Hi Sandra and Jakub,
I have now updated the patch; on the way, I found an issue in -fopenacc ('!$' is
not OpenACC and no longer supported) and the same @code/@samp.
I also updated invoke.texi for the same @code/@samp - and added both '!$'
and mentioned the 'c$'/'*$' Fortran fixed-form variant. I think the most
important bit is that '!$' is also supported by -fopenmp-simd as that's not
covered by the OpenMP specification.
Otherwise:
On 14.10.23 23:46, Sandra Loosemore wrote:
On 10/14/23 13:43, Tobias Burnus wrote:
The attached patch tries to improve this. Note that it talks about C and
C++ attributes, even though C23's [[omp::]] support has not yet landed.
(But is expected very soon.)
Is somebody actively working on implementing that, and expecting to
get it in before Stage 1 closes? I don't think we should document
features that don't exist yet.
Yes. But I have now sneaked in an 'in C++' which can also be easily
removed once Jakub's patch is committed or as part of Jakub's patch.
This syntax for C also isn't even in the draft OpenMP 6.0 document so
at this point
Well, it is in the git version, which will be released as TR12 in about
a month (in time for SC23). It is very unlikely to get removed before
OpenMP 6.0 as it is an obvious extension to C++11's attribute support,
now that C supports attributes as well.
Other than that...
Use @option markup on options, not @command.
Fixed. Was preexisting and I copied it once. I've now checked, the only
other use in libgomp.texi was for an actual command (nvprof).
And I think all those @code markups should be @samp instead, or you
could just replace this whole blurb with something like "This flag
enables recognition of the directive syntax documented in the OpenMP
specification, and also arranges for automatic linking..."
I think it is more user friendly to document the sentinels. However, I
concur that @samp is better.
+OpenMP directives, which do not require the linking of neither the
s/, which/ that/
I have now used it, but I think it sound odd:
"enables *a* subset of OpenMP directives *that* do not require the linking"
I concur that with "*the* subset ... *that*" makes sense but I want to
avoid stating that *all* directives that do not require linking of
libgomp/libpthread are supported.
invoke.texi lists all supported directives, but I am not really fond of
repeating that list.
s/neither/either/
The fun of whether double negation cancels or enforces the negation or
.. ("not .. neither / nor").
Cf. https://en.wikipedia.org/wiki/Double_negative
In German and English, both cancellation and enforcement seem to be
possible, the latter especially with dialects - while the standard
language tends to avoid double negation.
Updated patch attached.
Thanks,
Tobias
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libgomp.texi: Update "Enabling OpenMP" + OpenACC / invoke.texi: -fopenacc/-fopenmp update
The OpenACC specification does not mention the '!$ ' sentinel for conditional
compilation and the feature was removed in r11-5572-g1d6f6ac693a860
for PR fortran/98011.
libgomp/
* libgomp.texi (Enabling OpenMP): Update for C/C++ attributes;
improve wording especially for Fortran; mention -fopenmp-simd.
(Enabling OpenACC): Minor cleanup; remove conditional compilation
sentinel.
gcc/
* doc/invoke.texi (-fopenacc, -fopenmp, -fopenmp-simd): Use @samp not
@code; document more completely the supported Fortran sentinels.
gcc/fortran
* scanner.cc (skip_free_comments, skip_fixed_comments): Remove
leftover 'OpenACC' from comments about OpenMP's conditional
compilation sentinel.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index fee659462ff..eb714d18511 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -2748,9 +2748,10 @@ Typical command lines are
@opindex fopenacc
@cindex OpenACC accelerator programming
@item -fopenacc
-Enable handling of OpenACC directives @code{#pragma acc} in C/C++ and
-@code{!$acc} in Fortran. When @option{-fopenacc} is specified, the
-compiler generates accelerated code according to the OpenACC Application
+Enable handling of OpenACC directives @samp{#pragma acc} in C/C++ and
+@samp{!$acc} in free-form Fortran and @samp{!$acc}, @samp{c$acc} and
+@samp{*$acc} in fixed-form Fortran. When @option{-fopenacc} is specified,
+the compiler generates accelerated code according to the OpenACC Application
Programming Interface v2.6 @w{@uref{https://www.openacc.org}}. This option
implies @option{-pthread}, and thus is only supported on targets that
have support for @option{-pthread}.
@@ -2766,10 +2767,12 @@ can be omitted, to use a target-specific default value.
@opindex fopenmp
@cindex OpenMP parallel
@item -fopenmp
-Enable handling of OpenMP directives @code{#pragma omp} in C/C++,
-@code{[[omp::directive(...)]]}, @code{[[omp::sequence(...)]]} and
-@code{[[omp::decl(...)]]} in C++ and @code{!$omp} in Fortran.
-When @option{-fopenmp} is specified, the
+Enable handling of OpenMP directives @samp{#pragma omp} in C/C++,
+@samp{[[omp::directive(...)]]}, @samp{[[omp::sequence(...)]]} and
+@samp{[[omp::decl(...)]]} in C++ and @samp{!$omp} in Fortran. It
+additionally enables the conditional compilation sentinel @samp{!$} in
+Fortran. In fixed source form Fortran, the sentinels can also start with
+@samp{c} or @samp{*}. When @option{-fopenmp} is specified, the
compiler generates parallel code according to the OpenMP Application
Program Interface v4.5 @w{@uref{https://www.openmp.org}}. This option
implies @option{-pthread}, and thus is only supported on targets that
@@ -2785,10 +2788,12 @@ Enable handling of OpenMP's @code{simd}, @code{declare simd},
and @code{loop} directive, and of combined or composite directives with
@code{simd} as constituent with @code{#pragma omp} in C/C++,
@code{[[omp::directive(...)]]}, @code{[[omp::sequence(...)]]} and
-@code{[[omp::decl(...)]]} in C++ and @code{!$omp} in Fortran.
