Measured on RDNA2 (gfx1035) in review:
- the shared and private apertures are 4 GB windows (the gfx9+ layout of kfd_flat_memory.c), so a flat
address routes by its whole high dword, 0x80000000 or 0x70000000, not by its top 16 bits;
- a dword or short access whose last byte is past the end of LDS reads 0 or writes nothing as a whole;
multi-dword accesses are checked per dword.
The aperture test gets rows that straddle and pass the end of LDS; the TechnicalDebt line names the
public source of the layout and keeps only the PS5's base values as inferred.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>