Optimize expressions of the form (expr === true) when expr has boolean type.

vm/compiler.cc

 // Copyright (c) 2012, 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/compiler.h"
 
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 160 matching lines @@
         block_order.Add(graph_builder.postorder_block_entries()[i]);
       }
       if (optimized) {
         FlowGraphOptimizer optimizer(block_order);
         optimizer.ApplyICData();
 
         // Propagate types and eliminate more type tests.
         FlowGraphTypePropagator propagator(parsed_function, block_order);
         propagator.PropagateTypes();
 
+        // Do optimizations that depend on the propagated type information.
+        optimizer.OptimizeComputations();
+
         if (use_ssa) {
           // Perform register allocation on the SSA graph.
           FlowGraphAllocator allocator(block_order, &graph_builder);
           allocator.AllocateRegisters();
         }
         if (FLAG_print_flow_graph) {
           OS::Print("After Optimizations:\n");
           FlowGraphPrinter printer(Function::Handle(), block_order);
           printer.PrintBlocks();
         }
@@ skipping 189 matching lines @@
     if (FLAG_trace_compiler) {
       OS::Print("--> '%s' entry: 0x%x\n",
                 function.ToFullyQualifiedCString(),
                 Code::Handle(function.CurrentCode()).EntryPoint());
     }
     if (Isolate::Current()->debugger()->IsActive()) {
       Isolate::Current()->debugger()->NotifyCompilation(function);
     }
     if (FLAG_disassemble) {
       DisassembleCode(function, optimized);
-    }
-    if (FLAG_disassemble_optimized && optimized) {
+    } else if (FLAG_disassemble_optimized && optimized) {
       // Print unoptimized code along with the optimized code.
       DisassembleCode(function, false);
       DisassembleCode(function, true);
     }
     isolate->set_long_jump_base(base);
     return Error::null();
   } else {
     Error& error = Error::Handle();
     // We got an error during compilation.
     error = isolate->object_store()->sticky_error();
@@ skipping 114 matching lines @@
     result = isolate->object_store()->sticky_error();
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart