S390: [Atomics] Make Atomics.store a builtin using TF

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

Index: src/compiler/s390/instruction-selector-s390.cc
diff --git a/src/compiler/s390/instruction-selector-s390.cc b/src/compiler/s390/instruction-selector-s390.cc
index 150e2bd7d4cc21819002f64613c21a047e044261..6fdd7ec87fd56695c7c7eefd3c5cfd4f13a4514a 100644
--- a/src/compiler/s390/instruction-selector-s390.cc
+++ b/src/compiler/s390/instruction-selector-s390.cc
@@ -1768,6 +1768,37 @@ void InstructionSelector::VisitAtomicLoad(Node* node) {
        g.DefineAsRegister(node), g.UseRegister(base), g.UseRegister(index));
 }
 
+void InstructionSelector::VisitAtomicStore(Node* node) {
+  MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
+  S390OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+  ArchOpcode opcode = kArchNop;
+  switch (rep) {
+    case MachineRepresentation::kWord8:
+      opcode = kAtomicStoreWord8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kAtomicStoreWord16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kAtomicStoreWord32;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+
+  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);
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {