[Bug fortran/42866] New: ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[Bug fortran/42866] New: ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[longb at cray dot com]

For this test case:

program F03_2_9_3_6_2c
! derived from OpenMP test omp3f/F03_2_9_3_6_2c.f90
! REFERENCES
!     OpenMP 3.0, p. 100, lines 10-12
!     OpenMP 3.0, p. 316, lines 18-22
   use omp_lib
   implicit none
   integer, parameter :: NT = 4
   integer :: thread_num1, thread_num2, thread_num3
   integer, allocatable :: thread_num_sums(:)
   integer :: i

   call omp_set_dynamic(.false.)
   call omp_set_num_threads(NT)

   allocate(thread_num_sums(NT))
   thread_num_sums = 0

   !$omp parallel 
      !$omp sections reduction(+:thread_num_sums)
         !$omp section
            thread_num_sums = omp_get_thread_num()
            thread_num1 = omp_get_thread_num()
         !$omp section
            thread_num_sums = omp_get_thread_num()
            thread_num2 = omp_get_thread_num()
         !$omp section
            thread_num_sums = omp_get_thread_num()
            thread_num3 = omp_get_thread_num()
      !$omp end sections
   !$omp end parallel

   do i = 1, NT
      if (thread_num_sums(i) /= thread_num1+thread_num2+thread_num3) then
         write (*,fmt="('FAIL - thread_num_sums(',i2, ') == ',i10,  &
                ' (expected',i2,')')") &
                i, thread_num_sums(i), thread_num1+thread_num2+thread_num3
                                                                     else
         write (*,fmt="('thread',i2,'  thread_num_sums(i) = ',i2)") &
                                 i, thread_num_sums(i)
      end if
   end do
end program F03_2_9_3_6_2c

the compiler aborts:

> gfortran -fopenmp test.f90
test.f90: In function 'f03_2_9_3_6_2c':
test.f90:20: internal compiler error: in single_pred_edge, at basic-block.h:658
Please submit a full bug report,
with preprocessed source if appropriate.


Additional comment from the OpenMP testers:

The GNU gfortran compiler gets an internal error when compiling this
test case when the REDUCTION appears on a SECTIONS.

The OpenMP API version 3 (May 2008) p. 316 lines 18-20 states:

"In Version 3.0, Fortran allocatable arrays may appear in ...
 reduction ... clauses."

The API also states on p. 100 line 10-23:

"An original list item with the ALLOCATABLE attribute must be in the 
 allocated state at entry to the construct containing the reduction clause.
 Additionally, the list item must not be deallocated and/or allocated
 within the region."


-- 
           Summary: ICE for REDUCTION with ALLOCATABLE array as variable on
                    SECTIONS
           Product: gcc
           Version: 4.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: longb at cray dot com
 GCC build triplet: x86_64-suse-linux
  GCC host triplet: x86_64-suse-linux
GCC target triplet: x86_64-suse-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866

[Bug fortran/42866] ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2010-01-26 09:14 -------
Created an attachment (id=19708)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19708&action=view)
gcc45-pr42866.patch

Patch I'm testing.

BTW, the provided testcase is wrong, if more than one section is scheduled on
the same thread, it will abort.  The problem is that it overwrites the
reduction array in each section rather than adds to it, so it can only succeed
if each section is scheduled in a different thread.  But scheduling of !$omp
sections
is implementation defined, there are no restrictions on that choice.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jakub at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866

[Bug fortran/42866] ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[jakub at gcc dot gnu dot org]

------- Comment #2 from jakub at gcc dot gnu dot org  2010-01-26 09:48 -------
Subject: Bug 42866

Author: jakub
Date: Tue Jan 26 09:47:45 2010
New Revision: 156235

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=156235
Log:
        PR fortran/42866
        * omp-low.c (expand_omp_sections): Only use single_pred if
        l2_bb is single_pred_p.

        * testsuite/libgomp.fortran/allocatable5.f90: New test.

Added:
    trunk/libgomp/testsuite/libgomp.fortran/allocatable5.f90
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/omp-low.c
    trunk/libgomp/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866

[Bug fortran/42866] ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2010-01-26 09:51 -------
Subject: Bug 42866

Author: jakub
Date: Tue Jan 26 09:51:23 2010
New Revision: 156236

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=156236
Log:
        PR fortran/42866
        * omp-low.c (expand_omp_sections): Only use single_pred if
        l2_bb is single_pred_p.

        * testsuite/libgomp.fortran/allocatable5.f90: New test.

Added:
    branches/gcc-4_4-branch/libgomp/testsuite/libgomp.fortran/allocatable5.f90
Modified:
    branches/gcc-4_4-branch/gcc/ChangeLog
    branches/gcc-4_4-branch/gcc/omp-low.c
    branches/gcc-4_4-branch/libgomp/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866

[Bug fortran/42866] ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2010-01-26 09:56 -------
Fixed.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu dot org
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866

[Bug fortran/42866] ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[jakub at gcc dot gnu dot org]

------- Comment #5 from jakub at gcc dot gnu dot org  2010-04-20 11:26 -------
*** Bug 43338 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866

[Bug fortran/42866] ICE for REDUCTION with ALLOCATABLE array as variable on SECTIONS

[jakub at gcc dot gnu dot org]

------- Comment #6 from jakub at gcc dot gnu dot org  2010-04-20 11:33 -------
*** Bug 43712 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42866