If a function has `amdgpu-flat-work-group-size`, honor it in `initialize` by
taking its value directly; otherwise, it uses the default range as a starting
point. We will no longer manipulate the known range, which can cause issues
because the known range is a "throttle" to the assumed range such that the
assumed range can't get widened properly in `updateImpl` if the known range is
not set properly for whatever reasons. Another benefit of not touching the known
range is, if we indicate pessimistic state, it also invalidates the AA such that
`manifest` will not be called. Since we honor the attribute, we don't want and
will not add any half-baked attribute added to a function.
The AMDGPUAnnotateKernelFeatures pass infers the "amdgpu-calls" and
"amdgpu-stack-objects" attributes, which are used to infer whether we
need to initialize flat scratch. This is, however, not precise. Instead,
we should use AMDGPUAttributor and infer amdgpu-no-flat-scratch-init on
kernels. Refer to https://github.com/llvm/llvm-project/issues/63586 .
SIMachineFunctionInfo has a scan of the function body for inline asm
which may use AGPRs, or callees in SIMachineFunctionInfo. Move this
into the attributor, so it actually works interprocedurally.
Could probably avoid most of the test churn if this bothered to avoid
adding this on subtargets without AGPRs. We should also probably
try to delete the MIR scan in usesAGPRs but it seems to be trickier
to eliminate.
The previous name 'amdgpu_code_object_version', was misleading since
this is really a property of the HSA OS. The new spelling also matches
the asm directive I added in bc82cfb.
This is in preparation for moving the run of AMDGPUAttributor earlier.
Currently it infers the lack of the corresponding intrinsic calls,
so if we introduce new ones we need to remove the attribute from any
possible transitive callers. This is more conservative than necessary,
we could try to identify specific subgraphs where LDS globals are not
used.
Other options include teaching the attributor to avoid adding it in
cases
where the lowering may choose the table, but this seems more complex.
Alternatively could add a second run which doesn't seem worth it.
Depends #71349
