After the support goes into the middle end, cf. http://gcc.gnu.org/ml/fortran/2010-04/msg00012.html and http://gcc.gnu.org/ml/gcc-patches/2009-11/msg01257.html , one should use the the new function call argument/return value attributes. Note: One needs to be careful about this in terms of multi-image coarrays (SYNC ALL, array single-side access) and true asynchronous I/O (WRITE ... WAIT) as otherwise the middle end optimizes too much. (Telling this the middle end via a specifically tailored attribute might be better, though.) + /* Call argument flags. */ + + /* Nonzero if the argument is not dereferenced recursively, thus only + directly reachable memory is read or written. */ + #define EAF_DIRECT (1 << 0) + /* Nonzero if memory reached by the argument is not clobbered. */ + #define EAF_NOCLOBBER (1 << 1) + /* Nonzero if the argument does not escape. */ + #define EAF_NOESCAPE (1 << 2) + /* Nonzero if the argument is not used by the function. */ + #define EAF_UNUSED (1 << 3) + + /* Call return flags. */ + + /* Mask for the argument number that is returned. Lower two bits of + the return flags, encodes argument slots zero to three. */ + #define ERF_RETURN_ARG_MASK (3) + /* Nonzero if the return value is equal to the argument number + flags & ERF_RETURN_ARG_MASK. */ + #define ERF_RETURNS_ARG (1 << 2) + /* Nonzero if the return value does not alias with anything. Functions + with the malloc attribute have this set on their return value. */ + #define ERF_NOALIAS (1 << 3)
Some more quotes: > You can mark parameters 1) unused, 2) pointed-to read-only, > 3) not escaping, 4) only once dereferenced (thus, access only > *p, not **p) > > You can mark return values as being a direct copy of arguments > or as non-aliasing (similar to the malloc attribute). + attr = lookup_attribute ("fnspec", TYPE_ATTRIBUTES (type)); + switch (TREE_STRING_POINTER (attr)[1 + arg]) + { + case 'x': + case 'X': + return EAF_UNUSED; + + case 'R': + return EAF_DIRECT | EAF_NOCLOBBER | EAF_NOESCAPE; + + case 'r': + return EAF_NOCLOBBER | EAF_NOESCAPE; + + case 'W': + return EAF_DIRECT | EAF_NOESCAPE; + + case 'w': + return EAF_NOESCAPE;
I/O: Currently both READ an WRITE map to the same function; this should be changed such that for WRITE the arguments are marked as EAF_NOCLOBBER. This can be done using aliases, cf. http://gcc.gnu.org/ml/fortran/2010-05/msg00048.html For the committal of the middle-end / front end, see - http://gcc.gnu.org/ml/fortran/2010-05/msg00092.html (committal) - http://gcc.gnu.org/ml/fortran/2010-05/msg00032.html (patch)
Initial patch (trans-decl.c, trans.io.c) here: http://gcc.gnu.org/ml/fortran/2010-05/msg00124.html Mapping formal arguments to fnspec should be doable, but I'm experienced enough in tree-things to continue.
Subject: Bug 43665 Author: burnus Date: Tue Jul 13 13:20:52 2010 New Revision: 162140 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=162140 Log: 2010-07-13 Daniel Franke <franke.daniel@gmail.com> Tobias Burnus <burnus@net-b.de> PR fortran/43665 * trans-decl.c (gfc_build_intrinsic_function_decls): Add noclobber/noescape annotations to function calls. (gfc_build_builtin_function_decls): Likewise. Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/trans-decl.c
Subject: Bug 43665 Author: burnus Date: Tue Jul 13 17:26:02 2010 New Revision: 162147 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=162147 Log: 2010-07-13 Tobias Burnus <burnus@net-b.de> Daniel Franke <franke.daniel@gmail.com> PR fortran/43665 * trans.h (gfc_build_library_function_decl_with_spec): New prototype. * trans-decl.c (gfc_build_library_function_decl_with_spec): Removed static. * trans-io (gfc_build_io_library_fndecls): Add "fn spec" annotations. Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/trans-decl.c trunk/gcc/fortran/trans-io.c trunk/gcc/fortran/trans.h
Main library calls are done. TODO: - Intrinsic calls such as "call ctime()" which do not have a function declaration - Nonintrinsic functions with non-pointer INTENT(IN/OUT); handle also (non)clobber [target/pointer ...] - I/O transfer: Split somehow to make it possible to distinguish READ from WRITE. - Possibly, handle somehow unused arguments / not-explicitly given INTENT(in)s by saving this information
Created attachment 21265 [details] Draft patch for external/user procs with INTENT (mostly OK, but breaks existing test) The attached patch mostly works, except for gfortran.dg/allocatable_scalar_4.f90. The latter file works fine with -O1 but with -O2 it crashes. At -O1 with -fdump-tree-original, essentially only one "if" is optimized away: b = 7482 call checkOptional(.false.,.true., 7482) if (b /= 7482) call abort() ! <<<< This line is removed for -O1 call checkOptional(.true., .true., 7482, b) I could not see anything suspicious for -O{2,1} -fdump-tree-optimized; one should check -fdump-tree-optimized-all. I somehow have the feeling that some other DECL is wrong. Cf. PR 44945 for another manifestation of DECL problems (though there for derived types). Note: Using -fwhole-file does not help.
