diff mbox

Openacc launch API

Message ID 55FAD0D9.1050205@acm.org
State New
Headers show

Commit Message

Nathan Sidwell Sept. 17, 2015, 2:40 p.m. UTC
Updated patch addressing your points.  Some  further comments though ...

>> +  while (GOMP_LAUNCH_PACK (GOMP_LAUNCH_END, 0, 0)
>> +     != (tag = va_arg (ap, unsigned)))
>
> That's a somewhat non-idiomatic way to write this, with the constant first and
> not obviously a constant. I'd initialize a variable with the constant before the
> loop.

I went with
   while ((tag = va_arg (...)) != 0) ...

and killed GOMP_LAUNCH_END throughout, using explicit '0'.

>> +      assert (!GOMP_LAUNCH_DEVICE (tag));
>
> Uh, that seems unfriendly, and not exactly forwards compatible. Can that fail a
> bit more gracefully? (Alternatively, implement the device_type stuff now so that
> we don't have TODOs in the code and don't have to worry about compatibility
> issues.)

Added call to gomp_fatal, indicating libgomp is out of date. Also added a 
default to the switch following with the same effect.  The trouble  with 
implementing handling of device_type here now, is difficulty in testing its 
correctness.  If it were  buggy we'd be in a worse position than not having it.

>> +GOACC_2.0,1 {
>> +  global:
>> +    GOACC_parallel_keyed;
>> +} GOACC_2.0;
>
> Did you mean to use a comma?

I misunderstood your comment as 'did you mean to use a comma where you used 
something else', not 'is that comma a typo?'  well spotted!

>> +    else if (!tagging)
>
> Oh... so tagging controls two different methods for constructing argument lists,
> one for GOACC_parallel and the other for whatever OMP uses? That's a bit
> unfortunate, I'll need to think about it for a bit or defer to Jakub.

My earlier description was lacking.  The memory arguments have already been 
pushed before that switch.  This is just dealing with async & wait args.  I 
found it easier to modify the existing code path and have a tagging flag, rather 
than duplicate it.

nathan

Comments

Bernd Schmidt Sept. 18, 2015, 9:13 a.m. UTC | #1
On 09/17/2015 04:40 PM, Nathan Sidwell wrote:

> Added call to gomp_fatal, indicating libgomp is out of date. Also added
> a default to the switch following with the same effect.  The trouble
> with implementing handling of device_type here now, is difficulty in
> testing its correctness.  If it were  buggy we'd be in a worse position
> than not having it.

Is that so difficult though? See if nvptx ignores (let's say) intelmic 
arguments in favour of the default and accepts nvptx ones.

> +  if (num_waits > 8)
> +    gomp_fatal ("too many waits for legacy interface");
> +
> +  va_start (ap, num_waits);
> +  for (ix = 0; ix != num_waits; ix++)
> +    waits[ix] = va_arg (ap, int);
> +  waits[ix] = 0;
> +  va_end (ap);

I still don't like this. I think there are at least two better 
alternatives: add a new GOMP_LAUNCH_key which makes GOACC_parallel read 
a number of waits from a va_list * pointer passed after it, or just 
admit that the legacy function always does host fallback and just 
truncate the current version after

   if (host_fallback)
     {
       goacc_save_and_set_bind (acc_device_host);
       fn (hostaddrs);
       goacc_restore_bind ();
       return;
     }

(which incidentally ignores all the wait arguments).

Other than that the patch is fine with me, but Jakub should have the 
last word.


Bernd
Nathan Sidwell Sept. 18, 2015, 6:48 p.m. UTC | #2
On 09/18/15 05:13, Bernd Schmidt wrote:

> Is that so difficult though? See if nvptx ignores (let's say) intelmic arguments
> in favour of the default and accepts nvptx ones.

I'm sorry, I think it is unreasonable to require support in this patch for 
something that's not yet implemented in the rest of the toolchain.  The 
likelihood of implementing it correctly without  all the other bits filled in is 
low -- there are bound to be unanticipated subtleties.

> I still don't like this. I think there are at least two better alternatives: add
> a new GOMP_LAUNCH_key which makes GOACC_parallel read a number of waits from a
> va_list * pointer passed after it, or just admit that the legacy function always
> does host fallback and just truncate the current version after

I think you're worrying about  something that will not happen in practice.  As I 
said, the most waits I've seen on code has been 2, so a limit of 8 seems 
perfectly adequate.

nathan
Nathan Sidwell Sept. 21, 2015, 3:51 p.m. UTC | #3
Jakub?

