[regexp] Port RegExp.prototype.exec to TurboFan

src/builtins/builtins-regexp.cc

+// Copyright 2016 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.
+
+#include "src/builtins/builtins-utils.h"
+#include "src/builtins/builtins.h"
+
+#include "src/code-factory.h"
+#include "src/regexp/jsregexp.h"
+
+namespace v8 {
+namespace internal {
+
+namespace {
+
+compiler::Node* LoadLastIndex(CodeStubAssembler* a, compiler::Node* context,
+                              compiler::Node* has_initialmap,
+                              compiler::Node* regexp) {
+  typedef CodeStubAssembler::Variable Variable;
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+
+  Variable var_value(a, MachineRepresentation::kTagged);
+
+  Label out(a), if_unmodified(a), if_modified(a, Label::kDeferred);
+  a->Branch(has_initialmap, &if_unmodified, &if_modified);
+
+  a->Bind(&if_unmodified);
+  {
+    // Load the in-object field.
+    static const int field_offset =
+        JSRegExp::kSize + JSRegExp::kLastIndexFieldIndex;

[Igor Sheludko, 2016/09/29 12:55:29]

kLastIndexFieldIndex is an index, but not an offset. Please add "*kPointerSize"
to be correct.

Unfortunately we can't use Map::GetInObjectPropertyOffset() here because we
don't have a Map instance.

[jgruber, 2016/09/29 14:40:26]

Done.

+    var_value.Bind(a->LoadObjectField(regexp, field_offset));
+    a->Goto(&out);
+  }
+
+  a->Bind(&if_modified);
+  {
+    // Load through runtime.
+    Node* const name =
+        a->HeapConstant(a->isolate()->factory()->last_index_string());
+    var_value.Bind(
+        a->CallRuntime(Runtime::kGetProperty, context, regexp, name));

[Igor Sheludko, 2016/09/29 12:55:28]

You can call GetPropertyStub here instead.

[jgruber, 2016/09/29 14:40:26]

Done.

+    a->Goto(&out);
+  }
+
+  a->Bind(&out);
+  return var_value.value();
+}
+
+void StoreLastIndex(CodeStubAssembler* a, compiler::Node* context,
+                    compiler::Node* has_initialmap, compiler::Node* regexp,
+                    compiler::Node* value) {
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+
+  Label out(a), if_unmodified(a), if_modified(a, Label::kDeferred);
+  a->Branch(has_initialmap, &if_unmodified, &if_modified);
+
+  a->Bind(&if_unmodified);
+  {
+    static const int field_offset =
+        JSRegExp::kSize + JSRegExp::kLastIndexFieldIndex;

[Igor Sheludko, 2016/09/29 12:55:28]

Same here.

[jgruber, 2016/09/29 14:40:26]

Done.

+    a->StoreObjectField(regexp, field_offset, value);
+    a->Goto(&out);
+  }
+
+  a->Bind(&if_modified);
+  {
+    // Store through runtime.
+    Node* const name =
+        a->HeapConstant(a->isolate()->factory()->last_index_string());
+    Node* const language_mode = a->SmiConstant(Smi::FromInt(STRICT));
+    a->CallRuntime(Runtime::kSetProperty, context, regexp, name, value,

[Igor Sheludko, 2016/09/29 12:55:29]

// TODO(ishell): Use SetPropertyStub here once available.

[jgruber, 2016/09/29 14:40:26]

Done.

+                   language_mode);
+    a->Goto(&out);
+  }
+
+  a->Bind(&out);
+}
+
+compiler::Node* ConstructNewResultFromMatchInfo(Isolate* isolate,
+                                                CodeStubAssembler* a,
+                                                compiler::Node* context,
+                                                compiler::Node* match_elements,
+                                                compiler::Node* string) {
+  typedef CodeStubAssembler::Variable Variable;
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+
+  Label out(a);
+
+  Callable substring_callable = CodeFactory::SubString(isolate);

[Benedikt Meurer, 2016/09/29 11:10:08]

Nit: inline SubString here.

[jgruber, 2016/09/29 14:40:26]

Done.

+  Callable constructresult_callable =

[Benedikt Meurer, 2016/09/29 11:10:08]

Nit: Follow-up CL, please port construct result to TurboFan as well and inline
here.

[jgruber, 2016/09/29 14:40:27]

Acknowledged.

+      CodeFactory::RegExpConstructResult(isolate);
+
+  Node* const num_indices = a->SmiUntag(a->LoadFixedArrayElement(

[Igor Sheludko, 2016/09/29 12:55:28]

Once you avoid mixing int32/intptr indices, please pass INTPTR_PARAMETERS to
LoadFixedArrayElement() here and below to avoid generation of Int32ToIntPtr
convertions (sign extension instruction).

[jgruber, 2016/09/29 14:40:27]

Done.

