Revised patch after some re-considerations (and finding tons of issues
with VALUE + OPTIONAL in gfortran itself). – What the patch does [all
related to use_device_{addr,ptr} and 'optional' arguments]:
For assumed-shape arrays, the compiler generates code like "if (arg)
arg.0 = arg->data;". Hence, arg.0 was always available – but possibly
pointing to uninitialized memory. – Likewise, per-value-passed
arguments, 'arg' (i.e. &arg) is always available. — But, in the absent
case, if 'arg->data is not NULL or the per-value decl is not mapped (cf.
test case), that's not the best idea.
I thought that I don't need a condition in thoses case – but it turns
out that the offloading plugin might (rightly!) complain that the
address is not mapped. – Hence, I add the is-present condition now also
in for those case; as none remain, the do_optional_check is now gone.
However, after the library call, amp_arr.arg is known to be initialized.
In this case, I keep the do_optional_check check. – This avoids code
which boils down to "x0 = arg ? omp_arr.arg : NULL". – and keeps
generating condtions only for complex code such as: if (present) {
tmp.data = omp_arr.arg; arg = &tmp; } else {arg = NULL;}.
Finally, while testing/exploring value+optional bugs, I stumbled over
'type(c_ptr),value' which is 'void *'. In particular, it is pointer but
still the is-present status is passed as hidden argument. This patch
fixes both mapping and the is-present check.
Build on x86-64-gnu-linux + tested once on a system without offloading
support and with nvptx offloading.
OK?
Tobias
PS: Regarding the issues with OPTIONAL and VALUE, see PR fortran/92703
and PR fortran/92702. Found issues: const-len character strings are
passed as value w/o hidden is-present arg but func call passes them;
those and derived types/the outer class container are passed by value -
but the 'present()' check assumes pointers (hence: ICE); if basent
null_ptr_node is passed, I fear that this will give stack issues, at
least on some platforms. — Additionally, deferred-length character
strings and arrays are permitted since F2008 but not yet supported.
gcc/fortran/
* trans-openmp.c (gfc_omp_is_optional_argument,
gfc_omp_check_optional_argument): Handle type(c_ptr),value which uses a
hidden argument for the is-present check.
gcc/
* omp-low.c (lower_omp_target): For use_device_ptr/use_derice_addr
and Fortran's optional arguments, unconditionally add the is-present
condition before the libgomp call.
libgomp/
* testsuite/libgomp.fortran/use_device_ptr-optional-2.f90: Add
'type(c_ptr), value' test case. Conditionally map the per-value
passed arguments.
diff --git a/gcc/fortran/trans-openmp.c b/gcc/fortran/trans-openmp.c
index d9dfcabc65e..f21785fa8c3 100644
--- a/gcc/fortran/trans-openmp.c
+++ b/gcc/fortran/trans-openmp.c
@@ -60,7 +60,8 @@ gfc_omp_is_allocatable_or_ptr (const_tree decl)
/* True if the argument is an optional argument; except that false is also
returned for arguments with the value attribute (nonpointers) and for
- assumed-shape variables (decl is a local variable containing arg->data). */
+ assumed-shape variables (decl is a local variable containing arg->data).
+ Note that pvoid_type_node is for 'type(c_ptr), value. */
static bool
gfc_omp_is_optional_argument (const_tree decl)
@@ -68,6 +69,7 @@ gfc_omp_is_optional_argument (const_tree decl)
return (TREE_CODE (decl) == PARM_DECL
&& DECL_LANG_SPECIFIC (decl)
&& TREE_CODE (TREE_TYPE (decl)) == POINTER_TYPE
+ && TREE_TYPE (decl) != pvoid_type_node
&& GFC_DECL_OPTIONAL_ARGUMENT (decl));
}
@@ -99,9 +101,12 @@ gfc_omp_check_optional_argument (tree decl, bool for_present_check)
|| !GFC_DECL_OPTIONAL_ARGUMENT (decl))
return NULL_TREE;
- /* For VALUE, the scalar variable is passed as is but a hidden argument
- denotes the value. Cf. trans-expr.c. */
- if (TREE_CODE (TREE_TYPE (decl)) != POINTER_TYPE)
+ /* Scalars with VALUE attribute which are passed by value use a hidden
+ argument to denote the present status. They are passed as nonpointer type
