ARM, ARM64: Optimize array copy

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 93dc830dab30e3630bac62966133e5c35f3e8843..d0cfe95dc212f191a1b7aadf8099a2e42cc84833 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -344,6 +344,29 @@ void LLoadKeyed::PrintDataTo(StringStream* stream) {
 }
 
 
+void LFillElements::PrintDataTo(StringStream* stream) {
+  elements()->PrintTo(stream);
+  stream->Add("[");
+  from()->PrintTo(stream);
+  stream->Add("-");
+  to()->PrintTo(stream);
+  stream->Add("] <- ");
+  value()->PrintTo(stream);
+}
+
+
+void LCopyElements::PrintDataTo(StringStream* stream) {
+  dst()->PrintTo(stream);
+  stream->Add("[0-");
+  length()->PrintTo(stream);
+  stream->Add("] <- ");
+  src()->PrintTo(stream);
+  stream->Add("[0-");
+  length()->PrintTo(stream);
+  stream->Add("]");
+}
+
+
 void LStoreKeyed::PrintDataTo(StringStream* stream) {
   elements()->PrintTo(stream);
   stream->Add("[");
@@ -2207,6 +2230,34 @@ LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoFillElements(HFillElements* instr) {
+  LOperand* elements = UseRegister(instr->elements());
+  LOperand* from = UseRegisterOrConstant(instr->from());
+  LOperand* to = UseRegisterOrConstant(instr->to());
+  LOperand* value = UseRegister(instr->value());
+  LOperand* scratch;
+  if (instr->from()->IsConstant() && instr->to()->IsConstant()) {
+    HConstant* from = HConstant::cast(instr->from());
+    HConstant* to = HConstant::cast(instr->to());
+    scratch =
+        (to->Integer32Value() - from->Integer32Value() <=
+         LFillElements::kMaxUnrolledSize) ?
+            NULL : TempRegister();
+  } else {
+    scratch = TempRegister();
+  }
+  return new(zone()) LFillElements(elements, from, to, value, scratch);
+}
+
+
+LInstruction* LChunkBuilder::DoCopyElements(HCopyElements* instr) {
+  LOperand* src = UseTempRegister(instr->src());
+  LOperand* dst = UseTempRegister(instr->dst());
+  LOperand* length = UseTempRegister(instr->length());
+  return new(zone()) LCopyElements(src, dst, length);
+}
+
+
 LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
   if (!instr->is_typed_elements()) {
     ASSERT(instr->elements()->representation().IsTagged());