[C API] Make DSL API registerable, add copy from/to raw bytes (#222)

* [C API] Make DSL API registerable, add copy from/to raw bytes

* fix cython

include/tvm/c_api.h → include/tvm/c_dsl_api.h

 /*!
  *  Copyright (c) 2016 by Contributors
- * \file c_api.h
- * \brief C API of TVM DSL
+ * \file c_dsl_api.h
  *
- * \note The API is designed in a minimum way.
- *  Most of the API functions are registered and can be pulled out.
+ * \brief TVM DSL Node C API, used to interact to DSL compilation.
  *
- *  The common flow is:
- *   - Use TVMFuncListGlobalNames to get global function name
- *   - Use TVMFuncCall to call these functions.
+ *  These are only a few functions needed for DSL construction time.
+ *  These function are only available when link libtvm.
+ *  If only TVM runtime is linked, calling these function will trigger error.
+ *
+ * \note Most API functions are registerd as PackedFunc and
+ *  can be grabbed via TVMFuncGetGlobal
  */
-#ifndef TVM_C_API_H_
-#define TVM_C_API_H_
+#ifndef TVM_C_DSL_API_H_
+#define TVM_C_DSL_API_H_
 
 #include "./runtime/c_runtime_api.h"
 
+#ifdef __cplusplus
 TVM_EXTERN_C {
+#endif
+
 /*! \brief handle to node */
 typedef void* NodeHandle;
 
 /*!
- * \brief Inplace translate callback argument value to return value.
- *  This is only needed for non-POD arguments.
- *
- * \param value The value to be translated.
- * \param code The type code to be translated.
- * \note This function will do a shallow copy when necessary.
- *
- * \return 0 when success, -1 when failure happens.
- */
-TVM_DLL int TVMCbArgToReturn(TVMValue* value, int code);
-
-/*!
  * \brief free the node handle
  * \param handle The node handle to be freed.
  * \return 0 when success, -1 when failure happens
@@ -82,5 +74,7 @@ TVM_DLL int TVMNodeGetAttr(NodeHandle handle,
 TVM_DLL int TVMNodeListAttrNames(NodeHandle handle,
                                  int *out_size,
                                  const char*** out_array);
+#ifdef __cplusplus
 }  // TVM_EXTERN_C
-#endif  // TVM_C_API_H_
+#endif
+#endif  // TVM_C_DSL_API_H_

include/tvm/ir_pass.h

@@ -12,6 +12,7 @@
 #include <ir/IREquality.h>
 #include <arithmetic/Simplify.h>
 #include <tvm/ir_functor.h>
+#include <arithmetic/Simplify.h>
 #include <unordered_map>
 #include <vector>
 #include <string>

include/tvm/runtime/c_runtime_api.h

@@ -5,9 +5,15 @@
  *
  *  The philosophy of TVM project is to customize the compilation
  *  stage to generate code that can used by other projects transparently.
- *
  *  So this is a minimum runtime code gluing, and some limited
  *  memory management code to enable quick testing.
+ *
+ *  The runtime API is independent from TVM compilation stack and can
+ *  be linked via libtvm_runtime.
+ *
+ *  The common flow is:
+ *   - Use TVMFuncListGlobalNames to get global function name
+ *   - Use TVMFuncCall to call these functions.
  */
 #ifndef TVM_RUNTIME_C_RUNTIME_API_H_
 #define TVM_RUNTIME_C_RUNTIME_API_H_
@@ -243,6 +249,18 @@ TVM_DLL int TVMCFuncSetReturn(TVMRetValueHandle ret,
                               int type_code);
 
 /*!
+ * \brief Inplace translate callback argument value to return value.
+ *  This is only needed for non-POD arguments.
+ *
+ * \param value The value to be translated.
+ * \param code The type code to be translated.
+ * \note This function will do a shallow copy when necessary.
+ *
+ * \return 0 when success, -1 when failure happens.
+ */
+TVM_DLL int TVMCbArgToReturn(TVMValue* value, int code);
+
+/*!
  * \brief C type of packed function.
  *
  * \param args The arguments
@@ -378,6 +396,28 @@ TVM_DLL int TVMArrayAlloc(const tvm_index_t* shape,
 TVM_DLL int TVMArrayFree(TVMArrayHandle handle);
 
