[turbofan] Lower StringEqual and friends in EffectControlLinearizer.

Turn the StringEqualStub and friends into proper TurboFan builtins,
which means that we don't need to do on-demand compilation for those
stubs, and use those to defer lowering of the StringEqual, etc.
simplified operators to effect/control linearization (i.e. move it to
the concurrent recompilation part).

BUG=v8:5428
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2363333003
Cr-Commit-Position: refs/heads/master@{#39762}

src/builtins/builtins-string.cc

@@ -10,6 +10,408 @@
 namespace v8 {
 namespace internal {
 
+namespace {
+
+enum ResultMode { kDontNegateResult, kNegateResult };
+
+void GenerateStringEqual(CodeStubAssembler* assembler, ResultMode mode) {
+  // Here's pseudo-code for the algorithm below in case of kDontNegateResult
+  // mode; for kNegateResult mode we properly negate the result.
+  //
+  // if (lhs == rhs) return true;
+  // if (lhs->length() != rhs->length()) return false;
+  // if (lhs->IsInternalizedString() && rhs->IsInternalizedString()) {
+  //   return false;
+  // }
+  // if (lhs->IsSeqOneByteString() && rhs->IsSeqOneByteString()) {
+  //   for (i = 0; i != lhs->length(); ++i) {
+  //     if (lhs[i] != rhs[i]) return false;
+  //   }
+  //   return true;
+  // }
+  // return %StringEqual(lhs, rhs);
+
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+  typedef CodeStubAssembler::Variable Variable;
+
+  Node* lhs = assembler->Parameter(0);
+  Node* rhs = assembler->Parameter(1);
+  Node* context = assembler->Parameter(2);
+
+  Label if_equal(assembler), if_notequal(assembler);
+
+  // Fast check to see if {lhs} and {rhs} refer to the same String object.
+  Label if_same(assembler), if_notsame(assembler);
+  assembler->Branch(assembler->WordEqual(lhs, rhs), &if_same, &if_notsame);
+
+  assembler->Bind(&if_same);
+  assembler->Goto(&if_equal);
+
+  assembler->Bind(&if_notsame);
+  {
+    // The {lhs} and {rhs} don't refer to the exact same String object.
+
+    // Load the length of {lhs} and {rhs}.
+    Node* lhs_length = assembler->LoadStringLength(lhs);
+    Node* rhs_length = assembler->LoadStringLength(rhs);
+
+    // Check if the lengths of {lhs} and {rhs} are equal.
+    Label if_lengthisequal(assembler), if_lengthisnotequal(assembler);
+    assembler->Branch(assembler->WordEqual(lhs_length, rhs_length),
+                      &if_lengthisequal, &if_lengthisnotequal);
+
+    assembler->Bind(&if_lengthisequal);
+    {
+      // Load instance types of {lhs} and {rhs}.
+      Node* lhs_instance_type = assembler->LoadInstanceType(lhs);
+      Node* rhs_instance_type = assembler->LoadInstanceType(rhs);
+
+      // Combine the instance types into a single 16-bit value, so we can check
+      // both of them at once.
+      Node* both_instance_types = assembler->Word32Or(
+          lhs_instance_type,
+          assembler->Word32Shl(rhs_instance_type, assembler->Int32Constant(8)));
+
+      // Check if both {lhs} and {rhs} are internalized.
+      int const kBothInternalizedMask =
+          kIsNotInternalizedMask | (kIsNotInternalizedMask << 8);
+      int const kBothInternalizedTag =
+          kInternalizedTag | (kInternalizedTag << 8);
+      Label if_bothinternalized(assembler), if_notbothinternalized(assembler);
+      assembler->Branch(assembler->Word32Equal(
+                            assembler->Word32And(both_instance_types,
+                                                 assembler->Int32Constant(
+                                                     kBothInternalizedMask)),
+                            assembler->Int32Constant(kBothInternalizedTag)),
+                        &if_bothinternalized, &if_notbothinternalized);
+
+      assembler->Bind(&if_bothinternalized);
+      {
+        // Fast negative check for internalized-to-internalized equality.
+        assembler->Goto(&if_notequal);
+      }
+
+      assembler->Bind(&if_notbothinternalized);
+      {
+        // Check that both {lhs} and {rhs} are flat one-byte strings.
+        int const kBothSeqOneByteStringMask =
+            kStringEncodingMask | kStringRepresentationMask |
+            ((kStringEncodingMask | kStringRepresentationMask) << 8);
+        int const kBothSeqOneByteStringTag =
+            kOneByteStringTag | kSeqStringTag |
+            ((kOneByteStringTag | kSeqStringTag) << 8);
+        Label if_bothonebyteseqstrings(assembler),
+            if_notbothonebyteseqstrings(assembler);
+        assembler->Branch(
+            assembler->Word32Equal(
+                assembler->Word32And(
+                    both_instance_types,
+                    assembler->Int32Constant(kBothSeqOneByteStringMask)),
+                assembler->Int32Constant(kBothSeqOneByteStringTag)),
+            &if_bothonebyteseqstrings, &if_notbothonebyteseqstrings);
+
+        assembler->Bind(&if_bothonebyteseqstrings);
+        {
+          // Compute the effective offset of the first character.
+          Node* begin = assembler->IntPtrConstant(
+              SeqOneByteString::kHeaderSize - kHeapObjectTag);
+
+          // Compute the first offset after the string from the length.
+          Node* end =
+              assembler->IntPtrAdd(begin, assembler->SmiUntag(lhs_length));
+
+          // Loop over the {lhs} and {rhs} strings to see if they are equal.
