[Hexagon] Deprecate USE_HEXAGON_DEVICE, introduce USE_HEXAGON

The new cmake flag `USE_HEXAGON=[ON|OFF]` enables/disables Hexagon support in TVM and TVM runtime. It should be turned on _whenever_ Hexagon support is required, even when compiling TVM runtime for Hexagon itself. This is one in a series of commits intended to remove offload support, and make the whole-model support the default mode of operation. With `USE_HEXAGON_DEVICE` deprecated, offload runtime is not built anymore, so register `device_api.hexagon` to be same as `.v2` (presence of device API is taken as evidence of support for the device in TVM, so this step is necessary).
apache · mehrdadh · Apr 18, 2022 · Apr 15, 2022 · Apr 15, 2022 · 940ed8bf362ae8039fcd2f514f9c380ec1dc6f5a
commit 940ed8bf362ae8039fcd2f514f9c380ec1dc6f5a
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -40,8 +40,8 @@ tvm_option(USE_SPIRV_KHR_INTEGER_DOT_PRODUCT "whether enable SPIRV_KHR_DOT_PRODU
 tvm_option(USE_METAL "Build with Metal" OFF)
 tvm_option(USE_ROCM "Build with ROCM" OFF)
 tvm_option(ROCM_PATH "The path to rocm" /opt/rocm)
-tvm_option(USE_HEXAGON_DEVICE "Build with Hexagon device support in TVM runtime" OFF)
-tvm_option(USE_HEXAGON_SDK "Path to the Hexagon SDK root (required for Hexagon support in TVM runtime or for building TVM runtime for Hexagon)" /path/to/sdk)
+tvm_option(USE_HEXAGON "Build with Hexagon support" OFF)
+tvm_option(USE_HEXAGON_SDK "Path to the Hexagon SDK root (required for Hexagon support)" /path/to/sdk)
 tvm_option(USE_HEXAGON_RPC "Enable Hexagon RPC using minRPC implementation over Android." OFF)
 tvm_option(USE_RPC "Build with RPC" ON)
 tvm_option(USE_THREADS "Build with thread support" ON)

diff --git a/apps/hexagon_api/CMakeLists.txt b/apps/hexagon_api/CMakeLists.txt
@@ -35,6 +35,7 @@ ExternalProject_Add(x86_tvm_runtime_rpc
     "-DUSE_LIBBACKTRACE=OFF"
     "-DUSE_RPC=ON"
     "-DUSE_CPP_RPC=ON"
+    "-DUSE_HEXAGON=ON"
     "-DUSE_HEXAGON_RPC=ON"
     "-DBUILD_STATIC_RUNTIME=ON"
     "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}"
@@ -66,6 +67,7 @@ ExternalProject_Add(android_tvm_runtime_rpc
     "-DUSE_LIBBACKTRACE=OFF"
     "-DUSE_RPC=ON"
     "-DUSE_CPP_RPC=ON"
+    "-DUSE_HEXAGON=ON"
     "-DUSE_HEXAGON_RPC=ON"
     "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}"
     "-DUSE_ALTERNATIVE_LINKER=OFF"
@@ -101,6 +103,7 @@ ExternalProject_Add(hexagon_tvm_runtime_rpc
     "-DUSE_HEXAGON_ARCH=${USE_HEXAGON_ARCH}"
     "-DUSE_LIBBACKTRACE=OFF"
     "-DUSE_RPC=OFF"
+    "-DUSE_HEXAGON=ON"
     "-DUSE_HEXAGON_RPC=ON"
     "-DBUILD_STATIC_RUNTIME=ON"
     "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}"

