On Thu, Feb 9, 2023 at 3:25 PM Richard Biener via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> The following does low-hanging optimizations, combining bitmap
> test and set and removing redundant operations.
>
> This shaves off half of the testcase compile time.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, OK?
>
> Thanks,
> Richard.
>
> PR target/108738
> * config/i386/i386-features.cc (scalar_chain::add_to_queue):
> Combine bitmap test and set.
> (scalar_chain::add_insn): Likewise.
> (scalar_chain::analyze_register_chain): Remove redundant
> attempt to add to queue and instead strengthen assert.
> Sink common attempts to mark the def dual-mode.
> (scalar_chain::add_to_queue): Remove redundant insn bitmap
> check.
LGTM.
Thanks,
Uros.
> ---
> gcc/config/i386/i386-features.cc | 18 ++++++++----------
> 1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/gcc/config/i386/i386-features.cc
> b/gcc/config/i386/i386-features.cc
> index 9bd6d8677bb..eff91301009 100644
> --- a/gcc/config/i386/i386-features.cc
> +++ b/gcc/config/i386/i386-features.cc
> @@ -314,14 +314,12 @@ scalar_chain::~scalar_chain ()
> void
> scalar_chain::add_to_queue (unsigned insn_uid)
> {
> - if (bitmap_bit_p (insns, insn_uid)
> - || bitmap_bit_p (queue, insn_uid))
> + if (!bitmap_set_bit (queue, insn_uid))
> return;
>
> if (dump_file)
> fprintf (dump_file, " Adding insn %d into chain's #%d queue\n",
> insn_uid, chain_id);
> - bitmap_set_bit (queue, insn_uid);
> }
>
> /* For DImode conversion, mark register defined by DEF as requiring
> @@ -362,10 +360,9 @@ void
> scalar_chain::analyze_register_chain (bitmap candidates, df_ref ref)
> {
> df_link *chain;
> + bool mark_def = false;
>
> - gcc_assert (bitmap_bit_p (insns, DF_REF_INSN_UID (ref))
> - || bitmap_bit_p (candidates, DF_REF_INSN_UID (ref)));
> - add_to_queue (DF_REF_INSN_UID (ref));
> + gcc_checking_assert (bitmap_bit_p (insns, DF_REF_INSN_UID (ref)));
>
> for (chain = DF_REF_CHAIN (ref); chain; chain = chain->next)
> {
> @@ -398,9 +395,12 @@ scalar_chain::analyze_register_chain (bitmap candidates,
> df_ref ref)
> if (dump_file)
> fprintf (dump_file, " r%d use in insn %d isn't convertible\n",
> DF_REF_REGNO (chain->ref), uid);
> - mark_dual_mode_def (ref);
> + mark_def = true;
> }
> }
> +
> + if (mark_def)
> + mark_dual_mode_def (ref);
> }
>
> /* Add instruction into a chain. */
> @@ -408,14 +408,12 @@ scalar_chain::analyze_register_chain (bitmap
> candidates, df_ref ref)
> void
> scalar_chain::add_insn (bitmap candidates, unsigned int insn_uid)
> {
> - if (bitmap_bit_p (insns, insn_uid))
> + if (!bitmap_set_bit (insns, insn_uid))
> return;
>
> if (dump_file)
> fprintf (dump_file, " Adding insn %d to chain #%d\n", insn_uid,
> chain_id);
>
> - bitmap_set_bit (insns, insn_uid);
> -
> rtx_insn *insn = DF_INSN_UID_GET (insn_uid)->insn;
> rtx def_set = single_set (insn);
> if (def_set && REG_P (SET_DEST (def_set))
> --
> 2.35.3
