[dpdk-dev] [PATCH v14 07/12] build: use native machine args in Arm native build

[Ruifeng Wang]

> -----Original Message-----
> From: Juraj Linkeš <juraj.linkes at pantheon.tech>
> Sent: Wednesday, December 23, 2020 7:48 PM
> To: bruce.richardson at intel.com; Ruifeng Wang <Ruifeng.Wang at arm.com>;
> Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com>; Phil Yang
> <Phil.Yang at arm.com>; vcchunga at amazon.com; Dharmik Thakkar
> <Dharmik.Thakkar at arm.com>; jerinjacobk at gmail.com;
> hemant.agrawal at nxp.com; Ajit Khaparde (ajit.khaparde at broadcom.com)
> <ajit.khaparde at broadcom.com>; ferruh.yigit at intel.com
> Cc: dev at dpdk.org; Juraj Linkeš <juraj.linkes at pantheon.tech>
> Subject: [PATCH v14 07/12] build: use native machine args in Arm native build
> 
> Letting the compiler decide is going to yield the best results for native builds,
> so use native machine args usable for both GCC and Clang.
> 
> Signed-off-by: Juraj Linkeš <juraj.linkes at pantheon.tech>
> ---
>  config/arm/meson.build | 54 ++++++++++++++++++++++--------------------
>  1 file changed, 28 insertions(+), 26 deletions(-)
> 
> diff --git a/config/arm/meson.build b/config/arm/meson.build index
> 403e1a02f..4508f369c 100644
> --- a/config/arm/meson.build
> +++ b/config/arm/meson.build
> @@ -2,8 +2,6 @@
>  # Copyright(c) 2017 Intel Corporation.
>  # Copyright(c) 2017 Cavium, Inc
> 
> -arm_force_native_march = false
> -
>  # common flags to all aarch64 builds, with lowest priority  flags_common = [
>  	# Accelerate rte_memcpy. Be sure to run unit test
> (memcpy_perf_autotest) @@ -26,6 +24,7 @@ flags_common = [
>  	['RTE_ARCH_ARM64', true],
>  	['RTE_CACHE_LINE_SIZE', 128]
>  ]
> +native_machine_args = ['-mcpu=native']
> 
>  ## Part numbers are specific to Arm implementers  # implementer specific
> aarch64 flags have middle priority @@ -47,7 +46,6 @@ implementer_generic
> = {  }
> 
>  part_number_config_arm = {
> -	'native': {'machine_args':  ['-march=native']},
>  	'0xd03': {'machine_args':  ['-mcpu=cortex-a53']},
>  	'0xd04': {'machine_args':  ['-mcpu=cortex-a35']},
>  	'0xd07': {'machine_args':  ['-mcpu=cortex-a57']}, @@ -95,7 +93,6 @@
> implementer_cavium = {
>  		['RTE_MAX_NUMA_NODES', 2]
>  	],
>  	'part_number_config': {
> -		'native': {'machine_args': ['-march=native']},
>  		'0xa1': {
>  			'machine_args': ['-mcpu=thunderxt88'],
>  			'flags': flags_part_number_thunderx
> @@ -145,8 +142,7 @@ implementer_ampere = {
>  	],
>  	'part_number_config': {
>  		'0x0': {'machine_args':  ['-march=armv8-a+crc+crypto',
> -					  '-mtune=emag']},
> -		'native': {'machine_args':  ['-march=native']}
> +					  '-mtune=emag']}
>  	}
>  }
> 
> @@ -195,26 +191,27 @@ if dpdk_conf.get('RTE_ARCH_32')
>  	machine_args += '-mfpu=neon'
>  else
>  	# aarch64 build
> -	if machine == 'default' and not meson.is_cross_build()
> -		# default build
> -		implementer_id = 'generic'
> -		part_number = 'generic'
> -	elif not meson.is_cross_build()
> -		# native build
> -		# The script returns ['Implementer', 'Variant', 'Architecture',
> -		# 'Primary Part number', 'Revision']
> -		detect_vendor = find_program(join_paths(
> -				meson.current_source_dir(),
> 'armv8_machine.py'))
> -		cmd = run_command(detect_vendor.path())
> -		if cmd.returncode() == 0
> -			cmd_output = cmd.stdout().to_lower().strip().split(' ')
> -			implementer_id = cmd_output[0]
> -			part_number = cmd_output[3]
> +	use_native_machine_args = false
> +	if not meson.is_cross_build()
> +		if machine == 'default'
> +			# default build
> +			implementer_id = 'generic'
> +			part_number = 'generic'
>  		else
> -			error('Error when getting Arm Implementer ID and
> part number.')
> -		endif
> -		if arm_force_native_march == true
> -			part_number = 'native'
> +			# native build
> +			# The script returns ['Implementer', 'Variant',
> 'Architecture',
> +			# 'Primary Part number', 'Revision']
> +			detect_vendor = find_program(join_paths(
> +					meson.current_source_dir(),
> 'armv8_machine.py'))
> +			cmd = run_command(detect_vendor.path())
> +			if cmd.returncode() == 0
> +				cmd_output =
> cmd.stdout().to_lower().strip().split(' ')
> +				implementer_id = cmd_output[0]
> +				part_number = cmd_output[3]
> +			else
> +				error('Error when getting Arm Implementer
> ID and part number.')
> +			endif
> +			use_native_machine_args = true
>  		endif
>  	else
>  		# cross build
> @@ -250,7 +247,12 @@ else
> 
>  	# apply supported machine args
>  	machine_args = [] # Clear previous machine args
> -	foreach flag: part_number_config['machine_args']
> +	if use_native_machine_args
> +		candidate_machine_args = native_machine_args
> +	else
> +		candidate_machine_args =
> part_number_config['machine_args']
> +	endif
> +	foreach flag: candidate_machine_args
>  		if cc.has_argument(flag)
>  			machine_args += flag
>  		endif
> --
> 2.20.1

Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>