Fold BIT_NOT and NEGATE during constant propagation.

runtime/vm/constant_propagator.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/constant_propagator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_range_analysis.h"
@@ skipping 939 matching lines @@
   SetValue(instr, non_constant_);
 }
 
 
 void ConstantPropagator::VisitUnboxInt64(UnboxInt64Instr* instr) {
   // TODO(kmillikin): Handle unbox operation.
   SetValue(instr, non_constant_);
 }
 
 
+void ConstantPropagator::VisitUnaryIntegerOp(UnaryIntegerOpInstr* unary_op) {
+  const Object& value = unary_op->value()->definition()->constant_value();
+  if (IsConstant(value) && value.IsInteger()) {
+    const Integer& value_int = Integer::Cast(value);
+    const Integer& result =
+        Integer::Handle(I, unary_op->Evaluate(value_int));
+    if (!result.IsNull()) {
+      SetValue(unary_op, Integer::ZoneHandle(I, result.raw()));
+      return;
+    }
+  }
+
+  SetValue(unary_op, non_constant_);
+}
+
+
 void ConstantPropagator::VisitUnaryMintOp(UnaryMintOpInstr* instr) {
-  // TODO(kmillikin): Handle unary operations.
-  SetValue(instr, non_constant_);
+  VisitUnaryIntegerOp(instr);
 }
 
 
 void ConstantPropagator::VisitUnarySmiOp(UnarySmiOpInstr* instr) {
-  const Object& value = instr->value()->definition()->constant_value();
-  if (IsNonConstant(value)) {
-    SetValue(instr, non_constant_);
-  } else if (IsConstant(value)) {
-    // TODO(kmillikin): Handle unary operations.
-    SetValue(instr, non_constant_);
-  }
+  VisitUnaryIntegerOp(instr);
 }
 
 
 void ConstantPropagator::VisitUnaryDoubleOp(UnaryDoubleOpInstr* instr) {
   const Object& value = instr->value()->definition()->constant_value();
   if (IsNonConstant(value)) {
     SetValue(instr, non_constant_);
   } else if (IsConstant(value)) {
     // TODO(kmillikin): Handle unary operations.
     SetValue(instr, non_constant_);
@@ skipping 669 matching lines @@
   graph_->ComputeDominators(&dominance_frontier);
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 }  // namespace dart