diff --git a/apps/hexagon_launcher/cmake/android/CMakeLists.txt b/apps/hexagon_launcher/cmake/android/CMakeLists.txt
@@ -71,15 +71,16 @@ ExternalProject_Add(android_tvm_runtime
   SOURCE_DIR "${TVM_SOURCE_DIR}"
   BUILD_COMMAND $(MAKE) runtime
   CMAKE_ARGS
-  "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}"
-  "-DANDROID_PLATFORM=${ANDROID_PLATFORM}"
   "-DANDROID_ABI=${ANDROID_ABI}"
+  "-DANDROID_PLATFORM=${ANDROID_PLATFORM}"
   "-DCMAKE_CXX_STANDARD=14"
+  "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}"
+  "-DUSE_HEXAGON_ARCH=${USE_HEXAGON_ARCH}"
+  "-DUSE_HEXAGON=ON"
+  "-DUSE_HEXAGON_SDK=${USE_HEXAGON_SDK}"
   "-DUSE_LIBBACKTRACE=OFF"
   "-DUSE_LLVM=OFF"
   "-DUSE_RPC=OFF"
-  "-DUSE_HEXAGON_SDK=${USE_HEXAGON_SDK}"
-  "-DUSE_HEXAGON_ARCH=${USE_HEXAGON_ARCH}"
   INSTALL_COMMAND ""
   BUILD_ALWAYS ON
 )

diff --git a/apps/hexagon_launcher/cmake/hexagon/CMakeLists.txt b/apps/hexagon_launcher/cmake/hexagon/CMakeLists.txt
@@ -79,15 +79,16 @@ ExternalProject_Add(static_hexagon_tvm_runtime
   SOURCE_DIR "${TVM_SOURCE_DIR}"
   BUILD_COMMAND $(MAKE) runtime
   CMAKE_ARGS
+  "-DBUILD_STATIC_RUNTIME=ON"
   "-DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}"
   "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
-  "-DUSE_HEXAGON_ARCH=${USE_HEXAGON_ARCH}"
   "-DCMAKE_CXX_STANDARD=14"
+  "-DUSE_HEXAGON_ARCH=${USE_HEXAGON_ARCH}"
+  "-DUSE_HEXAGON=ON"
+  "-DUSE_HEXAGON_SDK=${USE_HEXAGON_SDK}"
   "-DUSE_LIBBACKTRACE=OFF"
   "-DUSE_LLVM=OFF"
   "-DUSE_RPC=OFF"
-  "-DBUILD_STATIC_RUNTIME=ON"
-  "-DUSE_HEXAGON_SDK=${USE_HEXAGON_SDK}"
   INSTALL_COMMAND ""
   BUILD_ALWAYS ON
 )

diff --git a/cmake/config.cmake b/cmake/config.cmake
@@ -293,20 +293,17 @@ set(USE_PT_TVMDSOOP OFF)
 # Whether to use STL's std::unordered_map or TVM's POD compatible Map
 set(USE_FALLBACK_STL_MAP OFF)
 
-# Whether to use hexagon device
-set(USE_HEXAGON_DEVICE OFF)
+# Whether to enable Hexagon support
+set(USE_HEXAGON OFF)
 set(USE_HEXAGON_SDK /path/to/sdk)
 
-# Whether to build the hexagon launcher
-set(USE_HEXAGON_LAUNCHER OFF)
-
-# Whether to build the minimal support android rpc server for hexagon
-set(USE_HEXAGON_PROXY_RPC OFF)
+# Whether to build the minimal support android rpc server for Hexagon
+set(USE_HEXAGON_RPC OFF)
 
 # Hexagon architecture to target when compiling TVM itself (not the target for
 # compiling _by_ TVM). This applies to components like the TVM runtime, but is
 # also used to select correct include/library paths from the Hexagon SDK when
-# building offloading runtime for Android.
+# building runtime for Android.
 # Valid values are v65, v66, v68, v69.
 set(USE_HEXAGON_ARCH "v66")
 

diff --git a/cmake/modules/Hexagon.cmake b/cmake/modules/Hexagon.cmake
@@ -18,10 +18,6 @@
 include(ExternalProject)
 include(cmake/modules/HexagonSDK.cmake)
 
