[Bug fortran/29952] New: Flag to give runtime information " array temporary was created for argument"

[Bug fortran/29952] New: Flag to give runtime information " array temporary was created for argument"

[burnus at gcc dot gnu dot org]

Intel has a nice feature to find bad array definitions.
Somehow thinking of C I wrote:
  real :: coord(N,3)
rather than coord(3,N). Using "ifort -check arg_temp_created" this gave then
such information at run time (in my example below 20 times):

"forrtl: warning (402): fort: (1): In call to DISTANCE, an array temporary was
created for argument #1"

While one can sometimes not prevent the need for a array temporary, one often
can and should do so to speed up the program.

Example program:
---------------------------------
program tmp
  implicit none
  integer, parameter :: N = 20
  real               :: coord(N,3) ! better: (3,N)
  integer            :: i
  real               :: d
  coord = 0.0
  do i=1,N
    d = distance(coord(i,:))
  end do
contains
  function distance(a)
    real :: a(3)
    real :: distance
    distance = sqrt(a(1)**2 + a(2)**2 + a(3)**2)
  end function distance
end program tmp


-- 
           Summary: Flag to give runtime information " array temporary was
                    created for argument"
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[pault at gcc dot gnu dot org]

------- Comment #1 from pault at gcc dot gnu dot org  2006-11-23 18:31 -------
Confirmed.... sort of.
> 
> While one can sometimes not prevent the need for a array temporary, one often
> can and should do so to speed up the program.

            {
              void * D.1019;
              struct array1_real4 parm.2;
              int4 D.1008;

              D.1008 = i;
              parm.2.dtype = 281;
              parm.2.dim[0].lbound = 1;
              parm.2.dim[0].ubound = 3;
              parm.2.dim[0].stride = 20;
              parm.2.data = (void *) &coord[D.1008 + -1];
              parm.2.offset = 0;
              D.1019 = _gfortran_internal_pack (&parm.2);
              d = distance (D.1019);
              if (D.1019 != (real4[0:] *) parm.2.data)
                {
                  _gfortran_internal_unpack (&parm.2, D.1019);
                  _gfortran_internal_free (D.1019);
                }
              else
                {
                  (void) 0;
                }
            }

It is the parm.2.dim[0].stride = 20; that determines the need for a temporary. 
If it has a value of 1, internal pack returns a pointer to the source array. 
Thus, such an option would work for constant strides of other than one but
would have to report in real-time for variable strides.

Paul 


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-11-23 18:31:25
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[tkoenig at gcc dot gnu dot org]

------- Comment #2 from tkoenig at gcc dot gnu dot org  2008-07-21 21:40 -------
Created an attachment (id=15936)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15936&action=view)
patch for compile-time check

This passes regression-tests, make info and make dvi.

All that's needed is a proper test case.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2008-07-23 16:12 -------
Test case for the run-time check. Only for the second call a warning is needed.
One way to add it is the following. One simply inserts

  if (parm.1.data != D.1036)
    printf("test.f90:5: In call to FOO, an array temporary "
           "was created for argument #1\n");

between the following lines:

      D.1036 = _gfortran_internal_pack (&parm.1);
      foo (D.1036);

(The "if" line is copied from the  _gfortran_internal_unpack block.)


Test case:

program test
  implicit none
  integer :: a(3,3)
  call foo(a(:,1))  ! OK, no temporary created
  call foo(a(1,:))  ! BAD, temporary var created
contains
  subroutine foo(x)
    integer :: x(3)
    x = 5
  end subroutine foo
end program test


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[burnus at gcc dot gnu dot org]

------- Comment #4 from burnus at gcc dot gnu dot org  2008-07-24 08:33 -------
(In reply to comment #3)
> Test case for the run-time check.

By itself this PR not related is PR 36909. However, both require that
gfc_conv_function_call passes on information. For PR 36909 one needs to have
the INTENT of the formal argument, for this PR one needs to pass the procedure
name and either the formal-argument name or its position.

Thus I think one could fix both PRs simultaneously.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[tkoenig at gcc dot gnu dot org]

------- Comment #5 from tkoenig at gcc dot gnu dot org  2008-07-24 09:27 -------
Subject: Bug 29952

Author: tkoenig
Date: Thu Jul 24 09:26:43 2008
New Revision: 138112

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=138112
Log:
2008-07-24  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/29952
        * gfortran.h:  Add "warn_array_temp" to gfc_option_t.
        * lang.opt:  Add -Warray-temporaries.
        * invoke.texi:  Document -Warray-temporaries
        * trans-array.h (gfc_trans_create_temp_array):  Add argument of
        type *locus.
        (gfc_conv_loop_setup):  Likewise.
        * trans-array.c (gfc_trans_create_temp_array):  If
        -Warray-temporaries is given and locus is present, warn about
        creation of array temporaries.
        (gfc_trans_array_constructor_subarray):  Add locus to call
        of gfc_conv_loop_setup.
        (gfc_trans_array_constructor):  Add where argument.  Pass where
        argument to call of gfc_trans_create_temp_array.
        (gfc_add_loop_ss_code):  Add where argument.  Pass where argument
        to recursive call of gfc_add_loop_ss_code and to call of
        gfc_trans_array_constructor.
        (gfc_conv_loop_setup):  Add where argument.  Pass where argument
        to calls to gfc_add_loop_ss_code and to gfc_trans_create_temp_array.
        (gfc_conv_expr_descriptor):  Pass location to call of
        gfc_conv_loop_setup.
        (gfc_conv_array_parameter):  If -Warray-temporaries is given,
        warn about creation of temporary arrays.
        * trans-expr.c (gfc_conv_subref_array_arg):  Add where argument
        to call to gfc_conv_loop_setup.
        (gfc_conv_function_call):  Add where argument to call to
        gfc_trans_creat_temp_array.
        (gfc_trans_subarray_assign):  Likewise.
        (gfc_trans_assignment_1):  Add where argument to call to
        gfc_conv_loop_setup.
        * trans-stmt.c (gfc_conv_elemental_dependencies):  Add where
        argument to call to gfc_trans_create_temp_array.
        (gfc_trans_call):  Add where argument to call to gfc_conv_loop_setup.
        (generate_loop_for_temp_to_lhs):  Likewise.
        (generate_loop_for_rhs_to_temp):  Likewise.
        (compute_inner_temp_size):  Likewise.
        (gfc_trans-pointer_assign_need_temp):  Likewise.
        (gfc_evaluate_where_mask):  Likewise.
        (gfc_trans_where_assign):  Likewise.
        (gfc_trans_where_3):  Likewise.
        * trans-io.c (transfer_srray_component):  Add where argument
        to function. Add where argument to call to gfc_conv_loop_setup.
        (transfer_expr):  Add where argument to call to
        transfer_array_component.
        (gfc_trans_transfer):  Add where expression to call to
        gfc_conv_loop_setup.
        * trans-intrinsic.c (gfc_conv_intrinsic_anyall):  Add
        where argument to call to gfc_conv_loop_setup.
        (gfc_conv_intrinsic_count):  Likewise.
        (gfc_conv_intrinsic_arith):  Likewise.
        (gfc_conv_intrinsic_dot_product):  Likewise.
        (gfc_conv_intrinsic_minmaxloc):  Likewise.
        (gfc_conv_intrinsic_minmaxval):  Likewise.
        (gfc_conv_intrinsic_array_transfer):  Warn about
        creation of temporary array.
        Add where argument to call to gfc_trans_create_temp_array.
        * options.c (gfc_init_options):  Initialize gfc_option.warn_array_temp.
        (gfc_handle_option):  Set gfc_option.warn_array_temp.

2008-07-24  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/29952
        * gfortran.dg/array_temporaries_1.f90: New test case.


