X64 Implementation: Implement Generate_Function(Call,Apply)

src/x64/builtins-x64.cc

Index: src/x64/builtins-x64.cc
===================================================================
--- src/x64/builtins-x64.cc	(revision 2286)
+++ src/x64/builtins-x64.cc	(working copy)
@@ -168,14 +168,292 @@
 }
 
 
-void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
-  masm->int3();  // UNIMPLEMENTED.
-  masm->movq(kScratchRegister, Immediate(0xBEFA));  // Debugging aid.
+void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
+  // Stack Layout:
+  // rsp: return address
+  //  +1: Argument n
+  //  +2: Argument n-1
+  //  ...
+  //  +n: Argument 1 = receiver
+  //  +n+1: Argument 0 = function to call
+  //
+  // rax contains the number of arguments, n, not counting the function.
+  //
+  // 1. Make sure we have at least one argument.
+  { Label done;
+    __ testq(rax, rax);
+    __ j(not_zero, &done);
+    __ pop(rbx);
+    __ Push(Factory::undefined_value());
+    __ push(rbx);
+    __ incq(rax);
+    __ bind(&done);
+  }
+
+  // 2. Get the function to call from the stack.
+  { Label done, non_function, function;
+    // The function to call is at position n+1 on the stack.
+    __ movq(rdi, Operand(rsp, rax, times_pointer_size, +1 * kPointerSize));
+    __ testl(rdi, Immediate(kSmiTagMask));
+    __ j(zero, &non_function);
+    __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
+    __ j(equal, &function);
+
+    // Non-function called: Clear the function to force exception.
+    __ bind(&non_function);
+    __ xor_(rdi, rdi);
+    __ jmp(&done);
+
+    // Function called: Change context eagerly to get the right global object.
+    __ bind(&function);
+    __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
+
+    __ bind(&done);
+  }
+
+  // 3. Make sure first argument is an object; convert if necessary.
+  { Label call_to_object, use_global_receiver, patch_receiver, done;
+    __ movq(rbx, Operand(rsp, rax, times_pointer_size, 0));
+
+    __ testl(rbx, Immediate(kSmiTagMask));
+    __ j(zero, &call_to_object);
+
+    __ Cmp(rbx, Factory::null_value());
+    __ j(equal, &use_global_receiver);
+    __ Cmp(rbx, Factory::undefined_value());
+    __ j(equal, &use_global_receiver);
+
+    __ CmpObjectType(rbx, FIRST_JS_OBJECT_TYPE, rcx);
+    __ j(below, &call_to_object);
+    __ CmpInstanceType(rcx, LAST_JS_OBJECT_TYPE);
+    __ j(below_equal, &done);
+
+    __ bind(&call_to_object);
+    __ EnterInternalFrame();  // preserves rax, rbx, rdi
+
+    // Store the arguments count on the stack (smi tagged).
+    ASSERT(kSmiTag == 0);
+    __ shl(rax, Immediate(kSmiTagSize));
+    __ push(rax);
+
+    __ push(rdi);  // save edi across the call
+    __ push(rbx);
+    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+    __ movq(rbx, rax);
+    __ pop(rdi);  // restore edi after the call
+
+    // Get the arguments count and untag it.
+    __ pop(rax);
+    __ shr(rax, Immediate(kSmiTagSize));
+
+    __ LeaveInternalFrame();
+    __ jmp(&patch_receiver);
+
+    // Use the global receiver object from the called function as the receiver.
+    __ bind(&use_global_receiver);
+    const int kGlobalIndex =
+        Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
+    __ movq(rbx, FieldOperand(rsi, kGlobalIndex));
+    __ movq(rbx, FieldOperand(rbx, GlobalObject::kGlobalReceiverOffset));
+
+    __ bind(&patch_receiver);
+    __ movq(Operand(rsp, rax, times_pointer_size, 0), rbx);
+
+    __ bind(&done);
+  }
+
+  // 4. Shift stuff one slot down the stack.
