[turbofan] Add comments to CodeAssembler

src/compiler/machine-operator.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.h"
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 
@@ skipping 519 matching lines @@
 #undef STORE
 
   struct DebugBreakOperator : public Operator {
     DebugBreakOperator()
         : Operator(IrOpcode::kDebugBreak, Operator::kNoThrow, "DebugBreak", 0,
                    0, 0, 0, 0, 0) {}
   };
   DebugBreakOperator kDebugBreak;
 };
 
+struct CommentOperator : public Operator1<const char*> {
+  explicit CommentOperator(const char* msg)
+      : Operator1<const char*>(IrOpcode::kComment, Operator::kNoThrow,
+                               "Comment", 0, 0, 0, 0, 0, 0, msg) {}
+};
 
 static base::LazyInstance<MachineOperatorGlobalCache>::type kCache =
     LAZY_INSTANCE_INITIALIZER;
 
 MachineOperatorBuilder::MachineOperatorBuilder(
     Zone* zone, MachineRepresentation word, Flags flags,
     AlignmentRequirements alignmentRequirements)
-    : cache_(kCache.Get()),
+    : zone_(zone),
+      cache_(kCache.Get()),
       word_(word),
       flags_(flags),
       alignment_requirements_(alignmentRequirements) {
   DCHECK(word == MachineRepresentation::kWord32 ||
          word == MachineRepresentation::kWord64);
 }
 
 
 #define PURE(Name, properties, value_input_count, control_input_count, \
              output_count)                                             \
@@ skipping 54 matching lines @@
       break;
   }
   UNREACHABLE();
   return nullptr;
 }
 
 const Operator* MachineOperatorBuilder::DebugBreak() {
   return &cache_.kDebugBreak;
 }
 
+const Operator* MachineOperatorBuilder::Comment(const char* msg) {
+  return new (zone_) CommentOperator(msg);
+}
+
 const Operator* MachineOperatorBuilder::CheckedLoad(
     CheckedLoadRepresentation rep) {
 #define LOAD(Type)                     \
   if (rep == MachineType::Type()) {    \
     return &cache_.kCheckedLoad##Type; \
   }
     MACHINE_TYPE_LIST(LOAD)
 #undef LOAD
   UNREACHABLE();
   return nullptr;
@@ skipping 48 matching lines @@
   }
   ATOMIC_REPRESENTATION_LIST(STORE)
 #undef STORE
   UNREACHABLE();
   return nullptr;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8