+          Variable var_offset(assembler, MachineType::PointerRepresentation());
+          Label loop(assembler, &var_offset);
+          var_offset.Bind(begin);
+          assembler->Goto(&loop);
+          assembler->Bind(&loop);
+          {
+            // Check if {offset} equals {end}.
+            Node* offset = var_offset.value();
+            Label if_done(assembler), if_notdone(assembler);
+            assembler->Branch(assembler->WordEqual(offset, end), &if_done,
+                              &if_notdone);
+
+            assembler->Bind(&if_notdone);
+            {
+              // Load the next characters from {lhs} and {rhs}.
+              Node* lhs_value =
+                  assembler->Load(MachineType::Uint8(), lhs, offset);
+              Node* rhs_value =
+                  assembler->Load(MachineType::Uint8(), rhs, offset);
+
+              // Check if the characters match.
+              Label if_valueissame(assembler), if_valueisnotsame(assembler);
+              assembler->Branch(assembler->Word32Equal(lhs_value, rhs_value),
+                                &if_valueissame, &if_valueisnotsame);
+
+              assembler->Bind(&if_valueissame);
+              {
+                // Advance to next character.
+                var_offset.Bind(
+                    assembler->IntPtrAdd(offset, assembler->IntPtrConstant(1)));
+              }
+              assembler->Goto(&loop);
+
+              assembler->Bind(&if_valueisnotsame);
+              assembler->Goto(&if_notequal);
+            }
+
+            assembler->Bind(&if_done);
+            assembler->Goto(&if_equal);
+          }
+        }
+
+        assembler->Bind(&if_notbothonebyteseqstrings);
+        {
+          // TODO(bmeurer): Add fast case support for flattened cons strings;
+          // also add support for two byte string equality checks.
+          Runtime::FunctionId function_id = (mode == kDontNegateResult)
+                                                ? Runtime::kStringEqual
+                                                : Runtime::kStringNotEqual;
+          assembler->TailCallRuntime(function_id, context, lhs, rhs);
+        }
+      }
+    }
+
+    assembler->Bind(&if_lengthisnotequal);
+    {
+      // Mismatch in length of {lhs} and {rhs}, cannot be equal.
+      assembler->Goto(&if_notequal);
+    }
+  }
+
+  assembler->Bind(&if_equal);
+  assembler->Return(assembler->BooleanConstant(mode == kDontNegateResult));
+
+  assembler->Bind(&if_notequal);
+  assembler->Return(assembler->BooleanConstant(mode == kNegateResult));
+}
+
+enum RelationalComparisonMode {
+  kLessThan,
+  kLessThanOrEqual,
+  kGreaterThan,
+  kGreaterThanOrEqual
+};
+
+void GenerateStringRelationalComparison(CodeStubAssembler* assembler,
+                                        RelationalComparisonMode mode) {
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+  typedef CodeStubAssembler::Variable Variable;
+
+  Node* lhs = assembler->Parameter(0);
+  Node* rhs = assembler->Parameter(1);
+  Node* context = assembler->Parameter(2);
+
+  Label if_less(assembler), if_equal(assembler), if_greater(assembler);
+
+  // Fast check to see if {lhs} and {rhs} refer to the same String object.
+  Label if_same(assembler), if_notsame(assembler);
+  assembler->Branch(assembler->WordEqual(lhs, rhs), &if_same, &if_notsame);
+
+  assembler->Bind(&if_same);
+  assembler->Goto(&if_equal);
+
+  assembler->Bind(&if_notsame);
+  {
+    // Load instance types of {lhs} and {rhs}.
+    Node* lhs_instance_type = assembler->LoadInstanceType(lhs);
+    Node* rhs_instance_type = assembler->LoadInstanceType(rhs);
+
+    // Combine the instance types into a single 16-bit value, so we can check
+    // both of them at once.
+    Node* both_instance_types = assembler->Word32Or(
+        lhs_instance_type,
+        assembler->Word32Shl(rhs_instance_type, assembler->Int32Constant(8)));
+
+    // Check that both {lhs} and {rhs} are flat one-byte strings.
+    int const kBothSeqOneByteStringMask =
+        kStringEncodingMask | kStringRepresentationMask |
+        ((kStringEncodingMask | kStringRepresentationMask) << 8);
+    int const kBothSeqOneByteStringTag =
+        kOneByteStringTag | kSeqStringTag |
+        ((kOneByteStringTag | kSeqStringTag) << 8);
+    Label if_bothonebyteseqstrings(assembler),
+        if_notbothonebyteseqstrings(assembler);
+    assembler->Branch(assembler->Word32Equal(
+                          assembler->Word32And(both_instance_types,
+                                               assembler->Int32Constant(
+                                                   kBothSeqOneByteStringMask)),
+                          assembler->Int32Constant(kBothSeqOneByteStringTag)),
+                      &if_bothonebyteseqstrings, &if_notbothonebyteseqstrings);
+
+    assembler->Bind(&if_bothonebyteseqstrings);
+    {
+      // Load the length of {lhs} and {rhs}.
+      Node* lhs_length = assembler->LoadStringLength(lhs);
+      Node* rhs_length = assembler->LoadStringLength(rhs);
+
+      // Determine the minimum length.
+      Node* length = assembler->SmiMin(lhs_length, rhs_length);
+
+      // Compute the effective offset of the first character.
+      Node* begin = assembler->IntPtrConstant(SeqOneByteString::kHeaderSize -
+                                              kHeapObjectTag);