+      match_elements, a->IntPtrConstant(RegExpImpl::kLastCaptureCount)));
+  Node* const num_results = a->SmiTag(a->Word32Shr(num_indices, 1));

[Igor Sheludko, 2016/09/29 12:55:28]

WordShr

[jgruber, 2016/09/29 14:40:26]

Done.

+  Node* const start = a->LoadFixedArrayElement(
+      match_elements, a->IntPtrConstant(RegExpImpl::kFirstCapture));
+  Node* const end = a->LoadFixedArrayElement(
+      match_elements, a->IntPtrConstant(RegExpImpl::kFirstCapture + 1));
+
+  // Calculate the substring of the first match before creating the result array
+  // to avoid an unnecessary write barrier storing the first result.
+  Node* const first =
+      a->CallStub(substring_callable, context, string, start, end);
+
+  Node* const result = a->CallStub(constructresult_callable, context,
+                                   num_results, start, string);
+  Node* const result_elements = a->LoadElements(result);
+
+  a->StoreFixedArrayElement(result_elements, a->IntPtrConstant(0), first,
+                            SKIP_WRITE_BARRIER);
+
+  a->GotoIf(a->SmiEqual(num_results, a->SmiConstant(Smi::FromInt(1))), &out);
+
+  // Store all remaining captures.
+  Node* const limit =
+      a->IntPtrAdd(a->IntPtrConstant(RegExpImpl::kFirstCapture), num_indices);
+
+  Variable var_from_cursor(a, MachineRepresentation::kWord32);

[Igor Sheludko, 2016/09/29 12:55:28]

MachineType::PointerRepesentation() (which is intptr essentially).

[jgruber, 2016/09/29 14:40:26]

Done.

+  Variable var_to_cursor(a, MachineRepresentation::kWord32);

[Igor Sheludko, 2016/09/29 12:55:28]

Same here.

[jgruber, 2016/09/29 14:40:27]

Done.

+
+  var_from_cursor.Bind(a->IntPtrConstant(RegExpImpl::kFirstCapture + 2));
+  var_to_cursor.Bind(a->IntPtrConstant(1));
+
+  Variable* vars[] = {&var_from_cursor, &var_to_cursor};
+  Label loop(a, 2, vars);
+
+  a->Goto(&loop);
+  a->Bind(&loop);
+  {
+    Node* from_cursor = var_from_cursor.value();

[Igor Sheludko, 2016/09/29 12:55:28]

const?

[jgruber, 2016/09/29 14:40:26]

Done.

+    Node* const to_cursor = var_to_cursor.value();
+    Node* const start = a->LoadFixedArrayElement(match_elements, from_cursor);
+
+    Label next_iter(a);
+    a->GotoIf(a->SmiEqual(start, a->SmiConstant(Smi::FromInt(-1))), &next_iter);
+
+    Node* from_cursor_plus1 = a->IntPtrAdd(from_cursor, a->IntPtrConstant(1));

[Igor Sheludko, 2016/09/29 12:55:28]

const?

[jgruber, 2016/09/29 14:40:26]

Done.

+    Node* const end =
+        a->LoadFixedArrayElement(match_elements, from_cursor_plus1);
+
+    Node* const capture =
+        a->CallStub(substring_callable, context, string, start, end);
+    a->StoreFixedArrayElement(result_elements, to_cursor, capture);
+    a->Goto(&next_iter);
+
+    a->Bind(&next_iter);
+    var_from_cursor.Bind(a->IntPtrAdd(from_cursor, a->IntPtrConstant(2)));
+    var_to_cursor.Bind(a->IntPtrAdd(to_cursor, a->IntPtrConstant(1)));
+    a->Branch(a->IntPtrLessThan(var_from_cursor.value(), limit), &loop, &out);

[Igor Sheludko, 2016/09/29 12:55:28]

Since we don't expect negative indices here, I would suggest to use
UintPtrLessThan() instead.

[jgruber, 2016/09/29 14:40:26]

Done.

