VM: Small generated code size improvements on x64.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 1256 matching lines @@
     case kTypedDataInt8ArrayCid:
     case kTypedDataUint8ArrayCid:
     case kTypedDataUint8ClampedArrayCid:
     case kOneByteStringCid:
       // TODO(fschneider): Add location constraint for byte registers (RAX,
       // RBX, RCX, RDX) instead of using a fixed register.
       locs->set_in(2, Location::FixedRegisterOrSmiConstant(value(), RAX));
       break;
     case kTypedDataInt16ArrayCid:
     case kTypedDataUint16ArrayCid:
+      // Writable register because the value must be untagged before storing.
+      locs->set_in(2, Location::WritableRegister());
+      break;
     case kTypedDataInt32ArrayCid:
     case kTypedDataUint32ArrayCid:
-      // Writable register because the value must be untagged before storing.
-      locs->set_in(2, Location::WritableRegister());
+      locs->set_in(2, Location::RequiresRegister());

[zra, 2015/01/08 15:50:09]

Merge with Int64 case?

[Florian Schneider, 2015/01/08 16:15:30]

Done.

       break;
     case kTypedDataInt64ArrayCid:
       locs->set_in(2, Location::RequiresRegister());
       break;
     case kTypedDataFloat32ArrayCid:
     case kTypedDataFloat64ArrayCid:
       // TODO(srdjan): Support Float64 constants.
       locs->set_in(2, Location::RequiresFpuRegister());
       break;
     case kTypedDataInt32x4ArrayCid:
@@ skipping 5111 matching lines @@
   __ movq(R10, Immediate(kInvalidObjectPointer));
   __ movq(RBX, Immediate(kInvalidObjectPointer));
 #endif
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64