+  { Label loop;
+    __ lea(rcx, Operand(rax, +1));  // +1 ~ copy receiver too
+    __ bind(&loop);
+    __ movq(rbx, Operand(rsp, rcx, times_pointer_size, 0));
+    __ movq(Operand(rsp, rcx, times_pointer_size, 1 * kPointerSize), rbx);
+    __ decq(rcx);
+    __ j(not_zero, &loop);
+  }
+
+  // 5. Remove TOS (copy of last arguments), but keep return address.
+  __ pop(rbx);
+  __ pop(rcx);
+  __ push(rbx);
+  __ decq(rax);
+
+  // 6. Check that function really was a function and get the code to
+  //    call from the function and check that the number of expected
+  //    arguments matches what we're providing.
+  { Label invoke, trampoline;
+    __ testq(rdi, rdi);
+    __ j(not_zero, &invoke);
+    __ xor_(rbx, rbx);
+    __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION);
+    __ bind(&trampoline);
+    __ Jump(Handle<Code>(builtin(ArgumentsAdaptorTrampoline)),
+            RelocInfo::CODE_TARGET);
+
+    __ bind(&invoke);
+    __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+    __ movsxlq(rbx,
+           FieldOperand(rdx, SharedFunctionInfo::kFormalParameterCountOffset));
+    __ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset));
+    __ lea(rdx, FieldOperand(rdx, Code::kHeaderSize));
+    __ cmpq(rax, rbx);
+    __ j(not_equal, &trampoline);
+  }
+
+  // 7. Jump (tail-call) to the code in register edx without checking arguments.
+  ParameterCount expected(0);
+  __ InvokeCode(rdx, expected, expected, JUMP_FUNCTION);
 }
 
-void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
-  masm->int3();  // UNIMPLEMENTED.
-  masm->movq(kScratchRegister, Immediate(0xBEFC));  // Debugging aid.
+
+void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
+  // Stack at entry:
+  //    rsp: return address
+  //  rsp+8: arguments
+  // rsp+16: receiver ("this")
+  // rsp+24: function
+  __ EnterInternalFrame();
+  // Stack frame:
+  //    rbp: Old base pointer
+  // rbp[1]: return address
+  // rbp[2]: function arguments
+  // rbp[3]: receiver
+  // rbp[4]: function
+  static const int kArgumentsOffset = 2 * kPointerSize;
+  static const int kReceiverOffset = 3 * kPointerSize;
+  static const int kFunctionOffset = 4 * kPointerSize;
+  __ push(Operand(rbp, kFunctionOffset));
+  __ push(Operand(rbp, kArgumentsOffset));
+  __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
+
+  if (FLAG_check_stack) {
+    // We need to catch preemptions right here, otherwise an unlucky preemption
+    // could show up as a failed apply.
+    Label retry_preemption;
+    Label no_preemption;
+    __ bind(&retry_preemption);
+    ExternalReference stack_guard_limit =
+        ExternalReference::address_of_stack_guard_limit();
+    __ movq(kScratchRegister, stack_guard_limit);
+    __ movq(rcx, rsp);
+    __ subq(rcx, Operand(kScratchRegister, 0));
+    // rcx contains the difference between the stack limit and the stack top.
+    // We use it below to check that there is enough room for the arguments.
+    __ j(above, &no_preemption);
+
+    // Preemption!
+    // Because runtime functions always remove the receiver from the stack, we
+    // have to fake one to avoid underflowing the stack.
+    __ push(rax);
+    __ push(Immediate(Smi::FromInt(0)));
+
+    // Do call to runtime routine.
+    __ CallRuntime(Runtime::kStackGuard, 1);
+    __ pop(rax);
+    __ jmp(&retry_preemption);
+
+    __ bind(&no_preemption);
+
+    Label okay;
+    // Make rdx the space we need for the array when it is unrolled onto the
+    // stack.
+    __ movq(rdx, rax);
+    __ shl(rdx, Immediate(kPointerSizeLog2 - kSmiTagSize));
+    __ cmpq(rcx, rdx);
+    __ j(greater, &okay);
+
+    // Too bad: Out of stack space.
