With llvm/llvm-project@112499f landed, `MLIR_TABLEGEN_EXE` is given as a
cache variable in the MLIR core project. Other external projects, such
as TORCH-MLIR, should not set the variable as this breaks
cross-compilation.
Follows up on #623 for out-of-tree builds of torch-mlir, which
added building `torch-mir-dialects` as a subdirectory.
Our goal is to support both in-tree and out-of-tree builds of
`torch-mlir` with minimum hassle, for instance by using the same
variable names in both setups.
Specific changes to `externals/llvm-external-projects/torch-mlir-dialects/CMakeLists.txt`:
- We use `MLIR_FOUND` to detect that it is being build as a subdirectory
and the llvm+mlir cmake infrastructure is already set up (via
find_package in the parent build) as opposed to an in-tree build.
- For in-tree, the setting of variables and loading of llvm+mlir cmake
infrastructure is now conditionally performed.
- For in-tree, the names of cmake variables being defined for are
adjusted to match those `llvm-project` makes available through
`find_package(MLIR REQUIRED CONFIG)`, under the assumption that those
are the more "standardized" names.
Co-authored-by: Clément Fournier <clement.fournier@amd.com>
Co-authored-by: Liam Fitzpatrick <liam.fitzpatrick@xilinx.com>
Marius Brehler
Clément Fournier
Ahmed S. Taei