Matt Arsenault a8e1311a1c
[RFC] IR: Define noalias.addrspace metadata (#102461)
This is intended to solve a problem with lowering atomics in
OpenMP and C++ common to AMDGPU and NVPTX.

In OpenCL and CUDA, it is undefined behavior for an atomic instruction
to modify an object in thread private memory. In OpenMP, it is defined.
Correspondingly, the hardware does not handle this correctly. For
AMDGPU,
32-bit atomics work and 64-bit atomics are silently dropped. We
therefore
need to codegen this by inserting a runtime address space check,
performing
the private case without atomics, and fallback to issuing the real
atomic
otherwise. This metadata allows us to avoid this extra check and branch.

Handle this by introducing metadata intended to be applied to atomicrmw,
indicating they cannot access the forbidden address space.
2024-10-07 23:21:42 +04:00
..
2023-11-01 10:46:31 +01:00

This directory contains testcases that the verifier is supposed to detect as
malformed LLVM code.  Testcases for situations that the verifier incorrectly
identifies as malformed should go in the test/Assembler directory.