@item -march=@var{processor}
Specify which s390 processor variant is the target, @samp{g6}, @samp{g6},
@samp{z900}, @samp{z990}, @samp{z9-109}, @samp{z9-ec}, @samp{z10},
-@samp{z196}, or @samp{zEC12}.
+@samp{z196}, @samp{zEC12}, or @samp{z13}.
@item -mregnames
@itemx -mno-regnames
Allow or disallow symbolic names for registers.