[turbofan] Cache float32 constants on the JSGraph level.

src/compiler/js-graph.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 "src/code-stubs.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/typer.h"
 
 namespace v8 {
@@ skipping 156 matching lines @@
 Node* JSGraph::NumberConstant(double value) {
   Node** loc = cache_.FindNumberConstant(value);
   if (*loc == NULL) {
     *loc = graph()->NewNode(common()->NumberConstant(value));
   }
   return *loc;
 }
 
 
 Node* JSGraph::Float32Constant(float value) {
-  // TODO(turbofan): cache float32 constants.
-  return graph()->NewNode(common()->Float32Constant(value));
+  Node** loc = cache_.FindFloat32Constant(value);
+  if (*loc == NULL) {
+    *loc = graph()->NewNode(common()->Float32Constant(value));
+  }
+  return *loc;
 }
 
 
 Node* JSGraph::Float64Constant(double value) {
   Node** loc = cache_.FindFloat64Constant(value);
   if (*loc == NULL) {
     *loc = graph()->NewNode(common()->Float64Constant(value));
   }
   return *loc;
 }
@@ skipping 15 matching lines @@
       &true_constant_,         &false_constant_,     &null_constant_,
       &zero_constant_,         &one_constant_,       &nan_constant_};
   for (size_t i = 0; i < arraysize(ptrs); i++) {
     if (ptrs[i]->is_set()) nodes->push_back(ptrs[i]->get());
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8