[MacPorts] #51097: gcc5 -- xgcc internal compiler error: Illegal instruction: 4

[MacPorts]

#51097: gcc5 -- xgcc internal compiler error: Illegal instruction: 4
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  Reporter:  gnwiii@…  |      Owner:  mcalhoun@…
      Type:  defect    |     Status:  assigned
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.3.4
Resolution:            |   Keywords:
      Port:  gcc5      |
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Comment (by mcalhoun@…):

 Replying to [comment:13 gnwiii@…]:
 > I'm not entirely clear about the "problem".  GMP works on the older
 system when compiled with the "+core2" option or
 > when compiled locally (in which case I assume the configuration stage
 correctly identifies the processor and applies appropriate algorithms),
 but the macports binary fails.  Since the macports binary did work on the
 newer iMac, I assume it was built
 > on a system similar to the newer iMac.  Are you hoping to create a
 variant that works for both nehalem and skylake?

 Perhaps I misunderstood the problem.[[BR]]
 Please correct any misstatements.[[BR]]
 * On an iMac 27-inch mid-2010 machine:
   * default gmp
     * with prebuilt gcc/libgcc, compiler fails
     * building gcc/libgcc fails
   * gmp with +core2 variant
     * with prebuilt gcc/libgcc, everything works
 * On an iMac retina 27-inch late 2015 machine:
   * default gmp
     * with prebuilt gcc/libgcc, everything works

 If this is in fact the case, then I am simply trying to track down what
 aspect of GMP causes the problem:
 * the fact that GMP builds with {{{-mtune=corei7}}}
 * the fact that GMP builds with {{{-march=corei7}}}
 * the processor specific assembly code GMP uses
 * some combination of the above

 I am certainly open to suggestions on better ways to proceed.[[BR]]
 At this point, I am not sure whether this is a GMP problem, a GCC problem,
 an [http://ark.intel.com/products/48496/Intel-Core-i5-760-Processor-8M-
 Cache-2_80-GHz i5-760] quirk, or simply a misalignment of compiler
 flags.[[BR]]
 Thank you for your patience.

 If this is a GMP issue, we could create code specifically for this
 processor that make is use the +core2 variant.[[BR]]
 If might run slower, but at least it would run.[[BR]]
 We could also engage the upstream developers, but we would need more
 information on what the issue is.

 Just a side note: the command {{{archive_sites}}} should force gmp should
 to **always** build locally.

-- 
Ticket URL: <https://trac.macports.org/ticket/51097#comment:14>
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