builtins-arm.cc.svn-base

Google浏览器V8内核代码

  __ ldr(r0, MemOperand(fp, kFunctionOffset));  // get the function
  __ push(r0);
  __ ldr(r0, MemOperand(fp, kArgsOffset));  // get the args array
  __ push(r0);
  __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_JS);

  // Eagerly check for stack-overflow before starting to push the arguments.
  // r0: number of arguments
  Label okay;
  ExternalReference stack_guard_limit_address =
      ExternalReference::address_of_stack_guard_limit();
  __ mov(r2, Operand(stack_guard_limit_address));
  __ ldr(r2, MemOperand(r2));
  __ sub(r2, sp, r2);
  __ sub(r2, r2, Operand(3 * kPointerSize));  // limit, index, receiver

  __ cmp(r2, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
  __ b(hi, &okay);

  // Out of stack space.
  __ ldr(r1, MemOperand(fp, kFunctionOffset));
  __ push(r1);
  __ push(r0);
  __ InvokeBuiltin(Builtins::APPLY_OVERFLOW, CALL_JS);

  // Push current limit and index.
  __ bind(&okay);
  __ push(r0);  // limit
  __ mov(r1, Operand(0));  // initial index
  __ push(r1);

  // Change context eagerly to get the right global object if necessary.
  __ ldr(r0, MemOperand(fp, kFunctionOffset));
  __ ldr(cp, FieldMemOperand(r0, JSFunction::kContextOffset));

  // Compute the receiver.
  Label call_to_object, use_global_receiver, push_receiver;
  __ ldr(r0, MemOperand(fp, kRecvOffset));
  __ tst(r0, Operand(kSmiTagMask));
  __ b(eq, &call_to_object);
  __ mov(r1, Operand(Factory::null_value()));
  __ cmp(r0, r1);
  __ b(eq, &use_global_receiver);
  __ mov(r1, Operand(Factory::undefined_value()));
  __ cmp(r0, r1);
  __ b(eq, &use_global_receiver);

  // Check if the receiver is already a JavaScript object.
  // r0: receiver
  __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
  __ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
  __ cmp(r1, Operand(FIRST_JS_OBJECT_TYPE));
  __ b(lt, &call_to_object);
  __ cmp(r1, Operand(LAST_JS_OBJECT_TYPE));
  __ b(le, &push_receiver);

  // Convert the receiver to a regular object.
  // r0: receiver
  __ bind(&call_to_object);
  __ push(r0);
  __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_JS);
  __ b(&push_receiver);

  // Use the current global object as the receiver.
  __ bind(&use_global_receiver);
  __ ldr(r0, FieldMemOperand(cp, Context::kHeaderSize +
                             Context::GLOBAL_INDEX * kPointerSize));

  // Push the receiver.
  // r0: receiver
  __ bind(&push_receiver);
  __ push(r0);

  // Copy all arguments from the array to the stack.
  Label entry, loop;
  __ ldr(r0, MemOperand(fp, kIndexOffset));
  __ b(&entry);

  // Load the current argument from the arguments array and push it to the
  // stack.
  // r0: current argument index
  __ bind(&loop);
  __ ldr(r1, MemOperand(fp, kArgsOffset));
  __ push(r1);
  __ push(r0);

  // Call the runtime to access the property in the arguments array.
  __ CallRuntime(Runtime::kGetProperty, 2);
  __ push(r0);

  // Use inline caching to access the arguments.
  __ ldr(r0, MemOperand(fp, kIndexOffset));
  __ add(r0, r0, Operand(1 << kSmiTagSize));
  __ str(r0, MemOperand(fp, kIndexOffset));

  // Test if the copy loop has finished copying all the elements from the
  // arguments object.
  __ bind(&entry);
  __ ldr(r1, MemOperand(fp, kLimitOffset));
  __ cmp(r0, r1);
  __ b(ne, &loop);

  // Invoke the function.
  ParameterCount actual(r0);
  __ mov(r0, Operand(r0, ASR, kSmiTagSize));
  __ ldr(r1, MemOperand(fp, kFunctionOffset));
  __ InvokeFunction(r1, actual, CALL_FUNCTION);

  // Tear down the internal frame and remove function, receiver and args.
  __ LeaveInternalFrame();
  __ add(sp, sp, Operand(3 * kPointerSize));
  __ mov(pc, lr);
}


static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
  __ mov(r0, Operand(r0, LSL, kSmiTagSize));
  __ mov(r4, Operand(ArgumentsAdaptorFrame::SENTINEL));
  __ stm(db_w, sp, r0.bit() | r1.bit() | r4.bit() | fp.bit() | lr.bit());
  __ add(fp, sp, Operand(3 * kPointerSize));
}


static void ExitArgumentsAdaptorFrame(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r0 : result being passed through
  // -----------------------------------
  // Get the number of arguments passed (as a smi), tear down the frame and
  // then tear down the parameters.
  __ ldr(r1, MemOperand(fp, -3 * kPointerSize));
  __ mov(sp, fp);
  __ ldm(ia_w, sp, fp.bit() | lr.bit());
  __ add(sp, sp, Operand(r1, LSL, kPointerSizeLog2 - kSmiTagSize));
  __ add(sp, sp, Operand(kPointerSize));  // adjust for receiver
}


void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r0 : actual number of arguments
  //  -- r1 : function (passed through to callee)
  //  -- r2 : expected number of arguments
  //  -- r3 : code entry to call
  // -----------------------------------

