[turbofan] Add backend support for float32.

src/compiler/representation-change.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_REPRESENTATION_CHANGE_H_
 #define V8_COMPILER_REPRESENTATION_CHANGE_H_
 
 #include "src/base/bits.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 33 matching lines @@
     }
     if ((use_type & rWord) && (output_type & rWord)) {
       // Both are words less than or equal to 32-bits.
       // Since loads of integers from memory implicitly sign or zero extend the
       // value to the full machine word size and stores implicitly truncate,
       // no representation change is necessary.
       return node;
     }
     if (use_type & kRepTagged) {
       return GetTaggedRepresentationFor(node, output_type);
+    } else if (use_type & kRepFloat32) {
+      return GetFloat32RepresentationFor(node, output_type);
     } else if (use_type & kRepFloat64) {
       return GetFloat64RepresentationFor(node, output_type);
-    } else if (use_type & kRepFloat32) {
-      return TypeError(node, output_type, use_type);  // TODO(titzer): handle
     } else if (use_type & kRepBit) {
       return GetBitRepresentationFor(node, output_type);
     } else if (use_type & rWord) {
       return GetWord32RepresentationFor(node, output_type,
                                         use_type & kTypeUint32);
     } else if (use_type & kRepWord64) {
       return GetWord64RepresentationFor(node, output_type);
     } else {
       return node;
     }
@@ skipping 28 matching lines @@
     if (output_type & kRepBit) {
       op = simplified()->ChangeBitToBool();
     } else if (output_type & rWord) {
       if (output_type & kTypeUint32) {
         op = simplified()->ChangeUint32ToTagged();
       } else if (output_type & kTypeInt32) {
         op = simplified()->ChangeInt32ToTagged();
       } else {
         return TypeError(node, output_type, kRepTagged);
       }
+    } else if (output_type & kRepFloat32) {
+      node = jsgraph()->graph()->NewNode(machine()->ChangeFloat32ToFloat64(),
+                                         node);
+      op = simplified()->ChangeFloat64ToTagged();
     } else if (output_type & kRepFloat64) {
       op = simplified()->ChangeFloat64ToTagged();
     } else {
       return TypeError(node, output_type, kRepTagged);
     }
     return jsgraph()->graph()->NewNode(op, node);
   }
 
+  Node* GetFloat32RepresentationFor(Node* node, MachineTypeUnion output_type) {
+    // Eagerly fold representation changes for constants.
+    switch (node->opcode()) {
+      // TODO(turbofan): NumberConstant, Int32Constant, and Float64Constant?
+      case IrOpcode::kFloat32Constant:
+        return node;  // No change necessary.
+      default:
+        break;
+    }
+    // TODO(turbofan): Select the correct X -> Float32 operator.
+    return TypeError(node, output_type, kRepFloat32);
+  }
+
   Node* GetFloat64RepresentationFor(Node* node, MachineTypeUnion output_type) {
     // Eagerly fold representation changes for constants.
     switch (node->opcode()) {
       case IrOpcode::kNumberConstant:
         return jsgraph()->Float64Constant(OpParameter<double>(node));
       case IrOpcode::kInt32Constant:
         if (output_type & kTypeUint32) {
           uint32_t value = OpParameter<uint32_t>(node);
           return jsgraph()->Float64Constant(static_cast<double>(value));
         } else {
@@ skipping 10 matching lines @@
     if (output_type & kRepBit) {
       return TypeError(node, output_type, kRepFloat64);
     } else if (output_type & rWord) {
       if (output_type & kTypeUint32) {
         op = machine()->ChangeUint32ToFloat64();
       } else {
         op = machine()->ChangeInt32ToFloat64();
       }
     } else if (output_type & kRepTagged) {
       op = simplified()->ChangeTaggedToFloat64();
+    } else if (output_type & kRepFloat32) {
+      op = machine()->ChangeFloat32ToFloat64();
     } else {
       return TypeError(node, output_type, kRepFloat64);
     }
     return jsgraph()->graph()->NewNode(op, node);
   }
 
   Node* GetWord32RepresentationFor(Node* node, MachineTypeUnion output_type,
                                    bool use_unsigned) {
     // Eagerly fold representation changes for constants.
     switch (node->opcode()) {
@@ skipping 192 matching lines @@
                use_str.c_str());
     }
     return node;
   }
 
   JSGraph* jsgraph() { return jsgraph_; }
   Isolate* isolate() { return isolate_; }
   SimplifiedOperatorBuilder* simplified() { return simplified_; }
   MachineOperatorBuilder* machine() { return jsgraph()->machine(); }
 };
-}
-}
-}  // namespace v8::internal::compiler
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_COMPILER_REPRESENTATION_CHANGE_H_