[turbofan] Get rid of truncation by store.

src/compiler/js-typed-lowering.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-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/linkage.h"
@@ skipping 1045 matching lines @@
           if (number_reduction.Changed()) {
             value = number_reduction.replacement();
           } else {
             Node* frame_state_for_to_number =
                 NodeProperties::GetFrameStateInput(node, 1);
             value = effect =
                 graph()->NewNode(javascript()->ToNumber(), value, context,
                                  frame_state_for_to_number, effect, control);
           }
         }
-        // For integer-typed arrays, convert to the integer type.
-        if (access.machine_type().semantic() == MachineSemantic::kInt32 &&
-            !value_type->Is(Type::Signed32())) {
-          value = graph()->NewNode(simplified()->NumberToInt32(), value);
-        } else if (access.machine_type().semantic() ==
-                       MachineSemantic::kUint32 &&
-                   !value_type->Is(Type::Unsigned32())) {
-          value = graph()->NewNode(simplified()->NumberToUint32(), value);
-        }
         // Check if we can avoid the bounds check.
         if (key_type->Min() >= 0 && key_type->Max() < array->length_value()) {
           RelaxControls(node);
           node->ReplaceInput(0, buffer);
           DCHECK_EQ(key, node->InputAt(1));
           node->ReplaceInput(2, value);
           node->ReplaceInput(3, effect);
           node->ReplaceInput(4, control);
           node->TrimInputCount(5);
           NodeProperties::ChangeOp(
@@ skipping 1613 matching lines @@
 }
 
 
 CompilationDependencies* JSTypedLowering::dependencies() const {
   return dependencies_;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8