From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuanhan Liu Subject: [PATCH] net/virtio: fix build error with clang Date: Tue, 23 Aug 2016 15:40:58 +0800 Message-ID: <1471938058-12385-1-git-send-email-yuanhan.liu@linux.intel.com> Cc: Yuanhan Liu , Jerin Jacob To: dev@dpdk.org Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 36EBF2956 for ; Tue, 23 Aug 2016 09:31:16 +0200 (CEST) List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 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 Signed-off-by: Yuanhan Liu --- 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