[BUILD/CODEGEN] Allow combine multiple functions in build stage. (#169)

* [BUILD/CODEGEN] Allow combine multiple functions in build stage.

* Enhance code module

* fix compile

include/tvm/lowered_func.h

@@ -37,6 +37,16 @@ class LoweredFunc : public FunctionRef {
   using ContainerType = LoweredFuncNode;
 };
 
+/*! \brief specific type of lowered function */
+enum LoweredFuncType : int {
+  /*! \brief Function that can mix device and host calls */
+  kMixedFunc = 0,
+  /*! \brief Only contains host code */
+  kHostFunc = 1,
+  /*! \brief Only contains device code */
+  kDeviceFunc = 2
+};
+
 /*! \brief Node container of LoweredFunc */
 class LoweredFuncNode : public FunctionBaseNode {
  public:
@@ -72,6 +82,8 @@ class LoweredFuncNode : public FunctionBaseNode {
    *  constant Expr of given type is used.
    */
   Map<Var, Expr> handle_data_type;
+  /*! \brief The type of the function */
+  LoweredFuncType func_type{kMixedFunc};
   /*! \brief Whether this function is packed function */
   bool is_packed_func{true};
   /*! \brief The body statment of the function */
@@ -90,6 +102,7 @@ class LoweredFuncNode : public FunctionBaseNode {
     v->Visit("args", &args);
     v->Visit("thread_axis", &thread_axis);
     v->Visit("handle_data_type", &handle_data_type);
+    v->Visit("func_type", &func_type);
     v->Visit("is_packed_func", &is_packed_func);
     v->Visit("body", &body);
   }

include/tvm/runtime/c_runtime_api.h

@@ -29,13 +29,15 @@
 #define TVM_DLL
 #endif
 
-#include <stdint.h>
-#include <stddef.h>
 // TVM Runtime is DLPack compatible.
 #include <dlpack/dlpack.h>
 
-
+#ifdef __cplusplus
 TVM_EXTERN_C {
+#endif
+#include <stdint.h>
+#include <stddef.h>
+
 /*! \brief type of array index. */
 typedef int64_t tvm_index_t;
 
@@ -405,6 +407,7 @@ TVM_DLL int TVMArrayCopyFromTo(TVMArrayHandle from,
  * \return 0 when success, -1 when failure happens
  */
 TVM_DLL int TVMSynchronize(TVMContext ctx, TVMStreamHandle stream);
+#ifdef __cplusplus
 }  // TVM_EXTERN_C
-
+#endif
 #endif  // TVM_RUNTIME_C_RUNTIME_API_H_

python/tvm/_ffi/function.py

@@ -4,7 +4,7 @@ from __future__ import absolute_import
 
 import sys
 import ctypes
-from .base import _LIB, check_call, py_str, c_str, _FFI_MODE
+from .base import _LIB, check_call, py_str, c_str, string_types, _FFI_MODE
 
