https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121498
--- Comment #5 from liu mirko <lw297073896 at gmail dot com> ---
(In reply to Andrew Pinski from comment #3)
> Confirmed. Though the code is not enough to reproduce the issue.
>
> ```
> (define_insn "*branch<mode>"
> [(set (pc)
> (if_then_else
> (match_operator 1 "ordered_comparison_operator"
> [(match_operand:X 2 "register_operand" "r")
> (match_operand:X 3 "reg_or_0_operand" "rJ")])
> (label_ref (match_operand 0 "" ""))
> (pc)))]
> "!TARGET_XCVBI"
> {
> if (get_attr_length (insn) == 12)
> return "b%r1\t%2,%z3,1f; jump\t%l0,ra; 1:";
>
> return "b%C1\t%2,%z3,%l0";
> }
> [(set_attr "type" "branch")
> (set_attr "mode" "none")])
> ```
> Basically the problem is the long conditional branch requires ra to do the
> jump in some cases but the rtl pattern does not model this at all.
In this instruction template, I also found another issue:the code in the branch
"if (get_attr_length (insn) == 12)" does not take effect when it contains asm
volatile("nop; nop; ... nop;//over 1MB code").