+
+      // Compute the first offset after the string from the length.
+      Node* end = assembler->IntPtrAdd(begin, assembler->SmiUntag(length));
+
+      // Loop over the {lhs} and {rhs} strings to see if they are equal.
+      Variable var_offset(assembler, MachineType::PointerRepresentation());
+      Label loop(assembler, &var_offset);
+      var_offset.Bind(begin);
+      assembler->Goto(&loop);
+      assembler->Bind(&loop);
+      {
+        // Check if {offset} equals {end}.
+        Node* offset = var_offset.value();
+        Label if_done(assembler), if_notdone(assembler);
+        assembler->Branch(assembler->WordEqual(offset, end), &if_done,
+                          &if_notdone);
+
+        assembler->Bind(&if_notdone);
+        {
+          // Load the next characters from {lhs} and {rhs}.
+          Node* lhs_value = assembler->Load(MachineType::Uint8(), lhs, offset);
+          Node* rhs_value = assembler->Load(MachineType::Uint8(), rhs, offset);
+
+          // Check if the characters match.
+          Label if_valueissame(assembler), if_valueisnotsame(assembler);
+          assembler->Branch(assembler->Word32Equal(lhs_value, rhs_value),
+                            &if_valueissame, &if_valueisnotsame);
+
+          assembler->Bind(&if_valueissame);
+          {
+            // Advance to next character.
+            var_offset.Bind(
+                assembler->IntPtrAdd(offset, assembler->IntPtrConstant(1)));
+          }
+          assembler->Goto(&loop);
+
+          assembler->Bind(&if_valueisnotsame);
+          assembler->BranchIf(assembler->Uint32LessThan(lhs_value, rhs_value),
+                              &if_less, &if_greater);
+        }
+
+        assembler->Bind(&if_done);
+        {
+          // All characters up to the min length are equal, decide based on
+          // string length.
+          Label if_lengthisequal(assembler), if_lengthisnotequal(assembler);
+          assembler->Branch(assembler->SmiEqual(lhs_length, rhs_length),
+                            &if_lengthisequal, &if_lengthisnotequal);
+
+          assembler->Bind(&if_lengthisequal);
+          assembler->Goto(&if_equal);
+
+          assembler->Bind(&if_lengthisnotequal);
+          assembler->BranchIfSmiLessThan(lhs_length, rhs_length, &if_less,
+                                         &if_greater);
+        }
+      }
+    }
+
+    assembler->Bind(&if_notbothonebyteseqstrings);
+    {
+      // TODO(bmeurer): Add fast case support for flattened cons strings;
+      // also add support for two byte string relational comparisons.
+      switch (mode) {
+        case kLessThan:
+          assembler->TailCallRuntime(Runtime::kStringLessThan, context, lhs,
+                                     rhs);
+          break;
+        case kLessThanOrEqual:
+          assembler->TailCallRuntime(Runtime::kStringLessThanOrEqual, context,
+                                     lhs, rhs);
+          break;
+        case kGreaterThan:
+          assembler->TailCallRuntime(Runtime::kStringGreaterThan, context, lhs,
+                                     rhs);
+          break;
+        case kGreaterThanOrEqual:
+          assembler->TailCallRuntime(Runtime::kStringGreaterThanOrEqual,
+                                     context, lhs, rhs);
+          break;
+      }
+    }
+  }
+
+  assembler->Bind(&if_less);
+  switch (mode) {
+    case kLessThan:
+    case kLessThanOrEqual:
+      assembler->Return(assembler->BooleanConstant(true));
+      break;
+
+    case kGreaterThan:
+    case kGreaterThanOrEqual:
+      assembler->Return(assembler->BooleanConstant(false));
+      break;
+  }
+
+  assembler->Bind(&if_equal);
+  switch (mode) {
+    case kLessThan:
+    case kGreaterThan:
+      assembler->Return(assembler->BooleanConstant(false));
+      break;
+
+    case kLessThanOrEqual:
+    case kGreaterThanOrEqual:
+      assembler->Return(assembler->BooleanConstant(true));
+      break;
+  }
+
+  assembler->Bind(&if_greater);
+  switch (mode) {
+    case kLessThan:
+    case kLessThanOrEqual:
+      assembler->Return(assembler->BooleanConstant(false));
+      break;
+
+    case kGreaterThan:
+    case kGreaterThanOrEqual:
+      assembler->Return(assembler->BooleanConstant(true));
+      break;
+  }
+}
+
+}  // namespace
+
+// static
+void Builtins::Generate_StringEqual(CodeStubAssembler* assembler) {
+  GenerateStringEqual(assembler, kDontNegateResult);
+}
+
+// static
+void Builtins::Generate_StringNotEqual(CodeStubAssembler* assembler) {
+  GenerateStringEqual(assembler, kNegateResult);
+}
+
+// static
+void Builtins::Generate_StringLessThan(CodeStubAssembler* assembler) {
+  GenerateStringRelationalComparison(assembler, kLessThan);
+}
+
+// static
+void Builtins::Generate_StringLessThanOrEqual(CodeStubAssembler* assembler) {
+  GenerateStringRelationalComparison(assembler, kLessThanOrEqual);
+}
+
+// static
+void Builtins::Generate_StringGreaterThan(CodeStubAssembler* assembler) {
+  GenerateStringRelationalComparison(assembler, kGreaterThan);
+}
+
+// static
+void Builtins::Generate_StringGreaterThanOrEqual(CodeStubAssembler* assembler) {
+  GenerateStringRelationalComparison(assembler, kGreaterThanOrEqual);
+}
+
 // -----------------------------------------------------------------------------
 // ES6 section 21.1 String Objects
 