  Label invoke, dont_adapt_arguments;

  Label enough, too_few;
  __ cmp(r0, Operand(r2));
  __ b(lt, &too_few);
  __ cmp(r2, Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
  __ b(eq, &dont_adapt_arguments);

  {  // Enough parameters: actual >= excpected
    __ bind(&enough);
    EnterArgumentsAdaptorFrame(masm);

    // Calculate copy start address into r0 and copy end address into r2.
    // r0: actual number of arguments as a smi
    // r1: function
    // r2: expected number of arguments
    // r3: code entry to call
    __ add(r0, fp, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
    // adjust for return address and receiver
    __ add(r0, r0, Operand(2 * kPointerSize));
    __ sub(r2, r0, Operand(r2, LSL, kPointerSizeLog2));

    // Copy the arguments (including the receiver) to the new stack frame.
    // r0: copy start address
    // r1: function
    // r2: copy end address
    // r3: code entry to call

    Label copy;
    __ bind(&copy);
    __ ldr(ip, MemOperand(r0, 0));
    __ push(ip);
    __ cmp(r0, r2);  // Compare before moving to next argument.
    __ sub(r0, r0, Operand(kPointerSize));
    __ b(ne, &copy);

    __ b(&invoke);
  }

  {  // Too few parameters: Actual < expected
    __ bind(&too_few);
    EnterArgumentsAdaptorFrame(masm);

    // Calculate copy start address into r0 and copy end address is fp.
    // r0: actual number of arguments as a smi
    // r1: function
    // r2: expected number of arguments
    // r3: code entry to call
    __ add(r0, fp, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));

    // Copy the arguments (including the receiver) to the new stack frame.
    // r0: copy start address
    // r1: function
    // r2: expected number of arguments
    // r3: code entry to call
    Label copy;
    __ bind(&copy);
    // Adjust load for return address and receiver.
    __ ldr(ip, MemOperand(r0, 2 * kPointerSize));
    __ push(ip);
    __ cmp(r0, fp);  // Compare before moving to next argument.
    __ sub(r0, r0, Operand(kPointerSize));
    __ b(ne, &copy);

    // Fill the remaining expected arguments with undefined.
    // r1: function
    // r2: expected number of arguments
    // r3: code entry to call
    __ mov(ip, Operand(Factory::undefined_value()));
    __ sub(r2, fp, Operand(r2, LSL, kPointerSizeLog2));
    __ sub(r2, r2, Operand(4 * kPointerSize));  // Adjust for frame.

    Label fill;
    __ bind(&fill);
    __ push(ip);
    __ cmp(sp, r2);
    __ b(ne, &fill);
  }

  // Call the entry point.
  Label return_site;
  __ bind(&invoke);

  __ Call(r3);
  __ bind(&return_site);

  ExitArgumentsAdaptorFrame(masm);
  __ mov(pc, lr);

  // Compute the offset from the beginning of the ArgumentsAdaptorTrampoline
  // builtin code object to the return address after the call.
  ASSERT(return_site.is_bound());
  arguments_adaptor_call_pc_offset_ = return_site.pos() + Code::kHeaderSize;


  // -------------------------------------------
  // Dont adapt arguments.
  // -------------------------------------------
  __ bind(&dont_adapt_arguments);
  __ mov(pc, r3);
}


static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
                                          RegList pointer_regs) {
  // Save the content of all general purpose registers in memory. This copy in
  // memory is later pushed onto the JS expression stack for the fake JS frame
  // generated and also to the C frame generated on top of that. In the JS
  // frame ONLY the registers containing pointers will be pushed on the
  // expression stack. This causes the GC to update these  pointers so that
  // they will have the correct value when returning from the debugger.
  __ SaveRegistersToMemory(kJSCallerSaved);

  // This is a direct call from a debug breakpoint. To build a fake JS frame
  // with no parameters push a function and a receiver, keep the current
  // return address in lr, and set r0 to zero.
  __ mov(ip, Operand(ExternalReference::the_hole_value_location()));
  __ ldr(r3, MemOperand(ip));
  __ mov(r0, Operand(0));  // Null receiver and zero arguments.
  __ stm(db_w, sp, r0.bit() | r3.bit());  // push function and receiver

  // r0: number of arguments.
  // What follows is an inlined version of EnterJSFrame(0, 0).
  // It needs to be kept in sync if any calling conventions are changed.

