9.1 Architecture support for Advanced SIMD

Advanced SIMD is an optional extension to the Arm®v8 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.


Advanced 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.

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