[turbofan] Add backend support for float32.

src/compiler/js-typed-lowering.cc

Index: src/compiler/js-typed-lowering.cc
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index 130c5cbcbdc8de9fb23d63c9baf838f355f6cc90..8c78412a4eace180962a2dc24f02d98a1c5befa5 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -556,6 +556,14 @@ Reduction JSTypedLowering::ReduceJSLoadProperty(Node* node) {
     Node* value =
         graph()->NewNode(simplified()->LoadElement(element_access), elements,
                          key, NodeProperties::GetEffectInput(node));
+    // TODO(titzer): Remove this hack once float32 is properly supported in
+    // simplified lowering.
+    if (element_access.machine_type == kRepFloat32) {

[titzer, 2014/09/24 10:55:23]

You can move this into simplified-lowering. A more general hack :)

+      Node* change =
+          graph()->NewNode(machine()->ChangeFloat32ToFloat64(), value);
+      NodeProperties::ReplaceWithValue(node, change, value);
+      return Changed(value);
+    }
     return ReplaceEagerly(node, value);
   }
   return NoChange();
@@ -599,6 +607,11 @@ Reduction JSTypedLowering::ReduceJSStoreProperty(Node* node) {
                                     NodeProperties::GetControlInput(node));
 
     Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
+    // TODO(titzer): Remove this hack once float32 is properly supported in
+    // simplified lowering.
+    if (element_access.machine_type == kRepFloat32) {
+      value = graph()->NewNode(machine()->TruncateFloat64ToFloat32(), value);
+    }
     Node* store = graph()->NewNode(
         simplified()->StoreElement(element_access), elements, key, value,
         NodeProperties::GetEffectInput(node), if_true);