-set(PICK_SIM  "sim")
-set(PICK_HW   "target")
-set(PICK_NONE "OFF")
-
 set(FOUND_HEXAGON_TOOLCHAIN FALSE)
 
 function(find_hexagon_toolchain)
@@ -56,27 +52,17 @@ endmacro()
 
 set(TVMRT_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/runtime")
 
-# First, verify that USE_HEXAGON_DEVICE has a valid value.
 if(DEFINED USE_HEXAGON_DEVICE)
-  if(NOT USE_HEXAGON_DEVICE STREQUAL "${PICK_SIM}" AND
-     NOT USE_HEXAGON_DEVICE STREQUAL "${PICK_HW}" AND
-     NOT USE_HEXAGON_DEVICE STREQUAL "${PICK_NONE}")
-    message(SEND_ERROR "USE_HEXAGON_DEVICE must be one of "
-            "[${PICK_NONE}|${PICK_SIM}|${PICK_HW}]")
-    set(USE_HEXAGON_DEVICE OFF)
-  endif()
+  message(WARNING "USE_HEXAGON_DEVICE is deprecated, use USE_HEXAGON instead")
 endif()
 
 # This .cmake file is included when building any part of TVM for any
-# architecture. It shouldn't require any Hexagon-specific parameters
-# (like the path to the SDK), unless it's needed.
-#
-# Aside from building the code for Hexagon, two flags can enable some
-# Hexagon-related functionality:
-# - USE_HEXAGON_DEVICE
-# - USE_HEXAGON_RPC
-#
-# USE_HEXAGON_RPC:
+# architecture. It shouldn't require any Hexagon-specific parameters (like
+# the path to the SDK), unless it's needed. The flag USE_HEXAGON decides
+# whether any Hexagon-related functionality is enabled. Specifically,
+# setting USE_HEXAGON=OFF, disables any form of Hexagon support.
+# 
+# Note on the function of USE_HEXAGON_RPC:
 # - When building for Hexagon, this will build the Hexagon endpoint of the
 #   RPC server: the FastRPC skel library (with TVM runtime built into it),
 #   and the standalone RPC server for simulator.
@@ -91,7 +77,7 @@ if(NOT BUILD_FOR_HEXAGON AND NOT BUILD_FOR_ANDROID)
 endif()
 
 
-if(NOT USE_HEXAGON_DEVICE AND NOT USE_HEXAGON_RPC AND NOT BUILD_FOR_HEXAGON)
+if(NOT USE_HEXAGON)
   # If nothing related to Hexagon is enabled, add phony Hexagon codegen,
   # and some stuff needed by cpptests (this part is a temporary workaround
   # until e2e support for Hexagon is enabled).
@@ -104,6 +90,7 @@ if(NOT USE_HEXAGON_DEVICE AND NOT USE_HEXAGON_RPC AND NOT BUILD_FOR_HEXAGON)
   return()
 endif()
 
+# From here on, USE_HEXAGON is assumed to be TRUE.
 
 function(add_android_paths)
   get_hexagon_sdk_property("${USE_HEXAGON_SDK}" "${USE_HEXAGON_ARCH}"
@@ -132,10 +119,12 @@ function(add_hexagon_wrapper_paths)
   link_directories("${HEXAGON_TOOLCHAIN}/lib/iss")
 endfunction()
 
+
 # Common sources for TVM runtime with Hexagon support
-file_glob_append(RUNTIME_HEXAGON_COMMON_SRCS
+file_glob_append(RUNTIME_HEXAGON_SRCS
   "${TVMRT_SOURCE_DIR}/hexagon/hexagon_module.cc"
   "${TVMRT_SOURCE_DIR}/hexagon/hexagon/*.cc"
+  "${TVMRT_SOURCE_DIR}/hexagon/host/*.cc"
 )
 
 
@@ -154,61 +143,10 @@ if(BUILD_FOR_HEXAGON)
   # Add SDK and QuRT includes when building for Hexagon.
   include_directories(SYSTEM ${SDK_INCLUDE_DIRS} ${QURT_INCLUDE_DIRS})
 