src/builtins/builtins.h

@@ -97,6 +97,14 @@ namespace internal {
   ASM(InterruptCheck)                                                         \
   ASM(StackCheck)                                                             \
                                                                               \
+  /* String helpers */                                                        \
+  TFS(StringEqual, BUILTIN, kNoExtraICState, Compare)                         \
+  TFS(StringNotEqual, BUILTIN, kNoExtraICState, Compare)                      \
+  TFS(StringLessThan, BUILTIN, kNoExtraICState, Compare)                      \
+  TFS(StringLessThanOrEqual, BUILTIN, kNoExtraICState, Compare)               \
+  TFS(StringGreaterThan, BUILTIN, kNoExtraICState, Compare)                   \
+  TFS(StringGreaterThanOrEqual, BUILTIN, kNoExtraICState, Compare)            \
+                                                                              \
   /* Interpreter */                                                           \
   ASM(InterpreterEntryTrampoline)                                             \
   ASM(InterpreterMarkBaselineOnReturn)                                        \

src/code-factory.cc

@@ -410,38 +410,38 @@ Callable CodeFactory::StringCompare(Isolate* isolate, Token::Value token) {
 
 // static
 Callable CodeFactory::StringEqual(Isolate* isolate) {
-  StringEqualStub stub(isolate);
-  return make_callable(stub);
+  return Callable(isolate->builtins()->StringEqual(),
+                  CompareDescriptor(isolate));
 }
 
 // static
 Callable CodeFactory::StringNotEqual(Isolate* isolate) {
-  StringNotEqualStub stub(isolate);
-  return make_callable(stub);
+  return Callable(isolate->builtins()->StringNotEqual(),
+                  CompareDescriptor(isolate));
 }
 
 // static
 Callable CodeFactory::StringLessThan(Isolate* isolate) {
-  StringLessThanStub stub(isolate);
-  return make_callable(stub);
+  return Callable(isolate->builtins()->StringLessThan(),
+                  CompareDescriptor(isolate));
 }
 
 // static
 Callable CodeFactory::StringLessThanOrEqual(Isolate* isolate) {
-  StringLessThanOrEqualStub stub(isolate);
-  return make_callable(stub);
+  return Callable(isolate->builtins()->StringLessThanOrEqual(),
+                  CompareDescriptor(isolate));
 }
 
 // static
 Callable CodeFactory::StringGreaterThan(Isolate* isolate) {
-  StringGreaterThanStub stub(isolate);
-  return make_callable(stub);
+  return Callable(isolate->builtins()->StringGreaterThan(),
+                  CompareDescriptor(isolate));
 }
 
 // static
 Callable CodeFactory::StringGreaterThanOrEqual(Isolate* isolate) {
-  StringGreaterThanOrEqualStub stub(isolate);
-  return make_callable(stub);
+  return Callable(isolate->builtins()->StringGreaterThanOrEqual(),
+                  CompareDescriptor(isolate));
 }
 
 // static

src/code-stubs.cc

@@ -4188,365 +4188,6 @@ compiler::Node* GenerateStrictEqual(CodeStubAssembler* assembler,
   return result.value();
 }
 
