Port and integrate the irregexp engine from V8

runtime/vm/intrinsifier_arm.cc

Index: runtime/vm/intrinsifier_arm.cc
diff --git a/runtime/vm/intrinsifier_arm.cc b/runtime/vm/intrinsifier_arm.cc
index 8451fce293ddaa003f171926bb937b9381dc0441..82e2253bb3bafbfbdf7b50f2dd900017d409896e 100644
--- a/runtime/vm/intrinsifier_arm.cc
+++ b/runtime/vm/intrinsifier_arm.cc
@@ -1599,6 +1599,94 @@ void Intrinsifier::TwoByteString_equality(Assembler* assembler) {
 }
 
 
+static void GenerateRegexpSpecializationFor(
+    Assembler* assembler,
+    intptr_t cid,
+    Label* entry,
+    Label* exit) {
+  ASSERT(cid == kOneByteStringCid || cid == kTwoByteStringCid ||
+         cid == kExternalOneByteStringCid || cid == kExternalTwoByteStringCid);
+
+  __ Bind(entry);
+
+  // The passed string is of class cid.
+
+  __ ldr(R0, FieldAddress(R2, JSRegExp::function_offset(cid)));
+
+  // Set the subject if it is currently unset.
+
+  __ LoadObject(R4, Object::null_object());
+  __ ldr(R5, FieldAddress(R2, JSRegExp::subject_offset(cid)));
+  __ cmp(R4, Operand(R5));
+  __ b(exit, NE);
+
+  __ StoreIntoObject(R2,
+                     FieldAddress(R2, JSRegExp::subject_offset(cid)),
+                     R1,
+                     false);
+
+  __ b(exit);
+}
+
+
+void Intrinsifier::JSRegExp_ExecuteMatch(Assembler* assembler) {
+  Label is_one_byte_string;
+  Label is_two_byte_string;
+  Label is_external_one_byte_string;
+  Label is_external_two_byte_string;
+  Label fallthrough;
+
+  static const intptr_t kRegExpParamOffset = + 2 * kWordSize;
+  static const intptr_t kStringParamOffset = + 1 * kWordSize;
+  // const Smi& start_index is located at   (+ 0 * kWordSize).
+
+  // Register assignments are as follows:
+  // R0: The appropriate (one- or two-byte specialized) matcher function.
+  // R2: The regexp object.
+  // R4: Temp.
+  // R5: Temp.
+  // R1: Temp, Pointer to the function's code which we then tail-call.
+
+  __ ldr(R2, Address(SP, kRegExpParamOffset));
+  __ ldr(R1, Address(SP, kStringParamOffset));
+
+  // Check if the string is a one byte string.
+
+  __ CompareClassId(R1, kOneByteStringCid, R4);
+  __ b(&is_one_byte_string, EQ);
+
+  __ CompareClassId(R1, kTwoByteStringCid, R4);
+  __ b(&is_two_byte_string, EQ);
+
+  __ CompareClassId(R1, kExternalOneByteStringCid, R4);
+  __ b(&is_external_one_byte_string, EQ);
+
+  __ CompareClassId(R1, kExternalTwoByteStringCid, R4);
+  __ b(&is_external_two_byte_string, EQ);
+
+  GenerateRegexpSpecializationFor(assembler, kExternalTwoByteStringCid,
+                                  &is_external_two_byte_string, &fallthrough);
+  GenerateRegexpSpecializationFor(assembler, kExternalOneByteStringCid,
+                                  &is_external_one_byte_string, &fallthrough);
+  GenerateRegexpSpecializationFor(assembler, kTwoByteStringCid,
+                                  &is_two_byte_string, &fallthrough);
+  GenerateRegexpSpecializationFor(assembler, kOneByteStringCid,
+                                  &is_one_byte_string, &fallthrough);
+
+  // R0 contains the appropriate (one- or two-byte string) function.
+
+  __ Bind(&fallthrough);
+
+  // Registers have been set up for the lazy compile stub at this point.
+  // It expects the function in R0 while; R5 and R4 are unused.
+
+  // Tail-call the function.
+  __ ldr(R1, FieldAddress(R0, Function::instructions_offset()));
+  __ AddImmediate(R1, Instructions::HeaderSize() - kHeapObjectTag);
+  __ bx(R1);
+}
+
+
 // On stack: user tag (+0).
 void Intrinsifier::UserTag_makeCurrent(Assembler* assembler) {
   // R1: Isolate.