[stubs] A new approach to TF stubs

src/compiler/code-stub-assembler.h

Index: src/compiler/code-stub-assembler.h
diff --git a/src/compiler/code-stub-assembler.h b/src/compiler/code-stub-assembler.h
new file mode 100644
index 0000000000000000000000000000000000000000..c9190e262acdce123f3e1053b31a831540a95725
--- /dev/null
+++ b/src/compiler/code-stub-assembler.h
@@ -0,0 +1,107 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_COMPILER_CODE_STUB_ASSEMBLER_H_
+#define V8_COMPILER_CODE_STUB_ASSEMBLER_H_
+
+// Clients of this interface shouldn't depend on lots of compiler internals.
+// Do not include anything from src/compiler here!
+#include "src/allocation.h"
+#include "src/base/smart-pointers.h"
+#include "src/builtins.h"
+#include "src/frames.h"
+#include "src/interpreter/bytecodes.h"

[Michael Starzinger, 2015/12/01 18:06:53]

nit: The "bytecodes.h" header shouldn't be needed here. Can we drop it just to
verify that it's not accidentally used here?

[danno, 2015/12/02 07:00:19]

Done.

+#include "src/runtime/runtime.h"
+#include "src/zone-containers.h"
+
+namespace v8 {
+namespace internal {
+
+class CallInterfaceDescriptor;
+class Isolate;
+class Zone;
+
+namespace compiler {
+
+class CallDescriptor;
+class Graph;
+class Node;
+class Operator;
+class RawMachineAssembler;
+class Schedule;
+
+class CodeStubAssembler {

[adamk, 2015/12/01 19:27:30]

Would love to see documentation for this class somewhere (though I realize it's
at an early state). Is there a design sketch/doc for this approach  (maybe could
just be stolen from whatever we have for the InterpreterAssembler)?

[danno, 2015/12/02 07:00:19]

Agreed. The InterpreterAssembler doesn't have any documentation to borrow, so
we'd need something new. I am not sure that document belongs in the code right
now, so I will start a separate document that gives an overview of the approach
and gives us a place to fill in details as more becomes clear.

+ public:
+  CodeStubAssembler(Isolate* isolate, Zone* zone,
+                    const CallInterfaceDescriptor& descriptor, Code::Kind kind,
+                    const char* name);
+  virtual ~CodeStubAssembler();
+
+  Handle<Code> GenerateCode();
+
+  // Constants.
+  Node* Int32Constant(int value);
+  Node* IntPtrConstant(intptr_t value);
+  Node* NumberConstant(double value);
+  Node* HeapConstant(Handle<HeapObject> object);
+  Node* BooleanConstant(bool value);
+
+  Node* Parameter(int value);
+  void Return(Node* value);
+
+  // Tag and untag Smi values.
+  Node* SmiTag(Node* value);
+  Node* SmiUntag(Node* value);
+
+  // Basic arithmetic operations.
+  Node* IntPtrAdd(Node* a, Node* b);
+  Node* IntPtrSub(Node* a, Node* b);
+  Node* WordShl(Node* value, int shift);
+
+  // Load a field from an object on the heap.
+  Node* LoadObjectField(Node* object, int offset);
+
+  // Call runtime function.
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1);
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1,
+                    Node* arg2);
+
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context,
+                        Node* arg1);
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context,
+                        Node* arg1, Node* arg2);
+
+ private:
+  friend class CodeStubAssemblerTester;
+  // Close the graph.
+  void End();
+
+  Graph* graph();

[Michael Starzinger, 2015/12/01 18:06:53]

nit: Can we move this accessor down so that it lives together with the ones for
Zone and Isolate?

[danno, 2015/12/02 07:00:19]

Done.

+
+  Node* CallN(CallDescriptor* descriptor, Node* code_target, Node** args);
+  Node* TailCallN(CallDescriptor* descriptor, Node* code_target, Node** args);
+
+  Node* SmiShiftBitsConstant();
+
+  // Adds an end node of the graph.
+  void AddEndInput(Node* input);
+
+  // Private helpers which delegate to RawMachineAssembler.
+  Isolate* isolate();
+  Zone* zone();
+
+  base::SmartPointer<RawMachineAssembler> raw_assembler_;
+  ZoneVector<Node*> end_nodes_;
+  Code::Kind kind_;
+  const char* name_;
+  bool code_generated_;
+
+  DISALLOW_COPY_AND_ASSIGN(CodeStubAssembler);
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_CODE_STUB_ASSEMBLER_H_