+    __ push(Operand(rbp, kFunctionOffset));
+    __ push(rax);
+    __ InvokeBuiltin(Builtins::APPLY_OVERFLOW, CALL_FUNCTION);
+    __ bind(&okay);
+  }
+
+  // Push current index and limit.
+  const int kLimitOffset =
+      StandardFrameConstants::kExpressionsOffset - 1 * kPointerSize;
+  const int kIndexOffset = kLimitOffset - 1 * kPointerSize;
+  __ push(rax);  // limit
+  __ push(Immediate(0));  // index
+
+  // Change context eagerly to get the right global object if
+  // necessary.
+  __ movq(rdi, Operand(rbp, kFunctionOffset));
+  __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
+
+  // Compute the receiver.
+  Label call_to_object, use_global_receiver, push_receiver;
+  __ movq(rbx, Operand(rbp, kReceiverOffset));
+  __ testl(rbx, Immediate(kSmiTagMask));
+  __ j(zero, &call_to_object);
+  __ Cmp(rbx, Factory::null_value());
+  __ j(equal, &use_global_receiver);
+  __ Cmp(rbx, Factory::undefined_value());
+  __ j(equal, &use_global_receiver);
+
+  // If given receiver is already a JavaScript object then there's no
+  // reason for converting it.
+  __ CmpObjectType(rbx, FIRST_JS_OBJECT_TYPE, rcx);
+  __ j(less, &call_to_object);
+  __ CmpInstanceType(rcx, LAST_JS_OBJECT_TYPE);
+  __ j(less_equal, &push_receiver);
+
+  // Convert the receiver to an object.
+  __ bind(&call_to_object);
+  __ push(rbx);
+  __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+  __ movq(rbx, rax);
+  __ jmp(&push_receiver);
+
+  // Use the current global receiver object as the receiver.
+  __ bind(&use_global_receiver);
+  const int kGlobalOffset =
+      Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
+  __ movq(rbx, FieldOperand(rsi, kGlobalOffset));
+  __ movq(rbx, FieldOperand(rbx, GlobalObject::kGlobalReceiverOffset));
+
+  // Push the receiver.
+  __ bind(&push_receiver);
+  __ push(rbx);
+
+  // Copy all arguments from the array to the stack.
+  Label entry, loop;
+  __ movq(rax, Operand(rbp, kIndexOffset));
+  __ jmp(&entry);
+  __ bind(&loop);
+  __ movq(rcx, Operand(rbp, kArgumentsOffset));  // load arguments
+  __ push(rcx);
+  __ push(rax);
+
+  // Use inline caching to speed up access to arguments.
+  Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
+  __ Call(ic, RelocInfo::CODE_TARGET);
+  // It is important that we do not have a test instruction after the
+  // call.  A test instruction after the call is used to indicate that
+  // we have generated an inline version of the keyed load.  In this
+  // case, we know that we are not generating a test instruction next.
+
+  // Remove IC arguments from the stack and push the nth argument.
+  __ addq(rsp, Immediate(2 * kPointerSize));
+  __ push(rax);
+
+  // Update the index on the stack and in register rax.
+  __ movq(rax, Operand(rbp, kIndexOffset));
+  __ addq(rax, Immediate(Smi::FromInt(1)));
+  __ movq(Operand(rbp, kIndexOffset), rax);
+
+  __ bind(&entry);
+  __ cmpq(rax, Operand(rbp, kLimitOffset));
+  __ j(not_equal, &loop);
+
+  // Invoke the function.
+  ParameterCount actual(rax);
+  __ shr(rax, Immediate(kSmiTagSize));
+  __ movq(rdi, Operand(rbp, kFunctionOffset));
+  __ InvokeFunction(rdi, actual, CALL_FUNCTION);
+
+  __ LeaveInternalFrame();
+  __ ret(3 * kPointerSize);  // remove function, receiver, and arguments
 }