[BACKEND] initial llvm codegen for amdgpu (#402)

* added initial llvm codegen for amdgpu

* fixed whitespace

* fixed hsaco gen from ir

* fixed targetmachine for rocm and added GetSource for rocm

* fixed whitespace issues

* changed statement to use less than 100 lines

* added intrinsics for workgroup - rocm

* whitespace - newline error fix

* fixed error msg for workitem-workgroup intrinsics

* added llvm ir dump for rocm codegen

* [ROCM] changed codegen to emit proper amdgpu kernel header

* fixed whitespace error

* fixed whitespace error- 2

* fixed AddFunction to not to use extra arg

1. Changed AddFunctionInternal to not to take extra arg for target type
2. Use Target from CodeGenLLVM to check for AMDGPU target

* fixed whitespaces

* fixed whitespaces 2

* fixed codegen for AMDGPU - now generating valid IR

* fixed codegen depending on code review

* reviewed alignment for amd devices

* added code to dump code object to file

* fixed cpplint errors

* print out IR after pass manager

* added code to dump asm, obj to file and std string

* fixed whitespaces

* Update codegen_amdgpu.cc

* used registry for amdgpu llvm

* Fixed whitespaces

* added code for calling linker

* fixed formatting errors

* added rocm link python interface

* fixed pylint issues and added more body to the function

* added doc string

* added doc string for module

* fixed python code after review, fixed llvm object codegen

* fixed linker to generate code object

* removed dumping to output file and debugging log out

* fixed lint for python code

* added fault check after running linker

* removed print statement in rocm.py

* changed rocm lld linker to raise runtimeerror than emitting error log to stderr

* changed the way linker command line is pass to subprocess.popen

* removed redundant code and reuse tvm utils

* removed commented out code

* removed cloning of unused modules, and put IR into string

dmlc-core

@@ -1 +1 @@
-Subproject commit 46886a6b47f660cda581e497378204ccc029a01e
+Subproject commit a527100d7d5001efc4954848a2fc6027e48c05f4

python/tvm/__init__.py

@@ -29,3 +29,4 @@ from .ndarray import register_extension
 from .schedule import create_schedule
 from .build_module import build, lower, build_config
 from .tag import tag_scope
+from .contrib import rocm as _rocm

python/tvm/_ffi/ndarray.py

@@ -59,6 +59,8 @@ def context(dev_type, dev_id=0):
         if dev_type not in TVMContext.STR2MASK:
             if dev_type.find("nvptx") != -1:
                 dev_type = "cuda"
+            if dev_type.find("rocm") != -1:
+                dev_type = "rocm"
         if dev_type not in TVMContext.STR2MASK:
             raise ValueError("Unknown device type %s" % dev_type)
         dev_type = TVMContext.STR2MASK[dev_type]

python/tvm/contrib/rocm.py

@@ -0,0 +1,50 @@
+"""Utility for ROCm backend"""
+import subprocess
+from . import util
+from ..api import register_func
+
+def rocm_link(in_file, out_file):
+    """Link relocatable ELF object to shared ELF object using lld
+
+    Parameters
+    ----------
+    in_file : str
+        Input file name (relocatable ELF object file)
+
+    out_file : str
+        Output file name (shared ELF object file)
+    """
+    args = ["ld.lld", "-shared", in_file, "-o", out_file]
+    proc = subprocess.Popen(
+        args,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT)
+    (out, _) = proc.communicate()
+
+    if proc.returncode != 0:
+        msg = "Linking error using ld.lld:\n"
+        msg += str(out)
+        raise RuntimeError(msg)
+
+@register_func("tvm_callback_rocm_link")
+def callback_rocm_link(obj_bin):
+    """Links object file generated from LLVM to HSA Code Object
+
+    Parameters
+    ----------
+    obj_bin : bytearray
+        The object file
+
+    Return
+    ------
+    cobj_bin : bytearray
+        The HSA Code Object
+    """
+    tmp_dir = util.tempdir()
+    tmp_obj = tmp_dir.relpath("rocm_kernel.o")
+    tmp_cobj = tmp_dir.relpath("rocm_kernel.co")
+    with open(tmp_obj, "wb") as out_file:
+        out_file.write(bytes(obj_bin))
+    rocm_link(tmp_obj, tmp_cobj)
+    cobj_bin = bytearray(open(tmp_cobj, "rb").read())
+    return cobj_bin

src/codegen/llvm/codegen_amdgpu.cc

@@ -0,0 +1,188 @@
+/*!
+ *  Copyright (c) 2017 by Contributors
+ * \file codegen_amdgpu.cc
+ * \brief AMDGPU code generator.
+ */
+#ifdef TVM_LLVM_VERSION
+#if TVM_ROCM_RUNTIME
+
+#include <tvm/runtime/device_api.h>
+#include <tvm/runtime/c_runtime_api.h>
+#include <tvm/runtime/registry.h>
+#include "./codegen_llvm.h"
+#include "../build_common.h"
+#include "../../pass/ir_util.h"
+#include "../../runtime/rocm/rocm_module.h"
+
+namespace tvm {
+namespace codegen {
+
+// AMDGPU code generator.
+class CodeGenAMDGPU : public CodeGenLLVM {
+ public:
+  void AddFunction(const LoweredFunc& f) final {
+    // add function as void return value
+    CodeGenLLVM::AddFunctionInternal(f, true);
+    function_->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);
+  }
+
+  void VisitStmt_(const Allocate* op) final {
+    CHECK(!is_zero(op->condition));
+    llvm::Value* buf = nullptr;
+    if (op->new_expr.defined()) {
+      CHECK_EQ(op->free_function, "nop");
+      buf = MakeValue(op->new_expr);
+    } else {
+      int32_t constant_size = op->constant_allocation_size();
+      CHECK_GT(constant_size, 0)
+          << "Can only handle constant size stack allocation in GPU";
+      StorageInfo& info = alloc_storage_info_[op->buffer_var.get()];
+      if (constant_size % 4 == 0 && info.alignment == 0) {
+        info.alignment = GetTempAllocaAlignment(op->type, constant_size);
+      }
+      // maximum necessary alignment in the AMD devices
+      if (info.alignment > 16) {
+        info.alignment = 16;
+      }
+      if (info.scope.rank == 2) {
+        // const int local_address_space = 5;
+        // TODO(tqchen): for higher version of LLVM, local address space can be set.
+        llvm::AllocaInst* alloca = builder_->CreateAlloca(
+            LLVMType(op->type), ConstInt32(constant_size));
+        if (alloca->getAlignment() < static_cast<uint32_t>(info.alignment)) {
+          alloca->setAlignment(info.alignment);
+        }
+        buf = alloca;
+      } else {
+        CHECK_EQ(info.scope.rank, 1)
+            << "Can only allocate shared or local memory inside kernel";
+        // Shared memory: address space  == 3
+        const unsigned shared_address_space = 3;
+        llvm::Type* type = llvm::ArrayType::get(LLVMType(op->type), constant_size);
+        // Allocate shared memory in global, address_space = 3
+        llvm::GlobalVariable *global = new llvm::GlobalVariable(
+            *module_, type, false, llvm::GlobalValue::PrivateLinkage, 0, ".shared",
+            nullptr, llvm::GlobalValue::NotThreadLocal, shared_address_space);
+        global->setAlignment(info.alignment);
+        buf = global;
+      }
+    }
+    buf = builder_->CreatePointerCast(
+        buf, LLVMType(op->type)->getPointerTo(
+            buf->getType()->getPointerAddressSpace()));
+    CHECK(!var_map_.count(op->buffer_var.get()));
+    var_map_[op->buffer_var.get()] = buf;
+    this->VisitStmt(op->body);
+  }
+
+  // Return the thread index via intrinsics.
+  llvm::Value* GetThreadIndex(const IterVar& iv) final {
+    runtime::ThreadScope ts = runtime::ThreadScope::make(iv->thread_tag);
+    llvm::Intrinsic::ID intrin_id = ::llvm::Intrinsic::amdgcn_workitem_id_x;
+    if (ts.rank == 1) {
+      switch (ts.dim_index) {
+        case 0: intrin_id = ::llvm::Intrinsic::amdgcn_workitem_id_x; break;
+        case 1: intrin_id = ::llvm::Intrinsic::amdgcn_workitem_id_y; break;
