Using as: AArch64 Extensions

9.1.2 Architecture Extensions

The table below lists the permitted architecture extensions that are supported by the assembler and the conditions under which they are automatically enabled.

Multiple extensions may be specified, separated by a +. Extension mnemonics may also be removed from those the assembler accepts. This is done by prepending no to the option that adds the extension. Extensions that are removed must be listed after all extensions that have been added.

Enabling an extension that requires other extensions will automatically cause those extensions to be enabled. Similarly, disabling an extension that is required by other extensions will automatically cause those extensions to be disabled.

Extension	Minimum Architecture	Enabled by default	Description
`i8mm`	ARMv8.2-A	ARMv8.6-A or later	Enable Int8 Matrix Multiply extension.
`f32mm`	ARMv8.2-A	No	Enable F32 Matrix Multiply extension.
`f64mm`	ARMv8.2-A	No	Enable F64 Matrix Multiply extension.
`bf16`	ARMv8.2-A	ARMv8.6-A or later	Enable BFloat16 extension.
`compnum`	ARMv8.2-A	ARMv8.3-A or later	Enable the complex number SIMD extensions. This implies `fp16` and `simd`.
`crc`	ARMv8-A	ARMv8.1-A or later	Enable CRC instructions.
`crypto`	ARMv8-A	No	Enable cryptographic extensions. This implies `fp`, `simd`, `aes` and `sha2`.
`aes`	ARMv8-A	No	Enable the AES cryptographic extensions. This implies `fp` and `simd`.
`sha2`	ARMv8-A	No	Enable the SHA2 cryptographic extensions. This implies `fp` and `simd`.
`sha3`	ARMv8.2-A	No	Enable the ARMv8.2-A SHA2 and SHA3 cryptographic extensions. This implies `fp`, `simd` and `sha2`.
`sm4`	ARMv8.2-A	No	Enable the ARMv8.2-A SM3 and SM4 cryptographic extensions. This implies `fp` and `simd`.
`fp`	ARMv8-A	ARMv8-A or later	Enable floating-point extensions.
`fp16`	ARMv8.2-A	ARMv8.2-A or later	Enable ARMv8.2 16-bit floating-point support. This implies `fp`.
`lor`	ARMv8-A	ARMv8.1-A or later	Enable Limited Ordering Regions extensions.
`lse`	ARMv8-A	ARMv8.1-A or later	Enable Large System extensions.
`pan`	ARMv8-A	ARMv8.1-A or later	Enable Privileged Access Never support.
`profile`	ARMv8.2-A	No	Enable statistical profiling extensions.
`ras`	ARMv8-A	ARMv8.2-A or later	Enable the Reliability, Availability and Serviceability extension.
`rcpc`	ARMv8.2-A	ARMv8.3-A or later	Enable the weak release consistency extension.
`rdma`	ARMv8-A	ARMv8.1-A or later	Enable ARMv8.1 Advanced SIMD extensions. This implies `simd`.
`simd`	ARMv8-A	ARMv8-A or later	Enable Advanced SIMD extensions. This implies `fp`.
`sve`	ARMv8.2-A	No	Enable the Scalable Vector Extensions. This implies `fp16`, `simd` and `compnum`.
`dotprod`	ARMv8.2-A	ARMv8.4-A or later	Enable the Dot Product extension. This implies `simd`.
`fp16fml`	ARMv8.2-A	ARMv8.4-A or later	Enable ARMv8.2 16-bit floating-point multiplication variant support. This implies `fp16`.
`sb`	ARMv8-A	ARMv8.5-A or later	Enable the speculation barrier instruction sb.
`predres`	ARMv8-A	ARMv8.5-A or later	Enable the Execution and Data and Prediction instructions.
`rng`	ARMv8.5-A	No	Enable ARMv8.5-A random number instructions.
`ssbs`	ARMv8-A	ARMv8.5-A or later	Enable Speculative Store Bypassing Safe state read and write.
`memtag`	ARMv8.5-A	No	Enable ARMv8.5-A Memory Tagging Extensions.
`tme`	ARMv8-A	No	Enable Transactional Memory Extensions.
`sve2`	ARMv8-A	No	Enable the SVE2 Extension.
`sve2-bitperm`	ARMv8-A	No	Enable SVE2 BITPERM Extension.
`sve2-sm4`	ARMv8-A	No	Enable SVE2 SM4 Extension.
`sve2-aes`	ARMv8-A	No	Enable SVE2 AES Extension. This also enables the .Q->.B form of the `pmullt` and `pmullb` instructions.
`sve2-sha3`	ARMv8-A	No	Enable SVE2 SHA3 Extension.