Alex Coplan <alex.cop...@arm.com> writes:
> Hi,
>
> This patch tweaks change_insns to also call ::remove_insn to ensure the
> underlying RTL insn gets removed from the insn chain in the case of a
> deletion.
>
> This avoids leaving NOTE_INSN_DELETED around after deleting insns.
>
> For movement, the RTL insn chain is updated earlier in change_insns with
> the call to move_insn. For deletion, it seems reasonable to do it here.
>
> Bootstrapped/regtested on aarch64-linux-gnu in combination with the upcoming
> aarch64 load pair pass, i.e.:
> https://gcc.gnu.org/pipermail/gcc-patches/2023-October/633601.html
> and all uncommitted prerequisites except for 6/11 i.e.:
> https://gcc.gnu.org/pipermail/gcc-patches/2023-October/633349.html
> which shows that 6/11 is no longer required in combination with this patch (as
> expected).
>
> Thanks,
> Alex
>
> gcc/ChangeLog:
>
> * rtl-ssa/changes.cc (function_info::change_insns): Ensure we call
> ::remove_insn on deleted insns.
OK, thanks.
Richard
> diff --git a/gcc/rtl-ssa/changes.cc b/gcc/rtl-ssa/changes.cc
> index b11a88e0919..d6874e5627c 100644
> --- a/gcc/rtl-ssa/changes.cc
> +++ b/gcc/rtl-ssa/changes.cc
> @@ -732,7 +732,11 @@ function_info::change_insns (array_slice<insn_change *>
> changes)
> insn_change &change = *changes[i];
> insn_info *insn = change.insn ();
> if (change.is_deletion ())
> - remove_insn (insn);
> + {
> + if (rtx_insn *rtl = insn->rtl ())
> + ::remove_insn (rtl); // Remove the underlying RTL insn.
> + remove_insn (insn);
> + }
> else if (insn_info *placeholder = placeholders[i])
> {
> // Check if earlier movements turned a move into a no-op.
