Support Float64Arrays

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index c242874c52b61b31e2c6cc20d686dbcb27911f01..688a557ee8710819abb682b569a939f45819b4cc 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2350,6 +2350,9 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
     XMMRegister result(ToDoubleRegister(instr->result()));
     __ movss(result, Operand(external_pointer, key, times_4, 0));
     __ cvtss2sd(result, result);
+  } else if (array_type == kExternalDoubleArray) {
+    __ movsd(ToDoubleRegister(instr->result()),
+             Operand(external_pointer, key, times_8, 0));
   } else {
     Register result(ToRegister(instr->result()));
     switch (array_type) {
@@ -2378,6 +2381,7 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
         DeoptimizeIf(negative, instr->environment());
         break;
       case kExternalFloatArray:
+      case kExternalDoubleArray:
         UNREACHABLE();
         break;
     }
@@ -3037,6 +3041,9 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
     XMMRegister value(ToDoubleRegister(instr->value()));
     __ cvtsd2ss(value, value);
     __ movss(Operand(external_pointer, key, times_4, 0), value);
+  } else if (array_type == kExternalDoubleArray) {
+    __ movsd(Operand(external_pointer, key, times_8, 0),
+             ToDoubleRegister(instr->value()));
   } else {
     Register value(ToRegister(instr->value()));
     switch (array_type) {
@@ -3064,6 +3071,7 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
         __ movl(Operand(external_pointer, key, times_4, 0), value);
         break;
       case kExternalFloatArray:
+      case kExternalDoubleArray:
         UNREACHABLE();
         break;
     }