Re: [dpdk-dev] [PATCH 1/3] net/thunderx: disable pmd for gcc < 4.7

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

-----Original Message-----
> Date: Thu,  6 Apr 2017 13:14:26 +0100
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>, Bruce Richardson
>  <bruce.richardson@intel.com>, Harry van Haaren
>  <harry.van.haaren@intel.com>, Thomas Monjalon <thomas.monjalon@6wind.com>
> Cc: dev@dpdk.org, Ferruh Yigit <ferruh.yigit@intel.com>
> Subject: [PATCH 1/3] net/thunderx: disable pmd for gcc < 4.7
> X-Mailer: git-send-email 2.8.4
> 
> PMD uses some compiler builtins and new compiler options. Tested with
> gcc 4.5.1 and following were not supported:
> 
> option:
> -Ofast
> 
> macros:
> _Static_assert
> 
> __ORDER_LITTLE_ENDIAN__
> __ORDER_BIG_ENDIAN__
> __BYTE_ORDER__
> 
> __atomic_fetch_add
> __ATOMIC_ACQUIRE
> __atomic_load_n
> __ATOMIC_RELAXED
> __atomic_store_n
> __ATOMIC_RELEASE
> 
> It is not easy to fix all in PMD, disabling PMD for gcc version < 4.7
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

> ---
>  drivers/net/thunderx/Makefile | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/net/thunderx/Makefile b/drivers/net/thunderx/Makefile
> index 706250b..0b9f0a2 100644
> --- a/drivers/net/thunderx/Makefile
> +++ b/drivers/net/thunderx/Makefile
> @@ -62,6 +62,14 @@ SRCS-$(CONFIG_RTE_LIBRTE_THUNDERX_NICVF_PMD) += nicvf_svf.c
>  
>  ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
>  CFLAGS_nicvf_rxtx.o += -fno-prefetch-loop-arrays
> +
> +# Disable PMD for gcc < 4.7
> +ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
> +$(warning thunderx pmd not supported by gcc < 4.7)
> +LIB = 
> +SRC-y = 
> +endif
> +
>  endif
>  CFLAGS_nicvf_rxtx.o += -Ofast
>  
> -- 
> 2.9.3
>