Hydrogen array constructor cleanup and improvements

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 1d1fe83c2fee9ae565381c5ccb206e5b78e7811e..5603de2ef3c6177afc8fdece0c6f1089fbf492ef 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -4647,12 +4647,7 @@ 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(masm->isolate(),
-                                                  LAST_FAST_ELEMENTS_KIND);
   __ JumpIfNotSmi(r3, &miss);
-  __ cmp(r3, Operand(terminal_kind_sentinel));
-  __ b(gt, &miss);
   // Make sure the function is the Array() function
   __ LoadArrayFunction(r3);
   __ cmp(r1, r3);
@@ -7192,6 +7187,10 @@ static void CreateArrayDispatchOneArgument(MacroAssembler* masm) {
   __ cmp(r2, Operand(undefined_sentinel));
   __ b(eq, &normal_sequence);
 
+  // The type cell may have gone megamorphic, don't overwrite if so
+  __ ldr(r5, FieldMemOperand(r2, kPointerSize));
+  __ JumpIfNotSmi(r5, &normal_sequence);
+
   // Save the resulting elements kind in type info
   __ SmiTag(r3);
   __ str(r3, FieldMemOperand(r2, kPointerSize));