spack/lib
Massimiliano Culpo b07460ab5f Added NEON to the list of features required for the aarch64 family
Both floating-point and NEON are required in all standard ARMv8
implementations. Theoretically though specialized markets can support
no NEON or floating-point at all. Source:

https://developer.arm.com/docs/den0024/latest/aarch64-floating-point-and-neon

On the other hand the base procedure call standard for Aarch64
"assumes the availability of the vector registers for passing
floating-point and SIMD arguments". Further "the Arm 64-bit
architecture defines two mandatory register banks: a general-purpose
register bank which can be used for scalar integer processing and
pointer arithmetic; and a SIMD and Floating-Point register bank".
Source:

https://developer.arm.com/docs/ihi0055/latest/procedure-call-standard-for-the-arm-64-bit-architecture

This makes customization of Aarch64 with no NEON instruction set
available so unlikely that we can consider them a feature of the
generic family.
2019-10-10 16:24:36 -07:00
..
spack Added NEON to the list of features required for the aarch64 family 2019-10-10 16:24:36 -07:00