On 2022-02-25 09:14, Richard Biener wrote:
The following replaces
/* Skip bits that are zero. */
for (; (word & 1) == 0; word >>= 1)
bit_num++;
idioms in ira-int.h in the attempt to speedup update_conflict_hard_regno_costs
which we're bound on in PR104686. The trick is to use ctz_hwi here
which should pay off even with dense bitmaps on architectures that
have HW support for this.
For the PR in question this speeds up compile-time from 31s to 24s for
me.
It is a really significant improvement.
Bootstrapped and tested on x86_64-unknown-linux-gnu.
OK for trunk?
Yes. Thank you for working on this PR, Richard.
2022-02-25 Richard Biener <rguent...@suse.de>
PR rtl-optimization/104686
* ira-int.h (minmax_set_iter_cond): Use ctz_hwi to elide loop
skipping bits that are zero.
(ira_object_conflict_iter_cond): Likewise.
