Support model debugging (#138)

* Call llc, ld from within onnx-mlir.

* Rename EmitLLVMBC -> EmitLib., reorder header files

* Checkpoint, debug.py works.

* Automatically generate inputs in debug.py.

* Use float.

* Fix merge conflict, remove RapidCheck from this patch.

* Remove submodule rapidcheck properly.

* Reformat code.

* More comments.

* Add documentation.

* Add documentation to navigation.

* Account for the fact that some initializers may also appear as input.

docs/DebuggingNumericalError.md

@@ -0,0 +1,26 @@
+# Debugging Numerical Error
+
+Use `util/debug.py` python script to debug numerical errors, when onnx-mlir-compiled inference executable produces 
+numerical results that are inconsistent with those produced by the training framework.
+This python script will run the model through onnx-mlir and a reference backend, and compare
+the intermediate results produced by these two backends layer by layer.
+
+## Rrerequisite
+- Set `ONNX_MLIR_HOME` environment variable to be the path to
+  the HOME directory for onnx-mlir. The HOME directory for onnx-mlir refers to 
+  the parent folder containing the `bin`, `lib`, etc sub-folders in which ONNX-MLIR 
+  executables and libraries can be found.
+- Install an ONNX backend, by default onnx-runtime is used as testing backend. Install by 
+  running `pip install onnxruntime`. To use a different testing backend, simply replace code
+  importing onnxruntime to some other ONNX-compliant backend.
+
+## Usage
+
+`util/debug.py` supports the following command-line options:
+
+```bash
+usage: debug.py [-h] model_path
+
+positional arguments:
+  model_path  Path to the model to debug.
+```

docs/_data/navigation.yml

@@ -29,5 +29,7 @@ toc:
 #        url: /piece1.html
   - title: Tools
     subfolderitems:
+      - page: debug.py - Debug Numerical Errors
+        url: /DebuggingNumericalError.html
       - page: DocCheck - Handling Necessary Code Duplication
         url: /doc_check/

src/MainUtils.cpp

@@ -10,12 +10,13 @@
 
 #include <cstdio>
 #include <fcntl.h>
-
+#include <llvm/Support/Program.h>
-#include "llvm/Support/Program.h"
 
 #include "src/ExternalUtil.hpp"
 #include "src/MainUtils.hpp"
 
+#include "MainUtils.hpp"
+
 #ifdef _WIN32
 #include <io.h>
 #else

src/Transform/LowerToLLVM.cpp

@@ -387,36 +387,57 @@ public:
       staticInputs.emplace_back(ptrToMemRef);
     }
 
-    // If more than one output exists, the struct becomes a nested struct,
-    // the unpacking logic can be more involved, so no support for now.
-    assert(numOutputs == 1 && "only support 1 output tensor now.");
-
     // Call static entry point with the memref ptrs created, and get output.
-    auto outputMemRefs = rewriter.create<LLVM::CallOp>(loc,
+    auto outMemRefs =
+        rewriter
+            .create<LLVM::CallOp>(loc,
                 staticEntryPointTy.getFunctionResultType(),
                 rewriter.getSymbolRefAttr(wrappedStaticEntryPointFuncName),
-        staticInputs);
+                staticInputs)
+            .getResult(0);
+    auto outMemRefsType = outMemRefs.getType().dyn_cast<LLVMType>();
+
+    std::vector<mlir::Value> outMemRefList;
+    if (numOutputs == 1) {
+      // If only one output tensor exists, the tensor's corresponding memref
+      // descriptor will be returned as is.
+      outMemRefList.emplace_back(outMemRefs);
+    } else {
+      // Otherwise, if multiple tensors are to be returned, the returned value
+      // is a struct. Multiple tensors' memref descriptors are packed into the
+      // same struct. So we unpack them iteratively to outMemRefList.
+      for (int i = 0; i < numOutputs; i++) {
+        auto position = rewriter.getArrayAttr({rewriter.getI64IntegerAttr(i)});
+        auto type = outMemRefsType.getStructElementType(i);
+        auto extractOp = rewriter.create<LLVM::ExtractValueOp>(loc,
+            /*res=*/type,
+            /*type=*/outMemRefs,
+            /*position=*/position);
+        outMemRefList.emplace_back(extractOp.getResult());
+      }
+    }
 
