binary-operator-reducer: reduce mul+div(shift)

src/compiler/machine-operator-reducer.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/compiler/machine-operator-reducer.h"
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/codegen.h"
 #include "src/compiler/diamond.h"
@@ skipping 630 matching lines @@
     return Changed(node);
   }
   return NoChange();
 }
 
 
 Reduction MachineOperatorReducer::ReduceTruncateFloat64ToInt32(Node* node) {
   Float64Matcher m(node->InputAt(0));
   if (m.HasValue()) return ReplaceInt32(DoubleToInt32(m.Value()));
   if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0));
+  if (m.IsRoundInt64ToFloat64()) return Replace(m.node()->InputAt(0));
   if (m.IsPhi()) {
     Node* const phi = m.node();
     DCHECK_EQ(kRepFloat64, RepresentationOf(OpParameter<MachineType>(phi)));
     if (phi->OwnedBy(node)) {
       // TruncateFloat64ToInt32[mode](Phi[Float64](x1,...,xn))
       //   => Phi[Int32](TruncateFloat64ToInt32[mode](x1),
       //                 ...,
       //                 TruncateFloat64ToInt32[mode](xn))
       const int value_input_count = phi->InputCount() - 1;
       for (int i = 0; i < value_input_count; ++i) {
@@ skipping 415 matching lines @@
 MachineOperatorBuilder* MachineOperatorReducer::machine() const {
   return jsgraph()->machine();
 }
 
 
 Graph* MachineOperatorReducer::graph() const { return jsgraph()->graph(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8