MIPS: stub fast api calls

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5674 matching lines @@
 
   Label fast_elements_case;
   __ Branch(&fast_elements_case, eq, a3, Operand(FAST_ELEMENTS));
   GenerateCase(masm, FAST_HOLEY_ELEMENTS);
 
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
+void CallApiFunctionStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- a0                  : callee
+  //  -- t0                  : call_data
+  //  -- a2                  : holder
+  //  -- a3                  : api_function_address
+  //  -- a1                  : thunk_arg
+  //  -- cp                  : context
+  //  --
+  //  -- esp[0]              : last argument
+  //  -- ...
+  //  -- esp[(argc - 1)* 4]  : first argument
+  //  -- esp[argc * 4]       : receiver

[Paul Lind, 2014/01/28 00:21:13]

nit: these should be sp, not esp.

[palfia, 2014/01/28 01:15:14]

Done.

+  // -----------------------------------
+
+  Register callee = a0;
+  Register call_data = t0;
+  Register holder = a2;
+  Register api_function_address = a3;
+  Register thunk_arg = a1;
+  Register context = cp;
+
+  int argc = ArgumentBits::decode(bit_field_);
+  bool restore_context = RestoreContextBits::decode(bit_field_);
+  bool call_data_undefined = CallDataUndefinedBits::decode(bit_field_);
+
+  typedef FunctionCallbackArguments FCA;
+
+  STATIC_ASSERT(FCA::kContextSaveIndex == 6);
+  STATIC_ASSERT(FCA::kCalleeIndex == 5);
+  STATIC_ASSERT(FCA::kDataIndex == 4);
+  STATIC_ASSERT(FCA::kReturnValueOffset == 3);
+  STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
+  STATIC_ASSERT(FCA::kIsolateIndex == 1);
+  STATIC_ASSERT(FCA::kHolderIndex == 0);
+  STATIC_ASSERT(FCA::kArgsLength == 7);
+
+  Isolate* isolate = masm->isolate();
+
+  // context save
+  __ push(context);
+  // load context from callee
+  __ lw(context, FieldMemOperand(callee, JSFunction::kContextOffset));
+
+  // callee
+  __ push(callee);
+
+  // call data
+  __ push(call_data);
+

[Paul Lind, 2014/01/28 00:21:13]

Suggest you combine push ops where possible. It saves instructions on mips (not
on arm). Please try to tidy up the nice commenting, so that it still makes
sense.

You can probably do Push(context, callee, call_data);
and update context reg afterwards.

[palfia, 2014/01/28 01:15:14]

Done.

+  Register scratch = call_data;
+  if (!call_data_undefined) {
+    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  }
+  // return value
+  __ push(scratch);
+  // return value default
+  __ push(scratch);

[Paul Lind, 2014/01/28 00:21:13]

__ Push(scratch, scratch);

[palfia, 2014/01/28 01:15:14]

Done.

+  // isolate
+  __ li(scratch,
+        Operand(ExternalReference::isolate_address(isolate)));
+  __ push(scratch);
+  // holder
+  __ push(holder);

[Paul Lind, 2014/01/28 00:21:13]

__ Push(scratch, holder);

[palfia, 2014/01/28 01:15:14]

Done.

+
+  // Prepare arguments.
+  __ mov(scratch, sp);
+
+  // Allocate the v8::Arguments structure in the arguments' space since
+  // it's not controlled by GC.
+  const int kApiStackSpace = 4;
+
+  FrameScope frame_scope(masm, StackFrame::MANUAL);
+  __ EnterExitFrame(false, kApiStackSpace);
+
+  ASSERT(!thunk_arg.is(a0) && !api_function_address.is(a0) && !scratch.is(a0));
+  // a0 = FunctionCallbackInfo&
+  // Arguments is after the return address.
+  __ Addu(a0, sp, Operand(1 * kPointerSize));
+  // FunctionCallbackInfo::implicit_args_
+  __ sw(scratch, MemOperand(a0, 0 * kPointerSize));
+  // FunctionCallbackInfo::values_
+  __ Addu(at, scratch, Operand((FCA::kArgsLength - 1 + argc) * kPointerSize));
+  __ sw(at, MemOperand(a0, 1 * kPointerSize));
+  // FunctionCallbackInfo::length_ = argc
+  __ li(at, Operand(argc));
+  __ sw(at, MemOperand(a0, 2 * kPointerSize));
+  // FunctionCallbackInfo::is_construct_call = 0
+  __ sw(zero_reg, MemOperand(a0, 3 * kPointerSize));
+
+  const int kStackUnwindSpace = argc + FCA::kArgsLength + 1;
+  Address thunk_address = FUNCTION_ADDR(&InvokeFunctionCallback);
+  ExternalReference::Type thunk_type = ExternalReference::PROFILING_API_CALL;
+  ApiFunction thunk_fun(thunk_address);
+  ExternalReference thunk_ref = ExternalReference(&thunk_fun, thunk_type,
+      masm->isolate());
+
+  AllowExternalCallThatCantCauseGC scope(masm);
+  MemOperand context_restore_operand(
+      fp, (2 + FCA::kContextSaveIndex) * kPointerSize);
+  MemOperand return_value_operand(fp,
+                                  (2 + FCA::kReturnValueOffset) * kPointerSize);
+
+  __ CallApiFunctionAndReturn(api_function_address,
+                              thunk_ref,
+                              thunk_arg,
+                              kStackUnwindSpace,
+                              return_value_operand,
+                              restore_context ?
+                                  &context_restore_operand : NULL);
+}
+
+
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS