Add support for WritableRegister policy in the register allocator.

runtime/vm/assembler_x64.cc

Index: runtime/vm/assembler_x64.cc
diff --git a/runtime/vm/assembler_x64.cc b/runtime/vm/assembler_x64.cc
index 20153ad438ceca507c377ac0b4605406633e2cd4..2936d98112c7401a0007b9aa0112c41373a4274e 100644
--- a/runtime/vm/assembler_x64.cc
+++ b/runtime/vm/assembler_x64.cc
@@ -1594,19 +1594,36 @@ void Assembler::StoreIntoObjectFilter(Register object,
 void Assembler::StoreIntoObject(Register object,
                                 const FieldAddress& dest,
                                 Register value) {
-  // TODO(kmillikin): pass temp registers to avoid pushing registers.
+  ASSERT(object != value);
   movq(dest, value);
-
-  Label done;
-  pushq(value);
+  Label done, fail;
   StoreIntoObjectFilter(object, value, &done);
   // A store buffer update is required.
+  pushq(RCX);
+  pushq(RDX);
+  pushq(RBX);
   if (value != RAX) pushq(RAX);
   leaq(RAX, dest);
   call(&StubCode::UpdateStoreBufferLabel());
   if (value != RAX) popq(RAX);
+  cmpq(RBX, Address(RSP, 0));

[Ivan Posva, 2012/09/11 11:57:30]

?

[Vyacheslav Egorov (Google), 2012/09/11 12:18:05]

reverted

+  j(NOT_ZERO, &fail);
+  popq(RBX);
+
+  cmpq(RDX, Address(RSP, 0));
+  j(NOT_ZERO, &fail);
+  popq(RDX);
+
+  cmpq(RCX, Address(RSP, 0));
+  j(NOT_ZERO, &fail);
+  popq(RCX);
+
+  jmp(&done);
+
+  Bind(&fail);
+  int3();
+
   Bind(&done);
-  popq(value);
 }