-void GenerateStringRelationalComparison(CodeStubAssembler* assembler,
-                                        RelationalComparisonMode mode) {
-  typedef CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
-  typedef CodeStubAssembler::Variable Variable;
-
-  Node* lhs = assembler->Parameter(0);
-  Node* rhs = assembler->Parameter(1);
-  Node* context = assembler->Parameter(2);
-
-  Label if_less(assembler), if_equal(assembler), if_greater(assembler);
-
-  // Fast check to see if {lhs} and {rhs} refer to the same String object.
-  Label if_same(assembler), if_notsame(assembler);
-  assembler->Branch(assembler->WordEqual(lhs, rhs), &if_same, &if_notsame);
-
-  assembler->Bind(&if_same);
-  assembler->Goto(&if_equal);
-
-  assembler->Bind(&if_notsame);
-  {
-    // Load instance types of {lhs} and {rhs}.
-    Node* lhs_instance_type = assembler->LoadInstanceType(lhs);
-    Node* rhs_instance_type = assembler->LoadInstanceType(rhs);
-
-    // Combine the instance types into a single 16-bit value, so we can check
-    // both of them at once.
-    Node* both_instance_types = assembler->Word32Or(
-        lhs_instance_type,
-        assembler->Word32Shl(rhs_instance_type, assembler->Int32Constant(8)));
-
-    // Check that both {lhs} and {rhs} are flat one-byte strings.
-    int const kBothSeqOneByteStringMask =
-        kStringEncodingMask | kStringRepresentationMask |
-        ((kStringEncodingMask | kStringRepresentationMask) << 8);
-    int const kBothSeqOneByteStringTag =
-        kOneByteStringTag | kSeqStringTag |
-        ((kOneByteStringTag | kSeqStringTag) << 8);
-    Label if_bothonebyteseqstrings(assembler),
-        if_notbothonebyteseqstrings(assembler);
-    assembler->Branch(assembler->Word32Equal(
-                          assembler->Word32And(both_instance_types,
-                                               assembler->Int32Constant(
-                                                   kBothSeqOneByteStringMask)),
-                          assembler->Int32Constant(kBothSeqOneByteStringTag)),
-                      &if_bothonebyteseqstrings, &if_notbothonebyteseqstrings);
-
-    assembler->Bind(&if_bothonebyteseqstrings);
-    {
-      // Load the length of {lhs} and {rhs}.
-      Node* lhs_length = assembler->LoadStringLength(lhs);
-      Node* rhs_length = assembler->LoadStringLength(rhs);
-
-      // Determine the minimum length.
-      Node* length = assembler->SmiMin(lhs_length, rhs_length);
-
-      // Compute the effective offset of the first character.
-      Node* begin = assembler->IntPtrConstant(SeqOneByteString::kHeaderSize -
-                                              kHeapObjectTag);
-
-      // Compute the first offset after the string from the length.
-      Node* end = assembler->IntPtrAdd(begin, assembler->SmiUntag(length));
-
-      // Loop over the {lhs} and {rhs} strings to see if they are equal.
-      Variable var_offset(assembler, MachineType::PointerRepresentation());
-      Label loop(assembler, &var_offset);
-      var_offset.Bind(begin);
-      assembler->Goto(&loop);
-      assembler->Bind(&loop);
-      {
-        // Check if {offset} equals {end}.
-        Node* offset = var_offset.value();
-        Label if_done(assembler), if_notdone(assembler);
-        assembler->Branch(assembler->WordEqual(offset, end), &if_done,
-                          &if_notdone);
-
-        assembler->Bind(&if_notdone);
-        {
-          // Load the next characters from {lhs} and {rhs}.
-          Node* lhs_value = assembler->Load(MachineType::Uint8(), lhs, offset);
-          Node* rhs_value = assembler->Load(MachineType::Uint8(), rhs, offset);
-
-          // Check if the characters match.
-          Label if_valueissame(assembler), if_valueisnotsame(assembler);
-          assembler->Branch(assembler->Word32Equal(lhs_value, rhs_value),
-                            &if_valueissame, &if_valueisnotsame);
-
-          assembler->Bind(&if_valueissame);
-          {
-            // Advance to next character.
-            var_offset.Bind(
-                assembler->IntPtrAdd(offset, assembler->IntPtrConstant(1)));
-          }
-          assembler->Goto(&loop);
-
-          assembler->Bind(&if_valueisnotsame);
-          assembler->BranchIf(assembler->Uint32LessThan(lhs_value, rhs_value),
-                              &if_less, &if_greater);
-        }
-
-        assembler->Bind(&if_done);
-        {
-          // All characters up to the min length are equal, decide based on
-          // string length.
-          Label if_lengthisequal(assembler), if_lengthisnotequal(assembler);
-          assembler->Branch(assembler->SmiEqual(lhs_length, rhs_length),
-                            &if_lengthisequal, &if_lengthisnotequal);
-
-          assembler->Bind(&if_lengthisequal);
-          assembler->Goto(&if_equal);
-
-          assembler->Bind(&if_lengthisnotequal);
-          assembler->BranchIfSmiLessThan(lhs_length, rhs_length, &if_less,
-                                         &if_greater);
-        }
-      }
-    }
-
-    assembler->Bind(&if_notbothonebyteseqstrings);
-    {
-      // TODO(bmeurer): Add fast case support for flattened cons strings;
-      // also add support for two byte string relational comparisons.
-      switch (mode) {
-        case kLessThan:
-          assembler->TailCallRuntime(Runtime::kStringLessThan, context, lhs,
-                                     rhs);
-          break;
-        case kLessThanOrEqual:
-          assembler->TailCallRuntime(Runtime::kStringLessThanOrEqual, context,
-                                     lhs, rhs);
-          break;
-        case kGreaterThan:
-          assembler->TailCallRuntime(Runtime::kStringGreaterThan, context, lhs,
-                                     rhs);
-          break;
-        case kGreaterThanOrEqual:
-          assembler->TailCallRuntime(Runtime::kStringGreaterThanOrEqual,
-                                     context, lhs, rhs);
-          break;
-      }
-    }
-  }
-
-  assembler->Bind(&if_less);
-  switch (mode) {
-    case kLessThan:
-    case kLessThanOrEqual:
-      assembler->Return(assembler->BooleanConstant(true));
-      break;
-
-    case kGreaterThan:
-    case kGreaterThanOrEqual:
-      assembler->Return(assembler->BooleanConstant(false));
-      break;
-  }
-
-  assembler->Bind(&if_equal);
-  switch (mode) {
-    case kLessThan:
-    case kGreaterThan:
-      assembler->Return(assembler->BooleanConstant(false));
-      break;
-
-    case kLessThanOrEqual:
-    case kGreaterThanOrEqual:
-      assembler->Return(assembler->BooleanConstant(true));
-      break;
-  }
-
-  assembler->Bind(&if_greater);
-  switch (mode) {
-    case kLessThan:
-    case kLessThanOrEqual:
-      assembler->Return(assembler->BooleanConstant(false));
-      break;
-
-    case kGreaterThan:
-    case kGreaterThanOrEqual:
-      assembler->Return(assembler->BooleanConstant(true));
-      break;
-  }
-}
-
-void GenerateStringEqual(CodeStubAssembler* assembler, ResultMode mode) {
-  // Here's pseudo-code for the algorithm below in case of kDontNegateResult
