PPC/s390: [Atomics] Make Atomics.exchange a builtin using TF

src/compiler/s390/instruction-selector-s390.cc

 // Copyright 2015 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/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/s390/frames-s390.h"
 
@@ skipping 2499 matching lines @@
 
   InstructionOperand inputs[4];
   size_t input_count = 0;
   inputs[input_count++] = g.UseUniqueRegister(value);
   inputs[input_count++] = g.UseUniqueRegister(base);
   inputs[input_count++] = g.UseUniqueRegister(index);
   Emit(opcode | AddressingModeField::encode(kMode_MRR), 0, nullptr, input_count,
        inputs);
 }
 
+void InstructionSelector::VisitAtomicExchange(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::kFloat32RoundDown |
          MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat64RoundUp |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesAway |
          MachineOperatorBuilder::kWord32Popcnt |
          MachineOperatorBuilder::kWord32ReverseBytes |
          MachineOperatorBuilder::kWord64ReverseBytes |
          MachineOperatorBuilder::kWord64Popcnt;
 }
 
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8