[turbofan] Parameter nodes are not idempotent.

src/compiler/common-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/common-operator.h"
 
 #include "src/assembler.h"
 #include "src/base/lazy-instance.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
@@ skipping 186 matching lines @@
               0, 0, kInputCount, 0, 0, 1) {}          // counts
   };
 #define CACHED_MERGE(input_count) \
   MergeOperator<input_count> kMerge##input_count##Operator;
   CACHED_MERGE_LIST(CACHED_MERGE)
 #undef CACHED_MERGE
 
   template <int kIndex>
   struct ParameterOperator FINAL : public Operator1<int> {
     ParameterOperator()
-        : Operator1<int>(                             // --
-              IrOpcode::kParameter, Operator::kPure,  // opcode
-              "Parameter",                            // name
-              1, 0, 0, 1, 0, 0,                       // counts,
-              kIndex) {}                              // parameter
+        : Operator1<int>(                                // --
+              IrOpcode::kParameter,                      // opcode
+              Operator::kFoldable | Operator::kNoThrow,  // flags
+              "Parameter",                               // name
+              1, 0, 0, 1, 0, 0,                          // counts,
+              kIndex) {}                                 // parameter
   };
 #define CACHED_PARAMETER(index) \
   ParameterOperator<index> kParameter##index##Operator;
   CACHED_PARAMETER_LIST(CACHED_PARAMETER)
 #undef CACHED_PARAMETER
 };
 
 
 static base::LazyInstance<CommonOperatorGlobalCache>::type kCache =
     LAZY_INSTANCE_INITIALIZER;
@@ skipping 77 matching lines @@
   switch (index) {
 #define CACHED_PARAMETER(index) \
   case index:                   \
     return &cache_.kParameter##index##Operator;
     CACHED_PARAMETER_LIST(CACHED_PARAMETER)
 #undef CACHED_PARAMETER
     default:
       break;
   }
   // Uncached.
-  return new (zone()) Operator1<int>(         // --
-      IrOpcode::kParameter, Operator::kPure,  // opcode
-      "Parameter",                            // name
-      1, 0, 0, 1, 0, 0,                       // counts
-      index);                                 // parameter
+  return new (zone()) Operator1<int>(            // --
+      IrOpcode::kParameter,                      // opcode
+      Operator::kFoldable | Operator::kNoThrow,  // flags
+      "Parameter",                               // name
+      1, 0, 0, 1, 0, 0,                          // counts
+      index);                                    // parameter
 }
 
 
 const Operator* CommonOperatorBuilder::OsrValue(int index) {
   return new (zone()) Operator1<int>(                // --
       IrOpcode::kOsrValue, Operator::kNoProperties,  // opcode
       "OsrValue",                                    // name
       0, 0, 1, 1, 0, 0,                              // counts
       index);                                        // parameter
 }
@@ skipping 184 matching lines @@
   } else {
     UNREACHABLE();
     return nullptr;
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8