[REFACTOR][TIR] Migrate low-level pass functions to Pass Manager,

- Migrate LowerTVMBultin
- Migrate inferFragment, LowerThreadAllreduce
- Migrate ThreadSync
- Refactor target::Build to directly take IRModule.
- Remove un-used legacy functions.

include/tvm/driver/driver_api.h

@@ -57,20 +57,6 @@ TVM_DLL Array<tir::LoweredFunc> lower(
     const std::string& name,
     const std::unordered_map<te::Tensor, tir::Buffer>& binds,
     const BuildConfig& config);
-/*!
-* \brief Split host/device function and running necessary pass before build
-* \param funcs The functions to be built.
-* \param target The target device to build for.
-* \param target_host The target for building host code. To use the default, pass Target()
-* \param config The build configuration.
-* \return The Array<Array<LoweredFunc>> with 2 elements. First is host function Array,
-          second is device function array
-*/
-TVM_DLL Array<Array<tir::LoweredFunc> > split_dev_host_funcs(
-    const Array<tir::LoweredFunc>& funcs,
-    const Target& target,
-    const Target& target_host,
-    const BuildConfig& config);
 
 /*!
 * \brief Build a device and host module for a specific target from an array of lowered functions.

include/tvm/target/codegen.h

@@ -25,6 +25,7 @@
 #define TVM_TARGET_CODEGEN_H_
 
 #include <tvm/runtime/packed_func.h>
+#include <tvm/ir/module.h>
 #include <tvm/tir/expr.h>
 #include <tvm/tir/lowered_func.h>
 #include <tvm/target/target.h>
@@ -40,16 +41,25 @@ using runtime::PackedFunc;
 using runtime::TVMArgs;
 using runtime::TVMRetValue;
 
+/*!
+ * \brief Temporary backward compatible function to convert a list
+ *  of LoweredFunc to a IRModule of PrimfFuncs
+ * \param funcs The input lowered function.
+ * \return The IRModule.
+ *
+ * \note This function is only used for code refactor and will be
+ *       removed once the refactor completes.
+ */
+IRModule ToIRModule(const Array<tir::LoweredFunc>& funcs);
+
 /*!
  * \brief Build a module from array of lowered function.
- * \param funcs The functions to be built.
+ * \param mod The Module to be built
  * \param target The target to be built.
- * \return The builded module.
- *
- * \note Calls global API function  "_codegen_build_" + target
+ * \return The result runtime::Module.
  */
-runtime::Module Build(const Array<tir::LoweredFunc>& funcs,
-                      const std::string& target);
+runtime::Module Build(IRModule mod, const Target& target);
+
 /*!
  * \brief Pack imported device library to a C file.
  *  Compile the C file and link with the host library

include/tvm/tir/ir_pass.h

@@ -477,12 +477,6 @@ LoweredFunc RemapThreadAxis(LoweredFunc f, Map<PrimExpr, IterVar> axis_map);
  */
 LoweredFunc LowerTVMBuiltin(LoweredFunc f);
 
-/*!
- * \brief Combine context function calls.
- * \param f The host function to be lowered.
- * \return Transformed function.
- */
-LoweredFunc CombineContextCall(LoweredFunc f);
 
 /*!
  * \brief Rewrite the pointer content type of arguments,
@@ -496,7 +490,6 @@ LoweredFunc CombineContextCall(LoweredFunc f);
  */
 LoweredFunc PointerValueTypeRewrite(LoweredFunc f);
 
-
 /*!
  * \brief Rewrite the pointer content type of arguments,
  *  as well as Alloc internal to the function to use
@@ -509,23 +502,6 @@ LoweredFunc PointerValueTypeRewrite(LoweredFunc f);
  */
 PrimFunc PointerValueTypeRewrite(PrimFunc f);
 
