MIPS: Utility functions for pretenure call new.

Port r19998 (6b07a42)

Original commit message:
These functions aren't yet called in the tree but will be in the next days. AssertUndefinedOrAllocationSite is to be used in several places where AllocationSite feedback is optional.

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/196423018

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20014 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/macro-assembler-mips.cc

@@ -4817,6 +4817,23 @@ void MacroAssembler::AssertName(Register object) {
 }
 
 
+void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
+                                                     Register scratch) {
+  if (emit_debug_code()) {
+    Label done_checking;
+    AssertNotSmi(object);
+    LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    Branch(&done_checking, eq, object, Operand(scratch));
+    push(object);
+    lw(object, FieldMemOperand(object, HeapObject::kMapOffset));
+    LoadRoot(scratch, Heap::kAllocationSiteMapRootIndex);
+    Assert(eq, kExpectedUndefinedOrCell, object, Operand(scratch));
+    pop(object);
+    bind(&done_checking);
+  }
+}
+
+
 void MacroAssembler::AssertIsRoot(Register reg, Heap::RootListIndex index) {
   if (emit_debug_code()) {
     ASSERT(!reg.is(at));

src/mips/macro-assembler-mips.h

@@ -1432,6 +1432,10 @@ const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
   // Abort execution if argument is not a name, enabled via --debug-code.
   void AssertName(Register object);
 
+  // Abort execution if argument is not undefined or an AllocationSite, enabled
+  // via --debug-code.
+  void AssertUndefinedOrAllocationSite(Register object, Register scratch);
+
   // Abort execution if reg is not the root value with the given index,
   // enabled via --debug-code.
   void AssertIsRoot(Register reg, Heap::RootListIndex index);