[Atomics] Make Atomics.exchange a builtin using TF

src/compiler/arm64/instruction-selector-arm64.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/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 2683 matching lines @@
   AddressingMode addressing_mode = kMode_MRR;
   InstructionOperand inputs[3];
   size_t input_count = 0;
   inputs[input_count++] = g.UseUniqueRegister(base);
   inputs[input_count++] = g.UseUniqueRegister(index);
   inputs[input_count++] = g.UseUniqueRegister(value);
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
   Emit(code, 0, nullptr, input_count, inputs);
 }
 
+void InstructionSelector::VisitAtomicExchange(Node* node) {
+  Arm64OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+  ArchOpcode opcode = kArchNop;
+  MachineType type = AtomicExchangeRepresentationOf(node->op());
+  if (type == MachineType::Int8()) {
+    opcode = kAtomicExchangeInt8;
+  } else if (type == MachineType::Uint8()) {
+    opcode = kAtomicExchangeUint8;
+  } else if (type == MachineType::Int16()) {
+    opcode = kAtomicExchangeInt16;
+  } else if (type == MachineType::Uint16()) {
+    opcode = kAtomicExchangeUint16;
+  } else if (type == MachineType::Int32() || type == MachineType::Uint32()) {
+    opcode = kAtomicExchangeWord32;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+
+  AddressingMode addressing_mode = kMode_MRR;
+  InstructionOperand inputs[3];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionOperand outputs[1];
+  outputs[0] = g.UseUniqueRegister(node);
+  InstructionOperand temp[2];
+  temp[0] = g.TempRegister();
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  Emit(code, 1, outputs, input_count, inputs, 1, temp);
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::kFloat32RoundDown |
          MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat32RoundUp |
          MachineOperatorBuilder::kFloat64RoundUp |
          MachineOperatorBuilder::kFloat32RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesAway |
          MachineOperatorBuilder::kFloat32RoundTiesEven |
          MachineOperatorBuilder::kFloat64RoundTiesEven |
          MachineOperatorBuilder::kWord32ShiftIsSafe |
          MachineOperatorBuilder::kInt32DivIsSafe |
          MachineOperatorBuilder::kUint32DivIsSafe |
          MachineOperatorBuilder::kWord32ReverseBits |
          MachineOperatorBuilder::kWord64ReverseBits;
 }
 
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8