From: "Wilco Dijkstra" <wdijkstr@arm.com>
To: "'GCC Patches'" <gcc-patches@gcc.gnu.org>
Subject: [PATCH][AArch64][0/5] Improve immediate generation
Date: Wed, 02 Sep 2015 12:34:00 -0000 [thread overview]
Message-ID: <000801d0e57b$a4d58860$ee809920$@com> (raw)
This is a set of patches to reduce the compile-time overhead of immediate generation on AArch64.
There have been discussions and investigations into reducing the overhead of immediate generation
using various caching strategies. However the statistics showed some of the expensive immediate
loops are not beneficial, and the algorithms can be improved significantly. The resulting speedups
are so large that caching can no longer show a measurable benefit.
aarch64_bitmask_imm is rewritten to use bitwise arithmetic rather than binary search.
aarch64_internal_mov_immediate is rewritten to remove slow linear and quadratic loops with constant
time logic, reduce the number of special cases and simplify the overall logic. There are slight
differences in the generated sequences however all immediate are the same size (no codesize
difference in SPEC2006). Overall buildtime improvement is 0.3% when building SPEC2006.
reply other threads:[~2015-09-02 12:34 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='000801d0e57b$a4d58860$ee809920$@com' \
--to=wdijkstr@arm.com \
--cc=gcc-patches@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).