Interestingly, clang and gcc has different prototype for _mm_prefetch().
For gcc, we have
_mm_prefetch (const void *__P, enum _mm_hint __I)
While for clang, it's
#define _mm_prefetch(a, sel) (__builtin_prefetch((void *)(a), 0, (sel)))
That how the following error comes with clang:
error: cast from 'const void *' to 'void *' drops const qualifier
[-Werror,-Wcast-qual]
_mm_prefetch((const void *)rused, _MM_HINT_T0);
/usr/lib/llvm-3.8/bin/../lib/clang/3.8.0/include/xmmintrin.h:684:58:
note: expanded from macro '_mm_prefetch'
#define _mm_prefetch(a, sel) (__builtin_prefetch((void *)(a),
0, (sel)))
What's weird is that the build was actaully Okay before. I met it while
apply Jerin's vector support for ARM patch set: he just move this peiece
of code to another file, nothing else changed.
This patch fix the issue when Jerin's patchset is applied. Thus, I think
it's still needed.
Fixes: fc3d66212fed ("virtio: add vector Rx")
Cc: Jerin Jacob <jerin.jacob at caviumnetworks.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
drivers/net/virtio/virtio_rxtx_simple.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/virtio/virtio_rxtx_simple.c
b/drivers/net/virtio/virtio_rxtx_simple.c
index 6517aa8..56195e5 100644
--- a/drivers/net/virtio/virtio_rxtx_simple.c
+++ b/drivers/net/virtio/virtio_rxtx_simple.c
@@ -200,7 +200,7 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf
**rx_pkts,
sw_ring = &vq->sw_ring[desc_idx];
sw_ring_end = &vq->sw_ring[vq->vq_nentries];
- _mm_prefetch((const void *)rused, _MM_HINT_T0);
+ _mm_prefetch(rused, _MM_HINT_T0);
if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
virtio_rxq_rearm_vec(rxvq);
--
1.9.0
