Architecture support for Advanced SIMD
Advanced SIMD is an optional extension to the ARMv8 and ARMv7 architectures.
All Advanced SIMD instructions are available on systems that support Advanced SIMD. In A32, some of these instructions are also available on systems that implement the floating-point extension without Advanced SIMD. These are called shared instructions.
In AArch32 state, the Advanced SIMD register bank consists of thirty-two 64-bit registers, and smaller registers are packed into larger ones, as in ARMv7.
In AArch64 state, the Advanced SIMD register bank includes thirty-two 128-bit registers and has a new register packing model.
NoteAdvanced SIMD and floating-point instructions share the same extension register bank.
Advanced SIMD instructions in A64 are closely based on VFPv4 and A32, but with new instruction mnemonics and some functional enhancements.