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 .
This mostly reverts commit 270e96f435596449002fc89962595497481c8770.
Keep the attributor related changes around, but functionally restore
the old behavior as a workaround. Device enqueue goes back to not
working at -O0 with this version.
Invert the sense of the attribute and let the attributor figure this
out like everything else. If needed we can have the not-OpenCL
languages set amdgpu-no-default-queue and amdgpu-no-completion-action
up front so they never have to pay the cost.
There are also so many of these now, the offset use API should
probably consider all of them at once. Maybe they should merge into
one attribute with used fields. Having separate functions for each
field in AMDGPUBaseInfo is also not the greatest API (might as well
fix this when the patch to get the object version from the module
lands).
Implement an intrinsic for use lowering LDS variables to different
addresses from different kernels. This will allow kernels that cannot
reach an LDS variable to avoid wasting space for it.
There are a number of implicit arguments accessed by intrinsic already
so this implementation closely follows the existing handling. It is slightly
novel in that this SGPR is written by the kernel prologue.
It is necessary in the general case to put variables at different addresses
such that they can be compactly allocated and thus necessary for an
indirect function call to have some means of determining where a
given variable was allocated. Claiming an arbitrary SGPR into which
an integer can be written by the kernel, in this implementation based
on metadata associated with that kernel, which is then passed on to
indirect call sites is sufficient to determine the variable address.
The intent is to emit a __const array of LDS addresses and index into it.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D125060
Summary:
Introduce a new function attribute, amdgpu-no-multigrid-sync-arg, which is default.
We use implicitarg_ptr + offset to check whether the multigrid synchronization
pointer is used. If yes, we remove this attribute and also remove
amdgpu-no-implicitarg-ptr. We generate metadata for the hidden_multigrid_sync_arg
only when the amdgpu-no-multigrid-sync-arg attribute is removed from the function.
Reviewers: arsenm, sameerds, b-sumner and foad
Differential Revision: https://reviews.llvm.org/D123548
The module flag to indicate use of hostcall is insufficient to catch
all cases where hostcall might be in use by a kernel. This is now
replaced by a function attribute that gets propagated to top-level
kernel functions via their respective call-graph.
If the attribute "amdgpu-no-hostcall-ptr" is absent on a kernel, the
default behaviour is to emit kernel metadata indicating that the
kernel uses the hostcall buffer pointer passed as an implicit
argument.
The attribute may be placed explicitly by the user, or inferred by the
AMDGPU attributor by examining the call-graph. The attribute is
inferred only if the function is not being sanitized, and the
implictarg_ptr does not result in a load of any byte in the hostcall
pointer argument.
Reviewed By: jdoerfert, arsenm, kpyzhov
Differential Revision: https://reviews.llvm.org/D119216
