Optimize type checks for boolean expressions using class-id information.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 1318 matching lines @@
 Instruction* Instruction::Canonicalize() {
   return this;
 }
 
 
 Definition* Definition::Canonicalize() {
   return this;
 }
 
 
+Definition* AssertBooleanInstr::Canonicalize() {
+  const intptr_t value_cid = value()->ResultCid();
+  return (value_cid == kBoolCid) ? value()->definition() : this;
+}
+
+
 Definition* StrictCompareInstr::Canonicalize() {
   if (!right()->BindsToConstant()) return this;
   const Object& right_constant = right()->BoundConstant();
   Definition* left_defn = left()->definition();
   // TODO(fschneider): Handle other cases: e === false and e !== true/false.
   // Handles e === true.
   if ((kind() == Token::kEQ_STRICT) &&
       (right_constant.raw() == Bool::True()) &&
       (left()->ResultCid() == kBoolCid)) {
     // Return left subexpression as the replacement for this instruction.
     return left_defn;
   }
   return this;
 }
 
 
 Instruction* CheckClassInstr::Canonicalize() {
-  const intptr_t v_cid = value()->ResultCid();
+  const intptr_t value_cid = value()->ResultCid();
   const intptr_t num_checks = unary_checks().NumberOfChecks();
   if ((num_checks == 1) &&
-      (v_cid == unary_checks().GetReceiverClassIdAt(0))) {
+      (value_cid == unary_checks().GetReceiverClassIdAt(0))) {
     // No checks needed.
     return NULL;
   }
   return this;
 }
 
 
 Instruction* CheckSmiInstr::Canonicalize() {
   return (value()->ResultCid() == kSmiCid) ?  NULL : this;
 }
@@ skipping 716 matching lines @@
     new_max = new_max.Clamp();
   }
 
   return Range::Update(&range_, new_min, new_max);
 }
 
 
 #undef __
 
 }  // namespace dart