5 Commits

Author SHA1 Message Date
Joseph Huber
41fba3c107 [Metadata] Add 'exclude' metadata to add the exclude flags on globals
This patchs adds a new metadata kind `exclude` which implies that the
global variable should be given the necessary flags during code
generation to not be included in the final executable. This is done
using the ``SHF_EXCLUDE`` flag on ELF for example. This should make it
easier to specify this flag on a variable without needing to explicitly
check the section name in the target backend.

Depends on D129053 D129052

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D129151
2022-07-07 12:20:40 -04:00
Joseph Huber
ed801ad5e5 [Clang] Use metadata to make identifying embedded objects easier
Currently we use the `embedBufferInModule` function to store binary
strings containing device offloading data inside the host object to
create a fatbinary. In the case of LTO, we need to extract this object
from the LLVM-IR. This patch adds a metadata node for the embedded
objects containing the embedded pointers and the sections they were
stored at. This should create a cleaner interface for identifying these
values.

In the future it may be worthwhile to also encode an `ID` in the
metadata corresponding to the object's special section type if relevant.
This would allow us to extract the data from an object file and LLVM-IR
using the same ID.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D129033
2022-07-07 12:20:25 -04:00
Joseph Huber
26eb04268f [Clang] Introduce clang-offload-packager tool to bundle device files
In order to do offloading compilation we need to embed files into the
host and create fatbainaries. Clang uses a special binary format to
bundle several files along with their metadata into a single binary
image. This is currently performed using the `-fembed-offload-binary`
option. However this is not very extensibile since it requires changing
the command flag every time we want to add something and makes optional
arguments difficult. This patch introduces a new tool called
`clang-offload-packager` that behaves similarly to CUDA's `fatbinary`.
This tool takes several input files with metadata and embeds it into a
single image that can then be embedded in the host.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D125165
2022-05-11 09:39:13 -04:00
Joseph Huber
984a0dc386 [OpenMP] Use new offloading binary when embedding offloading images
The previous patch introduced the offloading binary format so we can
store some metada along with the binary image. This patch introduces
using this inside the linker wrapper and Clang instead of the previous
method that embedded the metadata in the section name.

Differential Revision: https://reviews.llvm.org/D122683
2022-04-15 20:35:26 -04:00
Joseph Huber
806bbc49dc [OpenMP] Try to embed offloading objects after codegen
Currently we use the `-fembed-offload-object` option to embed a binary
file into the host as a named section. This is currently only used as a
codegen action, meaning we only handle this option correctly when the
input is a bitcode file. This patch adds the same handling to embed an
offloading object after we complete code generation. This allows us to
embed the object correctly if the input file is source or bitcode.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D120270
2022-03-14 20:08:24 -04:00