GMP-6.0.0 Fails Test Suite Using enable-cxx flag with icc

[Torbjörn Granlund]

Ricky Farr <refarr at uncg.edu> writes:

  I just wanted to report that I encountered an issue not by compiling
  GMP-6.0.0, but using the test suite after compiling.  The version was not
  patched at all, and directly downloaded from gmplib.org tonight.
  
  My machine is an intel i5-haswell running Ubuntu 14.04.2 and using Intel
  Compiler version 15.0.1 (gcc 4.9.0 compatible).  The environment variables
  for the compiler were set as CC=icc and CXX=icc.  The configure flags used
  were:
  
  ./configure --prefix=/usr/local --disable-static --enable-cxx
  --docdir=/usr/local/shared/gmp-6.0.0
  
  I was able to compile the library, but when I used "make check -j4" I
  failed one test.  The relevant output from the test suite is given below.
  Note that I was able to compile and pass all tests by removing the
  --enable-cxx configure flag.
  
  FAIL: t-ops2
  
  As a side note, using the intel compiler for my set up more than doubles
  the speed compared to compiling with gcc. Also with no special compile
  flags set except defaults determined by gmp during configuration.  If you'd
  like me to present benchmark comparisons, please let me know.
  
It would baffle me if GMP's speed would be significantly affected by the
compiler.  Doubling the speed would seem to be impossible, as surely
over 90% of the time used by GMP is spent in hand-written assembly code.

I am afraid that I cannot work on this t-ops2 failure, as I don't have a
license to run the non-free Intel compiler.  Experience tells me that
this is a compiler bug, not a GMP bug.

-- 
Torbjörn
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