Handle reverse_offload, unified_address, and unified_shared_memory
requirements in libgomp by saving them alongside the offload table.
When the device lto1 runs, it extracts the data for mkoffload. The
latter than passes the value on to GOMP_offload_register_ver.

lto1 (either the host one, with -flto [+ ENABLE_OFFLOADING], or in the
offload-device lto1) also does the the consistency check is done,
erroring out when the 'omp requires' clause use is inconsistent.

For all in-principle supported devices, if a requirement cannot be fulfilled,
the device is excluded from the (supported) devices list. Currently, none of
those requirements are marked as supported for any of the non-host devices.

gcc/c/ChangeLog:

	* c-parser.cc (c_parser_omp_target_data, c_parser_omp_target_update,
	c_parser_omp_target_enter_data, c_parser_omp_target_exit_data): Set
	OMP_REQUIRES_TARGET_USED.
	(c_parser_omp_requires): Remove sorry.

gcc/ChangeLog:

	* config/gcn/mkoffload.cc (process_asm): Write '#include <stdint.h>'.
	(process_obj): Pass omp_requires_mask to GOMP_offload_register_ver.
	(main): Ask lto1 to obtain omp_requires_mask and pass it on.
	* config/nvptx/mkoffload.cc (process, main): Likewise.
	* lto-cgraph.cc (omp_requires_to_name): New.
	(input_offload_tables): Save omp_requires_mask.
	(output_offload_tables): Read it, check for consistency,
	save value for mkoffload.
	* omp-low.cc (lower_omp_target): Force output_offloadtables
	call for OMP_REQUIRES_TARGET_USED.

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_omp_target_data,
	cp_parser_omp_target_enter_data, cp_parser_omp_target_exit_data,
	cp_parser_omp_target_update): Set OMP_REQUIRES_TARGET_USED.
	(cp_parser_omp_requires): Remove sorry.

gcc/fortran/ChangeLog:

	* openmp.cc (gfc_match_omp_requires): Remove sorry.
	* parse.cc (decode_omp_directive): Don't regard 'declare target'
	as target usage for 'omp requires'; add more flags to
	omp_requires_mask.

include/ChangeLog:

	* gomp-constants.h (GOMP_VERSION): Bump to 2.
	(GOMP_REQUIRES_UNIFIED_ADDRESS, GOMP_REQUIRES_UNIFIED_SHARED_MEMORY,
	GOMP_REQUIRES_REVERSE_OFFLOAD, GOMP_REQUIRES_TARGET_USED):
	New defines.

libgomp/ChangeLog:

	* libgomp-plugin.h (GOMP_OFFLOAD_get_num_devices): Add
	omp_requires_mask arg.
	* plugin/plugin-gcn.c (GOMP_OFFLOAD_get_num_devices): Likewise;
	return -1 when device available but omp_requires_mask != 0.
	* plugin/plugin-nvptx.c (GOMP_OFFLOAD_get_num_devices): Likewise.
	* oacc-host.c (host_get_num_devices, host_openacc_get_property):
	Update call.
	* oacc-init.c (resolve_device, acc_init_1, acc_shutdown_1,
	goacc_attach_host_thread_to_device, acc_get_num_devices,
	acc_set_device_num, get_property_any): Likewise.
	* target.c (omp_requires_mask): New global var.
	(gomp_requires_to_name): New.
	(GOMP_offload_register_ver): Handle passed omp_requires_mask.
	(gomp_target_init): Handle omp_requires_mask.
	* libgomp.texi (OpenMP 5.0): Update requires impl. status.
	(OpenMP 5.1): Add a missed item.
	(OpenMP 5.2): Mark linear-clause change as supported in C/C++.
	* testsuite/libgomp.c-c++-common/requires-1-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-1.c: New test.
	* testsuite/libgomp.c-c++-common/requires-2-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-2.c: New test.
	* testsuite/libgomp.c-c++-common/requires-3-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-3.c: New test.
	* testsuite/libgomp.c-c++-common/requires-4-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-4.c: New test.
	* testsuite/libgomp.c-c++-common/requires-5-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-5.c: New test.
	* testsuite/libgomp.c-c++-common/requires-6.c: New test.
	* testsuite/libgomp.c-c++-common/requires-7-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-7.c: New test.
	* testsuite/libgomp.fortran/requires-1-aux.f90: New test.
	* testsuite/libgomp.fortran/requires-1.f90: New test.

