Handle array construction in native code (x64 version)

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
===================================================================
--- src/x64/macro-assembler-x64.cc	(revision 2959)
+++ src/x64/macro-assembler-x64.cc	(working copy)
@@ -519,6 +519,18 @@
 }
 
 
+void MacroAssembler::JumpIfSmiGreaterEqualsConstant(Register src,
+                                                    int constant,
+                                                    Label* on_greater_equals) {
+  if (Smi::IsValid(constant)) {
+    Condition are_greater_equal = CheckSmiGreaterEqualsConstant(src, constant);
+    j(are_greater_equal, on_greater_equals);
+  } else if (constant < Smi::kMinValue){
+    jmp(on_greater_equals);
+  }
+}
+
+
 void MacroAssembler::JumpIfNotValidSmiValue(Register src, Label* on_invalid) {
   Condition is_valid = CheckInteger32ValidSmiValue(src);
   j(ReverseCondition(is_valid), on_invalid);
@@ -602,6 +614,22 @@
 }
 
 
+Condition MacroAssembler::CheckSmiGreaterEqualsConstant(Register src,
+                                                        int constant) {
+  if (constant == 0) {
+    testl(src, Immediate(static_cast<uint32_t>(0x80000000u)));
+    return positive;
+  }
+  if (Smi::IsValid(constant)) {
+    cmpl(src, Immediate(Smi::FromInt(constant)));
+    return greater_equal;
+  }
+  // Can't be equal.
+  UNREACHABLE();
+  return no_condition;
+}
+
+
 Condition MacroAssembler::CheckInteger32ValidSmiValue(Register src) {
   // A 32-bit integer value can be converted to a smi if it is in the
   // range [-2^30 .. 2^30-1]. That is equivalent to having its 32-bit