================ @@ -1206,17 +1211,51 @@ supported for the ``amdgcn`` target. have a value corresponding to a valid barrier ID on the target. Otherwise, the behavior is undefined - These pointers do not have a corresponding hardware aperture but safe round-tripping - through the generic address space is still possible. Attempting to dereference a - generic pointer derived from a barrier pointer is undefined behavior. - **Streamout Registers** Dedicated registers used by the GS NGG Streamout Instructions. The register file is modelled as a memory in a distinct address space because it is indexed by an address-like offset in place of named registers, and because register accesses affect LGKMcnt. This is an internal address space used only by the compiler. Do not use this address space for IR pointers. +.. _amdgpu-synthetic-apertures: + +Synthetic Apertures +~~~~~~~~~~~~~~~~~~~ + +*Synthetic apertures* are defined that enable safe roundtrips of pointers +from special address spaces through the generic address space. Attempting to +dereference generic pointers obtained in this way (using e.g. `load` or +`store`) has undefined behavior. The following synthetic apertures are defined: + +.. table:: AMDGPU Synthetic Apertures + :name: amdgpu-synthetic-apertures-table + :widths: 40 20 40 + + ============ ====== =============================================================== + Name Number Corresponding :ref:`Address Space<amdgpu-address-spaces-table>` + ============ ====== =============================================================== + BARRIER 1 Barrier ---------------- arsenm wrote:
> Or do you mean that this should spell out the entire value that gets OR'd > with the LDS apeture value (so something like 1 << 32 as a 64 bit hexadecimal > number) Yes https://github.com/llvm/llvm-project/pull/204127 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
