[turbofan] Add DebugBreak machine operator and support

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 508 matching lines @@
   struct AtomicStore##Type##Operator                                           \
       : public Operator1<MachineRepresentation> {                              \
     AtomicStore##Type##Operator()                                              \
         : Operator1<MachineRepresentation>(                                    \
               IrOpcode::kAtomicStore, Operator::kNoRead | Operator::kNoThrow,  \
               "AtomicStore", 3, 1, 1, 0, 1, 0, MachineRepresentation::Type) {} \
   };                                                                           \
   AtomicStore##Type##Operator kAtomicStore##Type;
   ATOMIC_REPRESENTATION_LIST(ATOMIC_STORE)
 #undef STORE
+
+  struct DebugBreakOperator : public Operator {
+    DebugBreakOperator()
+        : Operator(IrOpcode::kDebugBreak, Operator::kNoThrow, "DebugBreak", 0,
+                   1, 1, 0, 1, 0) {}

[Michael Starzinger, 2016/05/19 08:53:23]

I assume the effect inputs are there in the hope of constraining it in the
effect chain. For now this operator is only used in scheduled graph. Would you
be fine with making this a "pure" operator for now instead (i.e. just adding it
to PURE_OP_LIST). Constraining it in the effect chain would require further
testing.

[danno, 2016/05/19 09:05:04]

Done.

+  };
+  DebugBreakOperator kDebugBreak;
 };
 
 
 static base::LazyInstance<MachineOperatorGlobalCache>::type kCache =
     LAZY_INSTANCE_INITIALIZER;
 
 
 MachineOperatorBuilder::MachineOperatorBuilder(Zone* zone,
                                                MachineRepresentation word,
                                                Flags flags)
@@ skipping 58 matching lines @@
     MACHINE_REPRESENTATION_LIST(STORE)
 #undef STORE
     case MachineRepresentation::kBit:
     case MachineRepresentation::kNone:
       break;
   }
   UNREACHABLE();
   return nullptr;
 }
 
+const Operator* MachineOperatorBuilder::DebugBreak() {
+  return &cache_.kDebugBreak;
+}
 
 const Operator* MachineOperatorBuilder::CheckedLoad(
     CheckedLoadRepresentation rep) {
 #define LOAD(Type)                     \
   if (rep == MachineType::Type()) {    \
     return &cache_.kCheckedLoad##Type; \
   }
     MACHINE_TYPE_LIST(LOAD)
 #undef LOAD
   UNREACHABLE();
@@ skipping 49 matching lines @@
   }
   ATOMIC_REPRESENTATION_LIST(STORE)
 #undef STORE
   UNREACHABLE();
   return nullptr;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8