[turbofan] Add support for copy-on-write element stores.

src/compiler/simplified-operator.cc

 // Copyright 2012 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/simplified-operator.h"
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 #include "src/types.h"
@@ skipping 485 matching lines @@
   struct AllocateOperator final : public Operator1<PretenureFlag> {
     AllocateOperator()
         : Operator1<PretenureFlag>(
               IrOpcode::kAllocate,
               Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,
               "Allocate", 1, 1, 1, 1, 1, 0, kPretenure) {}
   };
   AllocateOperator<NOT_TENURED> kAllocateNotTenuredOperator;
   AllocateOperator<TENURED> kAllocateTenuredOperator;
 
+  struct EnsureWritableFastElementsOperator final : public Operator {
+    EnsureWritableFastElementsOperator()
+        : Operator(                                     // --
+              IrOpcode::kEnsureWritableFastElements,    // opcode
+              Operator::kNoDeopt | Operator::kNoThrow,  // flags
+              "EnsureWritableFastElements",             // name
+              2, 1, 1, 1, 1, 0) {}                      // counts
+  };
+  EnsureWritableFastElementsOperator kEnsureWritableFastElements;
+
 #define BUFFER_ACCESS(Type, type, TYPE, ctype, size)                          \
   struct LoadBuffer##Type##Operator final : public Operator1<BufferAccess> {  \
     LoadBuffer##Type##Operator()                                              \
         : Operator1<BufferAccess>(                                            \
               IrOpcode::kLoadBuffer,                                          \
               Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,   \
               "LoadBuffer", 3, 1, 1, 1, 1, 0,                                 \
               BufferAccess(kExternal##Type##Array)) {}                        \
   };                                                                          \
   struct StoreBuffer##Type##Operator final : public Operator1<BufferAccess> { \
@@ skipping 95 matching lines @@
   UNREACHABLE();
   return nullptr;
 }
 
 const Operator* SimplifiedOperatorBuilder::ReferenceEqual(Type* type) {
   return new (zone()) Operator(IrOpcode::kReferenceEqual,
                                Operator::kCommutative | Operator::kPure,
                                "ReferenceEqual", 2, 0, 0, 1, 0, 0);
 }
 
+const Operator* SimplifiedOperatorBuilder::EnsureWritableFastElements() {
+  return &cache_.kEnsureWritableFastElements;
+}
+
 const Operator* SimplifiedOperatorBuilder::TransitionElementsKind(
     ElementsTransition transition) {
   return new (zone()) Operator1<ElementsTransition>(  // --
       IrOpcode::kTransitionElementsKind,              // opcode
       Operator::kNoDeopt | Operator::kNoThrow,        // flags
       "TransitionElementsKind",                       // name
       3, 1, 1, 0, 1, 0,                               // counts
       transition);                                    // parameter
 }
 
@@ skipping 84 matching lines @@
                         Operator::kNoDeopt | Operator::kNoThrow | properties,  \
                         #Name, value_input_count, 1, control_input_count,      \
                         output_count, 1, 0, access);                           \
   }
 ACCESS_OP_LIST(ACCESS)
 #undef ACCESS
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8