[Atomics] Make Atomics.exchange a builtin using TF

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index 44eadb1ee78670f2199d4152ebb7a6cdd588c723..cfc1841bac507e11b23295d393814faa12151491 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -2246,13 +2246,13 @@ void InstructionSelector::VisitAtomicStore(Node* node) {
   ArchOpcode opcode = kArchNop;
   switch (rep) {
     case MachineRepresentation::kWord8:
-      opcode = kX64Xchgb;
+      opcode = kAtomicExchangeInt8;
       break;
     case MachineRepresentation::kWord16:
-      opcode = kX64Xchgw;
+      opcode = kAtomicExchangeInt16;
       break;
     case MachineRepresentation::kWord32:
-      opcode = kX64Xchgl;
+      opcode = kAtomicExchangeWord32;
       break;
     default:
       UNREACHABLE();
@@ -2261,6 +2261,7 @@ void InstructionSelector::VisitAtomicStore(Node* node) {
   AddressingMode addressing_mode;
   InstructionOperand inputs[4];
   size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(value);
   inputs[input_count++] = g.UseUniqueRegister(base);
   if (g.CanBeImmediate(index)) {
     inputs[input_count++] = g.UseImmediate(index);
@@ -2269,11 +2270,50 @@ void InstructionSelector::VisitAtomicStore(Node* node) {
     inputs[input_count++] = g.UseUniqueRegister(index);
     addressing_mode = kMode_MR1;
   }
-  inputs[input_count++] = g.UseUniqueRegister(value);
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
   Emit(code, 0, static_cast<InstructionOperand*>(nullptr), input_count, inputs);
 }
 
+void InstructionSelector::VisitAtomicExchange(Node* node) {
+  X64OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  MachineType type = AtomicExchangeRepresentationOf(node->op());
+  ArchOpcode opcode = kArchNop;
+  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;
+  }
+  InstructionOperand outputs[1];
+  AddressingMode addressing_mode;
+  InstructionOperand inputs[4];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  if (g.CanBeImmediate(index)) {
+    inputs[input_count++] = g.UseImmediate(index);
+    addressing_mode = kMode_MRI;
+  } else {
+    inputs[input_count++] = g.UseUniqueRegister(index);
+    addressing_mode = kMode_MR1;
+  }
+  outputs[0] = g.DefineSameAsFirst(node);
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  Emit(code, 1, outputs, input_count, inputs);
+}
+
 void InstructionSelector::VisitInt32x4Splat(Node* node) {
   X64OperandGenerator g(this);
   Emit(kX64Int32x4Splat, g.DefineAsRegister(node), g.Use(node->InputAt(0)));