Simple register allocation for ARM. Only top of expression...

src/virtual-frame-heavy.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 277 matching lines @@
     if (!elements_[i].is_memory()) {
       SpillElementAt(i);
     }
   }
 
   // Forget the frame elements that will be popped by the call.
   Forget(dropped_args);
 }
 
 
+// If there are any registers referenced only by the frame, spill one.
+Register VirtualFrame::SpillAnyRegister() {
+  // Find the leftmost (ordered by register number) register whose only
+  // reference is in the frame.
+  for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) {
+    if (is_used(i) && cgen()->allocator()->count(i) == 1) {
+      SpillElementAt(register_location(i));
+      ASSERT(!cgen()->allocator()->is_used(i));
+      return RegisterAllocator::ToRegister(i);
+    }
+  }
+  return no_reg;
+}
+
 } }  // namespace v8::internal