armv8-a has optional CRC32 extension, march=armv8-a+crc enables code
generation for the ARMv8-A architecture together with
the optional CRC32 extensions.
added RTE_MACHINE_CPUFLAG_CRC32 to detect the availability of
CRC32 extension in compile time. At run-time, The RTE_CPUFLAG_CRC32
can be used to find the availability.
armv8-a+crc target support added in GCC 4.9,
Used inline assembly and emulated __ARM_FEATURE_CRC32 to work
with tool-chain < 4.9
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
da8dcc27f6