[MacPorts] #48381: OpenBlas: difficulty detecting architecture

[MacPorts]

#48381: OpenBlas: difficulty detecting architecture
--------------------------+---------------------
  Reporter:  aaron.koe@…  |      Owner:  nicos@…
      Type:  defect       |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.3.3
Resolution:               |   Keywords:
      Port:  openblas     |
--------------------------+---------------------

Comment (by andy.nowacki@…):

 In fact, things are working as per the port file.  The portfile contains:

 {{{
     if { ![catch {sysctl hw.optional.avx1_0} has_avx] && $has_avx == 1 } {
         #Use clang if the processor has avx instructions
         default_variants +clang
     } else {
         #Else, use gcc48 as default
         default_variants +gcc48
     }
 }}}

 And then, if the variant is not clang, we do the following:
 {{{
         if {![variant_isset clang]} {
             puts $makeINC "NO_AVX = 1"
         }
 }}}

 (Note that `sysctl hw.optional.avx1_0` outputs 1 on my machine.)

 Because I have been using the +gcc48 variant (mainly just to avoid having
 to add dragonegg to my list of ports), the line `NO_AVX = 1` is added to
 the Makefile.rule file, and it is this which leads to `CORE=NEHALEM` from
 getarch.  If this is intended behaviour, probably something should be
 added to the information about the port to this effect.

 Building with gcc, not clang, doesn't appear to lead to any build problems
 when using AVX instructions, and these give a big boost to speed.  I
 wonder what the reason was to require (i) that gcc is needed for machines
 without AVX; and (ii) whether choosing a gcc?? variant should preclude
 using AVX instructions.  Perhaps the latter situation was an unintended
 side-effect?  Apologies if there are deeper causes I am missing.

 I think this means OpenBLAS @0.2.12_2 is actually fixed, but perhaps both
 ports need their portfile tweaking?

-- 
Ticket URL: <https://trac.macports.org/ticket/48381#comment:12>
MacPorts <https://www.macports.org/>
Ports system for OS X