[PATCH] tcg: Fix info_in_idx increment in layout_arg_by_ref

[Richard Henderson]

Off by one error, failing to take into account that layout_arg_1
already incremeneted info_in_idx for the first piece.  We only
need care for the n-1 TCG_CALL_ARG_BY_REF_N pieces here.

Cc: qemu-stable@nongnu.org
Fixes: 313bdea84d2 ("tcg: Add TCG_CALL_{RET,ARG}_BY_REF")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1751
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/tcg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcg/tcg.c b/tcg/tcg.c
index a0628fe424..652e8ea6b9 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1083,7 +1083,7 @@ static void layout_arg_by_ref(TCGCumulativeArgs *cum, 
TCGHelperInfo *info)
             .ref_slot = cum->ref_slot + i,
         };
     }
-    cum->info_in_idx += n;
+    cum->info_in_idx += n - 1;  /* i=0 accounted for in layout_arg_1 */
     cum->ref_slot += n;
 }
 
-- 
2.34.1