[Interpreter] Implements calls through CallICStub in the interpreter.

src/x64/code-stubs-x64.cc

 // Copyright 2013 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/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/ic/handler-compiler.h"
@@ skipping 1734 matching lines @@
   __ bind(&non_function);
   __ movp(rdx, rdi);
   __ Jump(isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
 }
 
 
 void CallICStub::HandleArrayCase(MacroAssembler* masm, Label* miss) {
   // rdi - function
   // rdx - slot id
   // rbx - vector
+  // rax - number of arguments if argc_in_register() is true.
   // rcx - allocation site (loaded from vector[slot]).
   __ LoadNativeContextSlot(Context::ARRAY_FUNCTION_INDEX, r8);
   __ cmpp(rdi, r8);
   __ j(not_equal, miss);
 
-  __ movp(rax, Immediate(arg_count()));
-
   // Increment the call count for monomorphic function calls.
   __ SmiAddConstant(FieldOperand(rbx, rdx, times_pointer_size,
                                  FixedArray::kHeaderSize + kPointerSize),
                     Smi::FromInt(CallICNexus::kCallCountIncrement));
 
   __ movp(rbx, rcx);
   __ movp(rdx, rdi);
-  ArrayConstructorStub stub(masm->isolate(), arg_count());
-  __ TailCallStub(&stub);
+  if (argc_in_register()) {
+    ArrayConstructorStub stub(masm->isolate());
+    __ TailCallStub(&stub);
+  } else {
+    ArrayConstructorStub stub(masm->isolate(), arg_count());
+    __ TailCallStub(&stub);
+  }
 }
 
 
 void CallICStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   // -- rdi - function
   // -- rdx - slot id
   // -- rbx - vector
+  // -- rax - number of arguments if argc_in_register() is true.
   // -----------------------------------
   Isolate* isolate = masm->isolate();
   Label extra_checks_or_miss, call, call_function;
-  int argc = arg_count();
-  StackArgumentsAccessor args(rsp, argc);
-  ParameterCount actual(argc);
+  if (!argc_in_register()) {
+    int argc = arg_count();
+    __ Set(rax, argc);
+  }
 
   // The checks. First, does rdi match the recorded monomorphic target?
   __ SmiToInteger32(rdx, rdx);
   __ movp(rcx,
           FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize));
 
   // We don't know that we have a weak cell. We might have a private symbol
   // or an AllocationSite, but the memory is safe to examine.
   // AllocationSite::kTransitionInfoOffset - contains a Smi or pointer to
   // FixedArray.
@@ skipping 13 matching lines @@
   // The compare above could have been a SMI/SMI comparison. Guard against this
   // convincing us that we have a monomorphic JSFunction.
   __ JumpIfSmi(rdi, &extra_checks_or_miss);
 
   // Increment the call count for monomorphic function calls.
   __ SmiAddConstant(FieldOperand(rbx, rdx, times_pointer_size,
                                  FixedArray::kHeaderSize + kPointerSize),
                     Smi::FromInt(CallICNexus::kCallCountIncrement));
 
   __ bind(&call_function);
-  __ Set(rax, argc);
   __ Jump(masm->isolate()->builtins()->CallFunction(convert_mode(),
                                                     tail_call_mode()),
           RelocInfo::CODE_TARGET);
 
   __ bind(&extra_checks_or_miss);
   Label uninitialized, miss, not_allocation_site;
 
   __ Cmp(rcx, TypeFeedbackVector::MegamorphicSentinel(isolate));
   __ j(equal, &call);
 
@@ skipping 18 matching lines @@
 
   // We are going megamorphic. If the feedback is a JSFunction, it is fine
   // to handle it here. More complex cases are dealt with in the runtime.
   __ AssertNotSmi(rcx);
   __ CmpObjectType(rcx, JS_FUNCTION_TYPE, rcx);
   __ j(not_equal, &miss);
   __ Move(FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize),
           TypeFeedbackVector::MegamorphicSentinel(isolate));
 
   __ bind(&call);
-  __ Set(rax, argc);
   __ Jump(masm->isolate()->builtins()->Call(convert_mode(), tail_call_mode()),
           RelocInfo::CODE_TARGET);
 
   __ bind(&uninitialized);
 
   // We are going monomorphic, provided we actually have a JSFunction.
   __ JumpIfSmi(rdi, &miss);
 
   // Goto miss case if we do not have a function.
   __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
@@ skipping 16 matching lines @@
                        FixedArray::kHeaderSize + kPointerSize),
           Smi::FromInt(CallICNexus::kCallCountIncrement));
 
   // Store the function. Use a stub since we need a frame for allocation.
   // rbx - vector
   // rdx - slot (needs to be in smi form)
   // rdi - function
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     CreateWeakCellStub create_stub(isolate);
 

[mvstanton, 2016/02/15 11:13:45]

Wow, is it just a bug that rax wasn't being saved?

[mythria, 2016/02/17 11:02:48]

Yes :(

+    __ Integer32ToSmi(rax, rax);
+    __ Push(rax);
     __ Integer32ToSmi(rdx, rdx);
     __ Push(rdi);
+
     __ CallStub(&create_stub);
+
     __ Pop(rdi);
+    __ Pop(rax);
+    __ SmiToInteger32(rax, rax);
   }
 
   __ jmp(&call_function);
 
   // We are here because tracing is on or we encountered a MISS case we can't
   // handle here.
   __ bind(&miss);
   GenerateMiss(masm);
 
   __ jmp(&call);
 
   // Unreachable
   __ int3();
 }
 
 
 void CallICStub::GenerateMiss(MacroAssembler* masm) {
   FrameScope scope(masm, StackFrame::INTERNAL);
 
+  // Store the number of arguments to be used later.
+  __ Integer32ToSmi(rax, rax);
+  __ Push(rax);
+
   // Push the receiver and the function and feedback info.
   __ Push(rdi);
   __ Push(rbx);
   __ Integer32ToSmi(rdx, rdx);
   __ Push(rdx);
 
   // Call the entry.
   __ CallRuntime(Runtime::kCallIC_Miss);
 
   // Move result to edi and exit the internal frame.
   __ movp(rdi, rax);
+  // rdi, rbx, rdx are arguments to CallIC_Miss. They will be popped by
+  // Runtime_CallIC_Miss.
+  __ Pop(rax);
+  __ SmiToInteger32(rax, rax);
 }
 
 
 bool CEntryStub::NeedsImmovableCode() {
   return false;
 }
 
 
 void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   CEntryStub::GenerateAheadOfTime(isolate);
@@ skipping 3604 matching lines @@
                            NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64