 /*!
+ * \brief Copy array data from CPU byte array.
+ * \param handle The array handle.
+ * \param data the data pointer
+ * \param nbytes The number of bytes to copy.
+ * \return 0 when success, -1 when failure happens
+ */
+TVM_DLL int TVMArrayCopyFromBytes(TVMArrayHandle handle,
+                                  void* data,
+                                  size_t nbytes);
+
+/*!
+ * \brief Copy array data to CPU byte array.
+ * \param handle The array handle.
+ * \param data the data pointer
+ * \param nbytes The number of bytes to copy.
+ * \return 0 when success, -1 when failure happens
+ */
+TVM_DLL int TVMArrayCopyToBytes(TVMArrayHandle handle,
+                                void* data,
+                                size_t nbytes);
+
+/*!
  * \brief Copy the array, both from and to must be valid during the copy.
  * \param from The array to be copied from.
  * \param to The target space.

python/tvm/_ffi/_cython/base.pxi

@@ -79,6 +79,7 @@ cdef extern from "tvm/runtime/c_runtime_api.h":
                                void* resource_handle,
                                TVMPackedCFuncFinalizer fin,
                                TVMFunctionHandle *out)
+    int TVMCbArgToReturn(TVMValue* value, int code)
     int TVMArrayAlloc(tvm_index_t* shape,
                       tvm_index_t ndim,
                       DLDataType dtype,
@@ -89,8 +90,7 @@ cdef extern from "tvm/runtime/c_runtime_api.h":
                            DLTensorHandle to,
                            TVMStreamHandle stream)
 
-cdef extern from "tvm/c_api.h":
-    int TVMCbArgToReturn(TVMValue* value, int code)
+cdef extern from "tvm/c_dsl_api.h":
     int TVMNodeFree(NodeHandle handle)
     TVMNodeTypeKey2Index(const char* type_key,
                          int* out_index)

python/tvm/_ffi/ndarray.py

@@ -60,7 +60,6 @@ def context(dev_type, dev_id=0):
         dev_type = TVMContext.STR2MASK[dev_type]
     return TVMContext(dev_type, dev_id)
 
-
 def numpyasarray(np_data):
     """Return a TVMArray representation of a numpy array.
     """
@@ -158,11 +157,10 @@ class NDArrayBase(_NDArrayBase):
         source_array = np.ascontiguousarray(source_array, dtype=self.dtype)
         if source_array.shape != self.shape:
             raise ValueError('array shape do not match the shape of NDArray')
-        source_tvm_arr, shape = numpyasarray(source_array)
-        check_call(_LIB.TVMArrayCopyFromTo(
-            ctypes.byref(source_tvm_arr), self.handle, None))
-        # de-allocate shape until now
-        _ = shape
+        assert source_array.flags['C_CONTIGUOUS']
+        data = source_array.ctypes.data_as(ctypes.c_void_p)
+        nbytes = ctypes.c_size_t(np.prod(source_array.shape) * source_array.dtype.itemsize)
+        check_call(_LIB.TVMArrayCopyFromBytes(self.handle, data, nbytes))
 
     def asnumpy(self):
         """Convert this array to numpy array
@@ -173,10 +171,10 @@ class NDArrayBase(_NDArrayBase):
             The corresponding numpy array.
         """
         np_arr = np.empty(self.shape, dtype=self.dtype)
-        tvm_arr, shape = numpyasarray(np_arr)
-        check_call(_LIB.TVMArrayCopyFromTo(
-            self.handle, ctypes.byref(tvm_arr), None))
-        _ = shape
+        assert np_arr.flags['C_CONTIGUOUS']
+        data = np_arr.ctypes.data_as(ctypes.c_void_p)
+        nbytes = ctypes.c_size_t(np.prod(np_arr.shape) * np_arr.dtype.itemsize)
+        check_call(_LIB.TVMArrayCopyToBytes(self.handle, data, nbytes))
         return np_arr
 
     def copyto(self, target):

python/tvm/_ffi/node.py

@@ -81,11 +81,9 @@ def register_node(type_key=None):
     def register(cls):
         """internal register function"""
         tindex = ctypes.c_int()
-        try:
-            check_call(_LIB.TVMNodeTypeKey2Index(c_str(node_name), ctypes.byref(tindex)))
+        ret = _LIB.TVMNodeTypeKey2Index(c_str(node_name), ctypes.byref(tindex))
+        if ret == 0:
             _register_node(tindex.value, cls)
-        except AttributeError:
-            pass
         return cls
 
     if isinstance(type_key, str):

python/tvm/api.py

@@ -390,7 +390,7 @@ def decl_buffer(shape,
                 strides=None,
                 elem_offset=None,
                 scope="",
-                data_alignment=0,
+                data_alignment=-1,
                 offset_factor=0):
     """Decleare a new symbolic buffer.
 
