Re: [PATCH next 10/11] block: Use a boolean expression instead of max() on booleans

[Jani Nikula]

On Sun, 28 Jan 2024, David Laight <David.Laight@xxxxxxxxxx> wrote:
> blk_stack_limits() contains:
> 	t->zoned = max(t->zoned, b->zoned);
> These are bool, so it is just a bitwise or.

Should be a logical or, really. And || in code.

BR,
Jani.


> However it generates:
> error: comparison of constant ‘0’ with boolean expression is always true [-Werror=bool-compare]
> inside the signedness check that max() does unless a '+ 0' is added.
> It is a shame the compiler generates this warning for code that will
> be optimised away.
>
> Change so that the extra '+ 0' can be removed.
>
> Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
> ---
>  block/blk-settings.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index 06ea91e51b8b..9ca21fea039d 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -688,7 +688,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
>  						   b->max_secure_erase_sectors);
>  	t->zone_write_granularity = max(t->zone_write_granularity,
>  					b->zone_write_granularity);
> -	t->zoned = max(t->zoned, b->zoned);
> +	t->zoned = t->zoned | b->zoned;
>  	return ret;
>  }
>  EXPORT_SYMBOL(blk_stack_limits);

-- 
Jani Nikula, Intel