[Bug libgomp/110364] New: [OpenMP] Environment vars - doc and device-specific cleanup; make GOMP_DEBUG more useful; janitorial takes

[Bug libgomp/110364] New: [OpenMP] Environment vars - doc and device-specific cleanup; make GOMP_DEBUG more useful; janitorial takes

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110364

            Bug ID: 110364
           Summary: [OpenMP] Environment vars - doc and device-specific
                    cleanup; make GOMP_DEBUG more useful; janitorial takes
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: documentation, openmp
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

OpenMP TR11 added the _ALL, _DEV, and _DEV_<number> suffix.


After the patch work stated, the following addition was done to the spec:
• Device-specific environment variables must not specify the initial device.

TODO: Implement this.


OMP_STACKSIZE_DEV etc. → Make this applicable to the non-host devices,
→ GCN_STACK_SIZE and nvptx's nvptx_stacks_size() (which is per warp!).


Improve the documentation (and implementation) with regards to the
device-specific ICVs - namely: which are handled, which aren't + possibly
implement some if needed.
Cross ref: PR 109620 (OMP_CANCELLATION), PR109875 (OMP_NUM_TEAMS)

(First step for the documentation bit was commit
r14-2032-g2cd0689a79498dcaaadc8cc5c1c4d0a452a4fb09)


GOMP_DEBUG: Currently, it is a 0 or all flag, it would be much more useful it
the numeric values could be used - either as (n) less output than (n+1) or
using some bitmap flags like 1<<0, 1<<1, 1<<2 turning on different outputs
(possibly with supporting some a comma-separated list of names for them.

In particular, plugin-nvptx outputs too much - and GCN has its own GCN_DEBUG.

* * *

BTW: While all OMP_* env vars are documented, the "OpenMP Runtime Library
Routines" lacks many routines there were added.

I additionally wonder whether the named-constants and kinds documentation
should be moved from Fortran's ../gcc/fortran/intrinsic.texi to libgomp and
extended to cover also the C/C++.

[Bug libgomp/110364] [OpenMP] Environment vars - doc and device-specific cleanup; make GOMP_DEBUG more useful; janitorial tasks

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110364

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tobias Burnus <burnus@gcc.gnu.org>:

https://gcc.gnu.org/g:506f068e7d01ad2fb107185b8fb204a0ec23785c

commit r14-2681-g506f068e7d01ad2fb107185b8fb204a0ec23785c
Author: Tobias Burnus <tobias@codesourcery.com>
Date:   Thu Jul 20 18:12:57 2023 +0200

    libgomp.texi: Split OpenMP routines chapter into sections

    The previous list of OpenMP routines was rather lengthy and the order
seemed
    to be rather random - especially for outputs which did not have @menu as
then
    the sectioning was not visible.

    The OpenMP specification split in 5.1 the lengthy list by adding
    sections to the chapter and grouping the routines under them.

    This patch follow suite and uses the same sections and order. The commit
also
    prepares for adding not-yet-documented routines by listening those in the
    @menu (@c commented - both for just undocumented and for also unimplemented
    routines). See also PR 110364.

    libgomp/ChangeLog:

            * libgomp.texi (OpenMP Runtime Library Routines):
            Split long list by adding sections and moving routines there.
            (OMP_ALLOCATORS): Fix typo.