[Interpreter] Save bytecode offset in interpreter stack frames.

src/x64/builtins-x64.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 575 matching lines @@
   // Open a frame scope to indicate that there is a frame on the stack.  The
   // MANUAL indicates that the scope shouldn't actually generate code to set up
   // the frame (that is done below).
   FrameScope frame_scope(masm, StackFrame::MANUAL);
   __ pushq(rbp);  // Caller's frame pointer.
   __ movp(rbp, rsp);
   __ Push(rsi);  // Callee's context.
   __ Push(rdi);  // Callee's JS function.
   __ Push(rdx);  // Callee's new target.
 
+  // Push zero for bytecode array offset.
+  __ movp(rax, Immediate(0));
+  __ Push(rax);

[Michael Starzinger, 2015/12/09 18:16:22]

nit: Here "Push(Immediate(0))" should do the trick.

[rmcilroy, 2015/12/10 14:17:12]

Done.

+
   // Get the bytecode array from the function object and load the pointer to the
   // first entry into edi (InterpreterBytecodeRegister).
   __ movp(rax, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
   __ movp(kInterpreterBytecodeArrayRegister,
           FieldOperand(rax, SharedFunctionInfo::kFunctionDataOffset));
 
   if (FLAG_debug_code) {
     // Check function data field is actually a BytecodeArray object.
     __ AssertNotSmi(kInterpreterBytecodeArrayRegister);
     __ CmpObjectType(kInterpreterBytecodeArrayRegister, BYTECODE_ARRAY_TYPE,
@@ skipping 10 matching lines @@
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ movp(rdx, rsp);
     __ subp(rdx, rcx);
     __ CompareRoot(rdx, Heap::kRealStackLimitRootIndex);
     __ j(above_equal, &ok, Label::kNear);
     __ CallRuntime(Runtime::kThrowStackOverflow, 0);
     __ bind(&ok);
 
     // If ok, push undefined as the initial value for all register file entries.
+    // (plus one for the accumulator save slot).
     Label loop_header;
     Label loop_check;
     __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
-    __ j(always, &loop_check);
     __ bind(&loop_header);
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
     __ Push(rdx);
     // Continue loop if not done.
     __ bind(&loop_check);
     __ subp(rcx, Immediate(kPointerSize));
     __ j(greater_equal, &loop_header, Label::kNear);
   }
 
   // TODO(rmcilroy): List of things not currently dealt with here but done in
@@ skipping 11 matching lines @@
     __ Push(kInterpreterBytecodeArrayRegister);
     __ CallRuntime(Runtime::kStackGuard, 0);
     __ Pop(kInterpreterBytecodeArrayRegister);
     __ bind(&ok);
   }
 
   // Load accumulator, register file, bytecode offset, dispatch table into
   // registers.
   __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
   __ movp(kInterpreterRegisterFileRegister, rbp);
-  __ subp(kInterpreterRegisterFileRegister,
-          Immediate(2 * kPointerSize +
-                    StandardFrameConstants::kFixedFrameSizeFromFp));
+  __ addp(kInterpreterRegisterFileRegister,
+          Immediate(InterpreterFrameConstants::kRegisterFilePointerFromFp));
   __ movp(kInterpreterBytecodeOffsetRegister,
           Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
   __ LoadRoot(kInterpreterDispatchTableRegister,
               Heap::kInterpreterTableRootIndex);
   __ addp(kInterpreterDispatchTableRegister,
           Immediate(FixedArray::kHeaderSize - kHeapObjectTag));
 
   // Dispatch to the first bytecode handler for the function.
   __ movzxbp(rbx, Operand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
@@ skipping 1377 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64