liboffloadmic/ChangeLog:

	* plugin/libgomp-plugin-intelmic.cpp (GOMP_OFFLOAD_get_num_devices):
	Return -1 when device available but omp_requires_mask != 0.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/requires-4.c: Update dg-*.
	* c-c++-common/gomp/reverse-offload-1.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-2.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-3.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-4.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-5.c: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-3.f90: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-4.f90: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-5.f90: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-2.f90: Likewise. Move
	post-FE checks to ...
	* gfortran.dg/gomp/target-device-ancestor-2a.f90: ... this new file.
	* gfortran.dg/gomp/requires-8.f90: Update as we don't regard
	'declare target' for the 'requires' usage requirement.

Co-authored-by: Chung-Lin Tang <cltang@codesourcery.com>
Co-authored-by: Thomas Schwinge <thomas@codesourcery.com>

The version of nvprof in CUDA 9.0 causes a hang when used to profile an
OpenACC program.  This is because it calls acc_get_device_type from
a callback called during device initialization, which then attempts
to acquire acc_device_lock while it is already taken, resulting in
deadlock.  This works around the issue by returning acc_device_none
from acc_get_device_type without attempting to acquire the lock when
initialization has not completed yet.

2020-07-14  Tom de Vries  <tom@codesourcery.com>
	    Cesar Philippidis  <cesar@codesourcery.com>
	    Thomas Schwinge  <thomas@codesourcery.com>
	    Kwok Cheung Yeung  <kcy@codesourcery.com>

	libgomp/
	* oacc-init.c (acc_init_state_lock, acc_init_state, acc_init_thread):
	New variable.
	(acc_init_1): Set acc_init_thread to pthread_self ().  Set
	acc_init_state to initializing at the start, and to initialized at the
	end.
	(self_initializing_p): New function.
	(acc_get_device_type): Return acc_device_none if called by thread that
	is currently executing acc_init_1.
	* libgomp.texi (acc_get_device_type): Update documentation.
	(Implementation Status and Implementation-Defined Behavior): Likewise.
	* testsuite/libgomp.oacc-c-c++-common/acc_prof-init-2.c: New.

..., per OpenACC 3.0, A.1.2. "AMD GPU Targets".

This complements commit 6687d13a87c42dddc7d1c7adade38d31ba0d1401 "Rename
acc_device_gcn to acc_device_radeon".

	libgomp/
	* oacc-init.c (get_openacc_name): Handle 'gcn'.
	* testsuite/lib/libgomp.exp
	(offload_target_to_openacc_device_type) [amdgcn*]: Return
	'radeon'.  Adjust all users.
	(check_effective_target_openacc_amdgcn_accel_present): Rename
	to...
	(check_effective_target_openacc_radeon_accel_present): ... this.
	Adjust all users.
	(check_effective_target_openacc_amdgcn_accel_selected): Rename to...
	(check_effective_target_openacc_radeon_accel_selected): ... this.
	Adjust all users.

libgomp/
	* oacc-init.c (name_of_acc_device_t): Handle acc_device_radeon.

Reviewed-by: Thomas Schwinge <thomas@codesourcery.com>

	include/
	* gomp-constants.h (enum gomp_device_property): Remove.
	libgomp/
	* libgomp-plugin.h (enum goacc_property): New.  Adjust all users
	to use this instead of 'enum gomp_device_property'.
	(GOMP_OFFLOAD_get_property): Rename to...
	(GOMP_OFFLOAD_openacc_get_property): ... this.  Adjust all users.
	* libgomp.h (struct gomp_device_descr): Move
	'GOMP_OFFLOAD_openacc_get_property'...
	(struct acc_dispatch_t): ... here.  Adjust all users.
	* plugin/plugin-hsa.c (GOMP_OFFLOAD_get_property): Remove.
	liboffloadmic/
	* plugin/libgomp-plugin-intelmic.cpp (GOMP_OFFLOAD_get_property):
	Remove.

From-SVN: r280150