@@ -426,7 +426,7 @@ def decl_buffer(shape,
 
     data_alignment: int, optional
         The alignment of data pointer in bytes.
-        If 0 is passed, the alignment will be set to TVM's internal default.
+        If -1 is passed, the alignment will be set to TVM's internal default.
 
     offset_factor: int, optional
         The factor of elem_offset field, when set,

python/tvm/build.py

@@ -28,7 +28,7 @@ class BuildConfig(object):
         'unroll_explicit': True,
         'detect_global_barrier': False,
         'offset_factor': 0,
-        'data_alignment': 0,
+        'data_alignment': -1,
         'restricted_func': True
     }
     def __init__(self, **kwargs):
@@ -81,7 +81,7 @@ def build_config(**kwargs):
 
     data_alignment: int, optional
         The alignment of data pointer in bytes.
-        If 0 is passed, the alignment will be set to TVM's internal default.
+        If -1 is passed, the alignment will be set to TVM's internal default.
 
     offset_factor: int, default=0
         The factor used in default buffer declaration.

src/api/c_api.cc → src/api/dsl_api.cc

 /*!
  *  Copyright (c) 2016 by Contributors
- * Implementation of C API
- * \file c_api.cc
+ *  Implementation of DSL API
+ * \file dsl_api.cc
  */
 #include <dmlc/base.h>
 #include <dmlc/logging.h>
 #include <dmlc/thread_local.h>
-#include <tvm/c_api.h>
 #include <tvm/api_registry.h>
 #include <vector>
 #include <string>
 #include <exception>
-#include "../runtime/runtime_base.h"
-
+#include "../runtime/dsl_api.h"
 
+namespace tvm {
+namespace runtime {
 /*! \brief entry to to easily hold returning information */
 struct TVMAPIThreadLocalEntry {
   /*! \brief result holder for returning strings */
@@ -24,8 +24,6 @@ struct TVMAPIThreadLocalEntry {
   std::string ret_str;
 };
 
-using namespace tvm;
-
 /*! \brief Thread local store that can be used to hold return values. */
 typedef dmlc::ThreadLocalStore<TVMAPIThreadLocalEntry> TVMAPIThreadLocalStore;
 
@@ -96,44 +94,25 @@ struct APIAttrDir : public AttrVisitor {
   }
 };
 
-
-int TVMNodeFree(NodeHandle handle) {
-  API_BEGIN();
+class DSLAPIImpl : public DSLAPI {
+ public:
+  void NodeFree(NodeHandle handle) const final {
     delete static_cast<TVMAPINode*>(handle);
-  API_END();
-}
-
-int TVMCbArgToReturn(TVMValue* value, int code) {
-  API_BEGIN();
-  tvm::runtime::TVMRetValue rv;
-  rv = tvm::runtime::TVMArgValue(*value, code);
-  int tcode;
-  rv.MoveToCHost(value, &tcode);
-  CHECK_EQ(tcode, code);
-  API_END();
-}
-
-int TVMNodeTypeKey2Index(const char* type_key,
-                         int* out_index) {
-  API_BEGIN();
+  }
+  void NodeTypeKey2Index(const char* type_key,
+                        int* out_index) const final {
     *out_index = static_cast<int>(Node::TypeKey2Index(type_key));
-  API_END();
-}
-
-int TVMNodeGetTypeIndex(NodeHandle handle,
-                        int* out_index) {
-  API_BEGIN();
+  }
+  void NodeGetTypeIndex(NodeHandle handle,
+                          int* out_index) const final {
     *out_index = static_cast<int>(
         (*static_cast<TVMAPINode*>(handle))->type_index());
-  API_END();
-}
-
-int TVMNodeGetAttr(NodeHandle handle,
+  }
+  void NodeGetAttr(NodeHandle handle,
                   const char* key,
                   TVMValue* ret_val,
                   int* ret_type_code,
-                   int* ret_success) {
-  API_BEGIN();
+                  int* ret_success) const final {
     TVMRetValue rv;
     APIAttrGetter getter;
     getter.skey = key;
@@ -156,14 +135,11 @@ int TVMNodeGetAttr(NodeHandle handle,
         rv.MoveToCHost(ret_val, ret_type_code);
       }
     }
-  API_END();
-}
-
-int TVMNodeListAttrNames(NodeHandle handle,
+  }
+  void NodeListAttrNames(NodeHandle handle,
                         int *out_size,
-                         const char*** out_array) {
+                        const char*** out_array) const final {
     TVMAPIThreadLocalEntry *ret = TVMAPIThreadLocalStore::Get();
-  API_BEGIN();
     ret->ret_vec_str.clear();
     TVMAPINode* tnode = static_cast<TVMAPINode*>(handle);
     APIAttrDir dir;
@@ -175,5 +151,14 @@ int TVMNodeListAttrNames(NodeHandle handle,
     }
     *out_array = dmlc::BeginPtr(ret->ret_vec_charp);
     *out_size = static_cast<int>(ret->ret_vec_str.size());
-  API_END();
-}
+  }
+};
+
+TVM_REGISTER_GLOBAL("dsl_api.singleton")
+.set_body([](TVMArgs args, TVMRetValue* rv) {
+    static DSLAPIImpl impl;
+    void* ptr = &impl;
+    *rv = ptr;
+  });
+}  // namespace runtime
+}  // namespace tvm