+ with one exception: 'type(c_ptr), value' as '*void'. */
+ /* Cf. trans-expr.c's gfc_conv_expr_present. */
+ if (TREE_CODE (TREE_TYPE (decl)) != POINTER_TYPE
+ || TREE_TYPE (decl) == pvoid_type_node)
{
char name[GFC_MAX_SYMBOL_LEN + 2];
tree tree_name;
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 19132f76da2..0e66a68ff36 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -11981,8 +11981,6 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
case OMP_CLAUSE_USE_DEVICE_PTR:
case OMP_CLAUSE_USE_DEVICE_ADDR:
case OMP_CLAUSE_IS_DEVICE_PTR:
- bool do_optional_check;
- do_optional_check = false;
ovar = OMP_CLAUSE_DECL (c);
var = lookup_decl_in_outer_ctx (ovar, ctx);
@@ -12004,10 +12002,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
}
type = TREE_TYPE (ovar);
if (lang_hooks.decls.omp_array_data (ovar, true))
- {
- var = lang_hooks.decls.omp_array_data (ovar, false);
- do_optional_check = true;
- }
+ var = lang_hooks.decls.omp_array_data (ovar, false);
else if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_USE_DEVICE_ADDR
&& !omp_is_reference (ovar)
&& !omp_is_allocatable_or_ptr (ovar))
@@ -12027,14 +12022,12 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
&& omp_is_allocatable_or_ptr (ovar))))
{
var = build_simple_mem_ref (var);
- do_optional_check = true;
}
var = fold_convert (TREE_TYPE (x), var);
}
}
tree present;
- present = (do_optional_check
- ? omp_check_optional_argument (ovar, true) : NULL_TREE);
+ present = omp_check_optional_argument (ovar, true);
if (present)
{
tree null_label = create_artificial_label (UNKNOWN_LOCATION);
diff --git a/libgomp/testsuite/libgomp.fortran/use_device_ptr-optional-2.f90 b/libgomp/testsuite/libgomp.fortran/use_device_ptr-optional-2.f90
index 41abf17eede..e57abfbed5c 100644
--- a/libgomp/testsuite/libgomp.fortran/use_device_ptr-optional-2.f90
+++ b/libgomp/testsuite/libgomp.fortran/use_device_ptr-optional-2.f90
@@ -1,33 +1,47 @@
! Check whether absent optional arguments are properly
! handled with use_device_{addr,ptr}.
program main
+ use iso_c_binding, only: c_ptr, c_loc
implicit none (type, external)
call foo()
contains
- subroutine foo(v, w, x, y, z)
+ subroutine foo(v, w, x, y, z, cptr)
integer, target, optional, value :: v
integer, target, optional :: w
integer, target, optional :: x(:)
integer, target, optional, allocatable :: y
integer, target, optional, allocatable :: z(:)
+ type(c_ptr), target, optional, value :: cptr
integer :: d
- !$omp target data map(d) use_device_addr(v, w, x, y, z)
- if(present(v)) stop 1
- if(present(w)) stop 2
- if(present(x)) stop 3
- if(present(y)) stop 4
- if(present(z)) stop 5
+ ! Need to map per-VALUE arguments, if present
+ if (present(v)) then
+ !$omp target enter data map(to:v)
+ stop 1 ! – but it shall not be present in this test case.
+ end if
+ if (present(cptr)) then
+ !$omp target enter data map(to:cptr)
+ stop 2 ! – but it shall not be present in this test case.
+ end if
+
+ !$omp target data map(d) use_device_addr(v, w, x, y, z, cptr)
+ if (present(v)) then; v = 5; stop 1; endif
+ if (present(w)) then; w = 5; stop 2; endif
+ if (present(x)) then; x(1) = 5; stop 3; endif
+ if (present(y)) then; y = 5; stop 4; endif
+ if (present(z)) then; z(1) = 5; stop 5; endif
+ if (present(cptr)) then; cptr = c_loc(v); stop 6; endif
!$omp end target data
! Using 'v' in use_device_ptr gives an ICE
! TODO: Find out what the OpenMP spec permits for use_device_ptr
- !$omp target data map(d) use_device_ptr(w, x, y, z)
- if(present(w)) stop 6
- if(present(x)) stop 7
- if(present(y)) stop 8
- if(present(z)) stop 9
+ !$omp target data map(d) use_device_ptr(w, x, y, z, cptr)
+ if(present(w)) then; w = 5; stop 11; endif
+ if(present(x)) then; x(1) = 5; stop 12; endif
+ if(present(y)) then; y = 5; stop 13; endif
+ if(present(z)) then; z(1) = 5; stop 14; endif
+ if(present(cptr)) then; cptr = c_loc(x); stop 15; endif
!$omp end target data
end subroutine foo
end program main
