https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120119
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ramana at gcc dot gnu.org
--- Comment #9 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #8)
> Cannot rename chain v30 (8) at insn 54 (mark_read)
> Creating chain v29 (13) at insn 54
> Cannot rename chain v29 (13) at insn 30 (mark_read)
> Widening register in chain v29 (13) at insn 30
> Cannot rename chain v30 (8) at insn 30 (mark_read)
> Failing basic block due to unhandled overlap
> Closing chain v29 (13) at insn 30 (terminate_dead, superset)
> Failing basic block due to unhandled overlap
> Failing basic block due to unhandled overlap
> Closing chain v28 (6) at insn 30 (terminate_write, superset)
> Creating chain v28 (14) at insn 30
> failed
>
> ```
> diff --git a/gcc/config/aarch64/cortex-a57-fma-steering.cc
> b/gcc/config/aarch64/cortex-a57-fma-steering.cc
> index fd6da66d855..2dc0fffed62 100644
> --- a/gcc/config/aarch64/cortex-a57-fma-steering.cc
> +++ b/gcc/config/aarch64/cortex-a57-fma-steering.cc
> @@ -948,6 +948,9 @@ func_fma_steering::analyze ()
>
> /* Search the chain where this instruction is (one of) the root.
> */
> dest_op_info = insn_rr[INSN_UID (insn)].op_info;
> + /* Register rename could fail. */
> + if (!dest_op_info)
> + continue;
> dest_regno = REGNO (SET_DEST (PATTERN (insn)));
> for (i = 0; i < dest_op_info->n_chains; i++)
> {
>
> ```
>
> Fixes the issue.
Looks reasonable from memory. Perhaps worth landing this after testing ?
regards
Ramana