 IMPORT_EXCEPT = RuntimeError if _FFI_MODE == "cython" else ImportError
 

python/tvm/build.py

@@ -220,30 +220,57 @@ def build(sch,
     if isinstance(sch, schedule.Schedule):
         if args is None:
             raise ValueError("args must be given for build from schedule")
-        fapi = lower(sch, args,
+        flist = lower(sch, args,
                       name=name,
                       binds=binds)
+        if isinstance(flist, collections.LoweredFunc):
+            flist = [flist]
     elif isinstance(sch, collections.LoweredFunc):
         if args:
             raise ValueError("args must be done when build from LoweredFunc")
-        fapi = sch
+        flist = [sch]
+    elif isinstance(sch, (list, tuple, collections.Array)):
+        flist = sch
     else:
-        raise ValueError("sch have to be Schedule or LoweredFunc")
-    # device related lowering
+        raise ValueError("sch have to be Schedule, LoweredFunc or list of LoweredFunc")
+    fname_set = set()
+    for x in flist:
+        if not isinstance(x, collections.LoweredFunc):
+            raise ValueError("sch have to be Schedule, LoweredFunc or list of LoweredFunc")
+        if x.name in fname_set:
+            raise ValueError("Duplicate function name %s" % x.name)
+
+    fhost = []
+    fdevice = []
+    for func in flist:
+        if func.func_type == collections.LoweredFunc.MixedFunc:
             if BuildConfig.current.detect_global_barrier:
-        fapi = ir_pass.StorageSync(fapi, "global")
-    fapi = ir_pass.StorageSync(fapi, "shared")
+                func = ir_pass.StorageSync(func, "global")
+            func = ir_pass.StorageSync(func, "shared")
             warp_size = 32 if target == "cuda" else 1
-    fapi = ir_pass.LowerThreadAllreduce(fapi, warp_size)
-    fsplits = [s for s in ir_pass.SplitHostDevice(fapi)]
-    fsplits[0] = ir_pass.LowerPackedCall(fsplits[0])
-    if len(fsplits) > 1:
+            func = ir_pass.LowerThreadAllreduce(func, warp_size)
+            fsplits = [s for s in ir_pass.SplitHostDevice(func)]
+            fhost.append(fsplits[0])
+            for x in fsplits[1:]:
+                fdevice.append(x)
+        elif func.func_type == collections.LoweredFunc.HostFunc:
+            fhost.append(func)
+        elif func.func_type == collections.LoweredFunc.DeviceFunc:
+            fdevice.append(func)
+        else:
+            raise ValueError("unknown function type %d" % func.func_type)
+    fhost = [ir_pass.LowerPackedCall(x) for x in fhost]
+
+    if not target.startswith("llvm") and target != "stackvm" and not fdevice:
+        raise ValueError(
+            "Specified target %s, but cannot find device code, did you do bind?" % target)
+    if fdevice:
         if not target_host:
             target_host = "llvm" if module.enabled("llvm") else "stackvm"
-        mhost = codegen.build_module(fsplits[0], target_host)
+        mhost = codegen.build_module(fhost, target_host)
         if target:
-            mdev = codegen.build_module(fsplits[1:], target)
+            mdev = codegen.build_module(fdevice, target)
             mhost.import_module(mdev)
         return mhost
     else:
-        return codegen.build_module(fsplits[0], target)
+        return codegen.build_module(fhost, target)

python/tvm/collections.py

@@ -68,4 +68,6 @@ class Range(NodeBase):
 @register_node
 class LoweredFunc(NodeBase):
     """Represent a LoweredFunc in TVM."""
-    pass
+    MixedFunc = 0
+    HostFunc = 1
+    DeviceFunc = 2

src/codegen/llvm/codegen_llvm.cc

@@ -96,7 +96,7 @@ void CodeGenLLVM::InitTarget(llvm::TargetMachine* tm) {
 void CodeGenLLVM::InitGlobalContext() {
   gv_mod_ctx_ = new llvm::GlobalVariable(
       *module_, t_void_p_, false,
-      llvm::GlobalValue::LinkOnceODRLinkage, 0, "__tvm_module_ctx");
+      llvm::GlobalValue::LinkOnceAnyLinkage, 0, "__tvm_module_ctx");
   gv_mod_ctx_->setAlignment(data_layout_->getTypeAllocSize(t_void_p_));
   gv_mod_ctx_->setInitializer(llvm::Constant::getNullValue(t_void_p_));
 }
@@ -142,21 +142,12 @@ void CodeGenLLVM::AddFunction(const LoweredFunc& f) {
 void CodeGenLLVM::AddMainFunction(const std::string& entry_func_name) {
   llvm::Function* f = module_->getFunction(entry_func_name);
   CHECK(f) << "Function " << entry_func_name << "does not in module";
-  CHECK(!module_->getFunction(runtime::symbol::tvm_module_main));
-  llvm::FunctionType* ftype = f->getFunctionType();
-  function_ = llvm::cast<llvm::Function>(
-      module_->getOrInsertFunction(runtime::symbol::tvm_module_main, ftype));
-  function_->setCallingConv(llvm::CallingConv::C);
-  std::vector<llvm::Value*> args;
-  for (auto it = function_->arg_begin();
-       it != function_->arg_end(); ++it) {
-    args.push_back(&(*it));
-  }
-  llvm::BasicBlock* block = llvm::BasicBlock::Create(*ctx_, "entry", function_);
-  builder_->SetInsertPoint(block);
-  llvm::CallInst* call = builder_->CreateCall(f, args);
-  call->setTailCall(true);
-  builder_->CreateRet(call);
+  llvm::Type* type = llvm::ArrayType::get(t_char_, entry_func_name.length() + 1);
+  llvm::GlobalVariable *global = new llvm::GlobalVariable(
+      *module_, type, true, llvm::GlobalValue::WeakAnyLinkage, 0,
+      runtime::symbol::tvm_module_main);
+  global->setAlignment(1);
+  global->setInitializer(llvm::ConstantDataArray::getString(*ctx_, entry_func_name));
 }
 
