[MacPorts] #34540: gaul-devel build varies based on number of CPUs
MacPorts
noreply at macports.org
Fri Dec 14 23:39:30 PST 2012
#34540: gaul-devel build varies based on number of CPUs
---------------------------+---------------------
Reporter: ryandesign@… | Owner: vince@…
Type: defect | Status: closed
Priority: Normal | Milestone:
Component: ports | Version: 2.1.1
Resolution: wontfix | Keywords:
Port: gaul-devel |
---------------------------+---------------------
Comment (by vince@…):
There is always a trade-off involved with binaries. For example, Qt
autodetects the vector units of the processor that performs the
compilation. If you happen to compile qt4-mac on an Ivy Bridge machine and
install the resulting binary on a Core Duo Mac, you face the risk of
crashing due to AVX/SSE4.2 instructions not being supported on the latter
(that’s what I do, though, and up to now it has been fine). If you proceed
the other way round, you won’t get the performance boost allowed by the
new hardware/instructions.
Since it is better to lose efficiency than to crash, ideally a binary
should be produced on the oldest machine of a given architecture. That’s
what plagues all the Window$®™ binary distributions, some of which have to
be compatible with old Pentium processors…
--
Ticket URL: <https://trac.macports.org/ticket/34540#comment:6>
MacPorts <http://www.macports.org/>
Ports system for Mac OS
More information about the macports-tickets
mailing list