Hydrogen array constructor cleanup and improvements

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 0ca56984ad0497a857ba9ea3f4406902e20b52d1..c1e1459ffb1b23271710ad5679c2bc8f01a086aa 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -4700,12 +4700,15 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // 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(isolate,
-                                                  LAST_FAST_ELEMENTS_KIND);
   __ JumpIfNotSmi(ecx, &miss);
-  __ cmp(ecx, Immediate(terminal_kind_sentinel));
-  __ j(above, &miss);
+  if (FLAG_debug_code) {
+    Handle<Object> terminal_kind_sentinel =
+        TypeFeedbackCells::MonomorphicArraySentinel(masm->isolate(),
+                                                    LAST_FAST_ELEMENTS_KIND);
+    __ cmp(ecx, Immediate(terminal_kind_sentinel));
+    __ Assert(less_equal, "Array function sentinel is not an ElementsKind");
+  }
+
   // Load the global or builtins object from the current context
   __ LoadGlobalContext(ecx);
   // Make sure the function is the Array() function
@@ -7793,6 +7796,10 @@ static void CreateArrayDispatchOneArgument(MacroAssembler* masm) {
   __ cmp(ebx, Immediate(undefined_sentinel));
   __ j(equal, &normal_sequence);
 
+  // The type cell may have gone megamorphic, don't overwrite if so
+  __ mov(ecx, FieldOperand(ebx, kPointerSize));
+  __ JumpIfNotSmi(ecx, &normal_sequence);
+
   // Save the resulting elements kind in type info
   __ SmiTag(edx);
   __ mov(FieldOperand(ebx, kPointerSize), edx);
@@ -7822,10 +7829,10 @@ static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
       TERMINAL_FAST_ELEMENTS_KIND);
   for (int i = 0; i <= to_index; ++i) {
     ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
-    T stub(kind, false);
+    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);
     }
   }