 class FPassManager : public llvm::legacy::FunctionPassManager {
@@ -424,7 +415,7 @@ llvm::Value* CodeGenLLVM::GetPackedFuncHandle(const std::string& fname) {
     // create the function handle
     hptr = new llvm::GlobalVariable(
         *module_, t_tvm_func_handle_, false,
-        llvm::GlobalValue::PrivateLinkage, 0, ".tvm_func");
+        llvm::GlobalValue::LinkOnceAnyLinkage, 0, ".tvm_func." + fname);
     hptr->setAlignment(align);
     hptr->setInitializer(llvm::Constant::getNullValue(t_tvm_func_handle_));
     func_handle_map_[fname] = hptr;

src/codegen/llvm/llvm_module.cc

@@ -36,8 +36,10 @@ class LLVMModuleNode final : public runtime::ModuleNode {
   void PreCompile(const std::string& name, TVMContext ctx) final {
     if (ee_ == nullptr) LazyInitJIT();
     std::lock_guard<std::mutex> lock(mutex_);
+    const std::string& fname = (name == runtime::symbol::tvm_module_main ?
+                                entry_func_ : name);
     BackendPackedCFunc faddr =
-        reinterpret_cast<BackendPackedCFunc>(ee_->getFunctionAddress(name));
+        reinterpret_cast<BackendPackedCFunc>(ee_->getFunctionAddress(fname));
     CHECK(faddr != nullptr)
         << "Failed to Precompile function " << name;
   }
@@ -47,8 +49,10 @@ class LLVMModuleNode final : public runtime::ModuleNode {
       const std::shared_ptr<ModuleNode>& sptr_to_self) final {
     if (ee_ == nullptr) LazyInitJIT();
     std::lock_guard<std::mutex> lock(mutex_);
+    const std::string& fname = (name == runtime::symbol::tvm_module_main ?
+                                entry_func_ : name);
     BackendPackedCFunc faddr =
-        reinterpret_cast<BackendPackedCFunc>(ee_->getFunctionAddress(name));
+        reinterpret_cast<BackendPackedCFunc>(ee_->getFunctionAddress(fname));
     if (faddr == nullptr) return PackedFunc();
     return PackedFunc([faddr, sptr_to_self](TVMArgs args, TVMRetValue* rv) {
         int ret = (*faddr)(
@@ -103,6 +107,7 @@ class LLVMModuleNode final : public runtime::ModuleNode {
     CHECK_NE(funcs.size(), 0U);
     ctx_ = std::make_shared<llvm::LLVMContext>();
     CodeGenLLVM cg;
+    entry_func_ = funcs[0]->name;
     cg.Init(funcs[0]->name, tm_, ctx_.get());
     for (LoweredFunc f :  funcs) {
       cg.AddFunction(f);
@@ -147,6 +152,8 @@ class LLVMModuleNode final : public runtime::ModuleNode {
   }
   // The target configuration string
   std::string target_;
+  // Name of entry function.
+  std::string entry_func_;
   // JIT lock
   std::mutex mutex_;
   // execution engine

src/codegen/source_module.cc

@@ -54,5 +54,10 @@ runtime::Module SourceModuleCreate(std::string code, std::string fmt) {
       std::make_shared<SourceModuleNode>(code, fmt);
   return runtime::Module(n);
 }
+
+TVM_REGISTER_GLOBAL("module.source_module_create")
+.set_body([](TVMArgs args, TVMRetValue* rv) {
+    *rv = SourceModuleCreate(args[0], args[1]);
+  });
 }  // namespace codegen
 }  // namespace tvm

src/pass/lower_thread_allreduce.cc

@@ -280,6 +280,7 @@ class ThreadAllreduceBuilder : public IRMutator {
 
 LoweredFunc
 LowerThreadAllreduce(LoweredFunc f, int warp_size) {
+  CHECK_NE(f->func_type, kHostFunc);
   auto n = std::make_shared<LoweredFuncNode>(*f.operator->());
   n->body = ThreadAllreduceBuilder(warp_size).Mutate(n->body);
   return LoweredFunc(n);

src/pass/split_host_device.cc

@@ -155,6 +155,7 @@ class HostDeviceSplitter : public IRMutator {
   }
 
   Array<LoweredFunc> Split(LoweredFunc f) {
+    CHECK_EQ(f->func_type, kMixedFunc);
     for (auto kv : f->handle_data_type) {
       handle_data_type_[kv.first.get()] = kv.second;
     }
@@ -162,6 +163,7 @@ class HostDeviceSplitter : public IRMutator {
     std::shared_ptr<LoweredFuncNode> n =
         std::make_shared<LoweredFuncNode>(*f.operator->());
     n->body = this->Mutate(f->body);
+    n->func_type = kHostFunc;
     Array<LoweredFunc> ret{LoweredFunc(n)};
     for (LoweredFunc x : device_funcs_) {
       ret.push_back(x);
@@ -179,6 +181,7 @@ class HostDeviceSplitter : public IRMutator {
     m.visit_thread_extent_ = false;
     n->body = m.Mutate(body);
     n->name = os.str();
+    n->func_type = kDeviceFunc;
     n->thread_axis = m.thread_axis_;
     // Strictly order the arguments: Var pointers, positional arguments.
     for (Var v : m.undefined_) {

src/pass/storage_sync.cc

@@ -397,6 +397,7 @@ Stmt StorageSync(Stmt stmt, std::string storage_scope) {
 }
 
 LoweredFunc StorageSync(LoweredFunc f, std::string storage_scope) {
+  CHECK_NE(f->func_type, kHostFunc);
   auto n = std::make_shared<LoweredFuncNode>(*f.operator->());
   n->body = StorageSync(f->body, storage_scope);
   return LoweredFunc(n);

src/runtime/cuda/cuda_module.cc

@@ -62,12 +62,18 @@ class CUDAModuleNode : public runtime::ModuleNode {
   void SaveToFile(const std::string& file_name,
                   const std::string& format) final {
     std::string fmt = GetFileFormat(file_name, format);
+    std::string meta_file = GetMetaFilePath(file_name);
+    if (fmt == "cu") {
+      CHECK_NE(cuda_source_.length(), 0);
+      SaveMetaDataToFile(meta_file, fmap_);
+      SaveBinaryToFile(file_name, cuda_source_);
+    } else {
       CHECK_EQ(fmt, fmt_)
           << "Can only save to format=" << fmt_;
-    std::string meta_file = GetMetaFilePath(file_name);
       SaveMetaDataToFile(meta_file, fmap_);
       SaveBinaryToFile(file_name, data_);
     }
+  }
 
   void SaveToBinary(dmlc::Stream* stream) final {
     stream->Write(fmt_);

src/runtime/dso_module.cc

@@ -101,6 +101,17 @@ class DSOModuleNode final : public ModuleNode {
   }
 
  private:
+  BackendPackedCFunc GetFuncPtr(const std::string& name) {
+    if (name == runtime::symbol::tvm_module_main) {
+      const char* entry_name = reinterpret_cast<const char*>(
+          GetGlobalVPtr(runtime::symbol::tvm_module_main));
+      CHECK(entry_name!= nullptr)
+          << "Symbol " << runtime::symbol::tvm_module_main << " is not presented";
+      return GetFuncPtr_(entry_name);
+    } else {
+      return GetFuncPtr_(name);
+    }
+  }
   // Platform dependent handling.
 #if defined(_WIN32)
   // library handle
@@ -111,7 +122,7 @@ class DSOModuleNode final : public ModuleNode {
     std::wstring wname(name.begin(), name.end());
     lib_handle_ = LoadLibraryW(wname.c_str());
   }
-  BackendPackedCFunc GetFuncPtr(const std::string& name) {
+  BackendPackedCFunc GetFuncPtr_(const std::string& name) {
     return reinterpret_cast<BackendPackedCFunc>(
         GetProcAddress(lib_handle_, (LPCSTR)name.c_str()));  // NOLINT(*)
   }
@@ -129,7 +140,7 @@ class DSOModuleNode final : public ModuleNode {
   void Load(const std::string& name) {
     lib_handle_ = dlopen(name.c_str(), RTLD_LAZY | RTLD_LOCAL);
   }
-  BackendPackedCFunc GetFuncPtr(const std::string& name) {
+  BackendPackedCFunc GetFuncPtr_(const std::string& name) {
     return reinterpret_cast<BackendPackedCFunc>(
         dlsym(lib_handle_, name.c_str()));
   }

tests/python/unittest/test_codegen_llvm.py

@@ -103,7 +103,42 @@ def test_llvm_temp_space():
             c.asnumpy(), a.asnumpy() + 1 + 1)
     check_llvm()
 
