Are armv8 and arm64 the same?

hasan picture hasan · Dec 11, 2016 · Viewed 16.6k times · Source

In xcode which is the developement environment for iOS. When creating a new project. Build settings states that it supports armv7, armv7s and arm64 architectures.

The following chart shows apple devices architectures: enter image description here

armv8 not mentioned anywhere. Does that mean armv8 and arm64 is the same thing?

I wonna use the following binary: http://www.libjpeg-turbo.org/Documentation/OfficialBinaries

It says that version 1.5.1 of this binary supports armv8 architecture. That also indicates that armv8 and arm64 are the same thing.

Another question but about the binary. Does the link indicates that its safe to use the 1.5.1 version for iOS?

Answer

Notlikethat picture Notlikethat · Dec 12, 2016

Oh, ambiguous terminology - "architecture" in this context doesn't actually mean architecture in the sense of the ISA or system architecture laid down by ARM, what it really means is "iOS target", i.e. a particular system configuration and level of ISA support:

  • "armv7" represents a certain configuration of the ARMv7-A architecture.
  • "armv7s" represents a slightly different configuration of the ARMv7-A architecture, with more optional features present over the base "armv7" target.
  • "arm64" represents the AArch64 state of the ARMv8-A architecture; there is no "armv8" target.