[turbofan] Add backend support for float32.

test/cctest/compiler/test-representation-change.cc

 // 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.
 
 #include <limits>
 
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/compiler/graph-builder-tester.h"
 
@@ skipping 71 matching lines @@
     Node* c = changer()->GetRepresentationFor(n, from, to);
     CHECK_EQ(n, c);
   }
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 
 // TODO(titzer): add kRepFloat32 when fully supported.
-static const MachineType all_reps[] = {kRepBit, kRepWord32, kRepWord64,
-                                       kRepFloat64, kRepTagged};
+static const MachineType all_reps[] = {kRepBit,     kRepWord32,  kRepWord64,
+                                       kRepFloat32, kRepFloat64, kRepTagged};
 
 
 // TODO(titzer): lift this to ValueHelper
 static const double double_inputs[] = {
     0.0,   -0.0,    1.0,    -1.0,        0.1,         1.4,    -1.7,
     2,     5,       6,      982983,      888,         -999.8, 3.1e7,
     -2e66, 2.3e124, -12e73, V8_INFINITY, -V8_INFINITY};
 
 
 static const int32_t int32_inputs[] = {
@@ skipping 184 matching lines @@
   r.CheckTypeError(kRepWord64, kRepWord32 | kTypeUint32);
   r.CheckTypeError(kRepWord32 | kTypeUint32, kRepWord64);
 
   for (size_t i = 0; i < arraysize(all_reps); i++) {
     for (size_t j = 0; j < arraysize(all_reps); j++) {
       if (i == j) continue;
       // Only a single from representation is allowed.
       r.CheckTypeError(all_reps[i] | all_reps[j], kRepTagged);
     }
   }
-
-  // TODO(titzer): Float32 representation changes trigger type errors now.
-  // Enforce current behavior to test all paths through representation changer.
-  for (size_t i = 0; i < arraysize(all_reps); i++) {
-    r.CheckTypeError(all_reps[i], kRepFloat32);
-    r.CheckTypeError(kRepFloat32, all_reps[i]);
-  }
 }