[Relay] Port param dict save/load from NNVM

python/tvm/api.py

@@ -136,7 +136,7 @@ def load_json(json_str):
 
 
 def save_json(node):
-    """Load tvm object as json string.
+    """Save tvm object as json string.
 
     Parameters
     ----------

python/tvm/relay/__init__.py

@@ -13,6 +13,7 @@
 from . import prelude
 from . import parser
 from . import debug
+from . import param_dict
 
 # Root operators
 from .op import Op
@@ -85,3 +86,7 @@
 
 # Parser
 fromtext = parser.fromtext
+
+# Param Serialization
+save_param_dict = param_dict.save_param_dict
+load_param_dict = param_dict.load_param_dict

python/tvm/relay/param_dict.py

@@ -0,0 +1,60 @@
+# pylint: disable=invalid-name
+"""Helper utility to save parameter dicts."""
+import tvm
+
+_save_param_dict = tvm.get_global_func("tvm.relay._save_param_dict")
+_load_param_dict = tvm.get_global_func("tvm.relay._load_param_dict")
+
+def save_param_dict(params):
+    """Save parameter dictionary to binary bytes.
+
+    The result binary bytes can be loaded by the
+    GraphModule with API "load_params".
+
+    Parameters
+    ----------
+    params : dict of str to NDArray
+        The parameter dictionary.
+
+    Returns
+    -------
+    param_bytes: bytearray
+        Serialized parameters.
+
+    Examples
+    --------
+    .. code-block:: python
+
+       # compile and save the modules to file.
+       graph, lib, params = tvm.relay.build(func, target=target, params=params)
+       module = graph_runtime.create(graph, lib, tvm.gpu(0))
+       # save the parameters as byte array
+       param_bytes = tvm.relay.save_param_dict(params)
+       # We can serialize the param_bytes and load it back later.
+       # Pass in byte array to module to directly set parameters
+       module.load_params(param_bytes)
+    """
+    args = []
+    for k, v in params.items():
+        args.append(k)
+        args.append(tvm.nd.array(v))
+    return _save_param_dict(*args)
+
+
+def load_param_dict(param_bytes):
+    """Load parameter dictionary to binary bytes.
+
+    Parameters
+    ----------
+    param_bytes: bytearray
+        Serialized parameters.
+
+    Returns
+    -------
+    params : dict of str to NDArray
+        The parameter dictionary.
+    """
+    if isinstance(param_bytes, (bytes, str)):
+        param_bytes = bytearray(param_bytes)
+    load_arr = _load_param_dict(param_bytes)
+    return {v.name : v.array for v in load_arr}

src/relay/backend/interpreter.cc

@@ -578,5 +578,10 @@ TVM_REGISTER_API("relay.backend.CreateInterpreter")
 .set_body([](TVMArgs args, TVMRetValue* ret) {
     *ret = CreateInterpreter(args[0], args[1], args[2]);
   });
+
+TVM_REGISTER_NODE_TYPE(ClosureNode);
+TVM_REGISTER_NODE_TYPE(TupleValueNode);
+TVM_REGISTER_NODE_TYPE(TensorValueNode);
+
 }  // namespace relay
 }  // namespace tvm

