MIPS: Hydrogen array constructor cleanup and improvements.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5027 matching lines @@
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
   __ Branch(&done, eq, a3, Operand(a1));
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   __ Branch(&done, eq, a3, Operand(at));
 
   // Special handling of the Array() function, which caches not only the
   // monomorphic Array function but the initial ElementsKind with special
   // sentinels
-  Handle<Object> terminal_kind_sentinel =
-      TypeFeedbackCells::MonomorphicArraySentinel(masm->isolate(),
-                                                  LAST_FAST_ELEMENTS_KIND);
   __ JumpIfNotSmi(a3, &miss);
-  __ Branch(&miss, gt, a3, Operand(terminal_kind_sentinel));
+  if (FLAG_debug_code) {
+    Handle<Object> terminal_kind_sentinel =
+    TypeFeedbackCells::MonomorphicArraySentinel(masm->isolate(),
+                                                LAST_FAST_ELEMENTS_KIND);
+    __ Assert(le, "Array function sentinel is not an ElementsKind",
+              a3, Operand(terminal_kind_sentinel));
+  }
+
   // Make sure the function is the Array() function
   __ LoadArrayFunction(a3);
   __ Branch(&megamorphic, ne, a1, Operand(a3));
   __ jmp(&done);
 
   __ bind(&miss);
 
   // A monomorphic miss (i.e, here the cache is not uninitialized) goes
   // megamorphic.
   __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
@@ skipping 2544 matching lines @@
 
   // look at the first argument
   __ lw(t1, MemOperand(sp, 0));
   __ Branch(&normal_sequence, eq, t1, Operand(zero_reg));
 
   // We are going to create a holey array, but our kind is non-holey.
   // Fix kind and retry
   __ Addu(a3, a3, Operand(1));
   __ Branch(&normal_sequence, eq, a2, Operand(undefined_sentinel));
 
+  // The type cell may have gone megamorphic, don't overwrite if so.
+  __ lw(t1, FieldMemOperand(a2, kPointerSize));
+  __ JumpIfNotSmi(t1, &normal_sequence);
+
   // Save the resulting elements kind in type info
   __ SmiTag(a3);
   __ sw(a3, FieldMemOperand(a2, kPointerSize));
   __ SmiUntag(a3);
 
   __ bind(&normal_sequence);
   int last_index = GetSequenceIndexFromFastElementsKind(
       TERMINAL_FAST_ELEMENTS_KIND);
   for (int i = 0; i <= last_index; ++i) {
     Label next;
@@ skipping 11 matching lines @@
 
 template<class T>
 static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
   int to_index = GetSequenceIndexFromFastElementsKind(
       TERMINAL_FAST_ELEMENTS_KIND);
   for (int i = 0; i <= to_index; ++i) {
     ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
     T stub(kind);
     stub.GetCode(isolate)->set_is_pregenerated(true);
     if (AllocationSiteInfo::GetMode(kind) != DONT_TRACK_ALLOCATION_SITE) {
-      T stub1(kind, true);
+      T stub1(kind, CONTEXT_CHECK_REQUIRED, DISABLE_ALLOCATION_SITES);
       stub1.GetCode(isolate)->set_is_pregenerated(true);
     }
   }
 }
 
 
 void ArrayConstructorStubBase::GenerateStubsAheadOfTime(Isolate* isolate) {
   ArrayConstructorStubAheadOfTimeHelper<ArrayNoArgumentConstructorStub>(
       isolate);
   ArrayConstructorStubAheadOfTimeHelper<ArraySingleArgumentConstructorStub>(
@@ skipping 170 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS