program fc106 ! Submitted by Walt Brainerd, The Fortran Company ! GNU Fortran 95 (GCC 4.1.0 20050322 (experimental)) ! Windows XP ! Output is ! 1 2 3 ! 1 1 1 ! 1 1 1 ! Output should be ! 1 2 3 ! 1 1 2 ! 1 2 3 real, dimension (3) :: a, b equivalence (a(2), b) a = (/ (i, i=1,3) /) print *, a b = a; print *, a print *, b end program fc106 I think this means that we don't see that in the assignment b = a the RHS and the LHS are dependent, and therefore don't copy via a temporary, but I haven't checked.
Yes this is the problem, as evidenced in the tree dumps, and as confirmed by looking through dependency.c.
A patch is on its way - it's regtesting right now. This fixes the problem with where_19.f90 as well. Paul
I might be a little late, given that you already posted a patch which completely fixes this issue <http://gcc.gnu.org/ml/fortran/2006-02/msg00420.html>, but I thought of fixing this back before we had the in_equivalence attribute, by simply assuming that the RHS and the LHS are dependent if both are members of equivalences. I'm not convinced that this pathological case is worth all the effort. Nevertheless I'll review your patch during the next 48 hours.
Subject: Re: Dependency checking fails for equivalences tobi, >------- Comment #3 from tobi at gcc dot gnu dot org 2006-02-19 18:56 ------- >I might be a little late, given that you already posted a patch which >completely fixes this issue ><http://gcc.gnu.org/ml/fortran/2006-02/msg00420.html>, but I thought of fixing >this back before we had the in_equivalence attribute, by simply assuming that >the RHS and the LHS are dependent if both are members of equivalences. I'm not >convinced that this pathological case is worth all the effort. Nevertheless >I'll review your patch during the next 48 hours. > > Thanks - I gave thought to the same fix. It has its advantages; like avoiding a quadratic term. However, it will cause temporaries to sprout, where none are necessary. The effort was not that great; similar code exists in match.c that I adapted. I could not quite see how to combine them into one function, though. Paul
Subject: Bug number PR20938 A patch for this bug has been added to the patch tracker. The mailing list url for the patch is http://gcc.gnu.org/ml/gcc-patches/2006-02/msg01891.html
Subject: Bug 20938 Author: pault Date: Wed Mar 1 22:24:19 2006 New Revision: 111616 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=111616 Log: 2006-03-01 Paul Thomas <pault@gcc.gnu.org> * iresolve.c (gfc_resolve_dot_product): Remove any difference in treatment of logical types. * trans-intrinsic.c (gfc_conv_intrinsic_dot_product): New function. PR fortran/26393 * trans-decl.c (gfc_get_symbol_decl): Extend condition that symbols must be referenced to include unreferenced symbols in an interface body. PR fortran/20938 * trans-array.c (gfc_conv_resolve_dependencies): Add call to gfc_are_equivalenced_arrays. * symbol.c (gfc_free_equiv_infos, gfc_free_equiv_lists): New functions. (gfc_free_namespace): Call them. * trans-common.c (copy_equiv_list_to_ns): New function. (add_equivalences): Call it. * gfortran.h: Add equiv_lists to gfc_namespace and define gfc_equiv_list and gfc_equiv_info. * dependency.c (gfc_are_equivalenced_arrays): New function. (gfc_check_dependency): Call it. * dependency.h: Prototype for gfc_are_equivalenced_arrays. 2006-03-01 Paul Thomas <pault@gcc.gnu.org> * gfortran.dg/logical_dot_product.f90: New test. PR fortran/26393 * gfortran.dg/used_interface_ref.f90: New test. PR fortran/20938 * gfortran.dg/dependency_2.f90: New test. * gfortran.fortran-torture/execute/where17.f90: New test. * gfortran.fortran-torture/execute/where18.f90: New test. * gfortran.fortran-torture/execute/where19.f90: New test. * gfortran.fortran-torture/execute/where20.f90: New test. Added: trunk/gcc/testsuite/gfortran.dg/dependency_2.f90 trunk/gcc/testsuite/gfortran.dg/logical_dot_product.f90 trunk/gcc/testsuite/gfortran.dg/used_interface_ref.f90 trunk/gcc/testsuite/gfortran.fortran-torture/execute/where17.f90 trunk/gcc/testsuite/gfortran.fortran-torture/execute/where18.f90 trunk/gcc/testsuite/gfortran.fortran-torture/execute/where19.f90 trunk/gcc/testsuite/gfortran.fortran-torture/execute/where20.f90 Modified: trunk/MAINTAINERS trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/dependency.c trunk/gcc/fortran/dependency.h trunk/gcc/fortran/gfortran.h trunk/gcc/fortran/iresolve.c trunk/gcc/fortran/symbol.c trunk/gcc/fortran/trans-array.c trunk/gcc/fortran/trans-common.c trunk/gcc/fortran/trans-decl.c trunk/gcc/fortran/trans-intrinsic.c trunk/gcc/testsuite/ChangeLog
Fixed on mainline. Patch ready for 4.1 to reopen. Paul
