On Wed, May 11, 2022 at 01:45:13PM +0200, Richard Biener via Gcc-patches wrote:
> On Wed, 11 May 2022, Richard Biener wrote:
>
> > When the insn to delete is a debug insn there's no point in figuring
> > out whether it might be the last real insn and thus we have to purge
> > dead edges.
> >
> > Bootstrap and regtest running on x86_64-unknown-linux-gnu.
>
> Actually revisiting PR94618 which introduced this the following is better
> and is what I'm going to test, making sure to never purge edges for
> DEBUG_INSNs.
>
> diff --git a/gcc/cfgrtl.cc b/gcc/cfgrtl.cc
> index 74ea14efc61..06be46d75df 100644
> --- a/gcc/cfgrtl.cc
> +++ b/gcc/cfgrtl.cc
> @@ -235,7 +235,7 @@ delete_insn_and_edges (rtx_insn *insn)
> {
> bool purge = false;
>
> - if (INSN_P (insn) && BLOCK_FOR_INSN (insn))
> + if (NONDEBUG_INSN_P (insn) && BLOCK_FOR_INSN (insn))
> {
> basic_block bb = BLOCK_FOR_INSN (insn);
> if (BB_END (bb) == insn)
Yeah, wanted to suggest the same. Because
purge_dead_edges actually doesn't punt on DEBUG_INSNs, but instead
it looks for the last non-debug insn in the same bb before it if any.
Jakub