-/*!
- * \brief Lower attached storage access information on device.
- * Do this pass after all storage access analysis finish.
- *
- * \param func The device function to be lowered.
- * \return Transformed function.
- */
-LoweredFunc LowerDeviceStorageAccessInfo(LoweredFunc func);
-
-/*!
- * \brief Lower intrinsic function calls.
- * \param f The device function to be lowered.
- * \param target The target device.
- * \return Transformed function.
- */
-LoweredFunc LowerIntrin(LoweredFunc f, const std::string& target);
-
 /*!
  * \brief Lower custom datatypes.
  *
@@ -545,13 +521,6 @@ LoweredFunc LowerCustomDatatypes(LoweredFunc f, const std::string& target);
  */
 LoweredFunc InferFragment(LoweredFunc f);
 
-/*!
- * \brief skip assert stmt generation
- * \param f The function to be transformed.
- * \return Transformed function.
- */
-LoweredFunc SkipAssert(LoweredFunc f);
-
 /*!
  * \brief Verify if memory accesses are legal for a specific target device type.
  *

include/tvm/tir/transform.h

@@ -59,11 +59,40 @@ TVM_DLL Pass CreatePrimFuncPass(const runtime::TypedPackedFunc<
                                 const tvm::Array<tvm::PrimExpr>& required);
 
 /*!
- * \brief Combine context calls in the host function.
+ * \brief skip assert stmt.
  *
  * \return The pass.
  */
-TVM_DLL Pass CombineContextCall();
+TVM_DLL Pass SkipAssert();
+
+/*!
+ * \brief Insert sync between parallel read/write of shared buffers.
+ *
+ * \param storage_scope The storage scope considered.
+ * \return The pass.
+ */
+TVM_DLL Pass ThreadSync(std::string storage_scope);
+
+
+/*!
+ * \brief Lower cross thread alleduce.
+ *
+ * \return The pass.
+ */
+TVM_DLL Pass LowerThreadAllreduce();
+
+/*!
+ * \brief Infer the TensorCore fragment infomation using tensor intrinsics
+ *
+ * \return The pass.
+ */
+TVM_DLL Pass InferFragment();
+
+/*!
+ * \brief Lower builtin intrinsics.
+ * \return The pass.
+ */
+TVM_DLL Pass LowerTVMBuiltin();
 
 /*!
  * \brief Lower the target specific function intrinsics in each of the function.
@@ -72,6 +101,12 @@ TVM_DLL Pass CombineContextCall();
  */
 TVM_DLL Pass LowerIntrin();
 
+/*!
+ * \brief Lower warp memory access to low-level device related function calls.
+ * \return The pass.
+ */
+TVM_DLL Pass LowerWarpMemory();
+
 /*!
  * \brief Lower attached storage access information on device.
  *
@@ -82,10 +117,11 @@ TVM_DLL Pass LowerIntrin();
 TVM_DLL Pass LowerDeviceStorageAccessInfo();
 
 /*!
- * \brief Lower warp memory access to low-level device related function calls.
+ * \brief Combine context calls in the host function.
+ *
  * \return The pass.
  */
-TVM_DLL Pass LowerWarpMemory();
+TVM_DLL Pass CombineContextCall();
 
 
 /*!

python/tvm/driver/build_module.py

@@ -222,6 +222,15 @@ def _build_for_device(flist, target, target_host):
     mdev : tvm.module
         A module that contains device code.
     """
+    @tvm.tir.transform.prim_func_pass(opt_level=0)
+    class BindTarget:
+        def __init__(self, target):
+            self.target = target
+
+        # pylint: disable=unused-argument
+        def transform_function(self, func, mod, ctx):
+            return func.with_attr("target", self.target)
+
     target = _target.create(target)
     device_type = ndarray.context(target.target_name, 0).device_type
     fhost = []
@@ -250,30 +259,39 @@ def _build_for_device(flist, target, target_host):
         else:
             raise ValueError("unknown function type %d" % func.func_type)
 
