Faster filling newly allocated arrays with the holes from the Array construction stub.

src/ia32/assembler-ia32.cc

Index: src/ia32/assembler-ia32.cc
diff --git a/src/ia32/assembler-ia32.cc b/src/ia32/assembler-ia32.cc
index 1365ac2be3c1d98bd044c4daee9f9fe9cc536398..f13556bd7aac1c10fc073499b3a33f81d0089c54 100644
--- a/src/ia32/assembler-ia32.cc
+++ b/src/ia32/assembler-ia32.cc
@@ -753,6 +753,13 @@ void Assembler::cmov(Condition cc, Register dst, const Operand& src) {
 }
 
 
+void Assembler::cld() {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  EMIT(0xFC);
+}
+
+
 void Assembler::rep_movs() {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
@@ -761,6 +768,14 @@ void Assembler::rep_movs() {
 }
 
 
+void Assembler::rep_stos() {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  EMIT(0xF3);
+  EMIT(0xAB);
+}
+
+
 void Assembler::xchg(Register dst, Register src) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;