     // Create wrapped output.
     auto wrappedOutput = callApi(
         rewriter, loc, apiRegistry, API::CREATE_ORDERED_DYN_MEM_REF_DICT, {});
 
-    // Get the first memref returned, convert to a dynamic memref and store
+    for (decltype(numOutputs) i = 0; i < outMemRefList.size(); i++) {
-    // it in the wrapped Output.
+      // Get the i-th memref returned, convert to a dynamic memref and store it
-    auto outMemRef = outputMemRefs.getResult(0);
+      // in the wrappedOutput.
-    auto outMemRefTy = outMemRef.getType().dyn_cast<LLVMType>();
+      auto memRef = outMemRefList.at(i);
+      auto outMemRefTy = memRef.getType().dyn_cast<LLVMType>();
       auto outMemRefRank = getRankFromMemRefType(outMemRefTy);
       auto outMemRefRankVal = rewriter.create<LLVM::ConstantOp>(
           loc, int32Ty, rewriter.getI32IntegerAttr(outMemRefRank));
       auto outDynMemRef = callApi(rewriter, loc, apiRegistry,
           API::CREATE_DYN_MEM_REF, {outMemRefRankVal});
       fillDynMemRefWithMemRef(
-        outMemRef, outDynMemRef, rewriter, loc, apiRegistry, llvmDialect);
+          memRef, outDynMemRef, rewriter, loc, apiRegistry, llvmDialect);
-    auto zero = rewriter.create<LLVM::ConstantOp>(
+      auto idx = rewriter.create<LLVM::ConstantOp>(
-        loc, int32Ty, rewriter.getI32IntegerAttr(0));
+          loc, int32Ty, rewriter.getI32IntegerAttr(i));
       callApi(rewriter, loc, apiRegistry, API::SET_DYN_MEM_REF,
-        {wrappedOutput, zero, outDynMemRef});
+          {wrappedOutput, idx, outDynMemRef});
-
+    }
     // Return wrapped output.
     rewriter.create<LLVM::ReturnOp>(
         loc, SmallVector<Value, 1>({wrappedOutput}));
@@ -613,7 +634,6 @@ void KrnlToLLVMLoweringPass::runOnOperation() {
   ConversionTarget target(getContext());
   target.addLegalDialect<LLVM::LLVMDialect>();
   target.addLegalOp<ModuleOp, ModuleTerminatorOp>();
-  //  target.addLegalOp<KrnlEntryPointOp>();
 
   // Lower the MemRef types to a representation in LLVM.
   LLVMTypeConverter typeConverter(&getContext());
@@ -626,7 +646,6 @@ void KrnlToLLVMLoweringPass::runOnOperation() {
   populateStdToLLVMConversionPatterns(typeConverter, patterns,
       /*emitCWrapperS=*/true,
       /*useAlignedAlloc=*/false);
-
   patterns.insert<KrnlGlobalOpLowering>(&getContext(), typeConverter);
 
   // Lower from the `krnl` dialect i.e. the Reshape operation.

