[Interpreter] Implements calls through CallICStub in the interpreter.

src/ia32/code-stubs-ia32.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_IA32
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 1879 matching lines @@
 
   __ bind(&non_function);
   __ mov(edx, edi);
   __ Jump(isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
 }
 
 
 void CallICStub::HandleArrayCase(MacroAssembler* masm, Label* miss) {
   // edi - function
   // edx - slot id
   // ebx - vector

[rmcilroy, 2016/02/12 14:21:03]

Add a comment here that eax contains arg_count if !argc_in_register()

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

Done.

   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ecx);
   __ cmp(edi, ecx);
   __ j(not_equal, miss);
 
-  __ mov(eax, arg_count());
+  if (!argc_in_register()) {
+    __ mov(eax, arg_count());
+  }
   // Reload ecx.
   __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
                            FixedArray::kHeaderSize));
 
   // Increment the call count for monomorphic function calls.
   __ add(FieldOperand(ebx, edx, times_half_pointer_size,
                       FixedArray::kHeaderSize + kPointerSize),
          Immediate(Smi::FromInt(CallICNexus::kCallCountIncrement)));
 
   __ mov(ebx, ecx);
   __ mov(edx, edi);
-  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);
+  }
   // Unreachable.
 }
 
 
 void CallICStub::Generate(MacroAssembler* masm) {
   // edi - function
   // edx - slot id
   // ebx - vector
+  // eax - 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();
-  ParameterCount actual(argc);
 
   // The checks. First, does edi match the recorded monomorphic target?
   __ mov(ecx, FieldOperand(ebx, edx, times_half_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.
   // WeakCell::kValueOffset - contains a JSFunction or Smi(0)
@@ skipping 12 matching lines @@
   // The compare above could have been a SMI/SMI comparison. Guard against this
   // convincing us that we have a monomorphic JSFunction.
   __ JumpIfSmi(edi, &extra_checks_or_miss);
 
   // Increment the call count for monomorphic function calls.
   __ add(FieldOperand(ebx, edx, times_half_pointer_size,
                       FixedArray::kHeaderSize + kPointerSize),
          Immediate(Smi::FromInt(CallICNexus::kCallCountIncrement)));
 
   __ bind(&call_function);
-  __ Set(eax, argc);
+  if (!argc_in_register()) {
+    __ Set(eax, argc);
+  }

[rmcilroy, 2016/02/12 14:21:03]

Could we just pull this up to be below "argc = arg_count()" (and move that line
into this if) and get rid of the __ Set(eax, argc); on line 2004 as well? That
would make the two versions of the stub much more similar (i.e., both would need
to retain eax throughout the stub)

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

Done.

   __ 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(ecx, Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate)));
   __ j(equal, &call);
 
@@ skipping 19 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(ecx);
   __ CmpObjectType(ecx, JS_FUNCTION_TYPE, ecx);
   __ j(not_equal, &miss);
   __ mov(
       FieldOperand(ebx, edx, times_half_pointer_size, FixedArray::kHeaderSize),
       Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate)));
 
   __ bind(&call);
-  __ Set(eax, argc);
+  if (!argc_in_register()) {
+    __ Set(eax, 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(edi, &miss);
 
   // Goto miss case if we do not have a function.
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
@@ skipping 16 matching lines @@
                       FixedArray::kHeaderSize + kPointerSize),
          Immediate(Smi::FromInt(CallICNexus::kCallCountIncrement)));
 
   // Store the function. Use a stub since we need a frame for allocation.
   // ebx - vector
   // edx - slot
   // edi - function
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     CreateWeakCellStub create_stub(isolate);
+    if (argc_in_register()) {
+      __ SmiTag(eax);
+      __ push(eax);
+    }
     __ push(edi);
     __ CallStub(&create_stub);
     __ pop(edi);
+    if (argc_in_register()) {
+      __ pop(eax);
+      __ SmiUntag(eax);
+    }
   }
 
   __ 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);
-
+  if (argc_in_register()) {
+    __ SmiTag(eax);
+    __ push(eax);
+  }
   // Push the function and feedback info.
   __ push(edi);
   __ push(ebx);
   __ push(edx);
 
   // Call the entry.
   __ CallRuntime(Runtime::kCallIC_Miss);
 
   // Move result to edi and exit the internal frame.
   __ mov(edi, eax);
+  if (argc_in_register()) {
+    __ pop(eax);
+    __ SmiUntag(eax);
+  }
 }
 
 
 bool CEntryStub::NeedsImmovableCode() {
   return false;
 }
 
 
 void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   CEntryStub::GenerateAheadOfTime(isolate);
@@ skipping 3738 matching lines @@
                            return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32