src/lang/buffer.cc

@@ -153,7 +153,7 @@ Buffer BufferNode::make(Var data,
   if (!elem_offset.defined()) {
     elem_offset = make_const(n->shape[0].type(), 0);
   }
-  if (data_alignment == 0) {
+  if (data_alignment <= 0) {
     data_alignment = runtime::kAllocAlignment;
   }
   if (offset_factor == 0) {

src/pass/arg_binder.cc

@@ -16,15 +16,15 @@ namespace ir {
 void BinderAddAssert(Expr cond,
                      const std::string& arg_name,
                      std::vector<Stmt>* asserts) {
-  cond = Simplify(cond);
-  if (is_zero(cond)) {
+  Expr scond = Simplify(cond);
+  if (is_zero(scond)) {
     LOG(FATAL) << "Bind have an unmet assertion: "
                << cond << ", " << " on argument " << arg_name;
   }
-  if (!is_one(cond)) {
+  if (!is_one(scond)) {
     std::ostringstream os;
     os << "Argument " << arg_name << " has an unsatisfied constraint";
-    asserts->emplace_back(AssertStmt::make(cond, os.str(), Evaluate::make(0)));
+    asserts->emplace_back(AssertStmt::make(scond, os.str(), Evaluate::make(0)));
   }
 }
 

src/pass/storage_flatten.cc

@@ -103,9 +103,11 @@ class StorageFlattener : public IRMutator {
       } else {
         skey = StorageScope::make(strkey);
       }
+
       // use small alignment for small arrays
       int32_t const_size = Allocate::constant_allocation_size(shape, key.GetName());
       int align = GetTempAllocaAlignment(op->type, const_size);
+
       e.buffer = BufferNode::make(
           Var(key.GetName(), Handle()),
           op->type, shape,

src/runtime/c_dsl_api.cc

+/*!
+ *  Copyright (c) 2017 by Contributors
+ * \file cpu_dsl_api.cc
+ * \brief DSL API dispatcher
+ */
+#include <tvm/runtime/registry.h>
+#include <tvm/c_dsl_api.h>
+#include "./dsl_api.h"
+#include "./runtime_base.h"
+
+namespace tvm {
+namespace runtime {
+
+DSLAPI* FindDSLAPI() {
+  auto* f = Registry::Get("dsl_api.singleton");
+  if (f == nullptr) {
+    throw dmlc::Error("TVM runtime only environment, "\
+                      "DSL API is not available");
+  }
+  void* ptr = (*f)();
+  return static_cast<DSLAPI*>(ptr);
+}
+
+static DSLAPI* GetDSLAPI() {
+  static DSLAPI* inst = FindDSLAPI();
+  return inst;
+}
+}  // namespace runtime
+}  // namespace tvm
+
+using namespace tvm::runtime;
+
+int TVMNodeFree(NodeHandle handle) {
+  API_BEGIN();
+  GetDSLAPI()->NodeFree(handle);
+  API_END();
+}
+
+int TVMNodeTypeKey2Index(const char* type_key,
+                         int* out_index) {
+  API_BEGIN();
+  GetDSLAPI()->NodeTypeKey2Index(type_key, out_index);
+  API_END();
+}
+
+
+int TVMNodeGetTypeIndex(NodeHandle handle,
+                        int* out_index) {
+  API_BEGIN();
+  GetDSLAPI()->NodeGetTypeIndex(handle, out_index);
+  API_END();
+}
+
+int TVMNodeGetAttr(NodeHandle handle,
+                   const char* key,
+                   TVMValue* out_value,
+                   int* out_type_code,
+                   int* out_success) {
+  API_BEGIN();
+  GetDSLAPI()->NodeGetAttr(
+      handle, key, out_value, out_type_code, out_success);
+  API_END();
+}
+
+int TVMNodeListAttrNames(NodeHandle handle,
+                         int *out_size,
+                         const char*** out_array) {
+  API_BEGIN();
+  GetDSLAPI()->NodeListAttrNames(
+      handle, out_size, out_array);
+  API_END();
+}

