IV46460: INCORRECT ARRAY BOUND CHECKS AT -O5

XL Fortran for AIX Fix Pack 11 (May 2015 PTF) for 14.1
XL Fortran for AIX Fix Pack 12 (August 2015 Update) for 14.1
XL Fortran for AIX Fix Pack 15 (April 2016 Update) for 14.1
XL Fortran for AIX Fix Pack 16 (July 2016 Update) for 14.1
XL Fortran for AIX Fix Pack 17 (November 2016 Update) for 14.1
XL Fortran for AIX Fix Pack 18 (February 2017 Update) for 14.1
XL Fortran for AIX Fix Pack 19 (August 2017 Update) for 14.1
XL Fortran for AIX Fix Pack 5 (September 2013 PTF) for 14.1
XL Fortran for AIX Fix Pack 6 (December 2013 PTF) for 14.1
XL Fortran for AIX Fix Pack 7 (March 2014 PTF) for 14.1
XL Fortran for AIX Fix Pack 8 (July 2014 PTF) for 14.1
XL Fortran for AIX Fix Pack 9 (October 2014 PTF) for 14.1
XL Fortran for AIX Fix Pack 10 (February 2015 PTF) for 14.1
XL Fortran for AIX Fix Pack 14 (December 2015 Update) for 14.1

APAR status

• Closed as program error.

Error description

• The compiler seems to be incorrectly inserting a trap statement
  for array bound checks at -O5 for line 42 in the test case
  mentioned below
  ie
  cos_sin(:)%co = inivalue
  
  This causes the exe to trap at runtime.
  
  ===== COMPILE COMMAND:
   xl f2003 -g -O5 -qcheck -qfullpath -qextname test.f90
  
  ===== TESTCASE:
  $ cat test.f90
  program test
  
    implicit none
  
    type my_type
      real (kind=4)   :: co
      real (kind=4)   :: si
    end type my_type
  
    integer :: dim1 , dim2
    real (kind=4) :: initializevalue
  
    type(my_type), allocatable, dimension(:)    :: cos_sin_1d
    type(my_type), allocatable, dimension(:,:)  :: cos_sin_2d
  
    integer :: istatus
  
    dim1 = 34
    dim2 = 256
  
    initializevalue = 0.
  
    call test_1d(cos_sin_1d, dim1, initializevalue)
    call test_2d(cos_sin_2d, dim1, dim2, initializevalue)
  
  contains
  
    subroutine test_1d(cos_sin, lendim1, inivalue)
  
      type (my_type), intent (inout), allocatable, dimension(:)
  :: cos_sin
      integer               , intent (in)
           :: lendim1
      real (kind=4)         , intent (in)
           :: inivalue
  
      print*, 'test_1d: lendim1 =', lendim1
      print*, 'test_1d: (m1) allocated = ', allocated(cos_sin)
      if ( .not. allocated( cos_sin ) ) then
        if ( lendim1 > 0 ) then
  
          allocate( cos_sin(1:lendim1) )
          print*, 'test_1d: (m2) allocated = ', allocated(cos_sin)
  
          cos_sin(:)%co = inivalue
          cos_sin(:)%si = inivalue
  
        endif
      end if
  
    end subroutine test_1d
  
    subroutine test_2d(cos_sin, lendim1, lendim2, inivalue)
  
      type (my_type), intent (inout), allocatable, dimension(:,:)
   :: cos_sin
      integer               , intent (in)
           :: lendim1
      integer               , intent (in)
           :: lendim2
      real (kind=4)         , intent (in)
           :: inivalue
  
      print*, 'test_2d: lendim1 , lendim2 =', lendim1 , lendim2
      print*, "test_2d: (m1) allocated = ", allocated(cos_sin)
      if ( .not. allocated( cos_sin ) ) then
        if ( lendim1         > 0 .and. &
             lendim2         > 0 ) then
  
          allocate( cos_sin(1:lendim1, 1:lendim2) )
          print*, 'test_2d: (m2) allocated = ', allocated(cos_sin)
  
          cos_sin(:,:)%co = inivalue
          cos_sin(:,:)%si = inivalue
  
        endif
      end if
  
    end subroutine test_2d
  
  end program test
  $
  
  
  ===== ACTUAL OUTPUT:
  $ ./a.out
   test_1d: lendim1 = 34
   test_1d: (m1) allocated =  F
   test_1d: (m2) allocated =  T
   test_2d: lendim1 , lendim2 = 34 256
   test_2d: (m1) allocated =  F
   test_2d: (m2) allocated =  T
  Trace/BPT trap
  $
  
  ===== EXPECTED OUTPUT:
  $ ./a.out
   test_1d: lendim1 = 34
   test_1d: (m1) allocated =  F
   test_1d: (m2) allocated =  T
   test_2d: lendim1 , lendim2 = 34 256
   test_2d: (m1) allocated =  F
   test_2d: (m2) allocated =  T
  $
  

Local fix

• N/A
  

Problem summary

• USERS AFFECTED:
  Users who use the -qcheck option may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  Users will get core dumps because -qcheck incorrectly adds a
  trap with an incorrect offset.
  

Problem conclusion

• The logic behind calculating the offset to include the trap was
  corrected to account for this scenario.
  

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:

  LI77677

Fix information

• Fixed component name

  XL FORTRAN FOR

• Fixed component ID

  5725C7400

Applicable component levels