The code generator doesn't need to put the argument count in eax for

call ICs.  Refactor CallRuntime on ARM to match the structure of IA32.
Update some comments.
Review URL: http://codereview.chromium.org/42598

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1607 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/codegen-arm.cc

@@ -3456,18 +3456,7 @@ void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
   Comment cmnt(masm_, "[ CallRuntime");
   Runtime::Function* function = node->function();
 
-  if (function != NULL) {
+  if (function == NULL) {
-    // Push the arguments ("left-to-right").
-    int arg_count = args->length();
-    for (int i = 0; i < arg_count; i++) {
-      LoadAndSpill(args->at(i));
-    }
-
-    // Call the C runtime function.
-    frame_->CallRuntime(function, arg_count);
-    frame_->EmitPush(r0);
-
-  } else {
     // Prepare stack for calling JS runtime function.
     __ mov(r0, Operand(node->name()));
     frame_->EmitPush(r0);
@@ -3475,18 +3464,25 @@ void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
     __ ldr(r1, GlobalObject());
     __ ldr(r0, FieldMemOperand(r1, GlobalObject::kBuiltinsOffset));
     frame_->EmitPush(r0);
+  }
 
+  // Push the arguments ("left-to-right").
   int arg_count = args->length();
   for (int i = 0; i < arg_count; i++) {
     LoadAndSpill(args->at(i));
   }
 
+  if (function == NULL) {
     // Call the JS runtime function.
-    Handle<Code> stub = ComputeCallInitialize(args->length());
+    Handle<Code> stub = ComputeCallInitialize(arg_count);
     frame_->CallCodeObject(stub, RelocInfo::CODE_TARGET, arg_count + 1);
     __ ldr(cp, frame_->Context());
     frame_->Drop();
     frame_->EmitPush(r0);
+  } else {
+    // Call the C runtime function.
+    frame_->CallRuntime(function, arg_count);
+    frame_->EmitPush(r0);
   }
   ASSERT(frame_->height() == original_height + 1);
 }

src/codegen-ia32.cc

@@ -4454,12 +4454,8 @@ void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
   if (function == NULL) {
     // Call the JS runtime function.
     Handle<Code> stub = ComputeCallInitialize(arg_count);
-
+    Result answer =
-    Result num_args = allocator()->Allocate(eax);
+        frame_->CallCodeObject(stub, RelocInfo::CODE_TARGET, arg_count + 1);
-    ASSERT(num_args.is_valid());
-    __ Set(num_args.reg(), Immediate(args->length()));
-    Result answer = frame_->CallCodeObject(stub, RelocInfo::CODE_TARGET,
-                                           &num_args, arg_count + 1);
     frame_->RestoreContextRegister();
     frame_->SetElementAt(0, &answer);
   } else {

src/virtual-frame-ia32.cc

@@ -784,10 +784,6 @@ Result VirtualFrame::CallCodeObject(Handle<Code> code,
                                     int dropped_args) {
   int spilled_args = 0;
   switch (code->kind()) {
-    case Code::CALL_IC:
-      ASSERT(arg->reg().is(eax));
-      spilled_args = dropped_args + 1;
-      break;
     case Code::LOAD_IC:
       ASSERT(arg->reg().is(ecx));
       ASSERT(dropped_args == 0);

src/virtual-frame.cc

@@ -179,12 +179,10 @@ void VirtualFrame::Spill(Register target) {
 }
 
 
-// Spill any register if possible, making its external reference count zero.
+// If there are any registers referenced only by the frame, spill one.
 Register VirtualFrame::SpillAnyRegister() {
-  // Find the leftmost (ordered by register code), least
+  // Find the leftmost (ordered by register code) register whose only
-  // internally-referenced register whose internal reference count matches
+  // reference is in the frame.
-  // its external reference count (so that spilling it from the frame frees
-  // it for use).
   for (int i = 0; i < kNumRegisters; i++) {
     if (is_used(i) && cgen_->allocator()->count(i) == 1) {
       Register result = { i };