src/runtime/c_runtime_api.cc

@@ -130,7 +130,7 @@ inline size_t GetDataSize(TVMArray* arr) {
   for (tvm_index_t i = 0; i < arr->ndim; ++i) {
     size *= arr->shape[i];
   }
-  size *= (arr->dtype.bits / 8) * arr->dtype.lanes;
+  size *= (arr->dtype.bits * arr->dtype.lanes + 7) / 8;
   return size;
 }
 
@@ -394,6 +394,40 @@ int TVMArrayCopyFromTo(TVMArrayHandle from,
   API_END();
 }
 
+int TVMArrayCopyFromBytes(TVMArrayHandle handle,
+                          void* data,
+                          size_t nbytes) {
+  API_BEGIN();
+  TVMContext cpu_ctx;
+  cpu_ctx.device_type = kCPU;
+  cpu_ctx.device_id = 0;
+  size_t arr_size = GetDataSize(handle);
+  CHECK_EQ(arr_size, nbytes)
+      << "TVMArrayCopyFromBytes: size mismatch";
+  DeviceAPIManager::Get(handle->ctx)->CopyDataFromTo(
+      data, 0,
+      handle->data, handle->byte_offset,
+      nbytes, cpu_ctx, handle->ctx, nullptr);
+  API_END();
+}
+
+int TVMArrayCopyToBytes(TVMArrayHandle handle,
+                        void* data,
+                        size_t nbytes) {
+  API_BEGIN();
+  TVMContext cpu_ctx;
+  cpu_ctx.device_type = kCPU;
+  cpu_ctx.device_id = 0;
+  size_t arr_size = GetDataSize(handle);
+  CHECK_EQ(arr_size, nbytes)
+      << "TVMArrayCopyToBytes: size mismatch";
+  DeviceAPIManager::Get(handle->ctx)->CopyDataFromTo(
+      handle->data, handle->byte_offset,
+      data, 0,
+      nbytes, handle->ctx, cpu_ctx, nullptr);
+  API_END();
+}
+
 int TVMSetStream(TVMContext ctx, TVMStreamHandle stream) {
   API_BEGIN();
   DeviceAPIManager::Get(ctx)->SetStream(ctx, stream);
@@ -406,6 +440,16 @@ int TVMSynchronize(TVMContext ctx, TVMStreamHandle stream) {
   API_END();
 }
 
+int TVMCbArgToReturn(TVMValue* value, int code) {
+  API_BEGIN();
+  tvm::runtime::TVMRetValue rv;
+  rv = tvm::runtime::TVMArgValue(*value, code);
+  int tcode;
+  rv.MoveToCHost(value, &tcode);
+  CHECK_EQ(tcode, code);
+  API_END();
+}
+
 // set device api
 TVM_REGISTER_GLOBAL(tvm::runtime::symbol::tvm_set_device)
 .set_body([](TVMArgs args, TVMRetValue *ret) {

src/runtime/dsl_api.h

+/*!
+ *  Copyright (c) 2017 by Contributors
+ * \file cpu_dsl_api.cc
+ * \brief DSL API dispatcher
+ */
+#ifndef TVM_RUNTIME_DSL_API_H_
+#define TVM_RUNTIME_DSL_API_H_
+
+#include <tvm/c_dsl_api.h>
+
+namespace tvm {
+namespace runtime {
+/*!
+ * \brief Common interface for DSL API
+ *  Used for runtime registration
+ */
+class DSLAPI {
+ public:
+  virtual void NodeFree(NodeHandle handle) const = 0;
+
+  virtual void NodeTypeKey2Index(const char* type_key,
+                                 int* out_index) const = 0;
+
+  virtual void NodeGetTypeIndex(NodeHandle handle,
+                                int* out_index) const = 0;
+
+  virtual void NodeGetAttr(NodeHandle handle,
+                           const char* key,
+                           TVMValue* out_value,
+                           int* out_type_code,
+                           int* out_success) const = 0;
+
+  virtual void NodeListAttrNames(NodeHandle handle,
+                                 int *out_size,
+                                 const char*** out_array) const = 0;
+};
+}  // namespace runtime
+}  // namespace tvm
+#endif  // TVM_RUNTIME_DSL_API_H_