  // Compute parameter pointer before making changes
  // ip = sp + kPointerSize*(args_len+1);  // +1 for receiver, args_len == 0
  __ add(ip, sp, Operand(kPointerSize));

  __ mov(r3, Operand(0));  // args_len to be saved
  __ mov(r2, Operand(cp));  // context to be saved

  // push in reverse order: context (r2), args_len (r3), caller_pp, caller_fp,
  // sp_on_exit (ip == pp), return address
  __ stm(db_w, sp, r2.bit() | r3.bit() | pp.bit() | fp.bit() |
         ip.bit() | lr.bit());
  // Setup new frame pointer.
  __ add(fp, sp, Operand(-StandardFrameConstants::kContextOffset));
  __ mov(pp, Operand(ip));  // setup new parameter pointer
  // r0 is already set to 0 as spare slot to store caller code object during GC
  __ push(r0);  // code pointer

  // Inlined EnterJSFrame ends here.

  // Store the registers containing object pointers on the expression stack to
  // make sure that these are correctly updated during GC.
  // Use sp as base to push.
  __ CopyRegistersFromMemoryToStack(sp, pointer_regs);

#ifdef DEBUG
  __ RecordComment("// Calling from debug break to runtime - come in - over");
#endif
  // r0 is already 0, no arguments
  __ mov(r1, Operand(ExternalReference::debug_break()));

  CEntryDebugBreakStub ceb;
  __ CallStub(&ceb);

  // Restore the register values containing object pointers from the expression
  // stack in the reverse order as they where pushed.
  // Use sp as base to pop.
  __ CopyRegistersFromStackToMemory(sp, r3, pointer_regs);

  // What follows is an inlined version of ExitJSFrame(0).
  // It needs to be kept in sync if any calling conventions are changed.
  // NOTE: loading the return address to lr and discarding the (fake) function
  //       is an addition to this inlined copy.

  __ mov(sp, Operand(fp));  // respect ABI stack constraint
  __ ldm(ia, sp, pp.bit() | fp.bit() | sp.bit() | lr.bit());
  __ pop();  // discard fake function

  // Inlined ExitJSFrame ends here.

  // Finally restore all registers.
  __ RestoreRegistersFromMemory(kJSCallerSaved);

  // Now that the break point has been handled, resume normal execution by
  // jumping to the target address intended by the caller and that was
  // overwritten by the address of DebugBreakXXX.
  __ mov(ip, Operand(ExternalReference(Debug_Address::AfterBreakTarget())));
  __ ldr(ip, MemOperand(ip));
  __ Jump(ip);
}


void Builtins::Generate_LoadIC_DebugBreak(MacroAssembler* masm) {
  // Calling convention for IC load (from ic-arm.cc).
  // ----------- S t a t e -------------
  //  -- r0    : receiver
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------
  // Registers r0 and r2 contain objects that needs to be pushed on the
  // expression stack of the fake JS frame.
  Generate_DebugBreakCallHelper(masm, r0.bit() | r2.bit());
}


void Builtins::Generate_StoreIC_DebugBreak(MacroAssembler* masm) {
  // Calling convention for IC store (from ic-arm.cc).
  // ----------- S t a t e -------------
  //  -- r0    : receiver
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------
  // Registers r0 and r2 contain objects that needs to be pushed on the
  // expression stack of the fake JS frame.
  Generate_DebugBreakCallHelper(masm, r0.bit() | r2.bit());
}


void Builtins::Generate_KeyedLoadIC_DebugBreak(MacroAssembler* masm) {
  // Keyed load IC not implemented on ARM.
}


void Builtins::Generate_KeyedStoreIC_DebugBreak(MacroAssembler* masm) {
  // Keyed store IC not implemented on ARM.
}


void Builtins::Generate_CallIC_DebugBreak(MacroAssembler* masm) {
  // Calling convention for IC call (from ic-arm.cc)
  // ----------- S t a t e -------------
  //  -- r0: number of arguments
  //  -- r1: receiver
  //  -- lr: return address
  // -----------------------------------
  // Register r1 contains an object that needs to be pushed on the expression
  // stack of the fake JS frame. r0 is the actual number of arguments not
  // encoded as a smi, therefore it cannot be on the expression stack of the
  // fake JS frame as it can easily be an invalid pointer (e.g. 1). r0 will be
  // pushed on the stack of the C frame and restored from there.
  Generate_DebugBreakCallHelper(masm, r1.bit());
}


void Builtins::Generate_ConstructCall_DebugBreak(MacroAssembler* masm) {
  // In places other than IC call sites it is expected that r0 is TOS which
  // is an object - this is not generally the case so this should be used with
  // care.
  Generate_DebugBreakCallHelper(masm, r0.bit());
}


void Builtins::Generate_Return_DebugBreak(MacroAssembler* masm) {
  // In places other than IC call sites it is expected that r0 is TOS which
  // is an object - this is not generally the case so this should be used with
  // care.
  Generate_DebugBreakCallHelper(masm, r0.bit());
}


void Builtins::Generate_Return_DebugBreakEntry(MacroAssembler* masm) {
  // Generate nothing as this handling of debug break return is not done this
  // way on ARM  - yet.
}

void Builtins::Generate_StubNoRegisters_DebugBreak(MacroAssembler* masm) {
  // Generate nothing as CodeStub CallFunction is not used on ARM.
}


#undef __

} }  // namespace v8::internal