-  // mode; for kNegateResult mode we properly negate the result.
-  //
-  // if (lhs == rhs) return true;
-  // if (lhs->length() != rhs->length()) return false;
-  // if (lhs->IsInternalizedString() && rhs->IsInternalizedString()) {
-  //   return false;
-  // }
-  // if (lhs->IsSeqOneByteString() && rhs->IsSeqOneByteString()) {
-  //   for (i = 0; i != lhs->length(); ++i) {
-  //     if (lhs[i] != rhs[i]) return false;
-  //   }
-  //   return true;
-  // }
-  // return %StringEqual(lhs, rhs);
-
-  typedef CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
-  typedef CodeStubAssembler::Variable Variable;
-
-  Node* lhs = assembler->Parameter(0);
-  Node* rhs = assembler->Parameter(1);
-  Node* context = assembler->Parameter(2);
-
-  Label if_equal(assembler), if_notequal(assembler);
-
-  // Fast check to see if {lhs} and {rhs} refer to the same String object.
-  Label if_same(assembler), if_notsame(assembler);
-  assembler->Branch(assembler->WordEqual(lhs, rhs), &if_same, &if_notsame);
-
-  assembler->Bind(&if_same);
-  assembler->Goto(&if_equal);
-
-  assembler->Bind(&if_notsame);
-  {
-    // The {lhs} and {rhs} don't refer to the exact same String object.
-
-    // Load the length of {lhs} and {rhs}.
-    Node* lhs_length = assembler->LoadStringLength(lhs);
-    Node* rhs_length = assembler->LoadStringLength(rhs);
-
-    // Check if the lengths of {lhs} and {rhs} are equal.
-    Label if_lengthisequal(assembler), if_lengthisnotequal(assembler);
-    assembler->Branch(assembler->WordEqual(lhs_length, rhs_length),
-                      &if_lengthisequal, &if_lengthisnotequal);
-
-    assembler->Bind(&if_lengthisequal);
-    {
-      // Load instance types of {lhs} and {rhs}.
-      Node* lhs_instance_type = assembler->LoadInstanceType(lhs);
-      Node* rhs_instance_type = assembler->LoadInstanceType(rhs);
-
-      // Combine the instance types into a single 16-bit value, so we can check
-      // both of them at once.
-      Node* both_instance_types = assembler->Word32Or(
-          lhs_instance_type,
-          assembler->Word32Shl(rhs_instance_type, assembler->Int32Constant(8)));
-
-      // Check if both {lhs} and {rhs} are internalized.
-      int const kBothInternalizedMask =
-          kIsNotInternalizedMask | (kIsNotInternalizedMask << 8);
-      int const kBothInternalizedTag =
-          kInternalizedTag | (kInternalizedTag << 8);
-      Label if_bothinternalized(assembler), if_notbothinternalized(assembler);
-      assembler->Branch(assembler->Word32Equal(
-                            assembler->Word32And(both_instance_types,
-                                                 assembler->Int32Constant(
-                                                     kBothInternalizedMask)),
-                            assembler->Int32Constant(kBothInternalizedTag)),
-                        &if_bothinternalized, &if_notbothinternalized);
-
-      assembler->Bind(&if_bothinternalized);
-      {
-        // Fast negative check for internalized-to-internalized equality.
-        assembler->Goto(&if_notequal);
-      }
-
-      assembler->Bind(&if_notbothinternalized);
-      {
-        // Check that both {lhs} and {rhs} are flat one-byte strings.
-        int const kBothSeqOneByteStringMask =
-            kStringEncodingMask | kStringRepresentationMask |
-            ((kStringEncodingMask | kStringRepresentationMask) << 8);
-        int const kBothSeqOneByteStringTag =
-            kOneByteStringTag | kSeqStringTag |
-            ((kOneByteStringTag | kSeqStringTag) << 8);
-        Label if_bothonebyteseqstrings(assembler),
-            if_notbothonebyteseqstrings(assembler);
-        assembler->Branch(
-            assembler->Word32Equal(
-                assembler->Word32And(
-                    both_instance_types,
-                    assembler->Int32Constant(kBothSeqOneByteStringMask)),
-                assembler->Int32Constant(kBothSeqOneByteStringTag)),
-            &if_bothonebyteseqstrings, &if_notbothonebyteseqstrings);
-
-        assembler->Bind(&if_bothonebyteseqstrings);
-        {
-          // Compute the effective offset of the first character.
-          Node* begin = assembler->IntPtrConstant(
-              SeqOneByteString::kHeaderSize - kHeapObjectTag);
-
-          // Compute the first offset after the string from the length.
-          Node* end =
-              assembler->IntPtrAdd(begin, assembler->SmiUntag(lhs_length));
-
-          // Loop over the {lhs} and {rhs} strings to see if they are equal.
-          Variable var_offset(assembler, MachineType::PointerRepresentation());
-          Label loop(assembler, &var_offset);
-          var_offset.Bind(begin);
-          assembler->Goto(&loop);
-          assembler->Bind(&loop);
-          {
-            // Check if {offset} equals {end}.
-            Node* offset = var_offset.value();
-            Label if_done(assembler), if_notdone(assembler);
-            assembler->Branch(assembler->WordEqual(offset, end), &if_done,
-                              &if_notdone);
-
-            assembler->Bind(&if_notdone);
-            {
-              // Load the next characters from {lhs} and {rhs}.
-              Node* lhs_value =
-                  assembler->Load(MachineType::Uint8(), lhs, offset);
-              Node* rhs_value =
-                  assembler->Load(MachineType::Uint8(), rhs, offset);
-
-              // Check if the characters match.
-              Label if_valueissame(assembler), if_valueisnotsame(assembler);
-              assembler->Branch(assembler->Word32Equal(lhs_value, rhs_value),
-                                &if_valueissame, &if_valueisnotsame);
-
-              assembler->Bind(&if_valueissame);
-              {
-                // Advance to next character.
-                var_offset.Bind(
-                    assembler->IntPtrAdd(offset, assembler->IntPtrConstant(1)));
-              }
-              assembler->Goto(&loop);
-
-              assembler->Bind(&if_valueisnotsame);
-              assembler->Goto(&if_notequal);
-            }
-
-            assembler->Bind(&if_done);
-            assembler->Goto(&if_equal);
-          }
-        }
-
-        assembler->Bind(&if_notbothonebyteseqstrings);
-        {
-          // TODO(bmeurer): Add fast case support for flattened cons strings;
-          // also add support for two byte string equality checks.
-          Runtime::FunctionId function_id = (mode == kDontNegateResult)
-                                                ? Runtime::kStringEqual
-                                                : Runtime::kStringNotEqual;
-          assembler->TailCallRuntime(function_id, context, lhs, rhs);
-        }
-      }
-    }
-
-    assembler->Bind(&if_lengthisnotequal);
-    {
-      // Mismatch in length of {lhs} and {rhs}, cannot be equal.
-      assembler->Goto(&if_notequal);
-    }
-  }
-
-  assembler->Bind(&if_equal);
-  assembler->Return(assembler->BooleanConstant(mode == kDontNegateResult));
-
-  assembler->Bind(&if_notequal);
-  assembler->Return(assembler->BooleanConstant(mode == kNegateResult));
-}
-
 }  // namespace
 
