https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100854
--- Comment #3 from Hongtao.liu <crazylht at gmail dot com> ---
I'm testing
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index a25d59fa77b..4dab4d60773 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -8842,6 +8842,10 @@ excess_precision_mode_join (enum flt_eval_method x,
|| y == FLT_EVAL_METHOD_UNPREDICTABLE)
return FLT_EVAL_METHOD_UNPREDICTABLE;
+ /* FLT_EVAL_METHOD only accepts negative values, 0, 1 or 2, but
+ FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16 is 16. */
+ if (x == y && x == FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16)
+ return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT;
/* GCC only supports one interchange type right now, _Float16. If
we're evaluating _Float16 in 16-bit precision, then flt_eval_method
will be FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16. */
