openmp, fortran: Add support for OpenMP declare variant directive in Fortran

2021-10-14  Kwok Cheung Yeung  <kcy@codesourcery.com>

gcc/c-family/

	* c-omp.c (c_omp_check_context_selector): Rename to
	omp_check_context_selector and move to omp-general.c.
	(c_omp_mark_declare_variant): Rename to omp_mark_declare_variant and
	move to omp-general.c.

gcc/c/

	* c-parser.c (c_finish_omp_declare_variant): Change call from
	c_omp_check_context_selector to omp_check_context_selector. Change
	call from c_omp_mark_declare_variant to omp_mark_declare_variant.

gcc/cp/

	* decl.c (omp_declare_variant_finalize_one): Change call from
	c_omp_mark_declare_variant to omp_mark_declare_variant.
	* parser.c (cp_finish_omp_declare_variant): Change call from
	c_omp_check_context_selector to omp_check_context_selector.

gcc/fortran/

	* gfortran.h (enum gfc_statement): Add ST_OMP_DECLARE_VARIANT.
	(enum gfc_omp_trait_property_kind): New.
	(struct gfc_omp_trait_property): New.
	(gfc_get_omp_trait_property): New macro.
	(struct gfc_omp_selector): New.
	(gfc_get_omp_selector): New macro.
	(struct gfc_omp_set_selector): New.
	(gfc_get_omp_set_selector): New macro.
	(struct gfc_omp_declare_variant): New.
	(gfc_get_omp_declare_variant): New macro.
	(struct gfc_namespace): Add omp_declare_variant field.
	(gfc_free_omp_declare_variant_list): New prototype.
	* match.h (gfc_match_omp_declare_variant): New prototype.
	* openmp.c (gfc_free_omp_trait_property_list): New.
	(gfc_free_omp_selector_list): New.
	(gfc_free_omp_set_selector_list): New.
	(gfc_free_omp_declare_variant_list): New.
	(gfc_match_omp_clauses): Add extra optional argument.  Handle end of
	clauses for context selectors.
	(omp_construct_selectors, omp_device_selectors,
	omp_implementation_selectors, omp_user_selectors): New.
	(gfc_match_omp_context_selector): New.
	(gfc_match_omp_context_selector_specification): New.
	(gfc_match_omp_declare_variant): New.
	* parse.c: Include tree-core.h and omp-general.h.
	(decode_omp_directive): Handle 'declare variant'.
	(case_omp_decl): Include ST_OMP_DECLARE_VARIANT.
	(gfc_ascii_statement): Handle ST_OMP_DECLARE_VARIANT.
	(gfc_parse_file): Initialize omp_requires_mask.
	* symbol.c (gfc_free_namespace): Call
	gfc_free_omp_declare_variant_list.
	* trans-decl.c (gfc_get_extern_function_decl): Call
	gfc_trans_omp_declare_variant.
	(gfc_create_function_decl): Call gfc_trans_omp_declare_variant.
	* trans-openmp.c (gfc_trans_omp_declare_variant): New.
	* trans-stmt.h (gfc_trans_omp_declare_variant): New prototype.

gcc/

	* omp-general.c (omp_check_context_selector):  Move from c-omp.c.
	(omp_mark_declare_variant): Move from c-omp.c.
	(omp_context_name_list_prop): Update for Fortran strings.
	* omp-general.h (omp_check_context_selector): New prototype.
	(omp_mark_declare_variant): New prototype.

gcc/testsuite/

	* gfortran.dg/gomp/declare-variant-1.f90: New test.
	* gfortran.dg/gomp/declare-variant-10.f90: New test.
	* gfortran.dg/gomp/declare-variant-11.f90: New test.
	* gfortran.dg/gomp/declare-variant-12.f90: New test.
	* gfortran.dg/gomp/declare-variant-13.f90: New test.
	* gfortran.dg/gomp/declare-variant-14.f90: New test.
	* gfortran.dg/gomp/declare-variant-15.f90: New test.
	* gfortran.dg/gomp/declare-variant-16.f90: New test.
	* gfortran.dg/gomp/declare-variant-17.f90: New test.
	* gfortran.dg/gomp/declare-variant-18.f90: New test.
	* gfortran.dg/gomp/declare-variant-19.f90: New test.
	* gfortran.dg/gomp/declare-variant-2.f90: New test.
	* gfortran.dg/gomp/declare-variant-2a.f90: New test.
	* gfortran.dg/gomp/declare-variant-3.f90: New test.
	* gfortran.dg/gomp/declare-variant-4.f90: New test.
	* gfortran.dg/gomp/declare-variant-5.f90: New test.
	* gfortran.dg/gomp/declare-variant-6.f90: New test.
	* gfortran.dg/gomp/declare-variant-7.f90: New test.
	* gfortran.dg/gomp/declare-variant-8.f90: New test.
	* gfortran.dg/gomp/declare-variant-9.f90: New test.

libgomp/

	* testsuite/libgomp.fortran/declare-variant-1.f90: New test.

1 files changed, 33 insertions, 0 deletions

diff --git a/libgomp/testsuite/libgomp.fortran/declare-variant-1.f90 b/libgomp/testsuite/libgomp.fortran/declare-variant-1.f90
new file mode 100644
index 00000000000..e6f69dccb49
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/declare-variant-1.f90
@@ -0,0 +1,33 @@
+! { dg-do run }
+
+program main
+  implicit none
+
+  integer :: v
+  !$omp target map(from:v)
+  v = on ()
+  !$omp end target
+
+  select case (v)
+    case default
+      write (*,*) "Host fallback or unknown offloading"
+    case (1)
+      write (*,*) "Offloading to NVidia PTX"
+    case (2)
+      write (*,*) "Offloading to AMD GCN"
+  end select
+contains
+  integer function on_nvptx ()
+    on_nvptx = 1
+  end function
+
+  integer function on_gcn ()
+    on_gcn = 2
+  end function
+
+  integer function on ()
+    !$omp declare variant (on_nvptx) match(construct={target},device={arch(nvptx)})
+    !$omp declare variant (on_gcn) match(construct={target},device={arch(gcn)})
+    on = 0
+  end function
+end program