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> -----Original Message-----
> From: Juraj Linkeš <juraj.lin...@pantheon.tech>
> Sent: Tuesday, August 17, 2021 12:57 PM
> To: tho...@monjalon.net; david.march...@redhat.com;
> bruce.richard...@intel.com; honnappa.nagaraha...@arm.com;
> ruifeng.w...@arm.com; fengcheng...@huawei.com;
> ferruh.yi...@intel.com; jerinjac...@gmail.com; jer...@marvell.com;
> pbhagavat...@marvell.com
> Cc: dev@dpdk.org; Juraj Linkeš <juraj.lin...@pantheon.tech>
> Subject: [PATCH v4 1/2] config/arm: split march cfg into arch and features
>
> Older compilers may not support all arch versions and all features that the
> target
> SoC supports, in which case it's better to figure out the highest arch
> version and
> features that the compiler supports. Implement a way to achieve this:
> 1. Find the highest arch version that the compiler supports, keeping in mind
> the
> SoC arch version we're building. For example, if the SoC arch version is
> arm8.2-
> a, but the compiler only supports arm8.1-a, use arm8.1-a. On the other hand,
> if
> the compiler supports arm8.3-a (or higher), use armv8.2-a.
> 2. With the architecture version locked, iterate over SoC features and use all
> that are supported.
>
> In all cases, emit a warning if there's something unsupported by the compiler.
>
> Signed-off-by: Juraj Linkeš <juraj.lin...@pantheon.tech>
> ---
> v4: rebase
> ---
> config/arm/meson.build | 124 ++++++++++++++++++++++++++++++++---------
> 1 file changed, 99 insertions(+), 25 deletions(-)
>
> diff --git a/config/arm/meson.build b/config/arm/meson.build index
> 14987c634a..c11efa1583 100644
> --- a/config/arm/meson.build
> +++ b/config/arm/meson.build
> @@ -38,7 +38,9 @@ implementer_generic = {
> ],
> 'part_number_config': {
> 'generic': {
> - 'machine_args': ['-march=armv8-a+crc', '-moutline-atomics']
> + 'march': 'armv8-a',
> + 'march_features': ['crc'],
> + 'compiler_options': ['-moutline-atomics']
> },
> 'generic_aarch32': {
> 'machine_args': ['-march=armv8-a', '-mfpu=neon'], @@ -53,15
> +55,17
> @@ implementer_generic = { }
>
> part_number_config_arm = {
> - '0xd03': {'machine_args': ['-mcpu=cortex-a53']},
> - '0xd04': {'machine_args': ['-mcpu=cortex-a35']},
> - '0xd07': {'machine_args': ['-mcpu=cortex-a57']},
> - '0xd08': {'machine_args': ['-mcpu=cortex-a72']},
> - '0xd09': {'machine_args': ['-mcpu=cortex-a73']},
> - '0xd0a': {'machine_args': ['-mcpu=cortex-a75']},
> - '0xd0b': {'machine_args': ['-mcpu=cortex-a76']},
> + '0xd03': {'compiler_options': ['-mcpu=cortex-a53']},
> + '0xd04': {'compiler_options': ['-mcpu=cortex-a35']},
> + '0xd07': {'compiler_options': ['-mcpu=cortex-a57']},
> + '0xd08': {'compiler_options': ['-mcpu=cortex-a72']},
> + '0xd09': {'compiler_options': ['-mcpu=cortex-a73']},
> + '0xd0a': {'compiler_options': ['-mcpu=cortex-a75']},
> + '0xd0b': {'compiler_options': ['-mcpu=cortex-a76']},
> '0xd0c': {
> - 'machine_args': ['-march=armv8.2-a+crypto', '-mcpu=neoverse-n1'],
> + 'march': 'armv8.2-a',
> + 'march_features': ['crypto'],
> + 'compiler_options': ['-mcpu=neoverse-n1'],
> 'flags': [
> ['RTE_MACHINE', '"neoverse-n1"'],
> ['RTE_ARM_FEATURE_ATOMICS', true], @@ -71,7 +75,8 @@
> part_number_config_arm = {
> ]
> },
> '0xd49': {
> - 'machine_args': ['-march=armv8.5-a+crypto+sve2'],
> + 'march': 'armv8.5-a',
> + 'march_features': ['crypto', 'sve2'],
> 'flags': [
> ['RTE_MACHINE', '"neoverse-n2"'],
> ['RTE_ARM_FEATURE_ATOMICS', true], @@ -105,19 +110,21 @@
> implementer_cavium = {
> ],
> 'part_number_config': {
> '0xa1': {
> - 'machine_args': ['-mcpu=thunderxt88'],
> + 'compiler_options': ['-mcpu=thunderxt88'],
> 'flags': flags_part_number_thunderx
> },
> '0xa2': {
> - 'machine_args': ['-mcpu=thunderxt81'],
> + 'compiler_options': ['-mcpu=thunderxt81'],
> 'flags': flags_part_number_thunderx
> },
> '0xa3': {
> - 'machine_args': ['-mcpu=thunderxt83'],
> + 'compiler_options': ['-mcpu=thunderxt83'],
> 'flags': flags_part_number_thunderx
> },
> '0xaf': {
> - 'machine_args': ['-march=armv8.1-a+crc+crypto', '-
> mcpu=thunderx2t99'],
> + 'march': 'armv8.1-a',
> + 'march_features': ['crc', 'crypto'],
> + 'compiler_options': ['-mcpu=thunderx2t99'],