+def test_multiple_func():
+    nn = 1024
+    n = tvm.convert(nn)
+    A = tvm.placeholder((n,), name='A')
+    B = tvm.placeholder((n,), name='B')
+    C = tvm.compute(A.shape, lambda *i: A(*i) + B(*i), name='C')
+    s = tvm.create_schedule(C.op)
+    xo, xi = s[C].split(C.op.axis[0], factor=4)
+    s[C].parallel(xo)
+    s[C].vectorize(xi)
+    def check_llvm():
+        if not tvm.module.enabled("llvm"):
+            return
+        # build two functions
+        f2 = tvm.lower(s, [A, B, C], name="fadd1")
+        f1 = tvm.lower(s, [A, B, C], name="fadd2")
+        m = tvm.build([f1, f2], "llvm")
+        fadd1 = m['fadd1']
+        fadd2 = m['fadd2']
+        ctx = tvm.cpu(0)
+        # launch the kernel.
+        n = nn
+        a = tvm.nd.array(np.random.uniform(size=n).astype(A.dtype), ctx)
+        b = tvm.nd.array(np.random.uniform(size=n).astype(B.dtype), ctx)
+        c = tvm.nd.array(np.zeros(n, dtype=C.dtype), ctx)
+        fadd1(a, b, c)
+        np.testing.assert_allclose(
+            c.asnumpy(), a.asnumpy() + b.asnumpy())
+        fadd2(a, b, c)
+        np.testing.assert_allclose(
+            c.asnumpy(), a.asnumpy() + b.asnumpy())
+    check_llvm()
+
+
 if __name__ == "__main__":
+    test_multiple_func()
     test_llvm_add_pipeline()
     test_llvm_flip_pipeline()
     test_llvm_madd_pipeline()

tests/python/unittest/test_module_load.py

@@ -101,6 +101,44 @@ def test_device_module_dump():
     check_device("opencl")
     check_device("metal")
 
+
+def test_combine_module_llvm():
+    """Test combine multiple module into one shared lib."""
+    # graph
+    nn = 12
+    n = tvm.convert(nn)
+    A = tvm.placeholder((n,), name='A')
+    B = tvm.compute(A.shape, lambda *i: A(*i) + 1.0, name='B')
+    s = tvm.create_schedule(B.op)
+
+    def check_llvm():
+        ctx = tvm.cpu(0)
+        if not tvm.module.enabled("llvm"):
+            print("Skip because llvm is not enabled" )
+            return
+        temp = util.tempdir()
+        fadd1 = tvm.build(s, [A, B], "llvm", name="myadd1")
+        fadd2 = tvm.build(s, [A, B], "llvm", name="myadd2")
+        path1 = temp.relpath("myadd1.o")
+        path2 = temp.relpath("myadd2.o")
+        path_dso = temp.relpath("mylib.so")
+        fadd1.save(path1)
+        fadd2.save(path2)
+        # create shared library with multiple functions
+        cc.create_shared(path_dso, [path1, path2])
+        m = tvm.module.load(path_dso)
+        fadd1 = m['myadd1']
+        fadd2 = m['myadd2']
+        a = tvm.nd.array(np.random.uniform(size=nn).astype(A.dtype), ctx)
+        b = tvm.nd.array(np.zeros(nn, dtype=A.dtype), ctx)
+        fadd1(a, b)
+        np.testing.assert_equal(b.asnumpy(), a.asnumpy() + 1)
+        fadd2(a, b)
+        np.testing.assert_equal(b.asnumpy(), a.asnumpy() + 1)
+    check_llvm()
+
+
 if __name__ == "__main__":
+    test_combine_module_llvm()
     test_device_module_dump()
     test_dso_module_load()