Reduced test case (of allocatable_scalar_4.f90) - fails with "ERROR STOP 1": program test implicit none integer, allocatable :: b allocate(b) b = 7482 call checkOptional(.false.,.true., 7482) call checkOptional(.true., .true., 7482, b) if (b /= 46) error stop 1 contains subroutine checkOptional(prsnt, alloc, val, x) logical, intent(in) :: prsnt, alloc integer, allocatable, optional :: x integer, intent(in) :: val if (present(x)) then if (allocated(x) .neqv. alloc) error stop 2 end if if (present(x)) then if (allocated(x)) then if (x /= val) error stop 3 end if end if if (present(x)) then x = 46 end if end subroutine checkOptional end program test
The procedure 'checkoptional' gets '.rrrw' set as the fn spec. With -O1, the if after the first "checkoptional" gets properly optimized away (cf. comment 7 and original test case). With -O2, the number of arguments is reduced to one (NULL vs. &b) and the condition if (b /= 46) error stop 1 is changed to error stop 1 (cf. -fdump-tree-optimized) For me it looks as if the "fn spec" information is not moved along when arguments are eliminated but remain at the previous position. It works if one swaps the order (i.e. it works if the optional argument is at position one). Richard, does this make sense or am I completely off track?
No, this problem was present for ipa-sra, but I thought it was fixed. Does -fno-ipa-sra help? Martin?
(In reply to comment #10) > No, this problem was present for ipa-sra, but I thought it was fixed. > Does -fno-ipa-sra help? No, it doesn't. But with that option, the number of arguments still reduces from 4 to 2 (before: 1). But again, the code works if one reorders the arguments such that the "w" attribute matches the "x" argument (now at position 2 instead of 1).
Subject: Re: INTENT(IN) etc. optimization of calls: function annotations for noclobber/noescape arguments On Tue, 20 Jul 2010, burnus at gcc dot gnu dot org wrote: > ------- Comment #11 from burnus at gcc dot gnu dot org 2010-07-20 16:12 ------- > (In reply to comment #10) > > No, this problem was present for ipa-sra, but I thought it was fixed. > > Does -fno-ipa-sra help? > > No, it doesn't. But with that option, the number of arguments still reduces > from 4 to 2 (before: 1). But again, the code works if one reorders the > arguments such that the "w" attribute matches the "x" argument (now at position > 2 instead of 1). So I wonder what code removes the arguments then. Richard.
(In reply to comment #12) > So I wonder what code removes the arguments then. > IPA-CP can do that for quite some time please try with -fno-ipa-cp. (I don't have a trunk built with enabled fortran at hand and I am a bit overwhelmed with bugs and other stuff recently so I can have a look at this but it will take at least a few days before I get to it.)
(In reply to comment #13) > (In reply to comment #12) > IPA-CP can do that for quite some time please try with -fno-ipa-cp. As expected: It works with -fno-ipa-cp. > (I don't have a trunk built with enabled fortran at hand and I am a > bit overwhelmed with bugs and other stuff recently so I can have a > look at this but it will take at least a few days before I get to it.) Thanks. Some pre-analysis: The "fn spec" (the space is there to prevent other than internal use - thus I cannot create a C test case) is converted in gimple.c's gimple_call_arg_flags to EAF_* constants. tree-ssa-structalias.c's handle_rhs_call uses them via: for (i = 0; i < gimple_call_num_args (stmt); ++i) [...] int flags = gimple_call_arg_flags (stmt, i); thus, the position seems to matter here. The latter is called by find_func_aliases in an "if (!in_ipa_mode ..." block.
I tried compiling the testcase from comment #8 and it did not fail for me either on i686-linux ox x86_64-linux. Can you please check that it still fails for you?
Created attachment 21714 [details] Patch to address IPA-CP parameter removal issues This patch makes IPA-CP to refrain from modifying a function when it sees a any type attributes. It fixes the test case. I do not expect it to cause any problems elsewhere but I have not yet bootstrapped or tested it (I have just scheduled both for tonight). As far as I understand it there is already a test in our testsuite that fails (with the patch from comment #7 applied) and so I am not going to add an extra one. I think it's best to check this in separately and I will submit it for approval tomorrow if there are no unforeseen problems.
(In reply to comment #16) > This patch makes IPA-CP to refrain from modifying a function when it > sees a any type attributes. In a way that's unfortunate: Both "fn attr" and argument removal are optimization options. > As far as I understand it there is already a test in our testsuite > that fails (with the patch from comment #7 applied) and so I am not > going to add an extra one. OK. > I think it's best to check this in separately and I will submit it for > approval tomorrow if there are no unforeseen problems. I will also submit my patch - for committal after yours is in.