-    for i, func in enumerate(fdevice):
-        warp_size = target.thread_warp_size
-        fdevice[i] = ir_pass.LowerWarpMemory(func, warp_size)
-
     if "gpu" in target.keys and not fdevice:
         warnings.warn(
             "Specified target %s, but cannot find device code, did you do "
             "bind?" % target)
 
     fhost = [ir_pass.BindDeviceType(x, device_type) for x in fhost]
-    fhost = [ir_pass.LowerTVMBuiltin(x) for x in fhost]
 
     if device_type == ndarray.cpu(0).device_type and target_host == target:
         assert not fdevice
 
     target_host = _target.create(target_host)
-    fdevice = [ir_pass.LowerDeviceStorageAccessInfo(x) for x in fdevice]
-    fhost = [ir_pass.LowerDeviceStorageAccessInfo(x) for x in fhost]
-    fdevice = [ir_pass.LowerIntrin(x, target.target_name) for x in fdevice]
-    fhost = [ir_pass.LowerIntrin(x, target_host.target_name) for x in fhost]
-    fhost = [ir_pass.CombineContextCall(x) for x in fhost]
-    mdev = codegen.build_module(fdevice, str(target)) if fdevice else None
 
-    return fhost, mdev
+    # device optimizations
+    mod_dev = tvm.testing.LoweredFuncsToIRModule(fdevice)
+    opt_device = tvm.ir.transform.Sequential(
+        [BindTarget(target),
+         tvm.tir.transform.LowerWarpMemory(),
+         tvm.tir.transform.LowerDeviceStorageAccessInfo(),
+         tvm.tir.transform.LowerIntrin()])
+    mod_dev = opt_device(mod_dev)
+
+    # host optimizations
+    mod_host = tvm.testing.LoweredFuncsToIRModule(fhost)
+    opt_host = tvm.ir.transform.Sequential(
+        [BindTarget(target_host),
+         tvm.tir.transform.LowerTVMBuiltin(),
+         tvm.tir.transform.LowerDeviceStorageAccessInfo(),
+         tvm.tir.transform.LowerIntrin(),
+         tvm.tir.transform.CombineContextCall()])
+    mod_host = opt_host(mod_host)
+
+    rt_mod_dev = codegen.build_module(mod_dev, target) if fdevice else None
+    return mod_host, rt_mod_dev
 
 
 def build(inputs,
@@ -402,19 +420,19 @@ def build(inputs,
     if not target_host:
         target_host = "llvm" if tvm.runtime.enabled("llvm") else "stackvm"
 
-    fhost_all = []
+    mod_host_all = tvm.IRModule({})
+
     device_modules = []
     for tar, flist in target_flist.items():
-        fhost, mdev = _build_for_device(flist, tar, target_host)
-        # Save the current lowered functions of the host and the device module.
-        fhost_all += fhost
+        mod_host, mdev = _build_for_device(flist, tar, target_host)
+        mod_host_all.update(mod_host)
         device_modules.append(mdev)
 
     # Generate a unified host module.
-    mhost = codegen.build_module(fhost_all, str(target_host))
+    rt_mod_host = codegen.build_module(mod_host_all, target_host)
 
     # Import all modules.
     for mdev in device_modules:
         if mdev:
-            mhost.import_module(mdev)
-    return mhost
+            rt_mod_host.import_module(mdev)
+    return rt_mod_host

python/tvm/target/codegen.py

@@ -17,15 +17,16 @@
 # under the License.
 """Code generation related functions."""
 from . import _ffi_api
+from . import target as _tgt
 
 
-def build_module(lowered_func, target):
-    """Build lowered_func into Module.
+def build_module(mod, target):
+    """Build IRModule into Module.
 
     Parameters
     ----------
-    lowered_func : LoweredFunc
-        The lowered function
+    mod : tvm.IRModule
+        The ir module.
 
     target : str
         The target module type.
@@ -35,7 +36,8 @@ def build_module(lowered_func, target):
     module : runtime.Module
         The corressponding module.
     """
-    return _ffi_api.Build(lowered_func, target)
+    target = _tgt.create(target) if isinstance(target, str) else target
+    return _ffi_api.Build(mod, target)
 
 
 def llvm_lookup_intrinsic_id(name):