Remove constant moves after emitting them in parallel resolver.

This fixes the case where a constant move requires a scratch
register. Note that there is no backend that needs this for now,
but X86 might with the move to hard float.

Change-Id: I37f6b8961b48f2cf6fbc0cd281e70d58466d018e

1 files changed, 24 insertions, 3 deletions

diff --git a/compiler/optimizing/parallel_move_test.cc b/compiler/optimizing/parallel_move_test.cc
index 62629bcd0c..210f7d7f09 100644
--- a/compiler/optimizing/parallel_move_test.cc
+++ b/compiler/optimizing/parallel_move_test.cc
@@ -31,9 +31,13 @@ class TestParallelMoveResolver : public ParallelMoveResolver {
     if (!message_.str().empty()) {
       message_ << " ";
     }
-    message_ << "("
-             << move->GetSource().reg()
-             << " -> "
+    message_ << "(";
+    if (move->GetSource().IsConstant()) {
+      message_ << "C";
+    } else {
+      message_ << move->GetSource().reg();
+    }
+    message_ << " -> "
              << move->GetDestination().reg()
              << ")";
   }
@@ -129,4 +133,21 @@ TEST(ParallelMoveTest, Swap) {
   }
 }
 
+TEST(ParallelMoveTest, ConstantLast) {
+  ArenaPool pool;
+  ArenaAllocator allocator(&pool);
+  TestParallelMoveResolver resolver(&allocator);
+  HParallelMove* moves = new (&allocator) HParallelMove(&allocator);
+  moves->AddMove(new (&allocator) MoveOperands(
+      Location::ConstantLocation(new (&allocator) HIntConstant(0)),
+      Location::RegisterLocation(0),
+      nullptr));
+  moves->AddMove(new (&allocator) MoveOperands(
+      Location::RegisterLocation(1),
+      Location::RegisterLocation(2),
+      nullptr));
+  resolver.EmitNativeCode(moves);
+  ASSERT_STREQ("(1 -> 2) (C -> 0)", resolver.GetMessage().c_str());
+}
+
 }  // namespace art