[Bug fortran/44156] New: dot_product / matmul and signed zeros

tkoenig at gcc dot gnu dot org gcc-bugzilla@gcc.gnu.org
Sun May 16 11:36:00 GMT 2010


Strictly speaking, we should get -0.00000 in all cases.

ig25@linux-fd1f:~/Fort> cat intrinsic_signed_zero.f90
program main
  implicit none
  real, dimension(1) :: a, b
  real, dimension(1,1) :: aa, bb
  a(1) = -1.0
  b(1) = 0.0
  print *,a(1)*b(1)
  print *,dot_product(a,b)
  aa(1,1) = -1.0
  bb(1,1) = 0.0
  print *,matmul(aa,bb)
end program main
ig25@linux-fd1f:~/Fort> gfortran intrinsic_signed_zero.f90
ig25@linux-fd1f:~/Fort> ./a.out
  -0.0000000
   0.0000000
   0.0000000


-- 
           Summary: dot_product / matmul and signed zeros
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: minor
          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=44156



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