[PATCH] lib/fib: remove warning about implicit 64-bit conversion

[Stephen Hemminger]

On Tue,  3 Dec 2024 18:56:50 -0800
Andre Muezerie <andremue at linux.microsoft.com> wrote:

> MSVC issues the warning below:
> 
> ../lib/fib/trie.c(341): warning C4334: '<<':
> result of 32-bit shift implicitly converted to 64 bits
> (was 64-bit shift intended?)
> 
> The fix is to cast the result explicitly to ptrdiff_t since it is used
> in pointer arithmetic.
> 
> Signed-off-by: Andre Muezerie <andremue at linux.microsoft.com>
> ---
>  lib/fib/trie.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/fib/trie.c b/lib/fib/trie.c
> index 4893f6c636..997b7cc338 100644
> --- a/lib/fib/trie.c
> +++ b/lib/fib/trie.c
> @@ -338,7 +338,7 @@ write_edge(struct rte_trie_tbl *dp, const uint8_t *ip_part, uint64_t next_hop,
>  		if (ret < 0)
>  			return ret;
>  		if (edge == LEDGE) {
> -			write_to_dp((uint8_t *)p + (1 << dp->nh_sz),
> +			write_to_dp((uint8_t *)p + (ptrdiff_t)(1 << dp->nh_sz),
>  				next_hop << 1, dp->nh_sz, UINT8_MAX - *ip_part);

You would be better to use a 64 bit shift or RTE_BIT64 for this.

			write_to_dp((uint8_t *)p + ((uintptr_t)1 << dp->nh_sz),