utils/debug.py

@@ -0,0 +1,112 @@
+import os
+import sys
+import argparse
+import onnx
+import subprocess
+import numpy as np
+import tempfile
+
+from collections import OrderedDict
+
+# Reference backend, use onnxruntime by default
+import onnxruntime
+prepare = onnxruntime.InferenceSession
+
+if (not os.environ.get('ONNX_MLIR_HOME', None)):
+    raise RuntimeError(
+        "Environment variable ONNX_MLIR_HOME is not set, please set it to the path to "
+        "the HOME directory for onnx-mlir. The HOME directory for onnx-mlir refers to "
+        "the parent folder containing the bin, lib, etc sub-folders in which ONNX-MLIR "
+        "executables and libraries can be found.")
+
+VERBOSE = os.environ.get('VERBOSE', False)
+ONNX_MLIR = os.path.join(os.environ['ONNX_MLIR_HOME'], "bin/onnx-mlir")
+
+# Include runtime directory in python paths, so pyruntime can be imported.
+RUNTIME_DIR = os.path.join(os.environ['ONNX_MLIR_HOME'], "lib")
+sys.path.append(RUNTIME_DIR)
+
+try:
+    from pyruntime import ExecutionSession
+except ImportError:
+    raise ImportError(
+        "Looks like you did not build the pyruntime target, build it by running `make pyruntime`."
+    )
+
+
+def execute_commands(cmds):
+    if (VERBOSE):
+        print(" ".join(cmds))
+    subprocess.run(cmds, stdout=subprocess.PIPE, check=True)
+
+
+def extend_model_output(model, intermediate_outputs):
+    # onnx-mlir doesn't care about manually specified output types & shapes.
+    DUMMY_TENSOR_TYPE = onnx.TensorProto.FLOAT
+
+    while (len(model.graph.output)):
+        model.graph.output.pop()
+
+    for output_name in intermediate_outputs:
+        output_value_info = onnx.helper.make_tensor_value_info(
+            output_name, DUMMY_TENSOR_TYPE, None)
+        model.graph.output.extend([output_value_info])
+    return model
+
+
+def main(model_path):
+    model = onnx.load(model_path)
+    intermediate_outputs = sum(
+        [list(node.output) for node in model.graph.node], [])
+    intermediate_outputs = list(OrderedDict.fromkeys(intermediate_outputs))
+    model = extend_model_output(model, intermediate_outputs)
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        print("Temporary directory has been created at {}".format(temp_dir))
+
+        # Save modified model & invoke onnx-mlir to compile it.
+        temp_model_path = os.path.join(temp_dir, "model.onnx")
+        onnx.save(model, temp_model_path)
+        execute_commands([ONNX_MLIR, temp_model_path])
+
+        # Use the generated shared library to create an execution session.
+        temp_shared_lib_path = os.path.join(temp_dir, "model.so")
+        sess = ExecutionSession(temp_shared_lib_path,
+                                "_dyn_entry_point_main_graph")
+
+        # Generate random data as input.
+        inputs = []
+        input_names = []
+        initializers = list(map(lambda x: x.name, model.graph.initializer))
+        np.random.seed(42)
+        for input_proto in model.graph.input:
+            if input_proto.name not in initializers:
+                input_names.append(input_proto.name)
+                shape_proto = input_proto.type.tensor_type.shape
+                explicit_shape = []
+                for dim in shape_proto.dim:
+                    assert dim.dim_value, "Can only debug models with inputs that have explicit shapes."
+                    explicit_shape.append(dim.dim_value)
+                inputs.append(
+                    np.random.uniform(-1.0, 1.0, explicit_shape).astype(np.float32))
+
+        # Run the compiled inference function on the randomly generated data.
+        outs = sess.run(inputs)
+
+        # Run the model with reference backend and get results.
+        ref_session = prepare(temp_model_path)
+        output_names = list(map(lambda x: x.name, model.graph.output))
+        input_feed = dict(zip(input_names, inputs))
+        ref_outs = ref_session.run(output_names, input_feed)
+
+        # For each intermediate output tensor, compare results.
+        for i, name in enumerate(intermediate_outputs):
+            print("Verifying value of {}".format(name))
+            np.testing.assert_array_almost_equal(ref_outs[i], outs[i], decimal=5)
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    parser.add_argument('model_path', type=str, help="Path to the model to debug.")
+    args = parser.parse_args()
+    main(**vars(args))