[dpdk-dev] [PATCH v2 16/16] acl: check for SSE 4.1 support

[Ananyev, Konstantin]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Jan Viktorin
> Sent: Monday, October 26, 2015 4:38 PM
> To: Thomas Monjalon; Hunt, David; dev at dpdk.org
> Subject: [dpdk-dev] [PATCH v2 16/16] acl: check for SSE 4.1 support
> 
> The main goal of this check is to avoid passing the -msse4.1
> option to the GCC that does not support it (like arm toolchains).
> 
> Anyway, the ACL library does not compile on ARM.
> 
> Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>
> ---
>  lib/librte_acl/Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/librte_acl/Makefile b/lib/librte_acl/Makefile
> index 7a1cf8a..401fb8c 100644
> --- a/lib/librte_acl/Makefile
> +++ b/lib/librte_acl/Makefile
> @@ -50,7 +50,11 @@ SRCS-$(CONFIG_RTE_LIBRTE_ACL) += acl_gen.c
>  SRCS-$(CONFIG_RTE_LIBRTE_ACL) += acl_run_scalar.c
>  SRCS-$(CONFIG_RTE_LIBRTE_ACL) += acl_run_sse.c
> 
> +CC_SSE4_1_SUPPORT := $(shell $(CC) -msse4.1 -dM -E - < /dev/null >/dev/null 2>&1 && echo 1)
> +
> +ifeq ($(CC_SSE4_1_SUPPORT),1)
>  CFLAGS_acl_run_sse.o += -msse4.1
> +endif

I don't think acl_run_sse.c would compile if SSE4_1 is not supported.
So, I think you need to do same thing, as is done for AVX2:
Compile in acl_run_sse.c  only if SSE41 is supported by the compiler:  

- SRCS-$(CONFIG_RTE_LIBRTE_ACL) += acl_run_sse.c
-
-CFLAGS_acl_run_sse.o += -msse4.1

+CC_SSE41_SUPPORT=$(shell $(CC) -msse4.1 -dM -E - </dev/null 2>&1 | \
grep -q  && echo 1)
+ifeq ($(CC_SSE41_SUPPORT), 1)
+        SRCS-$(CONFIG_RTE_LIBRTE_ACL) += acl_run_sse.c
+        CFLAGS_rte_acl.o += -DCC_SSE41_SUPPORT
+        CFLAGS_acl_run_sse.o += -msse4.1	
+endif

And then change rte_acl_init() accordingly.
Something like:

int __attribute__ ((weak))
rte_acl_classify_sse(__rte_unused const struct rte_acl_ctx *ctx,
        __rte_unused const uint8_t **data,
        __rte_unused uint32_t *results,
        __rte_unused uint32_t num,
        __rte_unused uint32_t categories)
{
        return -ENOTSUP;
}

....

static void __attribute__((constructor))
rte_acl_init(void)
{
        enum rte_acl_classify_alg alg = RTE_ACL_CLASSIFY_DEFAULT;

#if defined(CC_AVX2_SUPPORT)
        if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2))
                alg = RTE_ACL_CLASSIFY_AVX2;
        else if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_1))
#elif defined (CC_SSE41_SUPPORT)
        if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_1))
                alg = RTE_ACL_CLASSIFY_SSE;
#endif

        rte_acl_set_default_classify(alg);
}

After that, I suppose, you should be able to build and (probably use) librte_acl on arm.
Konstantin