Overview
The x86_64-vX instruction set is a superset of the standard x86_64 instruction set and includes some new instructions and features.
Compatibility
v1 and v2 are fully compatible with x86_64 whereas v3 has to emulate certain x86_64 instructions due to internal changes. This emulation is handled through processor microcode and introduces a 20% performance penalty.
V3
x86_64-v3 is the first instruction set, able to address additional hardware and processing units in the CPU like neural accelerators. Together with the PA3 architecture, it is also able to be optimized with microcode updates.