-  list(APPEND RUNTIME_HEXAGON_SRCS ${RUNTIME_HEXAGON_COMMON_SRCS})
   set(USE_CUSTOM_LOGGING ON) # To use a custom logger
 endif()
 
 
-if(USE_HEXAGON_DEVICE)
-  function(invalid_device_value_for BUILD_TARGET)
-    message(SEND_ERROR
-      "USE_HEXAGON_DEVICE=${USE_HEXAGON_DEVICE} is not supported when "
-      "building for ${BUILD_TARGET}"
-    )
-  endfunction()
-
-  list(APPEND RUNTIME_HEXAGON_SRCS ${RUNTIME_HEXAGON_COMMON_SRCS})
-
-  if(BUILD_FOR_HOST)
-    if(NOT USE_HEXAGON_DEVICE STREQUAL "${PICK_SIM}")
-      invalid_device_value_for("host")
-    endif()
-    find_hexagon_toolchain()
-    add_hexagon_wrapper_paths()
-    file_glob_append(RUNTIME_HEXAGON_SRCS
-      "${TVMRT_SOURCE_DIR}/hexagon/android/*.cc"
-      "${TVMRT_SOURCE_DIR}/hexagon/android/sim/*.cc"
-    )
-    list(APPEND TVM_RUNTIME_LINKER_LIBS "-lwrapper")
-
-    ExternalProject_Add(sim_dev
-      SOURCE_DIR "${TVMRT_SOURCE_DIR}/hexagon/android/sim/driver"
-      CMAKE_ARGS
-        "-DCMAKE_C_COMPILER=${HEXAGON_TOOLCHAIN}/bin/hexagon-clang"
-        "-DCMAKE_CXX_COMPILER=${HEXAGON_TOOLCHAIN}/bin/hexagon-clang++"
-        "-DHEXAGON_ARCH=${USE_HEXAGON_ARCH}"
-      INSTALL_COMMAND "true"
-    )
-
-  elseif(BUILD_FOR_ANDROID)
-    if(NOT USE_HEXAGON_DEVICE STREQUAL "${PICK_HW}")
-      invalid_device_value_for("Android")
-    endif()
-    find_hexagon_toolchain()
-    add_android_paths()
-    file_glob_append(RUNTIME_HEXAGON_SRCS
-      "${TVMRT_SOURCE_DIR}/hexagon/android/*.cc"
-      "${TVMRT_SOURCE_DIR}/hexagon/android/target/*.cc"
-    )
-    # Hexagon runtime uses __android_log_print, which is in liblog.
-    list(APPEND TVM_RUNTIME_LINKER_LIBS dl log cdsprpc)
-
-  elseif(BUILD_FOR_HEXAGON)
-    invalid_device_value_for("Hexagon")
-  endif()
-endif()   # USE_HEXAGON_DEVICE
-
-
 if(USE_HEXAGON_RPC)
   function(build_rpc_idl)
     get_hexagon_sdk_property("${USE_HEXAGON_SDK}" "${USE_HEXAGON_ARCH}"
@@ -232,14 +170,11 @@ if(USE_HEXAGON_RPC)
     )
   endfunction()
 
-  list(APPEND RUNTIME_HEXAGON_SRCS ${RUNTIME_HEXAGON_COMMON_SRCS})
-
   if(BUILD_FOR_ANDROID)
     # Android part
     add_android_paths()
     build_rpc_idl()
     file_glob_append(RUNTIME_HEXAGON_SRCS
-      "${TVMRT_SOURCE_DIR}/hexagon/host/*.cc"
       "${TVMRT_SOURCE_DIR}/hexagon/rpc/android/*.cc"
     )
     # Add this file separately, because it's auto-generated, and glob won't
@@ -285,7 +220,6 @@ if(USE_HEXAGON_RPC)
     find_hexagon_toolchain()
     add_hexagon_wrapper_paths()
     file_glob_append(RUNTIME_HEXAGON_SRCS
-      "${TVMRT_SOURCE_DIR}/hexagon/host/*.cc"
       "${TVMRT_SOURCE_DIR}/hexagon/rpc/simulator/session.cc"
     )
     list(APPEND TVM_RUNTIME_LINKER_LIBS "-lwrapper")

