Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 05 Feb 2021 07:39:18 +0000
From:      bugzilla-noreply@freebsd.org
To:        bugs@FreeBSD.org
Subject:   [Bug 251570] Release script passes CPUTYPE variable to both host and target build from MAKE_CONF file
Message-ID:  <bug-251570-227-FVhbfC2sJq@https.bugs.freebsd.org/bugzilla/>
In-Reply-To: <bug-251570-227@https.bugs.freebsd.org/bugzilla/>
References:  <bug-251570-227@https.bugs.freebsd.org/bugzilla/>

next in thread | previous in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D251570

Mark Millard <marklmi26-fbsd@yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marklmi26-fbsd@yahoo.com

--- Comment #5 from Mark Millard <marklmi26-fbsd@yahoo.com> ---
My files analogous to src.conf or src-env.conf for
cross building (amd64->???) via system clang have
lines like:

XCFLAGS+=3D -mcpu=3Dcortex-a72
XCXXFLAGS+=3D -mcpu=3Dcortex-a72
# There is no XCPPFLAGS but XCPP gets XCFLAGS content.
ACFLAGS.arm64cpuid.S+=3D  -mcpu=3Dcortex-a72+crypto
ACFLAGS.aesv8-armx.S+=3D  -mcpu=3Dcortex-a72+crypto
ACFLAGS.ghashv8-armx.S+=3D        -mcpu=3Dcortex-a72+crypto

I've only experimented with such specific control for
cortex-a7, cortex-a53, cortex-a57, and cortex-a72, i.e.,
the armv7 and aarch64 systems that I've had access to,
not targetting powerpc64, powerpc, or amd64.

-mcpu=3D implicitly picks the matching -march=3D value and
also sets the -mtune=3D value. The A53, A57, and A72
share the same -march=3D (armv8-a if I remember the command
line notation correctly) but can have very different
tuning. (In part this is because the A53 does not do many
things that the architecture allows, such as: it only
executes in order.)

I've not dealt with using the release script in years,
so I make no specific claims for that context. And even
for just use with make, the above probably steps into
"you are on your own" space. But at the time I adopted
the technique, I did not find any way to avoid that
status while doing the targeting via the style of build.
I've not had any troubles attributed to the above.

--=20
You are receiving this mail because:
You are the assignee for the bug.=



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-251570-227-FVhbfC2sJq>