From: Martin Kepplinger <martink@posteo.de>
To: mingo@kernel.org, akpm@linux-foundation.org, linux@horizon.com,
linux@rasmusvillemoes.dk, maxime.coquelin@st.com,
dvlasenk@redhat.com, yury.norov@gmail.com,
torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: bitops.h: improve sign extending API
Date: Thu, 15 Oct 2015 18:18:27 +0200 [thread overview]
Message-ID: <1444925909-6013-1-git-send-email-martink@posteo.de> (raw)
PATCH 1/2 improves the doc of sign_extend32()
This should help to avoid different manual approaches to sign extension
PATCH 2/2 adds sign_extend64()
An informal example of what could follow in
arch/sh/kernel/traps_64.c after PATCH 2/2:
@@ -101,7 +102,7 @@ static int generate_and_check_address(struct pt_regs *regs,
__s64 displacement;
displacement = (opcode >> 10) & 0x3ff;
- displacement = ((displacement << 54) >> 54); /* sign extend */
+ displacement = sign_extend64(displacement, 9);
addr = (__u64)((__s64)base_address + (displacement << width_shift));
} else {
next reply other threads:[~2015-10-15 16:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-15 16:18 Martin Kepplinger [this message]
2015-10-15 16:18 ` [PATCH 1/2] bitops.h: Improve sign_extend32()'s documentation Martin Kepplinger
2015-10-15 18:06 ` George Spelvin
2015-10-15 16:18 ` [PATCH 2/2] bitops.h: add sign_extend64() Martin Kepplinger
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=1444925909-6013-1-git-send-email-martink@posteo.de \
--to=martink@posteo.de \
--cc=akpm@linux-foundation.org \
--cc=dvlasenk@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@horizon.com \
--cc=linux@rasmusvillemoes.dk \
--cc=maxime.coquelin@st.com \
--cc=mingo@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=yury.norov@gmail.com \
/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
all inboxes | Powered by JetHome®