Subject: Bug 43665 Author: jamborm Date: Tue Sep 7 17:00:44 2010 New Revision: 163960 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=163960 Log: 2010-09-07 Martin Jambor <mjambor@suse.cz> PR fortran/43665 * ipa-cp.c (ipcp_versionable_function_p): Return false if there are any type attributes. Modified: trunk/gcc/ChangeLog trunk/gcc/ipa-cp.c
Reviewed patch ("OK") available at http://gcc.gnu.org/ml/fortran/2010-09/msg00198.html however, it causes regressions as some of the intrinsics (in intrinsic.c) have the wrong intents - which causes wrong code (too much optimized away). Thus, one first needs to audit and fix intrinsic.c before this patch can be committed.
Subject: Bug 43665 Author: burnus Date: Thu Sep 9 08:42:52 2010 New Revision: 164052 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=164052 Log: 2010-09-09 Tobias Burnus <burnus@net-b.de> PR fortran/43665 * intrincic.texi (FGET, FGETC, FPUT, FPUTC, FSTAT, GETCWD, KILL, STAT): Show also syntax for the function version. * intrinsic.c (add_sym_1s_intent, add_sym_2s_intent, add_sym_3s_intent): Remove function. (add_sym_1s, add_sym_2s, add_sym_3s): Take always the intent as argument. (add_sym_2_intent): New function. (add_functions): Set intent for functions which modify the argument: fstat, fgetc, fget, hostnm, lstat, stat. Change argument name of hostnm from "a" to "c" (add_subroutines): Change add_sym_*s_intent to add_sym_*s and add intent to the add_sym_*s calls. Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/intrinsic.c trunk/gcc/fortran/intrinsic.texi
Created attachment 21765 [details] Updated patch Updated patch to fix review issues and the Cray patch issue. I won't be able to work on this (i.e. regtest + submit) for the next days thus I put it here. Cf. http://gcc.gnu.org/ml/fortran/2010-09/msg00198.html and http://gcc.gnu.org/ml/fortran/2010-09/msg00234.html
(In reply to comment #21) > Created an attachment (id=21765) [edit] > Updated patch Note: I forgot to include the test case from attachment 21265 [details]
I have applied the patch in comment #21 without regression, but the test case from attachment 21265 [details] fails: FAIL: gfortran.dg/intent_optimize_1.f90 -O scan-tree-dump-times optimized "does_not_exist" 0
(In reply to comment #23) > I have applied the patch in comment #21 without regression, but the test case > from attachment 21265 [details] [edit] fails: - create_fn_spec (sym, type); + type = create_fn_spec (sym, type); as in the original patch.
> - create_fn_spec (sym, type); > + type = create_fn_spec (sym, type); > > as in the original patch. With this change the test succeeds.
Subject: Bug 43665 Author: burnus Date: Thu Sep 16 21:30:05 2010 New Revision: 164348 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=164348 Log: 2010-09-16 Tobias Burnus <burnus@net-b.de> PR fortran/43665 * trans-types.c (create_fn_spec): New function. (gfc_get_function_type): Call it. 2010-09-16 Tobias Burnus <burnus@net-b.de> PR fortran/43665 * gfortran.dg/cray_pointers_2.f90: Disable inlining to avoid optimizations. * gfortran.dg/intent_optimize_1.f90: New test. Added: trunk/gcc/testsuite/gfortran.dg/intent_optimize_1.f90 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/trans-types.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gfortran.dg/cray_pointers_2.f90
Author: tkoenig Date: Sat Oct 16 16:06:07 2010 New Revision: 165559 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=165559 Log: 2010-10-16 Thomas Koenig <tkoenig@gcc.gnu.org> PR fortran/20165 PR fortran/31593 PR fortran/43665 * gfortran.map: Add _gfortran_transfer_array_write, _gfortran_transfer_array_write, _gfortran_transfer_character_write, _gfortran_transfer_character_wide_write, _gfortran_transfer_complex_write, _gfortran_transfer_integer_write, _gfortran_transfer_logical_write and _gfortran_transfer_real_write. * io/transfer.c (transfer_integer_write): Add prototype and function body as call to the original function, without the _write. (transfer_real_write): Likewise. (transfer_logical_write): Likewise. (transfer_character_write): Likewise. (transfer_character_wide_write): Likewise. (transfer_complex_write): Likewise. (transfer_array_write): Likewise. 2010-10-16 Thomas Koenig <tkoenig@gcc.gnu.org> PR fortran/20165 PR fortran/31593 PR fortran/43665 * trans-io.c (enum iocall): Add IOCALL_X_INTEGER_WRITE, IOCALL_X_LOGICAL_WRITE, IOCALL_X_CHARACTER_WRITE, IOCALL_X_CHARACTER_WIDE_WRIE, IOCALL_X_REAL_WRITE, IOCALL_X_COMPLEX_WRITE and IOCALL_X_ARRAY_WRITE. (gfc_build_io_library_fndecls): Add corresponding function decls. (transfer_expr): If the current transfer is a READ, use the iocall with the original version, otherwise the version with _WRITE. (transfer_array_desc): Likewise. Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/trans-io.c trunk/libgfortran/ChangeLog trunk/libgfortran/gfortran.map trunk/libgfortran/io/transfer.c
Can this be closed?
> Can this be closed? No answer since almost a year. Closing as FIXED.