Add external strings support to regexp in generated code.

src/x64/code-stubs-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2642 matching lines @@
   // Any other flat string must be a flat ascii string.
   __ andb(rbx, Immediate(kIsNotStringMask | kStringRepresentationMask));
   __ j(zero, &seq_ascii_string, Label::kNear);
 
   // Check for flat cons string or sliced string.
   // A flat cons string is a cons string where the second part is the empty
   // string. In that case the subject string is just the first part of the cons
   // string. Also in this case the first part of the cons string is known to be
   // a sequential string or an external string.
   // In the case of a sliced string its offset has to be taken into account.
-  Label cons_string, check_encoding;
+  Label cons_string, external_string, check_encoding;
   STATIC_ASSERT(kConsStringTag < kExternalStringTag);
   STATIC_ASSERT(kSlicedStringTag > kExternalStringTag);
   __ cmpq(rbx, Immediate(kExternalStringTag));
   __ j(less, &cons_string, Label::kNear);
-  __ j(equal, &runtime);
+  __ j(equal, &external_string);
 
   // String is sliced.
   __ SmiToInteger32(r14, FieldOperand(rdi, SlicedString::kOffsetOffset));
   __ movq(rdi, FieldOperand(rdi, SlicedString::kParentOffset));
   // r14: slice offset
   // r15: original subject string
   // rdi: parent string
   __ jmp(&check_encoding, Label::kNear);
   // String is a cons string, check whether it is flat.
   __ bind(&cons_string);
   __ CompareRoot(FieldOperand(rdi, ConsString::kSecondOffset),
                  Heap::kEmptyStringRootIndex);
   __ j(not_equal, &runtime);
   __ movq(rdi, FieldOperand(rdi, ConsString::kFirstOffset));
   // rdi: first part of cons string or parent of sliced string.
   // rbx: map of first part of cons string or map of parent of sliced string.
   // Is first part of cons or parent of slice a flat two byte string?
   __ bind(&check_encoding);
   __ movq(rbx, FieldOperand(rdi, HeapObject::kMapOffset));
   __ testb(FieldOperand(rbx, Map::kInstanceTypeOffset),
            Immediate(kStringRepresentationMask | kStringEncodingMask));
   STATIC_ASSERT((kSeqStringTag | kTwoByteStringTag) == 0);
   __ j(zero, &seq_two_byte_string, Label::kNear);
-  // Any other flat string must be ascii.
+  // Any other flat string must be sequential ascii or external.
   __ testb(FieldOperand(rbx, Map::kInstanceTypeOffset),
            Immediate(kStringRepresentationMask));
-  __ j(not_zero, &runtime);
+  __ j(not_zero, &external_string);
 
   __ bind(&seq_ascii_string);
   // rdi: subject string (sequential ascii)
   // rax: RegExp data (FixedArray)
   __ movq(r11, FieldOperand(rax, JSRegExp::kDataAsciiCodeOffset));
   __ Set(rcx, 1);  // Type is ascii.
   __ jmp(&check_code, Label::kNear);
 
   __ bind(&seq_two_byte_string);
   // rdi: subject string (flat two-byte)
@@ skipping 213 matching lines @@
   __ movq(pending_exception_operand, rdx);
 
   __ CompareRoot(rax, Heap::kTerminationExceptionRootIndex);
   Label termination_exception;
   __ j(equal, &termination_exception, Label::kNear);
   __ Throw(rax);
 
   __ bind(&termination_exception);
   __ ThrowUncatchable(TERMINATION, rax);
 
+  // String is external.
+  // rdi: subject string (expected to be external)
+  // rbx: scratch
+  __ bind(&external_string);
+  __ movq(rbx, FieldOperand(rdi, HeapObject::kMapOffset));
+  __ movzxbl(rbx, FieldOperand(rbx, Map::kInstanceTypeOffset));
+  if (FLAG_debug_code) {
+    // Assert that we do not have a cons or slice (indirect strings) here.
+    // Sequential strings have already been ruled out.
+    __ testb(rbx, Immediate(kIsIndirectStringMask));
+    __ Assert(zero, "external string expected, but not found");
+  }
+  // Rule out short external strings.
+  STATIC_CHECK(kShortExternalStringTag != 0);
+  __ testb(rbx, Immediate(kShortExternalStringMask));
+  __ j(not_zero, &runtime);
+  __ movq(rdi, FieldOperand(rdi, ExternalString::kResourceDataOffset));
+  // Move the pointer so that offset-wise, it looks like a sequential string.
+  STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqAsciiString::kHeaderSize);
+  __ subq(rdi, Immediate(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+  STATIC_ASSERT(kTwoByteStringTag == 0);
+  __ testb(rbx, Immediate(kStringEncodingMask));
+  __ j(not_zero, &seq_ascii_string);
+  __ jmp(&seq_two_byte_string);
+
   // Do the runtime call to execute the regexp.
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
 #endif  // V8_INTERPRETED_REGEXP
 }
 
 
 void RegExpConstructResultStub::Generate(MacroAssembler* masm) {
   const int kMaxInlineLength = 100;
   Label slowcase;
@@ skipping 3165 matching lines @@
                                  xmm0,
                                  &slow_elements);
   __ ret(0);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64