+        case 2: intrin_id = ::llvm::Intrinsic::amdgcn_workitem_id_z; break;
+        default: LOG(FATAL) << "unknown workitem idx";
+      }
+    } else {
+      CHECK_EQ(ts.rank, 0);
+      switch (ts.dim_index) {
+        case 0: intrin_id = ::llvm::Intrinsic::amdgcn_workgroup_id_x; break;
+        case 1: intrin_id = ::llvm::Intrinsic::amdgcn_workgroup_id_y; break;
+        case 2: intrin_id = ::llvm::Intrinsic::amdgcn_workgroup_id_z; break;
+        default: LOG(FATAL) << "unknown workgroup idx";
+      }
+    }
+    llvm::Function* f = llvm::Intrinsic::getDeclaration(module_.get(), intrin_id);
+    return builder_->CreateCall(f, {});
+  }
+
+  llvm::Value* CreateStorageSync(const Call* op) final {
+    const std::string& sync = op->args[0].as<StringImm>()->value;
+    if (sync == "warp") {
+      // TODO(tqchen) warp sync in CUDA9
+      return nullptr;
+    } else if (sync == "shared") {
+      llvm::Function* f = llvm::Intrinsic::getDeclaration(
+          module_.get(),
+          ::llvm::Intrinsic::amdgcn_s_barrier);
+      return builder_->CreateCall(f, {});
+    } else {
+      LOG(FATAL) << "Do not support sync " << sync;
+      return nullptr;
+    }
+  }
+
+  void InitPassManagerBuilder(llvm::PassManagerBuilder* builder) final {
+    // Additional optimization hook to tweak the builder.
+  }
+
+  unsigned GetGlobalAddressSpace() {
+    return 1;
+  }
+
+ protected:
+  void InitTarget(llvm::TargetMachine* tm) final {
+    // Maximum vector lane = float4
+    native_vector_bits_ = 4 * 32;
+    CodeGenLLVM::InitTarget(tm);
+  }
+};
+
+runtime::Module BuildAMDGPU(Array<LoweredFunc> funcs, std::string target) {
+  CHECK(target.length(
+) >= 4 &&
+        target.substr(0, 4) == "rocm");
+  llvm::TargetMachine* tm = \
+    GetLLVMTargetMachine("-mtriple=amdgcn-amd-amdhsa-hcc -mcpu=gfx900" + \
+    target.substr(4, target.length() - 4));
+
+  std::unique_ptr<CodeGenAMDGPU> cg(new CodeGenAMDGPU());
+  std::unique_ptr<llvm::LLVMContext> ctx(new llvm::LLVMContext());
+  cg->Init(funcs[0]->name, tm, ctx.get(), false, false);
+  for (LoweredFunc f :  funcs) {
+    cg->AddFunction(f);
+  }
+
+  std::unique_ptr<llvm::Module> module = cg->Finish();
+
+  llvm::SmallString<8> dataObj, data_ll, dataAsm;
+  llvm::raw_svector_ostream destObj(dataObj), dest_ll(data_ll), destAsm(dataAsm);
+  destObj.SetUnbuffered();
+  dest_ll.SetUnbuffered();
+  destAsm.SetUnbuffered();
+  module->print(dest_ll, nullptr);
+  std::unique_ptr<llvm::Module> mAsm = llvm::CloneModule(module.get());
+  std::unique_ptr<llvm::Module> mObj = llvm::CloneModule(module.get());
+  llvm::legacy::PassManager pass;
+
+  CHECK(tm->addPassesToEmitFile(
+            pass, destObj, llvm::TargetMachine::CGFT_ObjectFile) == 0)
+            << "Cannot emit target CGFT_ObjectFile";
+  pass.run(*mObj);
+  std::string obj(dataObj.begin(), dataObj.end());
+
+  const auto* f = tvm::runtime::Registry::Get("tvm_callback_rocm_link");
+  CHECK(f != nullptr) << "Require tvm_callback_rocm_link to exist, do import tvm.contrib.rocm";
+
+  TVMByteArray arr;
+  arr.data = &obj[0];
+  arr.size = obj.length();
+
+  std::string hsaco = (*f)(arr);
+  std::string ll(data_ll.begin(), data_ll.end());
+
+  return ROCMModuleCreate(hsaco, "hsaco", ExtractFuncInfo(funcs), ll);
+}
+
+TVM_REGISTER_API("codegen.build_rocm")
+.set_body([](TVMArgs args, TVMRetValue* rv) {
+    *rv = BuildAMDGPU(args[0], args[1]);
+  });
+
+}  // namespace codegen
+}  // namespace tvm
+#endif   // TVM_ROCM_RUNTIME
+#endif  // TVM_LLVM_VERSION

