Replace store array length builtin with codestub.

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 780eca3325b45061a4b60ab91fc781ddc7fbed13..8889e756f6cb4264c7c2ba570114c6e19596f1dc 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -4601,6 +4601,76 @@ void StringLengthStub::Generate(MacroAssembler* masm) {
 }
 
 
+void StoreArrayLengthStub::Generate(MacroAssembler* masm) {
+  // This accepts as a receiver anything JSArray::SetElementsLength accepts
+  // (currently anything except for external arrays which means anything with
+  // elements of FixedArray type).  Value must be a number, but only smis are
+  // accepted as the most common case.
+  Label miss;
+
+  Register receiver;
+  Register value;
+  if (kind() == Code::KEYED_STORE_IC) {
+    // ----------- S t a t e -------------
+    //  -- lr    : return address
+    //  -- r0    : value
+    //  -- r1    : key
+    //  -- r2    : receiver
+    // -----------------------------------
+    __ cmp(r1, Operand(masm->isolate()->factory()->length_symbol()));
+    __ b(ne, &miss);
+    receiver = r2;
+    value = r0;
+  } else {
+    ASSERT(kind() == Code::STORE_IC);
+    // ----------- S t a t e -------------
+    //  -- lr    : return address
+    //  -- r0    : value
+    //  -- r1    : receiver
+    //  -- r2    : key
+    // -----------------------------------
+    receiver = r1;
+    value = r0;
+  }
+  Register scratch = r3;
+
+  // Check that the receiver isn't a smi.
+  __ JumpIfSmi(receiver, &miss);
+
+  // Check that the object is a JS array.
+  __ CompareObjectType(receiver, scratch, scratch, JS_ARRAY_TYPE);
+  __ b(ne, &miss);
+
+  // Check that elements are FixedArray.
+  // We rely on StoreIC_ArrayLength below to deal with all types of
+  // fast elements (including COW).
+  __ ldr(scratch, FieldMemOperand(receiver, JSArray::kElementsOffset));
+  __ CompareObjectType(scratch, scratch, scratch, FIXED_ARRAY_TYPE);
+  __ b(ne, &miss);
+
+  // Check that the array has fast properties, otherwise the length
+  // property might have been redefined.
+  __ ldr(scratch, FieldMemOperand(receiver, JSArray::kPropertiesOffset));
+  __ ldr(scratch, FieldMemOperand(scratch, FixedArray::kMapOffset));
+  __ CompareRoot(scratch, Heap::kHashTableMapRootIndex);
+  __ b(eq, &miss);
+
+  // Check that value is a smi.
+  __ JumpIfNotSmi(value, &miss);
+
+  // Prepare tail call to StoreIC_ArrayLength.
+  __ Push(receiver, value);
+
+  ExternalReference ref =
+      ExternalReference(IC_Utility(IC::kStoreIC_ArrayLength), masm->isolate());
+  __ TailCallExternalReference(ref, 2, 1);
+
+  __ bind(&miss);
+
+  StubCompiler::GenerateStoreMiss(masm, kind());
+}
+
+
 Register InstanceofStub::left() { return r0; }