src/relay/backend/param_dict.cc

@@ -0,0 +1,87 @@
+/*!
+ *  Copyright (c) 2019 by Contributors
+ * \file param_dict.cc
+ * \brief Implementation and registration of parameter dictionary
+ * serializing/deserializing functions.
+ */
+#include "param_dict.h"
+
+#include <dmlc/memory_io.h>
+
+#include <string>
+#include <vector>
+
+namespace tvm {
+namespace relay {
+
+using namespace runtime;
+
+TVM_REGISTER_GLOBAL("tvm.relay._save_param_dict")
+.set_body([](TVMArgs args, TVMRetValue *rv) {
+    CHECK_EQ(args.size() % 2, 0u);
+    // `args` is in the form "key, value, key, value, ..."
+    size_t num_params = args.size() / 2;
+    std::vector<std::string> names;
+    names.reserve(num_params);
+    std::vector<DLTensor*> arrays;
+    arrays.reserve(num_params);
+    for (size_t i = 0; i < num_params * 2; i += 2) {
+      names.emplace_back(args[i].operator std::string());
+      arrays.emplace_back(args[i + 1].operator DLTensor*());
+    }
+    std::string bytes;
+    dmlc::MemoryStringStream strm(&bytes);
+    dmlc::Stream* fo = &strm;
+    uint64_t header = kTVMNDArrayListMagic, reserved = 0;
+    fo->Write(header);
+    fo->Write(reserved);
+    fo->Write(names);
+    {
+      uint64_t sz = static_cast<uint64_t>(arrays.size());
+      fo->Write(sz);
+      for (size_t i = 0; i < sz; ++i) {
+        tvm::runtime::SaveDLTensor(fo, arrays[i]);
+      }
+    }
+    TVMByteArray arr;
+    arr.data = bytes.c_str();
+    arr.size = bytes.length();
+    *rv = arr;
+  });
+
+TVM_REGISTER_GLOBAL("tvm.relay._load_param_dict")
+.set_body([](TVMArgs args, TVMRetValue *rv) {
+    std::string bytes = args[0];
+    std::vector<std::string> names;
+    dmlc::MemoryStringStream memstrm(&bytes);
+    dmlc::Stream* strm = &memstrm;
+    uint64_t header, reserved;
+    CHECK(strm->Read(&header))
+        << "Invalid parameters file format";
+    CHECK(header == kTVMNDArrayListMagic)
+        << "Invalid parameters file format";
+    CHECK(strm->Read(&reserved))
+        << "Invalid parameters file format";
+    CHECK(strm->Read(&names))
+        << "Invalid parameters file format";
+    uint64_t sz;
+    strm->Read(&sz, sizeof(sz));
+    size_t size = static_cast<size_t>(sz);
+    CHECK(size == names.size())
+        << "Invalid parameters file format";
+    tvm::Array<NamedNDArray> ret;
+    for (size_t i = 0; i < size; ++i) {
+      tvm::runtime::NDArray temp;
+      temp.Load(strm);
+      auto n = tvm::make_node<NamedNDArrayNode>();
+      n->name = std::move(names[i]);
+      n->array = temp;
+      ret.push_back(NamedNDArray(n));
+    }
+    *rv = ret;
+  });
+
+TVM_REGISTER_NODE_TYPE(NamedNDArrayNode);
+
+}  // namespace relay
+}  // namespace tvm

src/relay/backend/param_dict.h

@@ -0,0 +1,43 @@
+/*!
+ *  Copyright (c) 2019 by Contributors
+ * \file param_dict.h
+ * \brief Definitions for serializing and deserializing parameter dictionaries.
+ */
+#ifndef TVM_RELAY_BACKEND_PARAM_DICT_H_
+#define TVM_RELAY_BACKEND_PARAM_DICT_H_
+
+#include <tvm/node/node.h>
+#include <tvm/packed_func_ext.h>
+#include <tvm/runtime/ndarray.h>
+#include <tvm/runtime/packed_func.h>
+
+#include <string>
+
+namespace tvm {
+namespace relay {
+
+/*! \brief Magic number for NDArray list file  */
+constexpr uint64_t kTVMNDArrayListMagic = 0xF7E58D4F05049CB7;
+
+/*!
+ * \brief Wrapper node for naming `NDArray`s.
+ */
+struct NamedNDArrayNode : public ::tvm::Node {
+  std::string name;
+  tvm::runtime::NDArray array;
+
+  void VisitAttrs(tvm::AttrVisitor* v) final {
+    v->Visit("name", &name);
+    v->Visit("array", &array);
+  }
+
+  static constexpr const char* _type_key = "NamedNDArray";
+  TVM_DECLARE_NODE_TYPE_INFO(NamedNDArrayNode, Node);
+};
+
+TVM_DEFINE_NODE_REF(NamedNDArray, NamedNDArrayNode);
+
+}  // namespace relay
+}  // namespace tvm
+
+#endif  // TVM_RELAY_BACKEND_PARAM_DICT_H_

