Merge "[optimizing] Improve x86 parallel moves/swaps"

1 files changed, 7 insertions, 0 deletions

diff --git a/compiler/optimizing/parallel_move_resolver.h b/compiler/optimizing/parallel_move_resolver.h
index 3fa1b37afd..173cffc71e 100644
--- a/compiler/optimizing/parallel_move_resolver.h
+++ b/compiler/optimizing/parallel_move_resolver.h
@@ -42,10 +42,15 @@ class ParallelMoveResolver : public ValueObject {
  protected:
   class ScratchRegisterScope : public ValueObject {
    public:
+    // Spill a scratch register if no regs are free.
     ScratchRegisterScope(ParallelMoveResolver* resolver,
                          int blocked,
                          int if_scratch,
                          int number_of_registers);
+    // Grab a scratch register only if available.
+    ScratchRegisterScope(ParallelMoveResolver* resolver,
+                         int blocked,
+                         int number_of_registers);
     ~ScratchRegisterScope();
 
     int GetRegister() const { return reg_; }
@@ -62,6 +67,8 @@ class ParallelMoveResolver : public ValueObject {
   // Allocate a scratch register for performing a move. The method will try to use
   // a register that is the destination of a move, but that move has not been emitted yet.
   int AllocateScratchRegister(int blocked, int if_scratch, int register_count, bool* spilled);
+  // As above, but return -1 if no free register.
+  int AllocateScratchRegister(int blocked, int register_count);
 
   // Emit a move.
   virtual void EmitMove(size_t index) = 0;