-Other OpenMP directives are ignored. Unless @option{-fopenmp} is
-additionally specified, the @code{loop} region binds to the current
-task region, independent of the specified @code{bind} clause.
+@code{[[omp::decl(...)]]} in C++ and @code{!$omp} in Fortran. It
+additionally enables the conditional compilation sentinel @samp{!$} in
+Fortran. In fixed source form Fortran, the sentinels can also start with
+@samp{c} or @samp{*}. Other OpenMP directives are ignored. Unless
+@option{-fopenmp} is additionally specified, the @code{loop} region binds
+to the current task region, independent of the specified @code{bind} clause.
@opindex fopenmp-target-simd-clone
@cindex OpenMP target SIMD clone
diff --git a/gcc/fortran/scanner.cc b/gcc/fortran/scanner.cc
index 9f0d9a7dc5e..e2a25a1d465 100644
--- a/gcc/fortran/scanner.cc
+++ b/gcc/fortran/scanner.cc
@@ -877,7 +877,7 @@ skip_free_comments (void)
/* If -fopenmp/-fopenacc, we need to handle here 2 things:
1) don't treat !$omp/!$acc as comments, but directives
- 2) handle OpenMP/OpenACC conditional compilation, where
+ 2) handle OpenMP conditional compilation, where
!$ should be treated as 2 spaces (for initial lines
only if followed by space). */
if (at_bol)
@@ -1106,7 +1106,7 @@ skip_fixed_comments (void)
/* If -fopenmp/-fopenacc, we need to handle here 2 things:
1) don't treat !$omp/!$acc|c$omp/c$acc|*$omp / *$acc as comments,
but directives
- 2) handle OpenMP/OpenACC conditional compilation, where
+ 2) handle OpenMP conditional compilation, where
!$|c$|*$ should be treated as 2 spaces if the characters
in columns 3 to 6 are valid fixed form label columns
characters. */
diff --git a/libgomp/libgomp.texi b/libgomp/libgomp.texi
index 526d1be2955..e83010d378b 100644
--- a/libgomp/libgomp.texi
+++ b/libgomp/libgomp.texi
@@ -136,15 +136,22 @@ changed to GNU Offloading and Multi Processing Runtime Library.
@node Enabling OpenMP
@chapter Enabling OpenMP
-To activate the OpenMP extensions for C/C++ and Fortran, the compile-time
-flag @command{-fopenmp} must be specified. This enables the OpenMP directive
-@code{#pragma omp} in C/C++ and @code{!$omp} directives in free form,
-@code{c$omp}, @code{*$omp} and @code{!$omp} directives in fixed form,
-@code{!$} conditional compilation sentinels in free form and @code{c$},
-@code{*$} and @code{!$} sentinels in fixed form, for Fortran. The flag also
-arranges for automatic linking of the OpenMP runtime library
+To activate the OpenMP extensions for C/C++ and Fortran, the compile-time
+flag @option{-fopenmp} must be specified. For C and C++, this enables
+the handling of the OpenMP directives using @code{#pragma omp} and, for C++, the
+@code{[[omp::directive(...)]]}, @code{[[omp::sequence(...)]]} and
+@code{[[omp::decl(...)]]} attributes. For Fortran, it enables for
+free source form the @code{!$omp} sentinel for directives and the
+@code{!$} conditional compilation sentinel and for fixed source form the
+@code{c$omp}, @code{*$omp} and @code{!$omp} sentinels for directives and
+the @code{c$}, @code{*$} and @code{!$} conditional compilation sentinels.
+The flag also arranges for automatic linking of the OpenMP runtime library
(@ref{Runtime Library Routines}).
+The @option{-fopenmp-simd} flag can be used to enable a subset of
+OpenMP directives that do not require the linking of either the
+OpenMP runtime library or the POSIX threads library.
+
A complete description of all OpenMP directives may be found in the
@uref{https://www.openmp.org, OpenMP Application Program Interface} manuals.
See also @ref{OpenMP Implementation Status}.
@@ -3697,12 +3704,10 @@ pools available and their worker threads run at priority four.
To activate the OpenACC extensions for C/C++ and Fortran, the compile-time
flag @option{-fopenacc} must be specified. This enables the OpenACC directive
-@code{#pragma acc} in C/C++ and @code{!$acc} directives in free form,
-@code{c$acc}, @code{*$acc} and @code{!$acc} directives in fixed form,
-@code{!$} conditional compilation sentinels in free form and @code{c$},
-@code{*$} and @code{!$} sentinels in fixed form, for Fortran. The flag also
-arranges for automatic linking of the OpenACC runtime library
-(@ref{OpenACC Runtime Library Routines}).
+@samp{#pragma acc} in C/C++ and, in Fortran, the @samp{!$acc} sentinel in free
+source form and the @samp{c$acc}, @samp{*$acc} and @samp{!$acc} sentinels in
+fixed source form. The flag also arranges for automatic linking of the OpenACC
+runtime library (@ref{OpenACC Runtime Library Routines}).
See @uref{https://gcc.gnu.org/wiki/OpenACC} for more information.