tests/python/relay/test_param_dict.py

@@ -0,0 +1,78 @@
+import os
+import numpy as np
+import tvm
+import json
+import base64
+from tvm._ffi.base import py_str
+from tvm.relay.op import add
+from tvm import relay
+from tvm import rpc
+from tvm.contrib import util, graph_runtime
+
+
+def test_save_load():
+    x = np.ones((10, 2)).astype("float32")
+    y = np.ones((1, 2, 3)).astype("float32")
+    params = {"x": x, "y": y}
+    param_bytes = relay.save_param_dict(params)
+    assert isinstance(param_bytes, bytearray)
+    param2 = relay.load_param_dict(param_bytes)
+    assert len(param2) == 2
+    np.testing.assert_equal(param2["x"].asnumpy(), x)
+    np.testing.assert_equal(param2["y"].asnumpy(), y)
+
+
+def test_ndarray_reflection():
+    # Make two `NDArrayWrapper`s that point to the same underlying array.
+    np_array = np.random.uniform(size=(10, 2)).astype("float32")
+    tvm_array = tvm.nd.array(np_array)
+    param_dict = {'x': tvm_array, 'y': tvm_array}
+    assert param_dict['x'].same_as(param_dict['y'])
+    # Serialize then deserialize `param_dict`.
+    deser_param_dict = relay.load_param_dict(relay.save_param_dict(param_dict))
+    # Make sure the data matches the original data and `x` and `y` contain the same data.
+    np.testing.assert_equal(deser_param_dict['x'].asnumpy(), tvm_array.asnumpy())
+    # Make sure `x` and `y` contain the same data.
+    np.testing.assert_equal(deser_param_dict['x'].asnumpy(), deser_param_dict['y'].asnumpy())
+
+
+def test_bigendian_rpc_param():
+    """Test big endian rpc when there is a PowerPC RPC server available"""
+    host = os.environ.get("TVM_POWERPC_TEST_HOST", None)
+    port = os.environ.get("TVM_POWERPC_TEST_PORT", 9090)
+    if host is None:
+        return
+
+    def verify_graph_runtime(remote, target, shape, dtype):
+        x = relay.var('x')
+        y = relay.const(1)
+        z = relay.add(x, y)
+        func = relay.Function([x], z)
+
+        x_in = np.ones(shape).astype(dtype)
+        params = {'x': x_in}
+        graph, lib, params = relay.build(func, target=target, params=params)
+
+        temp = util.tempdir()
+        path_dso = temp.relpath("dev_lib.o")
+        lib.save(path_dso)
+        remote.upload(path_dso)
+        lib = remote.load_module("dev_lib.o")
+        ctx = remote.cpu(0)
+        mod = graph_runtime.create(graph, lib, ctx)
+        mod.load_params(relay.save_param_dict(params))
+        mod.run()
+        out = mod.get_output(0, tvm.nd.empty(shape, dtype=dtype, ctx=ctx))
+        tvm.testing.assert_allclose(x_in + 1, out.asnumpy())
+
+    print("Test RPC connection to PowerPC...")
+    remote = rpc.connect(host, port)
+    target = "llvm -mtriple=powerpc-linux-gnu"
+    for dtype in ["float32", "float64", "int32", "int8"]:
+        verify_graph_runtime(remote, target, (10,), dtype)
+
+
+if __name__ == "__main__":
+    test_save_load()
+    test_ndarray_reflection()
+    test_bigendian_rpc_param()