[COMPILER] GraphHash based cache system, allow dump and query duplica…

…ted functions. (apache#30)

nnvm/include/nnvm/graph.h

@@ -63,11 +63,11 @@ class Graph {
    * \return The indexed graph.
    * \sa IndexedGraph
    */
-  const IndexedGraph& indexed_graph();
+  const IndexedGraph& indexed_graph() const;
 
  private:
   // internal structure of indexed graph
-  std::shared_ptr<const IndexedGraph> indexed_graph_;
+  mutable std::shared_ptr<const IndexedGraph> indexed_graph_;
 };
 
 /*!

nnvm/include/nnvm/pass_functions.h

@@ -41,6 +41,17 @@ inline std::string SaveJSON(Graph graph) {
   return ret.GetAttr<std::string>("json");
 }
 
+
+/*!
+ * \brief Print graph ir
+ * \param graph The graph to be printed
+ * \return The graph ir string.
+ */
+inline std::string PrintGraphIR(Graph graph) {
+  Graph ret = ApplyPass(std::move(graph), "PrintGraphIR");
+  return ret.GetAttr<std::string>("graphir");
+}
+
 /*!
  * \brief Add control flow dependencies between nodes.
  *

nnvm/python/nnvm/compiler/__init__.py

@@ -5,6 +5,7 @@
 
 from . import build_module
 from . build_module import build, optimize, build_config
+from . compile_engine import engine, graph_key
 
 from .. import symbol as _symbol
 from .. import graph as _graph
@@ -14,5 +15,6 @@
 
 from .. import top as _top
 
+
 tvm.register_extension(_symbol.Symbol, _symbol.Symbol)
 tvm.register_extension(_graph.Graph, _graph.Graph)

nnvm/python/nnvm/compiler/build_module.py

@@ -184,7 +184,7 @@ def build(graph, target, shape, dtype="float32", params=None):
     graph._set_json_attr("target", target, "str")
     graph._set_json_attr("opt_level", cfg.opt_level, "int")
     graph = graph.apply("InferShape").apply("InferType")
-    graph = graph.apply("GraphFusePartition").apply("GraphFuse")
+    graph = graph.apply("GraphFusePartition").apply("GraphFuseCompile")
     libmod = graph_attr._move_out_module(graph, "module")
     return graph, libmod, params
 

nnvm/python/nnvm/compiler/compile_engine.py

@@ -0,0 +1,99 @@
+# pylint: disable=invalid-name
+"""Compiler engine interface to internal engine"""
+import tvm
+
+_list_cache_items = tvm.get_global_func("nnvm.compiler.ListCacheItems")
+_clear_cache = tvm.get_global_func("nnvm.compiler.ClearCache")
+_get_cache_item = tvm.get_global_func("nnvm.compiler.GetCacheItem")
+_set_cache_item = tvm.get_global_func("nnvm.compiler.SetCacheItem")
+_graph_key_get_graph = tvm.get_global_func("nnvm.compiler.GraphKeyGetGraph")
+_make_graph_key = tvm.get_global_func("nnvm.compiler.MakeGraphKey")
+
+@tvm.register_node
+class GraphKey(tvm.node.NodeBase):
+    """Key of a graph compilation context"""
+    @property
+    def graph(self):
+        return _graph_key_get_graph(self)
+
+
+@tvm.register_node
+class GraphCacheEntry(tvm.node.NodeBase):
+    """CacheEntry of compilation into a TVM Function"""
+    pass
+
+
+@tvm.register_node
+class GraphFunc(tvm.node.NodeBase):
+    """Compiled result of a graph into a TVM Function"""
+    pass
+
+
+class Engine(object):
+    """Global singleton compilation engine."""
+    def items(self):
+        """List the available cache key value pairs.
+
+        Returns
+        -------
+        item_list : list of (GraphKey, GraphCacheEntry)
+            The existing cache items
+        """
+        res = _list_cache_items()
+        assert len(res) % 2 == 0
+        return [(res[2*i], res[2*i+1]) for i in range(len(res)/2)]
+
+    def clear_cache(self):
+        """Clear the existing cached functions."""
+        _clear_cache()
+
+    def __setitem__(self, key, value):
+        """Clear the existing cached functions."""
+        if isinstance(value, GraphCacheEntry):
+            _set_cache_item(key, value.graph_func)
+        else:
+            _set_cache_item(key, value)
+
+    def __getitem__(self, key):
+        """Clear the existing cached functions."""
+        return _get_cache_item(key)
+
+    def dump(self):
+        """Return a string representation of engine dump
+
+        Returns
+        -------
+        dump : str
+            The dumped string representation
+        """
+        items = self.items()
+        res = "====================================\n"
+        res += "CompilerEngine dump, %d items cached\n" % len(items)
+        for key, value in items:
+            res += "------------------------------------\n"
+            res += "target={}\n".format(key.target)
+            res += "inputs={}\n".format(key.inputs)
+            res += "use_count={}\n".format(value.use_count)
+            res += "func_name={}\n".format(value.graph_func.func_name)
+            res += key.graph.ir() + "\n"
+        res += "===================================\n"
+        return res
+
+engine = Engine()
+
+
+def graph_key(graph, inputs, target):
+    """Construct a new graph key.
+
+    Parameters
+    ----------
+    graph : Graph
+        The computation graph structure
+
+    inputs : list of Tensor(placeholder)
+        The input requirement to the graph.
+
+    target : str
+        The target of compilation.
+    """
+    return _make_graph_key(graph, inputs, target)

nnvm/python/nnvm/testing/__init__.py

@@ -1 +1,3 @@
 """Utilities for testcase"""
+
+from .config import ctx_list

nnvm/python/nnvm/testing/config.py

@@ -2,7 +2,7 @@
 import os
 import tvm
 
-def test_ctx_list():
+def ctx_list():
     """Get context list for testcases"""
     device_list = os.environ.get("NNVM_TEST_TARGETS", "")
     device_list = (device_list.split(",") if device_list