[Interpreter] Bytecodes for exchanging registers.

test/cctest/interpreter/test-interpreter.cc

Index: test/cctest/interpreter/test-interpreter.cc
diff --git a/test/cctest/interpreter/test-interpreter.cc b/test/cctest/interpreter/test-interpreter.cc
index 3e7a1c470a57c1c73d9e51188827d8eea4837c54..055d7c695d36df49f7c783b0420cc3498d2520bf 100644
--- a/test/cctest/interpreter/test-interpreter.cc
+++ b/test/cctest/interpreter/test-interpreter.cc
@@ -361,6 +361,117 @@ TEST(InterpreterLoadStoreRegisters) {
 }
 
 
+TEST(InterpreterExchangeRegisters) {
+  for (int locals_count = 2; locals_count < 300; locals_count += 126) {
+    HandleAndZoneScope handles;
+    for (int exchanges = 1; exchanges < 4; exchanges++) {
+      BytecodeArrayBuilder builder(handles.main_isolate(), handles.main_zone());
+      builder.set_locals_count(locals_count);
+      builder.set_context_count(0);
+      builder.set_parameter_count(0);
+
+      Register r0(0);
+      Register r1(locals_count - 1);
+      builder.LoadTrue();
+      builder.StoreAccumulatorInRegister(r0);
+      builder.ExchangeRegisters(r0, r1);
+      builder.LoadFalse();
+      builder.StoreAccumulatorInRegister(r0);
+
+      bool expected = false;
+      for (int i = 0; i < exchanges; i++) {
+        builder.ExchangeRegisters(r0, r1);
+        expected = !expected;
+      }
+      builder.LoadAccumulatorWithRegister(r0);
+      builder.Return();
+      Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray();
+      InterpreterTester tester(handles.main_isolate(), bytecode_array);
+      auto callable = tester.GetCallable<>();
+      Handle<Object> return_val = callable().ToHandleChecked();
+      Handle<Object> expected_val =
+          handles.main_isolate()->factory()->ToBoolean(expected);
+      CHECK(return_val.is_identical_to(expected_val));
+    }
+  }
+}
+
+
+TEST(InterpreterExchangeRegistersWithParameter) {
+  for (int locals_count = 2; locals_count < 300; locals_count += 126) {
+    HandleAndZoneScope handles;
+    for (int exchanges = 1; exchanges < 4; exchanges++) {
+      BytecodeArrayBuilder builder(handles.main_isolate(), handles.main_zone());
+      builder.set_locals_count(locals_count);
+      builder.set_context_count(0);
+      builder.set_parameter_count(3);
+
+      Register r0 = Register::FromParameterIndex(2, 3);
+      Register r1(locals_count - 1);
+      builder.LoadTrue();
+      builder.StoreAccumulatorInRegister(r0);
+      builder.ExchangeRegisters(r0, r1);
+      builder.LoadFalse();
+      builder.StoreAccumulatorInRegister(r0);
+
+      bool expected = false;
+      for (int i = 0; i < exchanges; i++) {
+        builder.ExchangeRegisters(r0, r1);
+        expected = !expected;
+      }
+      builder.LoadAccumulatorWithRegister(r0);
+      builder.Return();
+      Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray();
+      InterpreterTester tester(handles.main_isolate(), bytecode_array);
+      auto callable = tester.GetCallable<>();
+      Handle<Object> return_val = callable().ToHandleChecked();
+      Handle<Object> expected_val =
+          handles.main_isolate()->factory()->ToBoolean(expected);
+      CHECK(return_val.is_identical_to(expected_val));
+    }
+  }
+}
+
+
+TEST(InterpreterExchangeWideRegisters) {
+  for (int locals_count = 3; locals_count < 300; locals_count += 126) {
+    HandleAndZoneScope handles;
+    for (int exchanges = 0; exchanges < 7; exchanges++) {
+      BytecodeArrayBuilder builder(handles.main_isolate(), handles.main_zone());
+      builder.set_locals_count(locals_count);
+      builder.set_context_count(0);
+      builder.set_parameter_count(0);
+
+      Register r0(0);
+      Register r1(locals_count - 1);
+      Register r2(locals_count - 2);
+      builder.LoadLiteral(Smi::FromInt(200));
+      builder.StoreAccumulatorInRegister(r0);
+      builder.ExchangeRegisters(r0, r1);
+      builder.LoadLiteral(Smi::FromInt(100));
+      builder.StoreAccumulatorInRegister(r0);
+      builder.ExchangeRegisters(r0, r2);
+      builder.LoadLiteral(Smi::FromInt(0));
+      builder.StoreAccumulatorInRegister(r0);
+      for (int i = 0; i < exchanges; i++) {
+        builder.ExchangeRegisters(r1, r2);
+        builder.ExchangeRegisters(r0, r1);
+      }
+      builder.LoadAccumulatorWithRegister(r0);
+      builder.Return();
+      Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray();
+      InterpreterTester tester(handles.main_isolate(), bytecode_array);
+      auto callable = tester.GetCallable<>();
+      Handle<Object> return_val = callable().ToHandleChecked();
+      Handle<Object> expected_val =
+          handles.main_isolate()->factory()->NewNumberFromInt(100 *
+                                                              (exchanges % 3));
+      CHECK(return_val.is_identical_to(expected_val));
+    }
+  }
+}
+
+
 static const Token::Value kShiftOperators[] = {
     Token::Value::SHL, Token::Value::SAR, Token::Value::SHR};