[snip]
>> +
>> + # 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
I think breaking it down into two steps is more intuitive.
step1: find the march version which target config.
If not find then error exit.
step2: start checking from step1's version.
>> + endforeach
>> + if candidate_march == ''
>> + error('No suitable armv8 march version found.')
>> + else
There no need use else, because meson will halt when execute error.
>> + 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
>> endif
>> - endforeach
>> + if part_number_config.has_key('march_features')
>> + feature_unsupported = false
>> + foreach feature: part_number_config['march_features']
>> + if cc.has_argument('+'.join([candidate_march, feature]))
>> + candidate_march = '+'.join([candidate_march, feature])
>> + else
>> + feature_unsupported = true
>> + endif
>> + endforeach
>> + if feature_unsupported
>> + warning('Configuration march features are ' +
>> + '@0@, but the compiler supports only @1@.'
>> + .format(part_number_config['march_features'],
>> + candidate_march))
the march_feature is some like 'crc sve', but candidate_march is
'-march=armv8.2a+crc'.
These two displays may be a little weird because later one has -march=armv8.2
prefix.
I think it's better move warning to place which feature_unsupported was set
true.
>> + endif
>> + endif
>> + 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)
Is it possible that -mcpu= conflicts with -march ?
>> + 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
>
