https://forum.beyond3d.com/posts/2070369/
Going from the differences:
"// First/last AMDGCN-based processors.
EF_AMDGPU_MACH_AMDGCN_FIRST = EF_AMDGPU_MACH_AMDGCN_GFX600,
- EF_AMDGPU_MACH_AMDGCN_LAST = EF_AMDGPU_MACH_AMDGCN_GFX909,
+ EF_AMDGPU_MACH_AMDGCN_LAST = EF_AMDGPU_MACH_AMDGCN_GFX1010,"
GFX6 was the first GCN architecture, and whatever the most recent GCN chip is gets put in the _LAST line.
It seems like the compiler developers do not consider it separate from its predecessors. At least from the standpoint of instruction generation, it has new features but still does the same general things.