Revert "Revert "Revert "Recognize and optimize a.runtimeType == b.runtimeType pattern."""

runtime/vm/intrinsifier_arm64.cc

Index: runtime/vm/intrinsifier_arm64.cc
diff --git a/runtime/vm/intrinsifier_arm64.cc b/runtime/vm/intrinsifier_arm64.cc
index 756010bed57d55ef3c90b7214a912285e5e660e7..050ae7361cdaac8d2c7ee73dfc3c6982d9a89c90 100644
--- a/runtime/vm/intrinsifier_arm64.cc
+++ b/runtime/vm/intrinsifier_arm64.cc
@@ -1653,103 +1653,16 @@ void Intrinsifier::ObjectEquals(Assembler* assembler) {
 }
 
 
-static void RangeCheck(Assembler* assembler,
-                       Register val,
-                       Register tmp,
-                       intptr_t low,
-                       intptr_t high,
-                       Condition cc,
-                       Label* target) {
-  __ AddImmediate(tmp, val, -low);
-  __ CompareImmediate(tmp, high - low);
-  __ b(target, cc);
-}
-
-
-const Condition kIfNotInRange = HI;
-const Condition kIfInRange = LS;
-
-
-static void JumpIfInteger(Assembler* assembler,
-                          Register cid,
-                          Register tmp,
-                          Label* target) {
-  RangeCheck(assembler, cid, tmp, kSmiCid, kBigintCid, kIfInRange, target);
-}
-
-
-static void JumpIfNotInteger(Assembler* assembler,
-                             Register cid,
-                             Register tmp,
-                             Label* target) {
-  RangeCheck(assembler, cid, tmp, kSmiCid, kBigintCid, kIfNotInRange, target);
-}
-
-
-static void JumpIfString(Assembler* assembler,
-                          Register cid,
-                          Register tmp,
-                          Label* target) {
-  RangeCheck(assembler,
-             cid,
-             tmp,
-             kOneByteStringCid,
-             kExternalTwoByteStringCid,
-             kIfInRange,
-             target);
-}
-
-
-static void JumpIfNotString(Assembler* assembler,
-                            Register cid,
-                            Register tmp,
-                            Label* target) {
-  RangeCheck(assembler,
-             cid,
-             tmp,
-             kOneByteStringCid,
-             kExternalTwoByteStringCid,
-             kIfNotInRange,
-             target);
-}
-
-
 // Return type quickly for simple types (not parameterized and not signature).
 void Intrinsifier::ObjectRuntimeType(Assembler* assembler) {
-  Label fall_through, use_canonical_type, not_double, not_integer;
+  Label fall_through;
   __ ldr(R0, Address(SP, 0 * kWordSize));
   __ LoadClassIdMayBeSmi(R1, R0);
-
   __ CompareImmediate(R1, kClosureCid);
   __ b(&fall_through, EQ);  // Instance is a closure.
-
-  __ CompareImmediate(R1, kNumPredefinedCids);
-  __ b(&use_canonical_type, HI);
-
-  __ CompareImmediate(R1, kDoubleCid);
-  __ b(&not_double, NE);
-
-  __ LoadIsolate(R0);
-  __ LoadFromOffset(R0, R0, Isolate::object_store_offset());
-  __ LoadFromOffset(R0, R0, ObjectStore::double_type_offset());
-  __ ret();
-
-  __ Bind(&not_double);
-  JumpIfNotInteger(assembler, R1, R0, &not_integer);
-  __ LoadIsolate(R0);
-  __ LoadFromOffset(R0, R0, Isolate::object_store_offset());
-  __ LoadFromOffset(R0, R0, ObjectStore::int_type_offset());
-  __ ret();
-
-  __ Bind(&not_integer);
-  JumpIfNotString(assembler, R1, R0, &use_canonical_type);
-  __ LoadIsolate(R0);
-  __ LoadFromOffset(R0, R0, Isolate::object_store_offset());
-  __ LoadFromOffset(R0, R0, ObjectStore::string_type_offset());
-  __ ret();
-
-  __ Bind(&use_canonical_type);
   __ LoadClassById(R2, R1);
+  // R2: class of instance (R0).
+
   __ ldr(R3, FieldAddress(R2, Class::num_type_arguments_offset()), kHalfword);
   __ CompareImmediate(R3, 0);
   __ b(&fall_through, NE);
@@ -1763,61 +1676,6 @@ void Intrinsifier::ObjectRuntimeType(Assembler* assembler) {
 }
 
 
-void Intrinsifier::ObjectHaveSameRuntimeType(Assembler* assembler) {
-  Label fall_through, different_cids, equal, not_equal, not_integer;
-  __ ldr(R0, Address(SP, 0 * kWordSize));
-  __ LoadClassIdMayBeSmi(R1, R0);
-
-  // Check if left hand size is a closure. Closures are handled in the runtime.
-  __ CompareImmediate(R1, kClosureCid);
-  __ b(&fall_through, EQ);
-
-  __ ldr(R0, Address(SP, 1 * kWordSize));
-  __ LoadClassIdMayBeSmi(R2, R0);
-
-  // Check whether class ids match. If class ids don't match objects can still
-  // have the same runtime type (e.g. multiple string implementation classes
-  // map to a single String type).
-  __ cmp(R1, Operand(R2));
-  __ b(&different_cids, NE);
-
-  // Objects have the same class and neither is a closure.
-  // Check if there are no type arguments. In this case we can return true.
-  // Otherwise fall through into the runtime to handle comparison.
-  __ LoadClassById(R3, R1);
-  __ ldr(R3, FieldAddress(R3, Class::num_type_arguments_offset()), kHalfword);
-  __ CompareImmediate(R3, 0);
-  __ b(&fall_through, NE);
-
-  __ Bind(&equal);
-  __ LoadObject(R0, Bool::True());
-  __ ret();
-
-  // Class ids are different. Check if we are comparing runtime types of
-  // two strings (with different representations) or two integers.
-  __ Bind(&different_cids);
-  __ CompareImmediate(R1, kNumPredefinedCids);
-  __ b(&not_equal, HI);
-
-  // Check if both are integers.
-  JumpIfNotInteger(assembler, R1, R0, &not_integer);
-  JumpIfInteger(assembler, R2, R0, &equal);
-  __ b(&not_equal);
-
-  __ Bind(&not_integer);
-  // Check if both are strings.
-  JumpIfNotString(assembler, R1, R0, &not_equal);
-  JumpIfString(assembler, R2, R0, &equal);
-
-  // Neither strings nor integers and have different class ids.
-  __ Bind(&not_equal);
-  __ LoadObject(R0, Bool::False());
-  __ ret();
-
-  __ Bind(&fall_through);
-}
-
-
 void Intrinsifier::String_getHashCode(Assembler* assembler) {
   Label fall_through;
   __ ldr(R0, Address(SP, 0 * kWordSize));