diff --git a/cmake/modules/LibInfo.cmake b/cmake/modules/LibInfo.cmake
@@ -71,7 +71,7 @@ function(add_lib_info src_file)
     TVM_INFO_USE_GRAPH_EXECUTOR_CUDA_GRAPH="${USE_GRAPH_EXECUTOR_CUDA_GRAPH}"
     TVM_INFO_USE_GRAPH_EXECUTOR="${USE_GRAPH_EXECUTOR}"
     TVM_INFO_USE_GTEST="${USE_GTEST}"
-    TVM_INFO_USE_HEXAGON_DEVICE="${USE_HEXAGON_DEVICE}"
+    TVM_INFO_USE_HEXAGON="${USE_HEXAGON}"
     TVM_INFO_USE_HEXAGON_RPC="${USE_HEXAGON_RPC}"
     TVM_INFO_USE_HEXAGON_SDK="${USE_HEXAGON_SDK}"
     TVM_INFO_USE_IOS_RPC="${USE_IOS_RPC}"

diff --git a/src/runtime/hexagon/README.md b/src/runtime/hexagon/README.md
@@ -17,61 +17,55 @@
 
 # Hexagon backend runtime
 
-The Hexagon runtime is a part of the TVM runtime that facilitates communication between a host and a Hexagon device. There are two types of host/device arrangements that are supported:
-- X86/Linux host running Hexagon simulator,
-- Android/AArch64 host running on a physical device containing a Hexagon module (i.e. CSDP or ADSP).
+The Hexagon runtime implements the functionality necessary for executing ML
+models on Hexagon hardware (or emulation).
 
-The TVM runtime that contains Hexagon runtime is the one executing on host.  In either case, there will need to be a separate TVM runtime (i.e.  the `libtvm_runtime.so` library) compiled for execution on Hexagon.
+The prerequisite is to have Hexagon SDK installed, version 4.0.0 or later.
 
-The prerequisite is to have Hexagon SDK installed, preferably version 3.5.0 or later. The Hexagon SDK can be downloaded from https://developer.qualcomm.com/software/hexagon-dsp-sdk.
+It is also recommended to use as recent version of LLVM as possible, version
+7.0.0 being the minimum (based on community feedback).
 
-It is also recommended to use as recent version of LLVM as possible, version 7.0.0 being the minimum (based on community feedback).
+### Compiling TVM with support for Hexagon for host (x86)
 
-### Compiling TVM runtime for x86
-
-This will use Hexagon simulator, which is provided in the Hexagon SDK.
-
-When configuring TVM (cmake), set the following variables:
+TVM running on host can serve as a cross-compiler that produces machine code
+for Hexagon. To enable that, certain elements of both, the compiler and the
+runtime need to include Hexagon-specific functionality. For the compiler, it
+is code generation, and for the runtime, it is the ability to represent
+modules with Hexagon code. Since Hexagon codegen is based on LLVM, LLVM
+codegen needs to be enabled as well. The set of cmake options to enable
+Hexagon support is
 ```
 USE_LLVM=llvm-config
-USE_HEXAGON_DEVICE=sim
+USE_HEXAGON=ON
 USE_HEXAGON_SDK=/path/to/sdk
 ```
 
-You can then build the entire TVM with the usual command (e.g. `make`).
-
-### Compiling TVM runtime for Android
+### Compiling TVM runtime for non-x86
 
-This will use FastRPC mechanism to communicate between the AArch64 host and Hexagon.
+Aside from x86, there are two other platforms where support for Hexagon may
+be relevant. One of them is obviously Hexagon itself, the other one is
+Android. Neither of these platforms supports the compiler side of TVM, only
+runtime, and so the only compiler-related cmake option from the x86 build
+above can be omitted: USE_LLVM.
 
