Add documentation of unbundling of heterogeneous device archives to
create device specific archives, as introduced by D93525. Also, add
documentation for supported text file formats.
Reviewed By: yaxunl
Differential Revision: https://reviews.llvm.org/D110083
Earlier BundleEntryID used to be <OffloadKind>-<Triple>-<GPUArch>.
This used to work because the clang-offload-bundler didn't need
GPUArch explicitly for any bundling/unbundling action. With
unbundleArchive it needs GPUArch to ensure compatibility between
device specific code objects. D93525 enforced triples to have
separators for all 4 components irrespective of number of
components, like "amdgcn-amd-amdhsa--". It was required to
to correctly parse a possible 4th environment component or a GPU.
But, this condition is breaking backward compatibility with
archive libraries compiled with compilers older than D93525.
This patch allows triples to have any number of components with
and without extra separator for empty environment field. Thus,
both the following bundle entry IDs are same:
openmp-amdgcn-amd-amdhsa--gfx906
openmp-amdgcn-amd-amdhsa-gfx906
Reviewed By: yaxunl, grokos
Differential Revision: https://reviews.llvm.org/D106809
This patch adds unbundling support of an archive file. It takes an
archive file along with a set of offload targets as input.
Output is a device specific archive for each given offload target.
Input archive contains bundled code objects bundled using
clang-offload-bundler. Each generated device specific archive contains
a set of device code object files which are named as
<Parent Bundle Name>-<CodeObject-GPUArch>.
Entries in input archive can be of any binary type which is
supported by clang-offload-bundler, like *.bc. Output archives will
contain files in same type.
Example Usuage:
clang-offload-bundler --unbundle --inputs=lib-generic.a -type=a
-targets=openmp-amdgcn-amdhsa--gfx906,openmp-amdgcn-amdhsa--gfx908
-outputs=devicelib-gfx906.a,deviceLib-gfx908.a
Reviewed By: jdoerfert, yaxunl
Differential Revision: https://reviews.llvm.org/D93525
Jacob Lambert