Hi!
On 2020-06-16T13:27:43+0200, Tobias Burnus <tob...@codesourcery.com> wrote:
> when looking into a PURE/ELEMENTAL issue with OpenACC, Thomas and
> I came across the analogous OpenMP code – and stumbled over
> ELEMENTAL.
>
> In Fortran, ELEMENTAL implies PURE but one can also have an IMPURE
> ELEMENTAL procedure.
>
> As PR 79154 quotes, OpenMP 4 had:
> "OpenMP directives may not appear in PURE or ELEMENTAL procedures."
>
> While OpenMP 4.5 (and later) have:
> "OpenMP directives, except SIMD and declare target directives,
> may not appear in pure procedures."
>
> ELEMENTAL is still mentioned – but only for:
> "OpenMP runtime library routines may not be called
> from PURE or ELEMENTAL procedures."
... but that's mentioned not only diagnoesd here:
> --- a/gcc/fortran/parse.c
> +++ b/gcc/fortran/parse.c
> @@ -849,7 +849,7 @@ decode_omp_directive (void)
> /* match is for directives that should be recognized only if
> -fopenmp, matchs for directives that should be recognized
> if either -fopenmp or -fopenmp-simd.
> - Handle only the directives allowed in PURE/ELEMENTAL procedures
> + Handle only the directives allowed in PURE procedures
> first (those also shall not turn off implicit pure). */
> switch (c)
> {
> @@ -868,7 +868,7 @@ decode_omp_directive (void)
> if (flag_openmp && gfc_pure (NULL))
> {
> gfc_error_now ("OpenMP directives other than SIMD or DECLARE TARGET "
> - "at %C may not appear in PURE or ELEMENTAL procedures");
> + "at %C may not appear in PURE procedures");
> gfc_error_recovery ();
> return ST_NONE;
> }
..., but also further down, in the 'finish' label:
finish:
if (!pure_ok)
{
gfc_unset_implicit_pure (NULL);
if (!flag_openmp && gfc_pure (NULL))
{
gfc_error_now ("OpenMP directives other than SIMD or DECLARE
TARGET "
"at %C may not appear in PURE or ELEMENTAL "
"procedures");
reject_statement ();
gfc_error_recovery ();
return ST_NONE;
}
}
return ret;
..., so I suppose this needs to be changed, too -- and maybe is missing
testsuite coverage?
> --- a/gcc/testsuite/gfortran.dg/gomp/pr79154-1.f90
> +++ b/gcc/testsuite/gfortran.dg/gomp/pr79154-1.f90
> @@ -2,7 +2,7 @@
> ! { dg-do compile }
>
> pure real function foo (a, b) ! { dg-warning "GCC does not
> currently support mixed size types for 'simd' functions" "" { target
> aarch64*-*-* } }
> -!$omp declare simd(foo) ! { dg-bogus "may not appear in
> PURE or ELEMENTAL" }
> +!$omp declare simd(foo) ! { dg-bogus "may not appear in
> PURE" }
> real, intent(in) :: a, b
> foo = a + b
> end function foo
> @@ -10,23 +10,28 @@ pure function bar (a, b)
> real, intent(in) :: a(8), b(8)
> real :: bar(8)
> integer :: i
> -!$omp simd ! { dg-bogus "may not appear in PURE or
> ELEMENTAL" }
> +!$omp simd ! { dg-bogus "may not appear in PURE" }
> do i = 1, 8
> bar(i) = a(i) + b(i)
> end do
> end function bar
> pure real function baz (a, b)
> -!$omp declare target ! { dg-bogus "may not appear in PURE or
> ELEMENTAL" }
> +!$omp declare target ! { dg-bogus "may not appear in PURE" }
> real, intent(in) :: a, b
> baz = a + b
> end function baz
> elemental real function fooe (a, b) ! { dg-warning "GCC does not currently
> support mixed size types for 'simd' functions" "" { target aarch64*-*-* } }
> -!$omp declare simd(fooe) ! { dg-bogus "may not appear in PURE or
> ELEMENTAL" }
> +!$omp declare simd(fooe) ! { dg-bogus "may not appear in PURE" }
> real, intent(in) :: a, b
> fooe = a + b
> end function fooe
> elemental real function baze (a, b)
> -!$omp declare target ! { dg-bogus "may not appear in PURE or
> ELEMENTAL" }
> +!$omp declare target ! { dg-bogus "may not appear in PURE" }
> real, intent(in) :: a, b
> baze = a + b
> end function baze
> +elemental impure real function bazei (a, b)
> +!$omp declare target ! { dg-bogus "may not appear in PURE" }
> + real, intent(in) :: a, b
> + baze = a + b
Shouldn't this assign to 'bazei' instead of 'baze'?
