[Bug fortran/37951] New: parallelization fails for MA57

["dennis dot wassel at googlemail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Compiling ma57 with 
"gfortran -O<n> -ftree-parallelize-loops=2 -c ma57.f -o ma57.o"
produces the following error messages:

<n> = 1,2
----------
ma57.f: In function 'ma57od':
ma57.f:2724: error: edge from 676 to 686 should be marked irreducible
ma57.f:2724: error: basic block 686 should be marked irreducible
ma57.f:2724: error: edge from 686 to 679 should be marked irreducible
ma57.f:2724: error: basic block 679 should be marked irreducible
ma57.f:2724: error: edge from 679 to 124 should be marked irreducible
ma57.f:2724: confused by earlier errors, bailing out

<n> = 3
--------
ma57.f: In function 'ma57od':
ma57.f:2724: error: edge from 840 to 850 should be marked irreducible
ma57.f:2724: error: basic block 850 should be marked irreducible
ma57.f:2724: error: edge from 850 to 843 should be marked irreducible
ma57.f:2724: error: basic block 843 should be marked irreducible
ma57.f:2724: error: edge from 843 to 160 should be marked irreducible
ma57.f:2724: confused by earlier errors, bailing out

Since the HSL codes are subject to restricted licenses, I am pretty sure that I
am not supposed to include its source-code here. You can have a look at
http://www.cse.scitech.ac.uk/nag/hsl/ though, if you are eligible to obtain a
copy of ma57!

My gcc version:

Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /localdata/install/gcc/gcc-4.3.2/configure
--prefix=/home/dwassel --program-suffix=-4.3.2 --enable-languages=c,c++,fortran
--with-gmp=/home/dwassel --with-mpfr=/home/dwassel --with-arch=athlon64
--with-tune=athlon64 --enable-version-specific-runtime-libs
Thread model: posix
gcc version 4.3.2 (GCC)


-- 
           Summary: parallelization fails for MA57
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dennis dot wassel at googlemail dot com
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37951