protected]>
> wrote:
> >> On 19 Apr 2022, at 18:20, Harry van Haaren wrote:
> >>
> >>> The code changes here are to handle (1 << i) shifts where 'i' is the
> >>> packet index in the batch, and 1 << 31 is an overflow of the signed '1'.
> >>>
> >>> Fixed by adding ULL suffix to the 1 character, ensuring compiler knows
> >>> the 1 is unsigned (and 32-bits minimum). Undefined Behaviour sanitizer
> >>> is now happy with the shifts at runtime.
> >>
> >> Change looks good to me, but should 1UL not be enough, as the destinations 
> >> are
> all 32-bit?
> >
> > For storing/comparing to explicit uint32_t variables, either
> > (uint32_t)1 or UINT32_C(1) are more natural.
> > Any reason not to use those?
> 
> Forgot about those :) They are even better...

OK, thanks folks, will respin a v2 with those.

Regards, -Harry
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