From: Ivo Doko <ivo.doko@gmail.com>
To: gcc-help@gcc.gnu.org
Subject: A possible bug
Date: Tue, 07 Oct 2014 05:01:00 -0000 [thread overview]
Message-ID: <54337368.4070407@gmail.com> (raw)
The OS I am using is Windows 7 64-bit. I am using Code::Blocks 13.12
with MinGW-w64 (x86_64-4.9.1-posix-seh-rt_v3-rev1). (I already asked in
mingw-w64-public and was told to ask here instead.)
For this particular instance I've used these compiler options:
-O2 -std=c++11 -Wextra -Wall -march=amdfam10 -pipe -lm -lstdc++
Now that that's out of the way, I have this:
https://sourceforge.net/projects/xorshift-cpp/files/
Compiling the "main.cpp" is fine, unless I remove the "-O2" flag (i.e.
disable compiler optimisation). Then I get the following build log:
http://pastebin.com/LXRX4Pq4
The same thing happens if I remove "-march=amdfam10".
What the linker seems to specifically be complaining about:
undefined reference to `xorshift_engine<unsigned long long, 64ull,
(signed char)-25, (signed char)3, (signed char)49,
8372773778140471301ull>::shift_3'
undefined reference to `xorshift_engine<unsigned long long, 64ull,
(signed char)-25, (signed char)3, (signed char)49,
8372773778140471301ull>::shift_2'
Which makes absolutely no sense, not only because those linker errors
don't come up when compiling even with just "-O", but because, in
"xorshift.h", three constexprs in the xorshift_engine class are defined
like so:
static constexpr int_fast8_t shift_1 = a >= 0 ? a : -a;
static constexpr int_fast8_t shift_2 = b >= 0 ? b : -b;
static constexpr int_fast8_t shift_3 = c >= 0 ? c : -c;
yet shift_1 is ok, but shift_2 and shift_3 somehow aren't...? (There is
no function which does not use all three of these, in order.)
This smells like a bug in the compiler to me, but I am not sure. Can
someone please help me?
--
Ivo Doko
next reply other threads:[~2014-10-07 5:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-07 5:01 Ivo Doko [this message]
2014-10-07 8:37 ` Ivo Doko
2014-10-07 8:57 ` Jonathan Wakely
2014-10-07 9:16 ` Ivo Doko
2014-10-07 10:45 ` Jonathan Wakely
2014-10-07 9:28 ` Ivo Doko
2014-10-07 10:48 ` Jonathan Wakely
2014-10-07 11:48 ` Ivo Doko
2014-10-07 11:49 ` Ivo Doko
2014-10-07 12:25 ` Jonathan Wakely
2014-10-07 12:25 ` Andrew Haley
2014-10-07 13:55 ` Ivo Doko
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=54337368.4070407@gmail.com \
--to=ivo.doko@gmail.com \
--cc=gcc-help@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).