Split LoadStatic into two instructions: load static filed, load value.

runtime/vm/intermediate_language_ia32.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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 1741 matching lines @@
     } else {
       Register value_reg = locs()->in(1).reg();
       __ StoreIntoObjectNoBarrier(instance_reg,
           FieldAddress(instance_reg, field().Offset()), value_reg);
     }
   }
 }
 
 
 LocationSummary* LoadStaticFieldInstr::MakeLocationSummary() const {
-  return LocationSummary::Make(0,
-                               Location::RequiresRegister(),
-                               LocationSummary::kNoCall);
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresRegister());
+  // By specifying same register as input, our simple register allocator can
+  // generate better code.
+  summary->set_out(Location::SameAsFirstInput());
+  return summary;
 }
 
 
 void LoadStaticFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register field = locs()->in(0).reg();
   Register result = locs()->out().reg();
-  __ LoadObject(result, field());
-  __ movl(result, FieldAddress(result, Field::value_offset()));
+  __ movl(result, FieldAddress(field, Field::value_offset()));
 }
 
 
 LocationSummary* StoreStaticFieldInstr::MakeLocationSummary() const {
   LocationSummary* locs = new LocationSummary(1, 1, LocationSummary::kNoCall);
   locs->set_in(0, value()->NeedsStoreBuffer() ? Location::WritableRegister()
                                               : Location::RequiresRegister());
   locs->set_temp(0, Location::RequiresRegister());
   return locs;
 }
@@ skipping 2955 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_IA32