Improve register allocation on x64.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/lj_asm.c b/src/lj_asm.c
index 34357e95..14d7dbd4 100644
--- a/src/lj_asm.c
+++ b/src/lj_asm.c
@@ -791,6 +791,11 @@ static Reg ra_allocref(ASMState *as, IRRef ref, RegSet allow)
         pick &= ~as->modset;
       r = rset_pickbot(pick);  /* Reduce conflicts with inverse allocation. */
     } else {
+#if LJ_64
+      /* We've got plenty of regs, so get callee-save regs if possible. */
+      if ((pick & ~RSET_SCRATCH))
+        pick &= ~RSET_SCRATCH;
+#endif
       r = rset_picktop(pick);
     }
   } else {