[Openmp-commits] [PATCH] D135280: [DeviceRTL] Allow IsSPMDMode to be optimized out in LTO mode

[Joseph Huber via Phabricator via Openmp-commits]

jhuber6 created this revision.
jhuber6 added reviewers: jdoerfert, tianshilei1992, JonChesterfield, ronlieb.
Herald added a subscriber: inglorion.
Herald added a project: All.
jhuber6 requested review of this revision.
Herald added subscribers: openmp-commits, sstefan1.
Herald added a project: OpenMP.

A previous patch merged the static and bitcode versions of the
deviceRTL. We previously used the static library's separate compilation
to set a special flag that prevented `IsSPMDMode` from being put in the
used list and preventing it from being optimized out. When they were
merged we could no longer do this separate compilation that allowed
users of LTO to get more optimal code.

This patch rearranges the code. The `IsSPMDMode` global is now
transitively used by its inclusion in the changed `__keep_alive`
function. This allows us to then manually delete the `__keep_alive`
function from the module when building the static library via
`llvm-extract`. The result is that the bitcode library correctly will
maintain the needed shared state, while the static library will be able
to internalize it and optimize it out.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D135280

Files:
  openmp/libomptarget/DeviceRTL/CMakeLists.txt
  openmp/libomptarget/DeviceRTL/include/Types.h
  openmp/libomptarget/DeviceRTL/src/Mapping.cpp
  openmp/libomptarget/DeviceRTL/src/Utils.cpp
  openmp/libomptarget/DeviceRTL/src/exports

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D135280.465428.patch
Type: text/x-patch
Size: 5702 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/openmp-commits/attachments/20221005/de9abbe4/attachment.bin>