Avoid HeapObject check in HStoreNamedField.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index b417c801d58f9b31cb0956cba3df95fd0ca58098..5f249c29054db0ba93772dbf902faf6236b5cdcf 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4062,23 +4062,12 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
     return;
   }
 
-  SmiCheck check_needed =
-      instr->hydrogen()->value()->IsHeapObject()
-          ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
+  __ AssertNotSmi(object);
 
-  ASSERT(!(representation.IsSmi() &&
-           instr->value()->IsConstantOperand() &&
-           !IsSmi(LConstantOperand::cast(instr->value()))));
-  if (representation.IsHeapObject()) {
-    Register value = ToRegister(instr->value());
-    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
-      __ SmiTst(value);
-      DeoptimizeIf(eq, instr->environment());
-
-      // We know now that value is not a smi, so we can omit the check below.
-      check_needed = OMIT_SMI_CHECK;
-    }
-  } else if (representation.IsDouble()) {
+  ASSERT(!representation.IsSmi() ||
+         !instr->value()->IsConstantOperand() ||
+         IsSmi(LConstantOperand::cast(instr->value())));
+  if (representation.IsDouble()) {
     ASSERT(access.IsInobject());
     ASSERT(!instr->hydrogen()->has_transition());
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
@@ -4120,7 +4109,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
                           GetLinkRegisterState(),
                           kSaveFPRegs,
                           EMIT_REMEMBERED_SET,
-                          check_needed);
+                          instr->hydrogen()->SmiCheckForWriteBarrier());
     }
   } else {
     __ ldr(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
@@ -4136,7 +4125,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
                           GetLinkRegisterState(),
                           kSaveFPRegs,
                           EMIT_REMEMBERED_SET,
-                          check_needed);
+                          instr->hydrogen()->SmiCheckForWriteBarrier());
     }
   }
 }