[Bug rtl-optimization/104777] [9/10/11/12 Regression] gcc crashes while compiling a custom coroutine library sample

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104777

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:e1133c0205a7e2a65834a1af780b8da15eead2a9

commit r12-7540-ge1133c0205a7e2a65834a1af780b8da15eead2a9
Author: Marek Polacek <polacek@redhat.com>
Date:   Mon Mar 7 16:15:46 2022 -0500

    rtl: ICE with thread_local and inline asm  [PR104777]

    In r270550, Jakub fixed classify_insn to handle asm goto: if the asm can
    jump to a label, the insn should be a JUMP_INSN.

    However, as the following testcase shows, non-null ASM_OPERANDS_LABEL_VEC
    doesn't guarantee that the rtx has any actual labels it can branch to.
    Here, the rtvec has 0 elements because expand_asm_stmt created it:

      rtvec labelvec = rtvec_alloc (nlabels); // nlabels == 0

    This causes an ICE in update_br_prob_note: BRANCH_EDGE (bb) crashes
    because there's no branch edge.  I think we can fix this by checking
    that there is at least one label the asm can jump to before wrapping
    the ASM_OPERANDS in a JUMP_INSN.

            PR rtl-optimization/104777

    gcc/ChangeLog:

            * rtl.cc (classify_insn): For ASM_OPERANDS, return JUMP_INSN only
if
            ASM_OPERANDS_LABEL_VEC has at least one element.

    gcc/testsuite/ChangeLog:

            * gcc.dg/torture/tls/pr104777.c: New test.