Generate better ARM64 code for indexed loads and stores.

runtime/vm/assembler_arm64.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_ARM64_H_
 #define VM_ASSEMBLER_ARM64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm64.h directly; use assembler.h instead.
 #endif
@@ skipping 165 matching lines @@
     const int32_t s = (scale == Scaled) ? B12 : 0;
     encoding_ =
         B21 | B11 | s |
         (static_cast<int32_t>(crn) << kRnShift) |
         (static_cast<int32_t>(crm) << kRmShift) |
         (static_cast<int32_t>(ext) << kExtendTypeShift);
     type_ = Reg;
     base_ = crn;
   }
 
+  static OperandSize OperandSizeFor(intptr_t cid) {
+    switch (cid) {
+      case kArrayCid:
+      case kImmutableArrayCid:
+        return kWord;
+      case kOneByteStringCid:
+        return kByte;
+      case kTwoByteStringCid:
+        return kHalfword;
+      case kTypedDataInt8ArrayCid:
+        return kByte;
+      case kTypedDataUint8ArrayCid:
+      case kTypedDataUint8ClampedArrayCid:
+      case kExternalTypedDataUint8ArrayCid:
+      case kExternalTypedDataUint8ClampedArrayCid:
+        return kUnsignedByte;
+      case kTypedDataInt16ArrayCid:
+        return kHalfword;
+      case kTypedDataUint16ArrayCid:
+        return kUnsignedHalfword;
+      case kTypedDataInt32ArrayCid:
+        return kWord;
+      case kTypedDataUint32ArrayCid:
+        return kUnsignedWord;
+      case kTypedDataInt64ArrayCid:
+      case kTypedDataUint64ArrayCid:
+        UNREACHABLE();
+        return kByte;
+      case kTypedDataFloat32ArrayCid:
+        return kSWord;
+      case kTypedDataFloat64ArrayCid:
+        return kDWord;
+      case kTypedDataFloat32x4ArrayCid:
+      case kTypedDataInt32x4ArrayCid:
+      case kTypedDataFloat64x2ArrayCid:
+        return kQWord;
+      case kTypedDataInt8ArrayViewCid:
+        UNREACHABLE();
+        return kByte;
+      default:
+        UNREACHABLE();
+        return kByte;
+    }
+  }
+
  private:
   uint32_t encoding() const { return encoding_; }
   AddressType type() const { return type_; }
   Register base() const { return base_; }
 
   Address() : encoding_(0), type_(Unknown), base_(kNoRegister) {}
 
   uint32_t encoding_;
   AddressType type_;
   Register base_;
@@ skipping 1407 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM64_H_