 void LoadApiGetterStub::GenerateAssembly(CodeStubAssembler* assembler) const {
@@ -4845,33 +4486,6 @@ compiler::Node* StrictNotEqualStub::Generate(CodeStubAssembler* assembler,
   return GenerateStrictEqual(assembler, kNegateResult, lhs, rhs, context);
 }
 
-void StringEqualStub::GenerateAssembly(CodeStubAssembler* assembler) const {
-  GenerateStringEqual(assembler, kDontNegateResult);
-}
-
-void StringNotEqualStub::GenerateAssembly(CodeStubAssembler* assembler) const {
-  GenerateStringEqual(assembler, kNegateResult);
-}
-
-void StringLessThanStub::GenerateAssembly(CodeStubAssembler* assembler) const {
-  GenerateStringRelationalComparison(assembler, kLessThan);
-}
-
-void StringLessThanOrEqualStub::GenerateAssembly(
-    CodeStubAssembler* assembler) const {
-  GenerateStringRelationalComparison(assembler, kLessThanOrEqual);
-}
-
-void StringGreaterThanStub::GenerateAssembly(
-    CodeStubAssembler* assembler) const {
-  GenerateStringRelationalComparison(assembler, kGreaterThan);
-}
-
-void StringGreaterThanOrEqualStub::GenerateAssembly(
-    CodeStubAssembler* assembler) const {
-  GenerateStringRelationalComparison(assembler, kGreaterThanOrEqual);
-}
-
 void ToLengthStub::GenerateAssembly(CodeStubAssembler* assembler) const {
   typedef CodeStubAssembler::Label Label;
   typedef compiler::Node Node;

src/code-stubs.h

@@ -148,12 +148,6 @@ class ObjectLiteral;
   V(StoreScriptContextField)                  \
   V(StrictEqual)                              \
   V(StrictNotEqual)                           \
-  V(StringEqual)                              \
-  V(StringNotEqual)                           \
-  V(StringLessThan)                           \
-  V(StringLessThanOrEqual)                    \
-  V(StringGreaterThan)                        \
-  V(StringGreaterThanOrEqual)                 \
   V(ToInteger)                                \
   V(ToLength)                                 \
   V(HasProperty)                              \
@@ -990,57 +984,6 @@ class StrictNotEqualStub final : public TurboFanCodeStub {
   DEFINE_TURBOFAN_BINARY_OP_CODE_STUB(StrictNotEqual, TurboFanCodeStub);
 };
 
-class StringEqualStub final : public TurboFanCodeStub {
- public:
-  explicit StringEqualStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
-  DEFINE_TURBOFAN_CODE_STUB(StringEqual, TurboFanCodeStub);
-};
-
-class StringNotEqualStub final : public TurboFanCodeStub {
- public:
-  explicit StringNotEqualStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
-  DEFINE_TURBOFAN_CODE_STUB(StringNotEqual, TurboFanCodeStub);
-};
-
-class StringLessThanStub final : public TurboFanCodeStub {
- public:
-  explicit StringLessThanStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
-  DEFINE_TURBOFAN_CODE_STUB(StringLessThan, TurboFanCodeStub);
-};
-
-class StringLessThanOrEqualStub final : public TurboFanCodeStub {
- public:
-  explicit StringLessThanOrEqualStub(Isolate* isolate)
-      : TurboFanCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
-  DEFINE_TURBOFAN_CODE_STUB(StringLessThanOrEqual, TurboFanCodeStub);
-};
-
-class StringGreaterThanStub final : public TurboFanCodeStub {
- public:
-  explicit StringGreaterThanStub(Isolate* isolate)
-      : TurboFanCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
-  DEFINE_TURBOFAN_CODE_STUB(StringGreaterThan, TurboFanCodeStub);
-};
-
-class StringGreaterThanOrEqualStub final : public TurboFanCodeStub {
- public:
-  explicit StringGreaterThanOrEqualStub(Isolate* isolate)
-      : TurboFanCodeStub(isolate) {}
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
-  DEFINE_TURBOFAN_CODE_STUB(StringGreaterThanOrEqual, TurboFanCodeStub);
-};
-
 class ToIntegerStub final : public TurboFanCodeStub {
  public:
   explicit ToIntegerStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}

src/compiler/effect-control-linearizer.cc

@@ -722,6 +722,15 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kStringCharCodeAt:
       state = LowerStringCharCodeAt(node, *effect, *control);
       break;
+    case IrOpcode::kStringEqual:
+      state = LowerStringEqual(node, *effect, *control);
+      break;
+    case IrOpcode::kStringLessThan:
+      state = LowerStringLessThan(node, *effect, *control);
+      break;
+    case IrOpcode::kStringLessThanOrEqual:
+      state = LowerStringLessThanOrEqual(node, *effect, *control);
+      break;
     case IrOpcode::kCheckFloat64Hole:
       state = LowerCheckFloat64Hole(node, frame_state, *effect, *control);
       break;
@@ -2604,6 +2613,43 @@ EffectControlLinearizer::LowerStringFromCharCode(Node* node, Node* effect,
   return ValueEffectControl(value, effect, control);
 }
 
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringComparison(Callable const& callable,
+                                               Node* node, Node* effect,
+                                               Node* control) {
+  Operator::Properties properties = Operator::kEliminatable;
+  CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
+  CallDescriptor* desc = Linkage::GetStubCallDescriptor(
+      isolate(), graph()->zone(), callable.descriptor(), 0, flags, properties);
+  node->InsertInput(graph()->zone(), 0,
+                    jsgraph()->HeapConstant(callable.code()));
+  node->AppendInput(graph()->zone(), jsgraph()->NoContextConstant());
+  node->AppendInput(graph()->zone(), effect);
+  NodeProperties::ChangeOp(node, common()->Call(desc));
+  return ValueEffectControl(node, node, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringEqual(Node* node, Node* effect,
+                                          Node* control) {
+  return LowerStringComparison(CodeFactory::StringEqual(isolate()), node,
+                               effect, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringLessThan(Node* node, Node* effect,
+                                             Node* control) {
+  return LowerStringComparison(CodeFactory::StringLessThan(isolate()), node,
+                               effect, control);
+}
+
+EffectControlLinearizer::ValueEffectControl
+EffectControlLinearizer::LowerStringLessThanOrEqual(Node* node, Node* effect,
+                                                    Node* control) {
+  return LowerStringComparison(CodeFactory::StringLessThanOrEqual(isolate()),
+                               node, effect, control);
+}
+
 EffectControlLinearizer::ValueEffectControl
 EffectControlLinearizer::LowerCheckFloat64Hole(Node* node, Node* frame_state,
                                                Node* effect, Node* control) {

src/compiler/effect-control-linearizer.h

@@ -12,6 +12,8 @@
 namespace v8 {
 namespace internal {
 
+// Forward declarations.
+class Callable;
 class Zone;
 