src/codegen/llvm/codegen_llvm.cc

@@ -100,7 +100,7 @@ void CodeGenLLVM::AddFunctionInternal(const LoweredFunc& f, bool ret_void) {
     Type t = arg.type();
     if (t.is_handle() && f->handle_data_type.count(arg)) {
       arg_type.push_back(
-          LLVMType(f->handle_data_type[arg].type())->getPointerTo());
+          LLVMType(f->handle_data_type[arg].type())->getPointerTo(GetGlobalAddressSpace()));
       if (!is_restricted_) {
         alias_var_set_.insert(arg.get());
       }
@@ -555,6 +555,10 @@ int CodeGenLLVM::NativeVectorBits(const runtime::StorageScope& storage_scope) co
   return native_vector_bits_;
 }
 
+unsigned CodeGenLLVM::GetGlobalAddressSpace() {
+  return 0;
+}
+
 void CodeGenLLVM::GetAlignment(
     Type t, const Variable* buf_var, const Expr& index,
     int* p_alignment, int* p_native_bits) {

src/codegen/llvm/codegen_llvm.h

@@ -23,6 +23,7 @@ namespace codegen {
 
 using namespace ir;
 
+
 /*!
  * \brief A base class to generate a LLVM.
  */
@@ -148,6 +149,9 @@ class CodeGenLLVM :
   virtual void Optimize();
   // Get the maximim storage align bits of buffer pointer given storage scope.
   virtual int NativeVectorBits(const runtime::StorageScope& storage_scope) const;
+  // Get correct address space depending on the backend
+  virtual unsigned GetGlobalAddressSpace();
+
   void AddFunctionInternal(const LoweredFunc& f, bool ret_void);
   // Create extern call
   llvm::CallInst* CreateCallExtern(llvm::Type* ret,

src/runtime/module.cc

@@ -125,6 +125,8 @@ bool RuntimeEnabled(const std::string& target) {
     f_name = "device_api.vpi";
   } else if (target.length() >= 5 && target.substr(0, 5) == "nvptx") {
     f_name = "codegen.build_nvptx";
+  } else if (target.length() >= 4 && target.substr(0, 4) == "rocm") {
+    f_name = "codegen.build_rocm";
   } else if (target.length() >= 4 && target.substr(0, 4) == "llvm") {
     const PackedFunc* pf = runtime::Registry::Get("codegen.llvm_target_enabled");
     if (pf == nullptr) return false;

src/runtime/rocm/rocm_module.cc

@@ -59,10 +59,17 @@ class ROCMModuleNode : public runtime::ModuleNode {
     stream->Write(data_);
   }
 
+  std::string GetSource(const std::string& format) final {
+    if (format == fmt_) { return data_; }
+    if (fmt_ == "hsaco") { return data_; }
+    return "";
+  }
+
   // get a CUfunction from primary context in device_id
   hipFunction_t GetFunc(int device_id, const std::string& func_name) {
     std::lock_guard<std::mutex> lock(mutex_);
     // must recheck under the lock scope
+
     if (module_[device_id] == nullptr) {
       ROCM_DRIVER_CALL(hipModuleLoadData(&(module_[device_id]), data_.c_str()));
     }
@@ -140,7 +147,9 @@ class ROCMWrappedFunc {
     if (fcache_[device_id] == nullptr) {
       fcache_[device_id] = m_->GetFunc(device_id, func_name_);
     }
+
     hipStream_t strm = static_cast<hipStream_t>(ROCMThreadEntry::ThreadLocal()->stream);
+
     ThreadWorkLoad wl = thread_axis_cfg_.Extract(args);
     void* config[] = {
       HIP_LAUNCH_PARAM_BUFFER_POINTER, &packed_args,
@@ -181,7 +190,6 @@ PackedFunc ROCMModuleNode::GetFunction(
   CHECK_EQ(sptr_to_self.get(), this);
   CHECK_NE(name, symbol::tvm_module_main)
       << "Device function do not have main";
-
   auto it = fmap_.find(name);
   if (it == fmap_.end()) return PackedFunc();
   const FunctionInfo& info = it->second;

tests/python/integration/test_gemm.py

@@ -85,6 +85,8 @@ def test_gemm():
         np.testing.assert_allclose(
             c.asnumpy(), np.dot(a_np, b_np.T), rtol=1e-5)
 
+    check_device("nvptx -mcpu=sm_20")
+    check_device("rocm")
     check_device("metal")
     check_device("opencl")
     check_device("cuda")

tests/python/unittest/test_codegen_device.py

@@ -82,6 +82,7 @@ def test_add_pipeline():
     check_target("cuda", host="llvm")
     check_module_save("cuda", host="stackvm")
     check_target("nvptx", host="llvm")
+    check_target("rocm", host="llvm")
 
 if __name__ == "__main__":
     test_add_pipeline()