[wasm] Prepare enabling liftoff by default on ia32 and x64

Before flipping the flag, some tests need to be adapted. This CL
prepares these tests, such that the flag flip CL really just flips a
flag.

R=titzer@chromium.org, hablich@chromium.org

Bug: v8:6600, chromium:787421
Change-Id: I8030df69cda5f3fb81354350a37f65c0d1c669bd
Reviewed-on: https://chromium-review.googlesource.com/1110363Reviewed-by: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53959}

test/fuzzer/wasm-fuzzer-common.cc

@@ -348,6 +348,7 @@ int WasmExecutionFuzzer::FuzzWasmModule(const uint8_t* data, size_t size,
   int32_t result_liftoff;
   {
     FlagScope<bool> liftoff(&FLAG_liftoff, true);
+    FlagScope<bool> no_tier_up(&FLAG_wasm_tier_up, false);
     ErrorThrower compiler_thrower(i_isolate, "Liftoff");
     // Re-compile with Liftoff.
     MaybeHandle<WasmInstanceObject> compiled_instance =

test/message/wasm-trace-memory-liftoff.js

@@ -3,5 +3,6 @@
 // found in the LICENSE file.
 
 // Flags: --no-stress-opt --wasm-trace-memory --liftoff --no-future
+// Flags: --no-wasm-tier-up
 
 load("test/message/wasm-trace-memory.js");

test/message/wasm-trace-memory.js

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 // Flags: --no-stress-opt --wasm-trace-memory --no-liftoff --no-future
+// Flags: --no-wasm-tier-up
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");

test/mjsunit/mjsunit.status

@@ -817,13 +817,6 @@
   'wasm/liftoff': [SKIP],
 }], # arch != x64 and arch != ia32
 
-##############################################################################
-['variant == liftoff or variant == future', {
-  # In the liftoff and future variant, liftoff compilation happens even
-  # though the test does not explicitly enable it.
-  'wasm/default-liftoff-setting': [SKIP],
-}], # variant == liftoff
-
 ##############################################################################
 ['variant == slow_path and gc_stress', {
   # Slow tests.

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),
-    'liftoff compilation should be off by default');

test/mjsunit/wasm/liftoff.js

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --liftoff --wasm-async-compilation
-// Flags: --no-future
+// Flags: --no-future --no-wasm-tier-up
 
 load('test/mjsunit/wasm/wasm-constants.js');
 load('test/mjsunit/wasm/wasm-module-builder.js');

tools/clusterfuzz/v8_foozzie.py

@@ -58,6 +58,7 @@ CONFIGS = dict(
   ],
   liftoff=[
     '--liftoff',
+    '--no-wasm-tier-up',
     '--suppress-asm-messages',
   ],
   slow_path=[

tools/testrunner/local/variants.py

@@ -10,7 +10,7 @@ ALL_VARIANT_FLAGS = {
   "gc_stats": [["--gc_stats=1"]],
   # Alias of exhaustive variants, but triggering new test framework features.
   "infra_staging": [[]],
-  "liftoff": [["--liftoff"]],
+  "no_liftoff": [["--no-wasm-tier-up"]],
   "minor_mc": [["--minor-mc"]],
   # No optimization means disable all optimizations. OptimizeFunctionOnNextCall
   # would not force optimization too. It turns into a Nop. Please see

tools/testrunner/standard_runner.py

@@ -43,7 +43,7 @@ VARIANT_ALIASES = {
   # Shortcut for the two above ("more" first - it has the longer running tests).
   "exhaustive": MORE_VARIANTS + VARIANTS,
   # Additional variants, run on a subset of bots.
-  "extra": ["future", "liftoff", "no_wasm_traps", "trusted"],
+  "extra": ["future", "no_liftoff", "no_wasm_traps", "trusted"],
 }
 
 GC_STRESS_FLAGS = ["--gc-interval=500", "--stress-compaction",