This change-set puts 93d08acaac functionality
under -add-omp-offload-notes switch that is OFF by default.
CUDA toolchain is not able to handle ELF images with LLVMOMPOFFLOAD
notes for unknown reason (see https://reviews.llvm.org/D99551#2950272).
I disable the ELF notes embedding until the CUDA issue is triaged and resolved.
Differential Revision: https://reviews.llvm.org/D108246
The patch adds ELF notes into SHT_NOTE sections of ELF offload images
passed to clang-offload-wrapper.
The new notes use a null-terminated "LLVMOMPOFFLOAD" note name.
There are currently three types of notes:
VERSION: a string (not null-terminated) representing the ELF offload
image structure. The current version '1.0' does not put any restrictions
on the structure of the image. If we ever need to come up with a common
structure for ELF offload images (e.g. to be able to analyze the images
in libomptarget in some standard way), then we will introduce new versions.
PRODUCER: a vendor specific name of the producing toolchain.
Upstream LLVM uses "LLVM" (not null-terminated).
PRODUCER_VERSION: a vendor specific version of the producing toolchain.
Upstream LLVM uses LLVM_VERSION_STRING with optional <space> LLVM_REVISION.
All three notes are not mandatory currently.
Differential Revision: https://reviews.llvm.org/D99551
Lower priority of __tgt_register_lib in order to make sure that __tgt_register_requires is called before loading a libomptarget plugin.
We want to know beforehand which requirements the user has asked for so that upon loading the plugin libomptarget can report how many devices there are that can satisfy these requirements.
Differential Revision: https://reviews.llvm.org/D75223
The final list of OpenMP offload targets becomes known only at the link time and since offload registration code depends on the targets list it makes sense to delay offload registration code generation to the link time instead of adding it to the host part of every fat object. This patch moves offload registration code generation from clang to the offload wrapper tool.
This is the last part of the OpenMP linker script elimination patch https://reviews.llvm.org/D64943
Differential Revision: https://reviews.llvm.org/D68746
llvm-svn: 374937
This patch removes the remaining part of the OpenMP offload linker scripts which was used for inserting device binaries into the output linked binary. Device binaries are now inserted into the host binary with a help of the wrapper bit-code file which contains device binaries as data. Wrapper bit-code file is dynamically created by the clang driver with a help of new tool clang-offload-wrapper which takes device binaries as input and produces bit-code file with required contents. Wrapper bit-code is then compiled to an object and resulting object is appended to the host linking by the clang driver.
This is the second part of the patch for eliminating OpenMP linker script (please see https://reviews.llvm.org/D64943).
Differential Revision: https://reviews.llvm.org/D68166
llvm-svn: 374219
Vyacheslav Zakharin