> 'flags': [
> ['RTE_MACHINE', '"thunderx2"'],
> ['RTE_ARM_FEATURE_ATOMICS', true], @@ -127,7 +134,9 @@
> implementer_cavium = {
> ]
> },
> '0xb2': {
> - 'machine_args': ['-march=armv8.2-a+crc+crypto+lse', '-
> mcpu=octeontx2'],
> + 'march': 'armv8.2-a',
> + 'march_features': ['crc', 'crypto', 'lse'],
> + 'compiler_options': ['-mcpu=octeontx2'],
> 'flags': [
> ['RTE_MACHINE', '"octeontx2"'],
> ['RTE_ARM_FEATURE_ATOMICS', true], @@ -148,7 +157,11 @@
> implementer_ampere = {
> ['RTE_MAX_NUMA_NODES', 1]
> ],
> 'part_number_config': {
> - '0x0': {'machine_args': ['-march=armv8-a+crc+crypto',
> '-mtune=emag']}
> + '0x0': {
> + 'march': 'armv8-a',
> + 'march_features': ['crc', 'crypto'],
> + 'compiler_options': ['-mtune=emag']
> + }
> }
> }
>
> @@ -160,7 +173,9 @@ implementer_hisilicon = {
> ],
> 'part_number_config': {
> '0xd01': {
> - 'machine_args': ['-march=armv8.2-a+crypto', '-mtune=tsv110'],
> + 'march': 'armv8.2-a',
> + 'march_features': ['crypto'],
> + 'compiler_options': ['-mtune=tsv110'],
> 'flags': [
> ['RTE_MACHINE', '"Kunpeng 920"'],
> ['RTE_ARM_FEATURE_ATOMICS', true], @@ -169,7 +184,8 @@
> implementer_hisilicon = {
> ]
> },
> '0xd02': {
> - 'machine_args': ['-march=armv8.2-a+crypto+sve'],
> + 'march': 'armv8.2-a',
> + 'march_features': ['crypto', 'sve'],
> 'flags': [
> ['RTE_MACHINE', '"Kunpeng 930"'],
> ['RTE_ARM_FEATURE_ATOMICS', true], @@ -190,8 +206,14 @@
> implementer_qualcomm = {
> ['RTE_MAX_NUMA_NODES', 1]
> ],
> 'part_number_config': {
> - '0x800': {'machine_args': ['-march=armv8-a+crc']},
> - '0xc00': {'machine_args': ['-march=armv8-a+crc']},
> + '0x800': {
> + 'march': 'armv8-a',
> + 'march_features': ['crc']
> + },
> + '0xc00': {
> + 'march': 'armv8-a',
> + 'march_features': ['crc']
> + }
> }
> }
>
> @@ -500,13 +522,65 @@ if update_flags
> # add/overwrite flags in the proper order
> dpdk_flags = flags_common + implementer_config['flags'] +
> part_number_config.get('flags', []) + soc_flags
>
> - # apply supported machine args
> machine_args = [] # Clear previous machine args
> - foreach flag: part_number_config['machine_args']
> - if cc.has_argument(flag)
> - machine_args += flag
> +
> + # probe supported marchs and their features
> + candidate_march = ''
> + if part_number_config.has_key('march')
> + supported_marchs = ['armv8.6-a', 'armv8.5-a', 'armv8.4-a',
> 'armv8.3-a',
> + 'armv8.2-a', 'armv8.1-a', 'armv8-a']
> + check_compiler_support = false
> + foreach supported_march: supported_marchs
> + if supported_march == part_number_config['march']
> + # start checking from this version downwards
> + check_compiler_support = true
> + endif
> + if (check_compiler_support and
> + cc.has_argument('-march=' + supported_march))
> + candidate_march = supported_march
> + # highest supported march version found
> + break
> + endif
> + endforeach
> + if candidate_march == ''
> + error('No suitable armv8 march version found.')
> endif
> - endforeach
> + if candidate_march != part_number_config['march']
> + warning('Configuration march version is ' +
> + '@0@, but the compiler supports only @1@.'
> + .format(part_number_config['march'], candidate_march))
> + endif
> + candidate_march = '-march=' + candidate_march
> +
> + march_features = []
> + if part_number_config.has_key('march_features')
> + march_features += part_number_config['march_features']
> + endif
> + if soc_config.has_key('extra_march_features')
> + march_features += soc_config['extra_march_features']
> + endif
> + foreach feature: march_features
> + if cc.has_argument('+'.join([candidate_march, feature]))
> + candidate_march = '+'.join([candidate_march, feature])
> + else
> + warning('The compiler does not support feature @0@'
> + .format(feature))
> + endif
> + endforeach
> + machine_args += candidate_march
> + endif
> +
> + # apply supported compiler options
> + if part_number_config.has_key('compiler_options')
> + foreach flag: part_number_config['compiler_options']
> + if cc.has_argument(flag)
> + machine_args += flag
> + else
> + warning('Configuration compiler option ' +
> + '@0@ isn\'t supported.'.format(flag))
> + endif
> + endforeach
> + endif
>
> # apply flags
> foreach flag: dpdk_flags
> --
> 2.20.1
