Re: [dpdk-dev] [PATCH v3] build: fix SVE compile error with gcc8.3

[fengchengwen <fengchengwen@huawei.com>]

Friendly ping


On 2021/5/27 15:12, Fengchengwen wrote:
> Hi, Thomas
> 
>     Could you review this patch? Thanks
> 
> 
> From:Ruifeng Wang <Ruifeng.Wang@arm.com>
> To:Fengchengwen <fengchengwen@huawei.com>;Thomas Monjalon <thomas@monjalon.net>;ferruh.yigit <ferruh.yigit@intel.com>
> Cc:dev <dev@dpdk.org>;Richardson, Bruce <bruce.richardson@intel.com>;vladimir.medvedkin <vladimir.medvedkin@intel.com>;viktorin <viktorin@rehivetech.com>;Jerin Jacob <jerinj@marvell.com>;nd <nd@arm.com>
> Date:2021-05-25 14:02:20
> Subject:RE: [PATCH v3] build: fix SVE compile error with gcc8.3
> 
>> -----Original Message-----
>> From: Chengwen Feng < fengchengwen@huawei.com<mailto:fengchengwen@huawei.com>>
>> Sent: Friday, May 21, 2021 9:53 AM
>> To: thomas@monjalon.net<mailto:thomas@monjalon.net>; ferruh.yigit@intel.com<mailto:ferruh.yigit@intel.com>; Ruifeng Wang
>> < Ruifeng.Wang@arm.com<mailto:Ruifeng.Wang@arm.com>>
>> Cc: dev@dpdk.org<mailto:dev@dpdk.org>; bruce.richardson@intel.com<mailto:bruce.richardson@intel.com>;
>> vladimir.medvedkin@intel.com<mailto:vladimir.medvedkin@intel.com>; viktorin@rehivetech.com<mailto:viktorin@rehivetech.com>;
>> jerinj@marvell.com<mailto:jerinj@marvell.com>
>> Subject: [PATCH v3] build: fix SVE compile error with gcc8.3
>>
>> If the target machine has SVE feature (e.g. "-march=armv8.2-a+sve'), and the
>> compiler are gcc8.3, it will compile error:
>>        In file included from ../dpdk-next-net/lib/eal/common/
>>        eal_common_options.c:38:
>>        ../dpdk-next-net/lib/eal/arm/include/rte_vect.h:13:10: fatal
>>        error: arm_sve.h: No such file or directory
>>        #include <arm_sve.h>
>>               ^~~~~~~~~~~
>>        compilation terminated.
>>
>> The root cause is that gcc8.3 supports SVE (the macro __ARM_FEATURE_SVE
>> was 1), but it doesn't support SVE ACLE [1].
>>
>> The solution:
>> a) Detect compiler whether support SVE ACLE, if support then define
>> CC_SVE_ACLE_SUPPORT macro.
>> b) Use the CC_SVE_ACLE_SUPPORT macro to include SVE header file.
>>
>> [1] ACLE: Arm C Language Extensions, the SVE ACLE header file is
>> <arm_sve.h>, user should include it when writing ACLE SVE code.
>>
>> Fixes: 67b68824a82d ("lpm/arm: support SVE")
>>
>> Signed-off-by: Chengwen Feng < fengchengwen@huawei.com<mailto:fengchengwen@huawei.com>>
>> ---
>> v3:
>> * double-indent 'cc.check_header('arm_sve.h')' line
>> * move set 'CC_SVE_ACLE_SUPPORT' logic to the back (not in the middle
>>   of compile_time_cpuflags setting)
>> * fix minor syntax error in commit log
>> v2:
>> * modify title start with 'build'
>>
>> ---
>> config/arm/meson.build         | 5 +++++
>> lib/eal/arm/include/rte_vect.h | 2 +-
>> lib/lpm/rte_lpm.h              | 2 +-
>> 3 files changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/config/arm/meson.build b/config/arm/meson.build index
>> e83a56e..08299b0 100644
>> --- a/config/arm/meson.build
>> +++ b/config/arm/meson.build
>> @@ -488,3 +488,8 @@ if cc.get_define('__ARM_FEATURE_CRYPTO', args:
>> machine_args) != ''
>>      compile_time_cpuflags += ['RTE_CPUFLAG_AES', 'RTE_CPUFLAG_PMULL',
>>      'RTE_CPUFLAG_SHA1', 'RTE_CPUFLAG_SHA2'] endif
>> +
>> +if (cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != '' and
>> +        cc.check_header('arm_sve.h'))
>> +    dpdk_conf.set('CC_SVE_ACLE_SUPPORT', 1) endif
>> diff --git a/lib/eal/arm/include/rte_vect.h b/lib/eal/arm/include/rte_vect.h
>> index 093e912..277b656 100644
>> --- a/lib/eal/arm/include/rte_vect.h
>> +++ b/lib/eal/arm/include/rte_vect.h
>> @@ -9,7 +9,7 @@
>> #include "generic/rte_vect.h"
>> #include "rte_debug.h"
>> #include "arm_neon.h"
>> -#ifdef __ARM_FEATURE_SVE
>> +#ifdef CC_SVE_ACLE_SUPPORT
>> #include <arm_sve.h>
>> #endif
>>
>> diff --git a/lib/lpm/rte_lpm.h b/lib/lpm/rte_lpm.h index 28b5768..9262814
>> 100644
>> --- a/lib/lpm/rte_lpm.h
>> +++ b/lib/lpm/rte_lpm.h
>> @@ -402,7 +402,7 @@ rte_lpm_lookupx4(const struct rte_lpm *lpm, xmm_t
>> ip, uint32_t hop[4],
>>        uint32_t defv);
>>
>> #if defined(RTE_ARCH_ARM)
>> -#ifdef __ARM_FEATURE_SVE
>> +#ifdef CC_SVE_ACLE_SUPPORT
>> #include "rte_lpm_sve.h"
>> #else
>> #include "rte_lpm_neon.h"
>> --
>> 2.8.1
> 
> Acked-by: Ruifeng Wang < ruifeng.wang@arm.com<mailto:ruifeng.wang@arm.com>>
>