[wasm] Test the --liftoff flag

This adds two tests to verify that the --liftoff flag has the indented
effect, and that Liftoff compilation is off by default.

R=titzer@chromium.org

Bug: v8:6600
Change-Id: Ie7e13184b5068f572b78dbdf7abbcded6d859fc5
Reviewed-on: https://chromium-review.googlesource.com/733561
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48995}

src/runtime/runtime-test.cc

@@ -1072,5 +1072,14 @@ RUNTIME_FUNCTION(Runtime_WasmTraceMemory) {
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_IsLiftoffFunction) {
+  HandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
+  CHECK(WasmExportedFunction::IsWasmExportedFunction(*function));
+  Handle<Code> wasm_code = WasmExportedFunction::cast(*function)->GetWasmCode();
+  return isolate->heap()->ToBoolean(!wasm_code->is_turbofanned());
+}
+
 }  // namespace internal
 }  // namespace v8

src/runtime/runtime.h

@@ -631,7 +631,8 @@ namespace internal {
   F(HeapObjectVerify, 1, 1)                   \
   F(WasmNumInterpretedCalls, 1, 1)            \
   F(RedirectToWasmInterpreter, 2, 1)          \
-  F(WasmTraceMemory, 4, 1)
+  F(WasmTraceMemory, 4, 1)                    \
+  F(IsLiftoffFunction, 1, 1)
 
 #define FOR_EACH_INTRINSIC_TYPEDARRAY(F) \
   F(ArrayBufferGetByteLength, 1, 1)      \

test/mjsunit/mjsunit.status

@@ -688,4 +688,11 @@
     'compiler/stress-deopt-count-*': [SKIP],
 }], # arch != x64 or deopt_fuzzer
 
+##############################################################################
+# Liftoff is currently only sufficiently implemented on x64 and ia32.
+# TODO(clemensh): Implement on all other platforms (crbug.com/v8/6600).
+['arch != x64 and arch != ia32', {
+  'wasm/liftoff': [SKIP],
+}], # arch != x64 and arch != ia32
+
 ]

test/mjsunit/wasm/default-liftoff-setting.js

+// Copyright 2017 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.
+
+// Flags: --allow-natives-syntax
+
+// This test makes sure that by default, we do not compile with liftoff.
+
+load("test/mjsunit/wasm/wasm-constants.js");
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+const builder = new WasmModuleBuilder();
+builder.addFunction("i32_add", kSig_i_ii)
+    .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32Add])
+    .exportFunc();
+
+const instance = builder.instantiate();
+
+assertFalse(%IsLiftoffFunction(instance.exports.i32_add));

test/mjsunit/wasm/liftoff.js

+// Copyright 2017 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.
+
+// Flags: --allow-natives-syntax --liftoff --wasm-async-compilation
+
+load('test/mjsunit/wasm/wasm-constants.js');
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+(function testLiftoffSync() {
+  print(arguments.callee.name);
+  const builder = new WasmModuleBuilder();
+  builder.addFunction('i32_add', kSig_i_ii)
+      .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32Add])
+      .exportFunc();
+
+  const instance = builder.instantiate();
+
+  assertTrue(%IsLiftoffFunction(instance.exports.i32_add));
+})();
+
+async function testLiftoffAsync() {
+  print(arguments.callee.name);
+  const builder = new WasmModuleBuilder();
+  builder.addFunction('i32_add', kSig_i_ii)
+      .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32Add])
+      .exportFunc();
+
+  print('Compiling...');
+  const module = await WebAssembly.compile(builder.toBuffer());
+  print('Instantiating...');
+  const instance = new WebAssembly.Instance(module);
+  assertTrue(%IsLiftoffFunction(instance.exports.i32_add));
+}
+
+assertPromiseResult(testLiftoffAsync());