Added:
    trunk/gcc/testsuite/gfortran.dg/array_temporaries_1.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/invoke.texi
    trunk/gcc/fortran/lang.opt
    trunk/gcc/fortran/options.c
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/fortran/trans-array.h
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/fortran/trans-intrinsic.c
    trunk/gcc/fortran/trans-io.c
    trunk/gcc/fortran/trans-stmt.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[burnus at gcc dot gnu dot org]

------- Comment #6 from burnus at gcc dot gnu dot org  2008-07-27 10:46 -------
Subject: Bug 29952

Author: burnus
Date: Sun Jul 27 10:45:44 2008
New Revision: 138186

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=138186
Log:
2008-07-27  Tobias Burnus  <burnus@net-b.de>

        PR fortran/36132
        PR fortran/29952
        PR fortran/36909
        * trans.c (gfc_trans_runtime_check): Allow run-time warning
        * besides
        run-time error.
        * trans.h (gfc_trans_runtime_check): Update declaration.
        * trans-array.c
        * (gfc_trans_array_ctor_element,gfc_trans_array_bound_check,
        gfc_conv_array_ref,gfc_conv_ss_startstride,gfc_trans_dummy_array_bias):
        Updated gfc_trans_runtime_check calls.
        (gfc_conv_array_parameter): Implement flag_check_array_temporaries,
        fix packing/unpacking for nonpresent optional actuals to optional
        formals.
        * trans-array.h (gfc_conv_array_parameter): Update declaration.
        * trans-expr.c (gfc_conv_substring,gfc_trans_arrayfunc_assign,
        gfc_conv_function_call): Updated gfc_trans_runtime_check calls.
        (gfc_conv_function_call): Update gfc_conv_array_parameter calls.
        * trans-expr.c (gfc_trans_goto): Updated gfc_trans_runtime_check
        calls.
        * trans-io.c (set_string,gfc_conv_intrinsic_repeat): Ditto.
        (gfc_conv_intrinsic_transfer,gfc_conv_intrinsic_loc): Same for
        gfc_conv_array_parameter.
        * trans-intrinsics.c (gfc_conv_intrinsic_bound): Ditto.
        * trans-decl.c (gfc_build_builtin_function_decls): Add
        gfor_fndecl_runtime_warning_at.
        * lang.opt: New option fcheck-array-temporaries.
        * gfortran.h (gfc_options): New flag_check_array_temporaries.
        * options.c (gfc_init_options, gfc_handle_option): Handle flag.
        * invoke.texi: New option fcheck-array-temporaries.

2008-07-27  Tobias Burnus  <burnus@net-b.de>

        PR fortran/36132
        PR fortran/29952
        PR fortran/36909
        * runtime/error.c: New function runtime_error_at.
        * gfortran.map: Ditto.
        * libgfortran.h: Ditto.

2008-07-27  Tobias Burnus  <burnus@net-b.de>

        PR fortran/36132
        PR fortran/29952
        PR fortran/36909
        gfortran.dg/internal_pack_4.f90: New.
        gfortran.dg/internal_pack_5.f90: New.
        gfortran.dg/array_temporaries_2.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/array_temporaries_2.f90
    trunk/gcc/testsuite/gfortran.dg/internal_pack_4.f90
    trunk/gcc/testsuite/gfortran.dg/internal_pack_5.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/invoke.texi
    trunk/gcc/fortran/lang.opt
    trunk/gcc/fortran/options.c
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/fortran/trans-array.h
    trunk/gcc/fortran/trans-decl.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/fortran/trans-intrinsic.c
    trunk/gcc/fortran/trans-io.c
    trunk/gcc/fortran/trans-stmt.c
    trunk/gcc/fortran/trans.c
    trunk/gcc/fortran/trans.h
    trunk/gcc/testsuite/ChangeLog
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/gfortran.map
    trunk/libgfortran/libgfortran.h
    trunk/libgfortran/runtime/error.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952

[Bug fortran/29952] Flag to give runtime information " array temporary was created for argument"

[burnus at gcc dot gnu dot org]

------- Comment #7 from burnus at gcc dot gnu dot org  2008-07-27 10:54 -------
Now also run-time warnings are printed.
-> FIXED on the trunk (4.4).


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29952