> +end function bazei
> --- a/gcc/testsuite/gfortran.dg/gomp/pr79154-2.f90
> +++ b/gcc/testsuite/gfortran.dg/gomp/pr79154-2.f90
> @@ -3,14 +3,14 @@
>
> pure real function foo (a, b)
> real, intent(in) :: a, b
> -!$omp taskwait ! { dg-error "may not appear in
> PURE or ELEMENTAL" }
> +!$omp taskwait ! { dg-error "may not appear in
> PURE" }
> foo = a + b
> end function foo
> pure function bar (a, b)
> real, intent(in) :: a(8), b(8)
> real :: bar(8)
> integer :: i
> -!$omp do simd ! { dg-error "may not appear in
> PURE or ELEMENTAL" }
> +!$omp do simd ! { dg-error "may not appear in
> PURE" }
> do i = 1, 8
> bar(i) = a(i) + b(i)
> end do
> @@ -19,26 +19,38 @@ pure function baz (a, b)
> real, intent(in) :: a(8), b(8)
> real :: baz(8)
> integer :: i
> -!$omp do ! { dg-error "may not appear in PURE or
> ELEMENTAL" }
> +!$omp do ! { dg-error "may not appear in PURE" }
> do i = 1, 8
> baz(i) = a(i) + b(i)
> end do
> -!$omp end do ! { dg-error "may not appear in PURE or
> ELEMENTAL" }
> +!$omp end do ! { dg-error "may not appear in PURE" }
> end function baz
> pure real function baz2 (a, b)
> real, intent(in) :: a, b
> -!$omp target map(from:baz2) ! { dg-error "may not appear in PURE or
> ELEMENTAL" }
> +!$omp target map(from:baz2) ! { dg-error "may not appear in PURE" }
> baz2 = a + b
> -!$omp end target ! { dg-error "may not appear in PURE or
> ELEMENTAL" }
> +!$omp end target ! { dg-error "may not appear in PURE" }
> end function baz2
> +! ELEMENTAL implies PURE
> elemental real function fooe (a, b)
> real, intent(in) :: a, b
> -!$omp taskyield ! { dg-error "may not appear in
> PURE or ELEMENTAL" }
> +!$omp taskyield ! { dg-error "may not appear in
> PURE" }
> fooe = a + b
> end function fooe
> elemental real function baze (a, b)
> real, intent(in) :: a, b
> -!$omp target map(from:baz) ! { dg-error "may not appear in PURE or
> ELEMENTAL" }
> +!$omp target map(from:baz) ! { dg-error "may not appear in PURE" }
> baze = a + b
> -!$omp end target ! { dg-error "may not appear in PURE or
> ELEMENTAL" }
> +!$omp end target ! { dg-error "may not appear in PURE" }
> end function baze
> +elemental impure real function fooei (a, b)
> + real, intent(in) :: a, b
> +!$omp taskyield ! { dg-bogus "may not appear in
> PURE" }
> + fooe = a + b
> +end function fooei
> +elemental impure real function bazei (a, b)
> + real, intent(in) :: a, b
> +!$omp target map(from:baz) ! { dg-bogus "may not appear in PURE" }
> + baze = a + b
Similar.
> +!$omp end target ! { dg-bogus "may not appear in PURE" }
> +end function bazei
Grüße
Thomas
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