Armv8-A Architecture support in GNU toolchain 

Armv8-A Architecture Feature GNU identifier Minimum Architecture Enabled by default Binutils GCC 
CRC instruction crc ARMv8-A ARMv8.1-A or later 2.25 GCC 6 
Crypto extension crypto ARMv8-A No 2.25 GCC 6
Floating-point extension fp ARMv8-A ARMv8-A or later 2.25 GCC 6
Advanced SIMD extension simd ARMv8-A ARMv8-A or later 2.25 GCC 6
Limited Ordering Regions extensions lor ARMv8-A ARMv8.1-A or later 2.26 NA
Privileged Access Never support pan ARMv8-A ARMv8.1-A or later 2.26 NA
ARMv8.1 Round Double Multiply Accumulate instructions rdma ARMv8-A ARMv8.1-A or later 2.26 GCC 8
FP16 extension fp16 ARMv8.2-A ARMv8.2-A or later 2.26 GCC 7
Statistical Profiling Extensions (SPE) profile ARMv8.2-A No 2.26 GCC 9
Large System Extension (LSE) lse ARMv8-A ARMv8.1-A or later 2.27 GCC 6
Reliability, Availability and Serviceability (RAS) extension. ras ARMv8-A ARMv8.2-A or later 2.27 NA
Scalable Vector Extension (SVE) sve ARMv8.2-A No 2.28 GCC 8
Complex number SIMD extension compnum ARMv8.2-A ARMv8.3-A or later 2.28 Planned
Weak release consistency extension rcpc ARMv8.2-A ARMv8.3-A or later 2.29 GCC 8
Pointer Authentication -msign-return-address=scope ARMv8-A No 2.27 GCC 7
Dot Product extension dotprod ARMv8.2-A ARMv8.4-A or later 2.29 GCC 8
AES cryptographic extension aes ARMv8-A No 2.30 GCC 8
SHA2 cryptographic extension sha2 ARMv8-A No 2.30 GCC 8
FP16 fmla extension fp16fml ARMv8.2-A ARMv8.4-A or later 2.30 GCC 8
SHA512 and SHA3 cryptographic extensions sha3 ARMv8.2-A No 2.30 GCC 8
SM3 and SM4 cryptographic extensions sm4 ARMv8.2-A No 2.30 GCC 8
Memory Tagging Extension (MTE) memtag ARMv8.5-A No 2.32 Planned
Branch Target Indicators (BTI)
ARMv8-A No 2.32 GCC 9
Execution and Data and Prediction instructions predres ARMv8-A ARMv8.5-A or later 2.32 GCC 9
Random number instructions rng ARMv8.5-A No 2.32 GCC 9
Speculation barrier instruction sb sb ARMv8-A ARMv8.5-A or later 2.32 GCC 9