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
crc	ARMv8-A	ARMv8.1-A or later	Enable CRC instructions.
crypto	ARMv8-A	No	Enable 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.
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.