ensure that Fortran Bool is interoperable

The kind C_BOOL for logical from ISO_C_binding only defines the size of
the logical as 1 Byte. It does not define which values (bit patterns) are
used to en

ensure that Fortran Bool is interoperable

The kind C_BOOL for logical from ISO_C_binding only defines the size of
the logical as 1 Byte. It does not define which values (bit patterns) are
used to encode true and false. In stdbool.h from C, true is defined as 1
and false as 0, but these values are not guaranteed by the Fortran standard.

There are (at least) two contemporary Fortran compilers that use a
difference convention: Intel Fortran (ifort and ifx) and NVIDIA Fortran
(nvfortran, former PGI). Both represent true as all bits set, i.e. -1 for
a signed integer or 255 for an unsigned integer.

Intel Fortran can be made interoperable with the "-standard-semantics" or
"-fpscomp logicals". The latter is now set by default to ensure
interoperability while avoiding effects such as modified name mangling
rules and performance degradations due to the former.

NVIDIA Fortran can be made interoperable with the "-Munixlogical" flag.
This is set manually in the "linux-cuda-single-cxx" pipeline. This is
now set by default.

show more ...

Merge branch 'release'

Increase patchlevel to 3.23.6

Merge branch 'sneslinesearch-improvements' into 'main'

SNESLinesearch: Minor improvements

See merge request petsc/petsc!8630

SNESLinesearch: Minor improvements

- add missing configuration options in the documentation of the line searches (some of the available options were not listed), and consistently list their respecti

SNESLinesearch: Minor improvements

- add missing configuration options in the documentation of the line searches (some of the available options were not listed), and consistently list their respective default values

- add proper convergence criteria for the secant method in the L2 line search based on ltol and atol (otherwise, the secant method is mostly running for the maximum number of iterations)

- fix a small bug in the CP line search, where steptol * lambda was used to check for convergence based on the change of lambda instead of the ltol parameter

- rename sneslinesearch->maxstep to sneslinesearch->maxlambda in the options database to be consistent with its purpose in the algorithms

- rename SNESLineSearchL2 to SNESLineSearchSecant to better represent its underlying approach

show more ...

Merge remote-tracking branch 'origin/release'

Merge branch 'knepley-main-patch-9228' into 'main'

Bib: Added ref

See merge request petsc/petsc!8650

Merge branch 'jolivet/disable-fortran-bindings' into 'main'

configure: disable Fortran bindings of external packages by default

See merge request petsc/petsc!8647

Update file petsc.bib

Test: Added EXTRA_OPTIONS_INITIAL to allow overridding of test options
- EXTRA_OPTIONS returns to its initial meaning

Proper capitalization of ExodusII

Annouce replacement of Hong Zhang with Pierre Jolivet on NumFocus group

configure: disable Fortran bindings of external packages by default

Merge branch 'zach/extern-plex-vec-get-oriented-closure' into 'main'

plex: Make DMPlexVecGetOrientedClosure externally visible

See merge request petsc/petsc!8637

Merge remote-tracking branch 'origin/release'

Merge branch 'jolivet/typos' into 'release'

Docs: typos

See merge request petsc/petsc!8636

plex: Make DMPlexVecGetOrientedClosure externally visible

Merge branch 'danofinn/ts-add-avg-dg' into 'main'

TSDiscgrad: Adding average DG and -ts_discgrad_type option; Swarm: Changes to field swarm field functions

See merge request petsc/petsc!7920

Test: globsearch was changed to search

TSDiscgrad: Adding average DG and -ts_discgrad_type option
- Also fixed automatic particle number determination

FOO

Docs: typos

KSP: Add HDF5 monitor

Merge remote-tracking branch 'origin/release'

Merge branch 'jolivet/feature-mumps-blk' into 'main'

MATSOLVERMUMPS: add support for -mat_mumps_icntl_15 1

See merge request petsc/petsc!8537

MATSOLVERMUMPS: add support for -mat_mumps_icntl_15 1