public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "senthil_kumar.selvaraj at atmel dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/60300] [avr] Suboptimal stack pointer manipulation for frame setup
Date: Mon, 12 May 2014 13:30:00 -0000	[thread overview]
Message-ID: <bug-60300-4-mhl2gRNWWD@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-60300-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60300

Senthil Kumar Selvaraj <senthil_kumar.selvaraj at atmel dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |senthil_kumar.selvaraj@atme
                   |                            |l.com

--- Comment #4 from Senthil Kumar Selvaraj <senthil_kumar.selvaraj at atmel dot com> ---
It doesn't actually get to that - avr_sp_immediate_operand returns false if the
operand is not IN_RANGE(-6,6). The comments are a bit misleading though - the
shortest sequence only applies if the addend is within that range.

Like Johann said, it must be a deliberate decision in favor of speed - the
attached program with a stub implementation of bar and main calling foo clocks
a couple of cycles lesser with DSIZE=7 than with DSIZE=6(as measured with
avrtest), although the code is 6 bytes longer. If RCALLs and PUSH had been
generated, the code would be 4 bytes shorter, but would need 4 more clock
cycles.


      parent reply	other threads:[~2014-05-12 13:30 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-60300-4@http.gcc.gnu.org/bugzilla/>
2014-02-21 17:56 ` matthijs at stdin dot nl
2014-04-07 13:33 ` gjl at gcc dot gnu.org
2014-04-08 13:09 ` matthijs at stdin dot nl
2014-05-12 13:30 ` senthil_kumar.selvaraj at atmel dot com [this message]

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=bug-60300-4-mhl2gRNWWD@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@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).