+  }
+
+  a->Bind(&out);
+  return result;
+}
+
+}  // namespace
+
+// ES#sec-regexp.prototype.exec
+// RegExp.prototype.exec ( string )
+void Builtins::Generate_RegExpPrototypeExec(CodeStubAssembler* a) {
+  typedef CodeStubAssembler::Variable Variable;
+  typedef CodeStubAssembler::Label Label;
+  typedef compiler::Node Node;
+
+  Isolate* const isolate = a->isolate();
+
+  Node* const receiver = a->Parameter(0);
+  Node* const maybe_string = a->Parameter(1);
+  Node* const context = a->Parameter(4);
+
+  Node* const null = a->NullConstant();
+  Node* const int_zero = a->Int32Constant(0);
+  Node* const smi_zero = a->SmiConstant(Smi::FromInt(0));
+
+  // Ensure {receiver} is a JSRegExp.
+  Node* const regexp_map = a->ThrowIfNotType(context, receiver, JS_REGEXP_TYPE,
+                                             "RegExp.prototype.exec");
+  Node* const regexp = receiver;
+
+  // Check whether the regexp instance is unmodified.
+  Node* const native_context = a->LoadNativeContext(context);
+  Node* const regexp_fun =
+      a->LoadContextElement(native_context, Context::REGEXP_FUNCTION_INDEX);
+  Node* const initial_map =
+      a->LoadObjectField(regexp_fun, JSFunction::kPrototypeOrInitialMapOffset);
+  Node* const has_initialmap = a->WordEqual(regexp_map, initial_map);
+
+  // Convert {maybe_string} to a string.
+  Callable tostring_callable = CodeFactory::ToString(isolate);
+  Node* const string = a->CallStub(tostring_callable, context, maybe_string);
+  Node* const string_length = a->LoadStringLength(string);
+
+  // Check whether the regexp is global or sticky, which determines whether we
+  // update last index later on.
+  Node* const flags = a->LoadObjectField(regexp, JSRegExp::kFlagsOffset);
+  Node* const is_global_or_sticky =
+      a->Word32And(a->SmiUntag(flags),

[Igor Sheludko, 2016/09/29 12:55:29]

You are mixing int32/intptr computations here. I think it's better to stick with
intptr.

[jgruber, 2016/09/29 14:40:26]

Done.

+                   a->Int32Constant(JSRegExp::kGlobal | JSRegExp::kSticky));
+  Node* const should_update_last_index =
+      a->Word32NotEqual(is_global_or_sticky, int_zero);
+
+  // Grab and possibly update last index.
+  Label run_exec(a);
+  Variable var_lastindex(a, MachineRepresentation::kTagged);
+  {
+    Label if_doupdate(a), if_dontupdate(a);
+    a->Branch(should_update_last_index, &if_doupdate, &if_dontupdate);
+
+    a->Bind(&if_doupdate);
+    {
+      Node* const regexp_lastindex =
+          LoadLastIndex(a, context, has_initialmap, regexp);
+
+      Callable tolength_callable = CodeFactory::ToLength(isolate);
+      Node* const lastindex =
+          a->CallStub(tolength_callable, context, regexp_lastindex);
+      var_lastindex.Bind(lastindex);
+
+      Label if_isoob(a, Label::kDeferred);
+      a->GotoUnless(a->WordIsSmi(lastindex), &if_isoob);
+      a->GotoUnless(a->SmiLessThanOrEqual(lastindex, string_length), &if_isoob);
+      a->Goto(&run_exec);
+
+      a->Bind(&if_isoob);
+      {
+        StoreLastIndex(a, context, has_initialmap, regexp, smi_zero);
+        a->Return(null);
+      }
+    }
+
+    a->Bind(&if_dontupdate);
+    {
+      var_lastindex.Bind(smi_zero);
+      a->Goto(&run_exec);
+    }
+  }
+
+  Node* match_indices;
+  Label successful_match(a);
+  a->Bind(&run_exec);
+  {
+    // Get last match info from the context.
+    Node* const native_context = a->LoadNativeContext(context);

[Igor Sheludko, 2016/09/29 12:55:28]

|native_context| loaded above should be still available.

[jgruber, 2016/09/29 14:40:27]

Done.

+    Node* const last_match_info = a->LoadContextElement(
+        native_context, Context::REGEXP_LAST_MATCH_INFO_INDEX);
+
+    // Call the exec stub.
+    Callable exec_callable = CodeFactory::RegExpExec(isolate);
+    match_indices = a->CallStub(exec_callable, context, regexp, string,
+                                var_lastindex.value(), last_match_info);
+
+    // {match_indices} is either null or the RegExpLastMatchInfo array.
+    // Return early if exec failed, possibly updating last index.
+    a->GotoUnless(a->WordEqual(match_indices, null), &successful_match);
+
+    Label return_null(a);
+    a->GotoUnless(should_update_last_index, &return_null);
+
+    StoreLastIndex(a, context, has_initialmap, regexp, smi_zero);
+    a->Goto(&return_null);
+
+    a->Bind(&return_null);
+    a->Return(null);
+  }
+
+  Label construct_result(a);
+  a->Bind(&successful_match);
+  {
+    Node* const match_elements = a->LoadElements(match_indices);
+
+    a->GotoUnless(should_update_last_index, &construct_result);
+
+    // Update the new last index from {match_indices}.
+    Node* const new_lastindex = a->LoadFixedArrayElement(
+        match_elements, a->IntPtrConstant(RegExpImpl::kFirstCapture + 1));
+
+    StoreLastIndex(a, context, has_initialmap, regexp, new_lastindex);
+    a->Goto(&construct_result);
+
+    a->Bind(&construct_result);
+    {
+      Node* result = ConstructNewResultFromMatchInfo(isolate, a, context,
+                                                     match_elements, string);
+      a->Return(result);
+    }
+  }
+}
+
+}  // namespace internal
+}  // namespace v8