 namespace compiler {
@@ -140,6 +142,11 @@ class EffectControlLinearizer {
                                            Node* control);
   ValueEffectControl LowerStringFromCharCode(Node* node, Node* effect,
                                              Node* control);
+  ValueEffectControl LowerStringEqual(Node* node, Node* effect, Node* control);
+  ValueEffectControl LowerStringLessThan(Node* node, Node* effect,
+                                         Node* control);
+  ValueEffectControl LowerStringLessThanOrEqual(Node* node, Node* effect,
+                                                Node* control);
   ValueEffectControl LowerCheckFloat64Hole(Node* node, Node* frame_state,
                                            Node* effect, Node* control);
   ValueEffectControl LowerCheckTaggedHole(Node* node, Node* frame_state,
@@ -179,6 +186,8 @@ class EffectControlLinearizer {
   ValueEffectControl BuildCheckedHeapNumberOrOddballToFloat64(
       CheckTaggedInputMode mode, Node* value, Node* frame_state, Node* effect,
       Node* control);
+  ValueEffectControl LowerStringComparison(Callable const& callable, Node* node,
+                                           Node* effect, Node* control);
 
   Node* ChangeInt32ToSmi(Node* value);
   Node* ChangeUint32ToSmi(Node* value);

src/compiler/pipeline.cc

@@ -622,14 +622,6 @@ PipelineCompilationJob::Status PipelineCompilationJob::PrepareJobImpl() {
     if (!Compiler::EnsureDeoptimizationSupport(info())) return FAILED;
   }
 
-  // TODO(mstarzinger): Hack to ensure that certain call descriptors are
-  // initialized on the main thread, since it is needed off-thread by the
-  // effect control linearizer.
-  CodeFactory::CopyFastSmiOrObjectElements(info()->isolate());
-  CodeFactory::GrowFastDoubleElements(info()->isolate());
-  CodeFactory::GrowFastSmiOrObjectElements(info()->isolate());
-  CodeFactory::ToNumber(info()->isolate());
-
   linkage_ = new (&zone_) Linkage(Linkage::ComputeIncoming(&zone_, info()));
 
   if (!pipeline_.CreateGraph()) {

src/compiler/simplified-lowering.cc

@@ -2040,62 +2040,11 @@ class RepresentationSelector {
         }
         return;
       }
-      case IrOpcode::kStringEqual: {
-        VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
-        if (lower()) {
-          // StringEqual(x, y) => Call(StringEqualStub, x, y, no-context)
-          Operator::Properties properties =
-              Operator::kCommutative | Operator::kEliminatable;
-          Callable callable = CodeFactory::StringEqual(jsgraph_->isolate());
-          CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
-          CallDescriptor* desc = Linkage::GetStubCallDescriptor(
-              jsgraph_->isolate(), jsgraph_->zone(), callable.descriptor(), 0,
-              flags, properties);
-          node->InsertInput(jsgraph_->zone(), 0,
-                            jsgraph_->HeapConstant(callable.code()));
-          node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
-          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
-          NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
-        }
-        return;
-      }
-      case IrOpcode::kStringLessThan: {
-        VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
-        if (lower()) {
-          // StringLessThan(x, y) => Call(StringLessThanStub, x, y, no-context)
-          Operator::Properties properties = Operator::kEliminatable;
-          Callable callable = CodeFactory::StringLessThan(jsgraph_->isolate());
-          CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
-          CallDescriptor* desc = Linkage::GetStubCallDescriptor(
-              jsgraph_->isolate(), jsgraph_->zone(), callable.descriptor(), 0,
-              flags, properties);
-          node->InsertInput(jsgraph_->zone(), 0,
-                            jsgraph_->HeapConstant(callable.code()));
-          node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
-          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
-          NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
-        }
-        return;
-      }
+      case IrOpcode::kStringEqual:
+      case IrOpcode::kStringLessThan:
       case IrOpcode::kStringLessThanOrEqual: {
-        VisitBinop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
-        if (lower()) {
-          // StringLessThanOrEqual(x, y)
-          //   => Call(StringLessThanOrEqualStub, x, y, no-context)
-          Operator::Properties properties = Operator::kEliminatable;
-          Callable callable =
-              CodeFactory::StringLessThanOrEqual(jsgraph_->isolate());
-          CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
-          CallDescriptor* desc = Linkage::GetStubCallDescriptor(
-              jsgraph_->isolate(), jsgraph_->zone(), callable.descriptor(), 0,
-              flags, properties);
-          node->InsertInput(jsgraph_->zone(), 0,
-                            jsgraph_->HeapConstant(callable.code()));
-          node->AppendInput(jsgraph_->zone(), jsgraph_->NoContextConstant());
-          node->AppendInput(jsgraph_->zone(), jsgraph_->graph()->start());
-          NodeProperties::ChangeOp(node, jsgraph_->common()->Call(desc));
-        }
-        return;
+        return VisitBinop(node, UseInfo::AnyTagged(),
+                          MachineRepresentation::kTagged);
       }
       case IrOpcode::kStringCharCodeAt: {
         VisitBinop(node, UseInfo::AnyTagged(), UseInfo::TruncatingWord32(),

src/isolate.cc

@@ -27,6 +27,7 @@
 #include "src/external-reference-table.h"
 #include "src/frames-inl.h"
 #include "src/ic/stub-cache.h"
+#include "src/interface-descriptors.h"
 #include "src/interpreter/interpreter.h"
 #include "src/isolate-inl.h"
 #include "src/libsampler/sampler.h"
@@ -2390,6 +2391,12 @@ bool Isolate::Init(Deserializer* des) {
     return false;
   }
 
+// Initialize the interface descriptors ahead of time.
+#define INTERFACE_DESCRIPTOR(V) \
+  { V##Descriptor(this); }
+  INTERFACE_DESCRIPTOR_LIST(INTERFACE_DESCRIPTOR)
+#undef INTERFACE_DESCRIPTOR
+
   deoptimizer_data_ = new DeoptimizerData(heap()->memory_allocator());
 
   const bool create_heap_objects = (des == NULL);