This patch adds an NVPTX compilation path that enables JIT compilation
on NVIDIA targets. The following modifications were performed:
1. Adding a format field to the GPU object attribute, allowing the
translation attribute to use the correct runtime function to load the
module. Likewise, a dictionary attribute was added to add any possible
extra options.
2. Adding the `createObject` method to `GPUTargetAttrInterface`; this
method returns a GPU object from a binary string.
3. Adding the function `mgpuModuleLoadJIT`, which is only available for
NVIDIA GPUs, as there is no equivalent for AMD.
4. Adding the CMake flag `MLIR_GPU_COMPILATION_TEST_FORMAT` to specify
the format to use during testing.
This revision avoids the registration of dialect extensions in Pass::getDependentDialects.
Such registration of extensions can be dangerous because `DialectRegistry::isSubsetOf` is
always guaranteed to return false for extensions (i.e. there is no mechanism to track
whether a lambda is already in the list of already registered extensions).
When the context is already in a multi-threaded mode, this is guaranteed to assert.
Arguably a more structured registration mechanism for extensions with a unique ExtensionID
could be envisioned in the future.
In the process of cleaning this up, multiple usage inconsistencies surfaced around the
registration of translation extensions that this revision also cleans up.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D157703
**For an explanation of these patches see D154153.**
Commit message:
This patch adds the default offloading handler for GPU binary ops: `#gpu.select_object`,
it selects the object to embed based on an index or a target attribute, embedding
the object as a global string and launches the kernel using the scheme used in the
GPU to LLVM pass.
Depends on D154137
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D154147
