[Bug fortran/33341] New: unnecessary stores for array constructor

[tkoenig at gcc dot gnu dot org]

The following idiom causes unnecessary runtime
overhead:

$ cat compare.f90
function foo(a,b,c,d)
  logical :: foo
  integer, intent(in):: a,b,c,d

  foo = all((/ a, b, c /) /= d)
end function foo
$ gfortran -fdump-tree-optimized -O3 -S compare.f90

The *.optimized file shows

<bb 2>:
  D.521 = (int4[0:] *) &A.2;
  D.522 = *a;
  (*D.521)[0] = D.522;
  D.523 = *b;
  (*D.521)[1] = D.523;
  D.524 = *c;
  (*D.521)[2] = D.524;
  D.516 = *d;

The stores are unneeded, as the array itself could
be eliminated.


-- 
           Summary: unnecessary stores for array constructor
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33341