DBC: Double converstion instructions

runtime/vm/intermediate_language_dbc.cc

Index: runtime/vm/intermediate_language_dbc.cc
diff --git a/runtime/vm/intermediate_language_dbc.cc b/runtime/vm/intermediate_language_dbc.cc
index 3566b6c4aeea2d93e78152b22c0c0335b9af7c4e..0c7aec875d911344cc62bb88e77409a530e8f666 100644
--- a/runtime/vm/intermediate_language_dbc.cc
+++ b/runtime/vm/intermediate_language_dbc.cc
@@ -34,9 +34,6 @@ DECLARE_FLAG(int, optimization_counter_threshold);
   M(BinaryInt32Op)                                                             \
   M(Int32ToDouble)                                                             \
   M(DoubleToInteger)                                                           \
-  M(DoubleToDouble)                                                            \
-  M(DoubleToFloat)                                                             \
-  M(FloatToDouble)                                                             \
   M(BoxInt64)                                                                  \
   M(MergedMath)                                                                \
   M(GuardFieldClass)                                                           \
@@ -1597,6 +1594,39 @@ EMIT_NATIVE_CODE(MathUnary, 1, Location::RequiresRegister()) {
 }
 
 
+EMIT_NATIVE_CODE(DoubleToDouble, 1, Location::RequiresRegister()) {
+  const Register in = locs()->in(0).reg();
+  const Register result = locs()->out(0).reg();
+  switch (recognized_kind()) {
+    case MethodRecognizer::kDoubleTruncate:
+      __ DTruncate(result, in);
+      break;
+    case MethodRecognizer::kDoubleFloor:
+      __ DFloor(result, in);
+      break;
+    case MethodRecognizer::kDoubleCeil:
+      __ DCeil(result, in);
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+EMIT_NATIVE_CODE(DoubleToFloat, 1, Location::RequiresRegister()) {

[Florian Schneider, 2016/09/15 02:02:26]

This won't be tested until you have support for optimized
LoadIndexed/StoreIndexed for Float32List. It would make sense to add these in
the same CL. 

[zra, 2016/09/15 15:09:31]

Done.

+  const Register in = locs()->in(0).reg();
+  const Register result = locs()->out(0).reg();
+  __ DoubleToFloat(result, in);
+}
+
+
+EMIT_NATIVE_CODE(FloatToDouble, 1, Location::RequiresRegister()) {

[Florian Schneider, 2016/09/15 02:02:26]

Same comment as above.

[zra, 2016/09/15 15:09:30]

Done.

+  const Register in = locs()->in(0).reg();
+  const Register result = locs()->out(0).reg();
+  __ FloatToDouble(result, in);
+}
+
+
 EMIT_NATIVE_CODE(InvokeMathCFunction,
                  InputCount(), Location::RequiresRegister()) {
   const Register left = locs()->in(0).reg();