This patch replaces all MHLO operations with their StableHLO
counterparts and adds a validation pass to ensure that no MHLO operations
remain before translating all Stablehlo operations to the MHLO dialect
for further lowering to the Linalg dialect.
This patch also updates all lit tests so that they refer to the
`convert-torch-to-stablehlo` pass and so that they check for StableHLO
operations.
A circular dependency was introduced in e7edcc62fd.
Specifically, the `makeShapeLLVMCompatible` and `makeShapeTorchCompatible` utilities were being called from `lib/Dialect/Torch/IR/TorchTypes.cpp` and `lib/Dialect/Torch/IR/TorchOps.cpp` defined under the `:TorchMLIRTorchDialect` bazel target, leading it to take a dependency on `:TorchMLIRConversionUtils` which already depends on `:TorchMLIRTorchDialect`, hence creating a circular dependency.
This commit resolves the same by moving said utilities from `lib/Conversion/Utils/Utils.cpp` to `lib/Dialect/Torch/Utils/Utils.cpp`. Please LMK if there's a better way to fix this and I will update the code.
This commit also adds the required targets to support building the new conversions from Torch to ML Program dialect that was introduced in f416953600.
Bazel build GHA triggered manually to verify: https://github.com/sjain-stanford/torch-mlir/actions/runs/3645944517
This introduces a new pass LowerToBackendContract (better name very
welcome) which performs the bulk of the simplifications that we do,
such as
- shape refinement
- dtype refinement
- maximizing value semantics
- inlining global slots
- decomposing complex ops
The key difference from before is that it iterates the set of
transformations, which can help to break a number of "catch-22" issues
where one simplification depends on another, the latest example being
here:
https://github.com/llvm/torch-mlir/issues/1131
This also exposed that RefineTypes was sometimes crashing/asserting for
certain inputs. This commit hardens it a bit.
The torch-mlir bazel build is [failing](https://github.com/llvm/torch-mlir/runs/7737425906?check_suite_focus=true) since [this commit](504de5e701) due to a linker failure (undefined symbol: `mlir::torch::Torch::createEraseModuleInitializerPass()`).
```
ERROR: /home/runner/.cache/bazel/_bazel_runner/db599744cd37f8c161e5034d9b9cd520/external/torch-mlir/BUILD.bazel:845:10: Linking external/torch-mlir/torch-mlir-opt failed: (Exit 1): clang failed: error executing command /usr/lib/llvm-11/bin/clang @bazel-out/k8-fastbuild/bin/external/torch-mlir/torch-mlir-opt-2.params
Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging
ld.lld: error: undefined symbol: mlir::torch::Torch::createEraseModuleInitializerPass()
>>> referenced by Passes.cpp
>>> bazel-out/k8-fastbuild/bin/external/torch-mlir/_objs/TorchMLIRTorchPasses/Passes.pic.o:(mlir::torch::Torch::createTorchFunctionToTorchBackendPipeline(mlir::OpPassManager&, mlir::torch::Torch::TorchLoweringPipelineOptions const&))
>>> referenced by Passes.cpp
>>> bazel-out/k8-fastbuild/bin/external/torch-mlir/_objs/TorchMLIRTorchPasses/Passes.pic.o:((anonymous namespace)::registerEraseModuleInitializerPass()::'lambda'()::operator()() const)
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
This PR adds `lib/Dialect/Torch/Transforms/EraseModuleInitializer.cpp` to `TorchMLIRTorchPasses` library.
A previous patch added a new file
("VerifyConversionToValueSemantics.cpp") to the build, but it did not
add it to the list files known to bazel. This patch fixes the problem.
Ashay Rane
Ahmed S. Taei
Vivek Khandelwal
Sambhav Jain
Tanyo Kwok
Sean Silva
Ramana Radhakrishnan
武家伟
Maksim Levental