Explicit conversions for Float32 array loads/stores.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
===================================================================
--- runtime/vm/intermediate_language_x64.cc	(revision 32847)
+++ runtime/vm/intermediate_language_x64.cc	(working copy)
@@ -885,8 +885,6 @@
     if (class_id() == kTypedDataFloat32ArrayCid) {
       // Load single precision float.
       __ movss(result, element_address);
-      // Promote to double.
-      __ cvtss2sd(result, locs()->out().fpu_reg());
     } else if (class_id() == kTypedDataFloat64ArrayCid) {
       __ movsd(result, element_address);
     } else {
@@ -1014,9 +1012,6 @@
       locs->set_in(2, Location::WritableRegister());
       break;
     case kTypedDataFloat32ArrayCid:
-      // Need temp register for float-to-double conversion.
-      locs->AddTemp(Location::RequiresFpuRegister());
-      // Fall through.
     case kTypedDataFloat64ArrayCid:
       // TODO(srdjan): Support Float64 constants.
       locs->set_in(2, Location::RequiresFpuRegister());
@@ -1131,10 +1126,7 @@
         break;
     }
     case kTypedDataFloat32ArrayCid:
-      // Convert to single precision.
-      __ cvtsd2ss(locs()->temp(0).fpu_reg(), locs()->in(2).fpu_reg());
-      // Store.
-      __ movss(element_address, locs()->temp(0).fpu_reg());
+      __ movss(element_address, locs()->in(2).fpu_reg());
       break;
     case kTypedDataFloat64ArrayCid:
       __ movsd(element_address, locs()->in(2).fpu_reg());
@@ -4189,6 +4181,38 @@
 }
 
 
+LocationSummary* DoubleToFloatInstr::MakeLocationSummary(bool opt) const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* result =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  result->set_in(0, Location::RequiresFpuRegister());
+  result->set_out(Location::SameAsFirstInput());
+  return result;
+}
+
+
+void DoubleToFloatInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  __ cvtsd2ss(locs()->out().fpu_reg(), locs()->in(0).fpu_reg());
+}
+
+
+LocationSummary* FloatToDoubleInstr::MakeLocationSummary(bool opt) const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* result =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  result->set_in(0, Location::RequiresFpuRegister());
+  result->set_out(Location::SameAsFirstInput());
+  return result;
+}
+
+
+void FloatToDoubleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  __ cvtss2sd(locs()->out().fpu_reg(), locs()->in(0).fpu_reg());
+}
+
+
 LocationSummary* InvokeMathCFunctionInstr::MakeLocationSummary(bool opt) const {
   // Calling convention on x64 uses XMM0 and XMM1 to pass the first two
   // double arguments and XMM0 to return the result. Unfortunately