Hi Konstantin,
I installed the clang version 4.0.1 to check for the issue you were facing with
-O2 compilation. I was able to compile with -O2 and -O0 optimization without
any errors. Please see the exact command I used and the following output for
your reference:
$ clang -O2 -target bpf -I /usr/include/aarch64-linux-gnu/ -c t1.c
$ clang -O0 -target bpf -I /usr/include/aarch64-linux-gnu/ -c t1.c
$ clang -v
clang version 4.0.1-10 (tags/RELEASE_401/final)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/6
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/6.4.0
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/8
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/8.0.1
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/6.4.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/8.0.1
Selected GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7.3.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
I hope this was helpful to you.
Best Regards,
Malvika Gupta
-----Original Message-----
From: Malvika Gupta
Sent: Wednesday, September 5, 2018 4:43 PM
To: Ananyev, Konstantin <konstantin.anan...@intel.com>
Cc: dev@dpdk.org; Gavin Hu (Arm Technology China) <gavin...@arm.com>; Honnappa
Nagarahalli <honnappa.nagaraha...@arm.com>; Brian Brooks
<brian.bro...@arm.com>; nd <n...@arm.com>
Subject: RE: [PATCH] test/bpf: use hton instead of __builtin_bswap
Hi Ananyev,
I used clang version 6.0.0. Please see the following output for your reference.
$ clang -v
clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
Target: aarch64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/6
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/6.4.0
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/8
Found candidate GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/8.0.1
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/6 Found
candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/6.4.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/7 Found
candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/8 Found
candidate GCC installation: /usr/lib/gcc/aarch64-linux-gnu/8.0.1
Selected GCC installation: /usr/bin/../lib/gcc/aarch64-linux-gnu/7.3.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
Also, the code compiles with both -O2 and -O0 for me.
I hope this was helpful
Best,
Malvika
-----Original Message-----
From: Ananyev, Konstantin <konstantin.anan...@intel.com>
Sent: Tuesday, September 4, 2018 8:56 AM
To: Malvika Gupta <malvika.gu...@arm.com>
Cc: dev@dpdk.org; Gavin Hu (Arm Technology China) <gavin...@arm.com>; Honnappa
Nagarahalli <honnappa.nagaraha...@arm.com>; Brian Brooks
<brian.bro...@arm.com>; nd <n...@arm.com>
Subject: RE: [PATCH] test/bpf: use hton instead of __builtin_bswap
Hi,
>
> Convert host machine endianness to networking endianness for
> comparison of incoming packets with BPF filter
>
>
> Signed-off-by: Malvika Gupta <malvika.gu...@arm.com>
> Reviewed-by: Gavin Hu <gavin...@arm.com>
> Reviewed-by: Brian Brooks <brian.bro...@arm.com>
> Suggested-by: Brian Brooks <brian.bro...@arm.com>
> ---
> test/bpf/t1.c | 7 ++++---
> test/bpf/t3.c | 3 ++-
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/test/bpf/t1.c b/test/bpf/t1.c index 60f9434ab..7943fcf34
> 100644
> --- a/test/bpf/t1.c
> +++ b/test/bpf/t1.c
> @@ -28,24 +28,25 @@
> #include <net/ethernet.h>
> #include <netinet/ip.h>
> #include <netinet/udp.h>
> +#include <arpa/inet.h>
>
> uint64_t
> entry(void *pkt)
> {
> struct ether_header *ether_header = (void *)pkt;
>
> - if (ether_header->ether_type != __builtin_bswap16(0x0800))
> + if (ether_header->ether_type != htons(0x0800))
Which version of clang do you use?
With my one I get:
$ clang -O2 -target bpf -c t1.c
t1.c:37:34: error: couldn't allocate output register for constraint 'r'
if (ether_header->ether_type != ntohs(0x0800))
^
/usr/include/netinet/in.h:402:21: note: expanded from macro 'ntohs'
# define ntohs(x) __bswap_16 (x)
^
/usr/include/bits/byteswap-16.h:31:14: note: expanded from macro '__bswap_16'
__asm__ ("rorw $8, %w0"
With '-O0' it compiles ok.
$ clang -v
clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/7
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/7
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
Konstantin
> return 0;
>
> struct iphdr *iphdr = (void *)(ether_header + 1);
> if (iphdr->protocol != 17 || (iphdr->frag_off & 0x1ffff) != 0 ||
> - iphdr->daddr != __builtin_bswap32(0x1020304))
> + iphdr->daddr != htonl(0x1020304))
> return 0;
>
> int hlen = iphdr->ihl * 4;
> struct udphdr *udphdr = (void *)iphdr + hlen;
>
> - if (udphdr->dest != __builtin_bswap16(5000))
> + if (udphdr->dest != htons(5000))
> return 0;
>
> return 1;
> diff --git a/test/bpf/t3.c b/test/bpf/t3.c index 531b9cb8c..24298b7c7
> 100644
> --- a/test/bpf/t3.c
> +++ b/test/bpf/t3.c
> @@ -17,6 +17,7 @@
> #include <net/ethernet.h>
> #include <rte_config.h>
> #include "mbuf.h"
> +#include <arpa/inet.h>
>
> extern void rte_pktmbuf_dump(FILE *, const struct rte_mbuf *,
> unsigned int);
>
> @@ -29,7 +30,7 @@ entry(const void *pkt)
> mb = pkt;
> eth = rte_pktmbuf_mtod(mb, const struct ether_header *);
>
> - if (eth->ether_type == __builtin_bswap16(ETHERTYPE_ARP))
> + if (eth->ether_type == htons(ETHERTYPE_ARP))
> rte_pktmbuf_dump(stdout, mb, 64);
>
> return 1;
> --
> 2.17.1
