Support for multiple register values

runtime/vm/locations.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/locations.h"
 
 #include "vm/assembler.h"
 #include "vm/il_printer.h"
 #include "vm/intermediate_language.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 69 matching lines @@
     LocationSummary::ContainsCall contains_call) {
   LocationSummary* summary = new LocationSummary(input_count, 0, contains_call);
   for (intptr_t i = 0; i < input_count; i++) {
     summary->set_in(i, Location::RequiresRegister());
   }
   summary->set_out(0, out);
   return summary;
 }
 
 
+Location Location::Pair(Location first, Location second) {
+  PairLocation* pair_location = new PairLocation();
+  ASSERT((reinterpret_cast<intptr_t>(pair_location) & kLocationTagMask) == 0);
+  pair_location->SetAt(0, first);
+  pair_location->SetAt(1, second);
+  Location loc(reinterpret_cast<uword>(pair_location) | kPairLocationTag);
+  return loc;
+}
+
+
+PairLocation* Location::AsPairLocation() const {
+  ASSERT(IsPairLocation());
+  return reinterpret_cast<PairLocation*>(value_ & ~kLocationTagMask);
+}
+
+
 Location Location::RegisterOrConstant(Value* value) {
   ConstantInstr* constant = value->definition()->AsConstant();
   return ((constant != NULL) && Assembler::IsSafe(constant->value()))
       ? Location::Constant(constant->value())
       : Location::RequiresRegister();
 }
 
 
 Location Location::RegisterOrSmiConstant(Value* value) {
   ConstantInstr* constant = value->definition()->AsConstant();
@@ skipping 69 matching lines @@
           return "R";
         case kRequiresFpuRegister:
           return "DR";
         case kWritableRegister:
           return "WR";
         case kSameAsFirstInput:
           return "0";
       }
       UNREACHABLE();
     default:
-      ASSERT(IsConstant());
-      return "C";
+      if (IsConstant()) {
+        return "C";
+      } else {
+        ASSERT(IsPairLocation());
+        return "2P";
+      }
   }
   return "?";
 }
 
 
 void Location::PrintTo(BufferFormatter* f) const {
   if (kind() == kStackSlot) {
     f->Print("S%+" Pd "", stack_index());
   } else if (kind() == kDoubleStackSlot) {
     f->Print("DS%+" Pd "", stack_index());
@@ skipping 35 matching lines @@
 
   if (!out(0).IsInvalid()) {
     f->Print(" => ");
     out(0).PrintTo(f);
   }
 
   if (always_calls()) f->Print(" C");
 }
 
 }  // namespace dart