LI73751: MATMUL PRODUCES Incorrect output

January 2010 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
August 2009 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
May 2010 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
August 2010 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
December 2010 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
April 2011 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
August 2011 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
December 2011 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
April 2012 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1
XL Fortran Advanced Edition for Blue Gene/P Fix Pack 17 (October 2013 Update) for 11.1
September 2008 Update for XL Fortran Advanced Edition for Blue Gene/P, V11.1

APAR status

• Closed as program error.

Error description

• The following test case failed on XLF 11.1.0.3 for BG/P. The job
  is killed with signal 7.
  
  !test28.f90
  
  
  MODULE test1
  !
    PUBLIC :: init_test1, run_test1
    COMPLEX, DIMENSION(:,:), ALLOCATABLE, SAVE :: sl
  !
  CONTAINS
  !
    SUBROUTINE init_test1
      ALLOCATE(sl(2,2))
      sl(:,:) = 1.0
    END SUBROUTINE init_test1
  !
    SUBROUTINE run_test1(p_rhs,lb)
      INTEGER, DIMENSION(1),      INTENT(IN)   :: lb
      COMPLEX, DIMENSION(lb(1):), INTENT(INOUT):: p_rhs
      INTEGER :: i
      COMPLEX, DIMENSION(2) :: zv
      zv(:) = 1.0
      PRINT *,'start'
      DO i = 1,10000000
         p_rhs(:) = MATMUL(sl,zv)
      END DO
      PRINT *,'passed'
  !
    END SUBROUTINE run_test1
  !
  END MODULE test1
  !
  MODULE test2
    PUBLIC :: run_test2
    COMPLEX, DIMENSION(:), ALLOCATABLE, SAVE :: rhs1
  !
  CONTAINS
  !
    SUBROUTINE run_test2
      USE test1, ONLY : init_test1, run_test1
      INTEGER, DIMENSION(1), SAVE :: lb_rhs
      ALLOCATE(rhs1(2))
      rhs1(:) = 1.0
      CALL init_test1
      lb_rhs(:) = LBOUND(rhs1)
      CALL run_test1(rhs1, lb_rhs)
    END SUBROUTINE run_test2
  !
  END MODULE test2
  !
  PROGRAM main
  !
  
  
  
    USE test2, ONLY : run_test2
    CALL run_test2
  !
  END PROGRAM main
  !test28.f90
  
  ! mpixlf95_r -qautodbl=dbl4 -o test28 test28.f90
  ! mpirun -exe ./test28 -mode SMP
  ! Job is killed by signal 7
  

Local fix

• N/A
  

Problem summary

• Users Affected:   Code with MATMUL in a loop on linux or BG
  
  Description:      Wrong results or NAN(S) with MATMUL intrinsic
  and allocatable arrays were generated. In some cases, programs
  will lead to segmentation fault due to bad memory access.
  

Problem conclusion

• Problem is fixed by moving alloc/dealloc code to the correct
  scope.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  XL FORTRAN AE B

• Fixed component ID

  5799HJF00

Applicable component levels

• RB10 PSY

     UP