Remove --string-slices and --serialize-eager.

Both flags are obsolete.

R=cbruni@chromium.org

Change-Id: I78f5980f2d0bd569b8e5f6e29539cf87293cab94
Reviewed-on: https://chromium-review.googlesource.com/684296Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48194}

src/code-stub-assembler.cc

@@ -4180,39 +4180,37 @@ Node* CodeStubAssembler::SubString(Node* context, Node* string, Node* from,
   // encoding at this point.
   Label external_string(this);
   {
-    if (FLAG_string_slices) {
-      Label next(this);
+    Label next(this);
 
-      // Short slice.  Copy instead of slicing.
-      GotoIf(SmiLessThan(substr_length, SmiConstant(SlicedString::kMinLength)),
-             &next);
+    // Short slice.  Copy instead of slicing.
+    GotoIf(SmiLessThan(substr_length, SmiConstant(SlicedString::kMinLength)),
+           &next);
 
-      // Allocate new sliced string.
+    // Allocate new sliced string.
 
-      Counters* counters = isolate()->counters();
-      IncrementCounter(counters->sub_string_native(), 1);
+    Counters* counters = isolate()->counters();
+    IncrementCounter(counters->sub_string_native(), 1);
 
-      Label one_byte_slice(this), two_byte_slice(this);
-      Branch(IsOneByteStringInstanceType(to_direct.instance_type()),
-             &one_byte_slice, &two_byte_slice);
+    Label one_byte_slice(this), two_byte_slice(this);
+    Branch(IsOneByteStringInstanceType(to_direct.instance_type()),
+           &one_byte_slice, &two_byte_slice);
 
-      BIND(&one_byte_slice);
-      {
-        var_result.Bind(
-            AllocateSlicedOneByteString(substr_length, direct_string, offset));
-        Goto(&end);
-      }
-
-      BIND(&two_byte_slice);
-      {
-        var_result.Bind(
-            AllocateSlicedTwoByteString(substr_length, direct_string, offset));
-        Goto(&end);
-      }
+    BIND(&one_byte_slice);
+    {
+      var_result.Bind(
+          AllocateSlicedOneByteString(substr_length, direct_string, offset));
+      Goto(&end);
+    }
 
-      BIND(&next);
+    BIND(&two_byte_slice);
+    {
+      var_result.Bind(
+          AllocateSlicedTwoByteString(substr_length, direct_string, offset));
+      Goto(&end);
     }
 
+    BIND(&next);
+
     // The subject string can only be external or sequential string of either
     // encoding at this point.
     GotoIf(to_direct.is_external(), &external_string);
@@ -4220,7 +4218,6 @@ Node* CodeStubAssembler::SubString(Node* context, Node* string, Node* from,
     var_result.Bind(AllocAndCopyStringCharacters(
         context, direct_string, instance_type, offset, substr_length));
 
-    Counters* counters = isolate()->counters();
     IncrementCounter(counters->sub_string_native(), 1);
 
     Goto(&end);

src/factory.cc

@@ -835,7 +835,7 @@ Handle<String> Factory::NewProperSubString(Handle<String> str,
     return MakeOrFindTwoCharacterString(isolate(), c1, c2);
   }
 
-  if (!FLAG_string_slices || length < SlicedString::kMinLength) {
+  if (length < SlicedString::kMinLength) {
     if (str->IsOneByteRepresentation()) {
       Handle<SeqOneByteString> result =
           NewRawOneByteString(length).ToHandleChecked();

src/flag-definitions.h

@@ -317,7 +317,6 @@ DEFINE_VALUE_IMPLICATION(optimize_for_size, max_semi_space_size, 1)
 
 // Flags for data representation optimizations
 DEFINE_BOOL(unbox_double_arrays, true, "automatically unbox arrays of doubles")
-DEFINE_BOOL(string_slices, true, "use string slices")
 
 // Flags for Ignition.
 DEFINE_BOOL(ignition_elide_noneffectful_bytecodes, true,
@@ -772,7 +771,6 @@ DEFINE_BOOL(always_opt, false, "always try to optimize functions")
 DEFINE_BOOL(always_osr, false, "always try to OSR functions")
 DEFINE_BOOL(prepare_always_opt, false, "prepare for turning on always opt")
 
-DEFINE_BOOL(serialize_eager, false, "compile eagerly when caching scripts")
 DEFINE_BOOL(trace_serializer, false, "print code serializer trace")
 #ifdef DEBUG
 DEFINE_BOOL(external_reference_stats, false,

test/cctest/test-strings.cc

@@ -1155,7 +1155,6 @@ TEST(CachedHashOverflow) {
 
 
 TEST(SliceFromCons) {
-  FLAG_string_slices = true;
   CcTest::InitializeVM();
   Factory* factory = CcTest::i_isolate()->factory();
   v8::HandleScope scope(CcTest::isolate());
@@ -1222,7 +1221,6 @@ TEST(InternalizeExternal) {
 }
 
 TEST(SliceFromExternal) {
-  FLAG_string_slices = true;
   CcTest::InitializeVM();
   Factory* factory = CcTest::i_isolate()->factory();
   v8::HandleScope scope(CcTest::isolate());
@@ -1243,7 +1241,6 @@ TEST(SliceFromExternal) {
 TEST(TrivialSlice) {
   // This tests whether a slice that contains the entire parent string
   // actually creates a new string (it should not).
-  FLAG_string_slices = true;
   CcTest::InitializeVM();
   Factory* factory = CcTest::i_isolate()->factory();
   v8::HandleScope scope(CcTest::isolate());
@@ -1273,7 +1270,6 @@ TEST(TrivialSlice) {
 TEST(SliceFromSlice) {
   // This tests whether a slice that contains the entire parent string
   // actually creates a new string (it should not).
-  FLAG_string_slices = true;
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
   v8::Local<v8::Value> result;