-When configuring TVM (cmake), set the following variables:
+Additionally, for Android, set the toolchain and target flags:
 ```
-USE_LLVM=llvm-config
-USE_HEXAGON_DEVICE=device
+ANDROID_ABI=aarch64-v8a
+ANDROID_PLATFORM=android-28
+CMAKE_TOOLCHAIN_FILE=/path/to/android-ndk/build/cmake/android.toolchain.cmake
+USE_HEXAGON=ON
+USE_HEXAGON_ARCH=v65|v66|v68|v69
 USE_HEXAGON_SDK=/path/to/sdk
 ```
 
-You will need Android clang toolchain to compile the runtime.  It is provided in Android NDK r19 or newer.
-
-Set the C/C++ compiler to the Android clang for aarch64, and pass `-DCMAKE_CXX_FLAGS='-stdlib=libc++'` to the cmake command.
-
-Only build the `runtime` component of TVM (e.g. `make runtime`), building the entire TVM will not work.
-
-### Compiling TVM runtime for Hexagon
-
-The TVM runtime executing on Hexagon does not need to have support for Hexagon device in it (as it is only for communication between host and Hexagon device). In fact, it's only needed for basic services (like thread control), and so it should not contain support for any devices.
-
-When configuring TVM (cmake), set the following variables:
+Building for Hexagon requires setting the C/C++ compiler to `hexagon-clang/++`:
 ```
-USE_RPC=OFF
-USE_LLVM=OFF
-USE_HEXAGON_DEVICE=OFF
+CMAKE_C_COMPILER=hexagon-clang
+CMAKE_CXX_COMPILER=hexagon-clang++
+USE_HEXAGON=ON
+USE_HEXAGON_ARCH=v65|v66|v68|v69
 USE_HEXAGON_SDK=/path/to/sdk
 ```
 
-Please note that while suport for a Hexagon device is disabled, the Hexagon SDK is still needed and the path to it needs to be passed to cmake.
-
-Set the C/C++ compiler to `hexagon-clang` (included in the Hexagon SDK), and set `CMAKE_CXX_FLAGS='-stdlib=libc++'`.
-
-As in the case of Android, only build the `runtime` component (e.g.  `make runtime`).
+As mentioned before, only build the `runtime` component (e.g. `make runtime`).
 
diff --git a/src/runtime/hexagon/android/hexagon_device_api.cc b/src/runtime/hexagon/android/hexagon_device_api.cc
@@ -124,7 +124,7 @@ inline void HexagonDeviceAPI::FreeWorkspace(Device dev, void* ptr) {
   DeviceAPI::FreeWorkspace(dev, ptr);
 }
 
-TVM_REGISTER_GLOBAL("device_api.hexagon").set_body([](TVMArgs args, TVMRetValue* rv) {
+TVM_REGISTER_GLOBAL("device_api.hexagon.v1").set_body([](TVMArgs args, TVMRetValue* rv) {
   DeviceAPI* ptr = HexagonDeviceAPI::Global();
   *rv = ptr;
 });

diff --git a/src/runtime/hexagon/hexagon/hexagon_device_api_v2.cc b/src/runtime/hexagon/hexagon/hexagon_device_api_v2.cc
@@ -231,6 +231,11 @@ TVM_REGISTER_GLOBAL("device_api.hexagon.free_nd").set_body([](TVMArgs args, TVMR
   *rv = static_cast<int32_t>(0);
 });
 
+TVM_REGISTER_GLOBAL("device_api.hexagon").set_body([](TVMArgs args, TVMRetValue* rv) {
+  DeviceAPI* ptr = HexagonDeviceAPIv2::Global();
+  *rv = static_cast<void*>(ptr);
+});
+
 TVM_REGISTER_GLOBAL("device_api.hexagon.v2").set_body([](TVMArgs args, TVMRetValue* rv) {
   DeviceAPI* ptr = HexagonDeviceAPIv2::Global();
   *rv = static_cast<void*>(ptr);