[interpreter] First implementation of stack unwinding.

src/x64/builtins-x64.cc

Index: src/x64/builtins-x64.cc
diff --git a/src/x64/builtins-x64.cc b/src/x64/builtins-x64.cc
index 33a11e3902494ba69decf931524367fbd6534d04..238412b3c360840352ac349882890c9df4da24f7 100644
--- a/src/x64/builtins-x64.cc
+++ b/src/x64/builtins-x64.cc
@@ -898,6 +898,57 @@ void Builtins::Generate_InterpreterNotifyLazyDeoptimized(MacroAssembler* masm) {
 }
 
 
+void Builtins::Generate_InterpreterEnterExceptionHandler(MacroAssembler* masm) {

[Michael Starzinger, 2016/01/19 18:21:51]

Note that this is an unmodified copy of the code from notify-deoptimized helper
above. Please advise on whether you want me to factor this out now, or in a
later CL.

[oth, 2016/01/20 07:49:08]

For now I'd settle for a comment at the start of the function explaining it's an
unmodified copy and then focus on other platforms.

[rmcilroy, 2016/01/20 08:52:13]

If it's unmodified let's just factor this out in this CL if it's not too much
trouble.

[Michael Starzinger, 2016/01/20 11:45:27]

Done. Since it's unmodified, I went with a minimal refactoring in this CL.

+  // Initialize register file register and dispatch table register.
+  __ movp(kInterpreterRegisterFileRegister, rbp);
+  __ addp(kInterpreterRegisterFileRegister,
+          Immediate(InterpreterFrameConstants::kRegisterFilePointerFromFp));
+  __ LoadRoot(kInterpreterDispatchTableRegister,
+              Heap::kInterpreterTableRootIndex);
+  __ addp(kInterpreterDispatchTableRegister,
+          Immediate(FixedArray::kHeaderSize - kHeapObjectTag));
+
+  // Get the context from the frame.
+  // TODO(rmcilroy): Update interpreter frame to expect current context at the
+  // context slot instead of the function context.
+  __ movp(kContextRegister,
+          Operand(kInterpreterRegisterFileRegister,
+                  InterpreterFrameConstants::kContextFromRegisterPointer));
+
+  // Get the bytecode array pointer from the frame.
+  __ movp(rbx,
+          Operand(kInterpreterRegisterFileRegister,
+                  InterpreterFrameConstants::kFunctionFromRegisterPointer));
+  __ movp(rbx, FieldOperand(rbx, JSFunction::kSharedFunctionInfoOffset));
+  __ movp(kInterpreterBytecodeArrayRegister,
+          FieldOperand(rbx, SharedFunctionInfo::kFunctionDataOffset));
+
+  if (FLAG_debug_code) {
+    // Check function data field is actually a BytecodeArray object.
+    __ AssertNotSmi(kInterpreterBytecodeArrayRegister);
+    __ CmpObjectType(kInterpreterBytecodeArrayRegister, BYTECODE_ARRAY_TYPE,
+                     rbx);
+    __ Assert(equal, kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
+  }
+
+  // Get the target bytecode offset from the frame.
+  __ movp(
+      kInterpreterBytecodeOffsetRegister,
+      Operand(kInterpreterRegisterFileRegister,
+              InterpreterFrameConstants::kBytecodeOffsetFromRegisterPointer));
+  __ SmiToInteger32(kInterpreterBytecodeOffsetRegister,
+                    kInterpreterBytecodeOffsetRegister);
+
+  // Dispatch to the target bytecode.
+  __ movzxbp(rbx, Operand(kInterpreterBytecodeArrayRegister,
+                          kInterpreterBytecodeOffsetRegister, times_1, 0));
+  __ movp(rbx, Operand(kInterpreterDispatchTableRegister, rbx,
+                       times_pointer_size, 0));
+  __ addp(rbx, Immediate(Code::kHeaderSize - kHeapObjectTag));
+  __ jmp(rbx);
+}
+
+
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   CallRuntimePassFunction(masm, Runtime::kCompileLazy);
   GenerateTailCallToReturnedCode(masm);