On Wed, May 13, 2020 at 5:36 PM Nithin Dabilpuram
<ndabilpu...@marvell.com> wrote:
>
> Older GCC(~4) complains about uninitialized 'dip'
> var though all the lanes of the vec register are set.
> Hence this patch explicitly initializes vec register
> to fix the issue.
>
> In file included from ip4_lookup.c:34:0:
> ip4_lookup_neon.h: n function ‘ip4_lookup_node_process’: \
> ip4_lookup_neon.h:25:12: error: ‘dip’ may be used uninitialized in \
> this function [-Werror=maybe-uninitialized]
> int32x4_t dip;
> ^
>
> Fixes: 16df6a2c6671 ("node: add IPv4 lookup for arm64")
>
Reported-by: David Marchand <david.march...@redhat.com>
> Signed-off-by: Nithin Dabilpuram <ndabilpu...@marvell.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
It is a false positive, all the lines are updated by the c code.
Just to make the old compiler to happy we need to add unnecessary
additional instruction.
Looks like there is no other clean way to suppress the warning.
Reviewed-by: Jerin Jacob <jer...@marvell.com>
> ---
> v2:
> - Add error in commit msg.
>
> lib/librte_node/ip4_lookup_neon.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/librte_node/ip4_lookup_neon.h
> b/lib/librte_node/ip4_lookup_neon.h
> index bb3150f..dd21cb2 100644
> --- a/lib/librte_node/ip4_lookup_neon.h
> +++ b/lib/librte_node/ip4_lookup_neon.h
> @@ -45,6 +45,7 @@ ip4_lookup_node_process(struct rte_graph *graph, struct
> rte_node *node,
> rte_prefetch0(rte_pktmbuf_mtod_offset(pkts[i], void *,
> sizeof(struct
> rte_ether_hdr)));
>
> + dip = vdupq_n_s32(0);
> /* Get stream for the speculated next node */
> to_next = rte_node_next_stream_get(graph, node, next_index, nb_objs);
> while (n_left_from >= 4) {
> --
> 2.8.4
>