Subject: Bug 20938 Author: pault Date: Tue Mar 7 00:06:37 2006 New Revision: 111796 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=111796 Log: 2006-03-07 Paul Thomas <pault@gcc.gnu.org> PR fortran/26107 * resolve.c (resolve_function): Add name after test for pureness. * iresolve.c (gfc_resolve_dot_product): Remove any difference in treatment of logical types. * trans-intrinsic.c (gfc_conv_intrinsic_dot_product): New function. PR fortran/26393 * trans-decl.c (gfc_get_symbol_decl): Extend condition that symbols must be referenced to include unreferenced symbols in an interface body. PR fortran/20938 * trans-array.c (gfc_conv_resolve_dependencies): Add call to gfc_are_equivalenced_arrays. * symbol.c (gfc_free_equiv_infos, gfc_free_equiv_lists): New functions. (gfc_free_namespace): Call them. * trans-common.c (copy_equiv_list_to_ns): New function. (add_equivalences): Call it. * gfortran.h: Add equiv_lists to gfc_namespace and define gfc_equiv_list and gfc_equiv_info. * dependency.c (gfc_are_equivalenced_arrays): New function. (gfc_check_dependency): Call it. * dependency.h: Prototype for gfc_are_equivalenced_arrays. PR fortran/24519 * dependency.c (gfc_is_same_range): Correct typo. (gfc_check_section_vs_section): Call gfc_is_same_range. PR fortran/25395 * trans-common.c (add_equivalences): Add a new flag that is set when an equivalence is seen that prevents more from being reset until the start of a new traversal of the list, thus ensuring completion of all the equivalences. PR fortran/25054 * resolve.c (is_non_constant_shape_array): New function. (resolve_fl_variable): Remove code for the new function and call it. (resolve_fl_namelist): New function. Add test for namelist array with non-constant shape, using is_non_constant_shape_array. (resolve_symbol): Remove code for resolve_fl_namelist and call it. PR fortran/25089 * match.c (match_namelist): Increment the refs field of an accepted namelist object symbol. * resolve.c (resolve_fl_namelist): Test namelist objects for a conflict with contained or module procedures. PR fortran/24557 * trans-expr.c (gfc_add_interface_mapping): Use the actual argument for character(*) arrays, rather than casting to the type and kind parameters of the formal argument. 2006-03-07 Paul Thomas <pault@gcc.gnu.org> PR fortran/26107 * resolve.c (resolve_function): Add name after test for pureness. * gfortran.dg/logical_dot_product.f90: New test. PR fortran/26393 * gfortran.dg/used_interface_ref.f90: New test. PR fortran/20938 * gfortran.dg/dependency_2.f90: New test. * gfortran.fortran-torture/execute/where17.f90: New test. * gfortran.fortran-torture/execute/where18.f90: New test. * gfortran.fortran-torture/execute/where19.f90: New test. * gfortran.fortran-torture/execute/where20.f90: New test. PR fortran/24519 * gfortran.dg/dependency_3.f90: New test. * gfortran.fortran-torture/execute/vect-3.f90: Remove two of the XFAILs. PR fortran/25395 * gfortran.dg/equiv_6.f90: New test. PR fortran/25054 * gfortran.dg/namelist_5.f90: New test. PR fortran/25089 * gfortran.dg/namelist_4.f90: New test. PR fortran/24557 * gfortran.dg/assumed_charlen_needed_1.f90: New test. Added: branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/assumed_charlen_needed_1.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/dependency_2.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/dependency_3.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/equiv_6.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/logical_dot_product.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/namelist_4.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/namelist_5.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/pure_dummy_length_1.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/used_interface_ref.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.fortran-torture/execute/where17.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.fortran-torture/execute/where18.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.fortran-torture/execute/where19.f90 branches/gcc-4_1-branch/gcc/testsuite/gfortran.fortran-torture/execute/where20.f90 Modified: branches/gcc-4_1-branch/MAINTAINERS branches/gcc-4_1-branch/gcc/fortran/ChangeLog branches/gcc-4_1-branch/gcc/fortran/dependency.c branches/gcc-4_1-branch/gcc/fortran/dependency.h branches/gcc-4_1-branch/gcc/fortran/dump-parse-tree.c branches/gcc-4_1-branch/gcc/fortran/gfortran.h branches/gcc-4_1-branch/gcc/fortran/iresolve.c branches/gcc-4_1-branch/gcc/fortran/match.c branches/gcc-4_1-branch/gcc/fortran/resolve.c branches/gcc-4_1-branch/gcc/fortran/symbol.c branches/gcc-4_1-branch/gcc/fortran/trans-array.c branches/gcc-4_1-branch/gcc/fortran/trans-common.c branches/gcc-4_1-branch/gcc/fortran/trans-decl.c branches/gcc-4_1-branch/gcc/fortran/trans-expr.c branches/gcc-4_1-branch/gcc/fortran/trans-intrinsic.c branches/gcc-4_1-branch/gcc/testsuite/ChangeLog branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/vect/vect-3.f90