Re: [dpdk-stable] [PATCH v5 1/4] eal: fix clang compilation error on x86

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

> 
> From: Gavin Hu <gavin.hu@arm.com>
> 
> When CONFIG_RTE_FORCE_INTRINSICS is enabled for x86, the clang
> compilation error was:
> 	include/generic/rte_atomic.h:215:9: error:
> 		implicit declaration of function '__atomic_exchange_2'
> 		is invalid in C99
> 	include/generic/rte_atomic.h:494:9: error:
> 		implicit declaration of function '__atomic_exchange_4'
> 		is invalid in C99
> 	include/generic/rte_atomic.h:772:9: error:
> 		implicit declaration of function '__atomic_exchange_8'
> 		is invalid in C99
> 
> Use __atomic_exchange_n instead of __atomic_exchange_(2/4/8).
> For more information, please refer to:
> http://mails.dpdk.org/archives/dev/2018-April/096776.html
> 
> Fixes: 7bdccb93078e ("eal: fix ARM build with clang")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Gavin Hu <gavin.hu@arm.com>
> Acked-by: Jerin Jacob <jerinj@marvell.com>
> ---
>  lib/librte_eal/common/include/generic/rte_atomic.h | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_eal/common/include/generic/rte_atomic.h
> b/lib/librte_eal/common/include/generic/rte_atomic.h
> index b99ba46..ed5b125 100644
> --- a/lib/librte_eal/common/include/generic/rte_atomic.h
> +++ b/lib/librte_eal/common/include/generic/rte_atomic.h
> @@ -212,7 +212,7 @@ rte_atomic16_exchange(volatile uint16_t *dst,
> uint16_t val);  static inline uint16_t  rte_atomic16_exchange(volatile
> uint16_t *dst, uint16_t val)  { -#if defined(RTE_ARCH_ARM64) &&
> defined(RTE_TOOLCHAIN_CLANG)
> +#if defined(RTE_TOOLCHAIN_CLANG)
Please check http://mails.dpdk.org/archives/dev/2019-January/123331.html
This needs to be changed to (__clang__). This applies for other similar changes here.

>  	return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);  #else
>  	return __atomic_exchange_2(dst, val, __ATOMIC_SEQ_CST); @@ -
> 495,7 +495,7 @@ rte_atomic32_exchange(volatile uint32_t *dst, uint32_t
> val);  static inline uint32_t  rte_atomic32_exchange(volatile uint32_t *dst,
> uint32_t val)  { -#if defined(RTE_ARCH_ARM64) &&
> defined(RTE_TOOLCHAIN_CLANG)
> +#if defined(RTE_TOOLCHAIN_CLANG)
>  	return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);  #else
>  	return __atomic_exchange_4(dst, val, __ATOMIC_SEQ_CST); @@ -
> 777,7 +777,7 @@ rte_atomic64_exchange(volatile uint64_t *dst, uint64_t
> val);  static inline uint64_t  rte_atomic64_exchange(volatile uint64_t *dst,
> uint64_t val)  { -#if defined(RTE_ARCH_ARM64) &&
> defined(RTE_TOOLCHAIN_CLANG)
> +#if defined(RTE_TOOLCHAIN_CLANG)
>  	return __atomic_exchange_n(dst, val, __ATOMIC_SEQ_CST);  #else
>  	return __atomic_exchange_8(dst, val, __ATOMIC_SEQ_CST);
> --
> 2.7.4