https://gcc.gnu.org/ml/gcc-patches/2015-09/msg01287.html


On 09/17/15 10:40, Nathan Sidwell wrote:
> Updated patch addressing your points.  Some  further comments though ...
>
>>> +  while (GOMP_LAUNCH_PACK (GOMP_LAUNCH_END, 0, 0)
>>> +     != (tag = va_arg (ap, unsigned)))
>>
>> That's a somewhat non-idiomatic way to write this, with the constant first and
>> not obviously a constant. I'd initialize a variable with the constant before the
>> loop.
>
> I went with
>    while ((tag = va_arg (...)) != 0) ...
>
> and killed GOMP_LAUNCH_END throughout, using explicit '0'.
>
>>> +      assert (!GOMP_LAUNCH_DEVICE (tag));
>>
>> Uh, that seems unfriendly, and not exactly forwards compatible. Can that fail a
>> bit more gracefully? (Alternatively, implement the device_type stuff now so that
>> we don't have TODOs in the code and don't have to worry about compatibility
>> issues.)
>
> Added call to gomp_fatal, indicating libgomp is out of date. Also added a
> default to the switch following with the same effect.  The trouble  with
> implementing handling of device_type here now, is difficulty in testing its
> correctness.  If it were  buggy we'd be in a worse position than not having it.
>
>>> +GOACC_2.0,1 {
>>> +  global:
>>> +    GOACC_parallel_keyed;
>>> +} GOACC_2.0;
>>
>> Did you mean to use a comma?
>
> I misunderstood your comment as 'did you mean to use a comma where you used
> something else', not 'is that comma a typo?'  well spotted!
>
>>> +    else if (!tagging)
>>
>> Oh... so tagging controls two different methods for constructing argument lists,
>> one for GOACC_parallel and the other for whatever OMP uses? That's a bit
>> unfortunate, I'll need to think about it for a bit or defer to Jakub.
>
> My earlier description was lacking.  The memory arguments have already been
> pushed before that switch.  This is just dealing with async & wait args.  I
> found it easier to modify the existing code path and have a tagging flag, rather
> than duplicate it.
>
> nathan
Jakub Jelinek Sept. 24, 2015, 8:40 a.m. UTC | #4
On Fri, Sep 18, 2015 at 11:13:03AM +0200, Bernd Schmidt wrote:
> On 09/17/2015 04:40 PM, Nathan Sidwell wrote:
> 
> >Added call to gomp_fatal, indicating libgomp is out of date. Also added
> >a default to the switch following with the same effect.  The trouble
> >with implementing handling of device_type here now, is difficulty in
> >testing its correctness.  If it were  buggy we'd be in a worse position
> >than not having it.
> 
> Is that so difficult though? See if nvptx ignores (let's say) intelmic
> arguments in favour of the default and accepts nvptx ones.
> 
> >+  if (num_waits > 8)
> >+    gomp_fatal ("too many waits for legacy interface");
> >+
> >+  va_start (ap, num_waits);
> >+  for (ix = 0; ix != num_waits; ix++)
> >+    waits[ix] = va_arg (ap, int);
> >+  waits[ix] = 0;
> >+  va_end (ap);
> 
> I still don't like this. I think there are at least two better alternatives:
> add a new GOMP_LAUNCH_key which makes GOACC_parallel read a number of waits
> from a va_list * pointer passed after it, or just admit that the legacy
> function always does host fallback and just truncate the current version
> after
> 
>   if (host_fallback)
>     {
>       goacc_save_and_set_bind (acc_device_host);
>       fn (hostaddrs);
>       goacc_restore_bind ();
>       return;
>     }
> 
> (which incidentally ignores all the wait arguments).

Iff GCC 5 compiled offloaded OpenACC/PTX code will always do host fallback
anyway because of the incompatible PTX version, then why don't you just
do
  goacc_save_and_set_bind (acc_device_host);
  fn (hostaddrs);
  goacc_restore_bind ();
and nothing else in GOACC_parallel?  If it doesn't always do host fallback,
then I wonder if e.g. the waits wouldn't be better represented as an array
of ints, GOMP_LAUNCH_WAIT op would then encode num_waits and be followed
by a va_arg (ap, int *) with num_waits entries in it.  No need to pass
va_list around, instead just the pointer, and the compatibility entry point
would alloca an array, stuff the waits in it and pass GOMP_LAUNCH_WAIT with
the allocated array.

Other than that, I think Bernd has covered all the issues I had.

	Jakub
Bernd Schmidt Sept. 24, 2015, 9:50 a.m. UTC | #5
On 09/24/2015 10:40 AM, Jakub Jelinek wrote:
> Iff GCC 5 compiled offloaded OpenACC/PTX code will always do host fallback
> anyway because of the incompatible PTX version, then why don't you just
> do
>    goacc_save_and_set_bind (acc_device_host);
>    fn (hostaddrs);
>    goacc_restore_bind ();
> and nothing else in GOACC_parallel?

That was essentially my suggestion.

> Other than that, I think Bernd has covered all the issues I had.

What is your opinion on the forward compatibility issue? Is it something 
we care about?


Bernd
Jakub Jelinek Sept. 24, 2015, 9:56 a.m. UTC | #6
On Thu, Sep 24, 2015 at 11:50:56AM +0200, Bernd Schmidt wrote:
> On 09/24/2015 10:40 AM, Jakub Jelinek wrote:
> >Iff GCC 5 compiled offloaded OpenACC/PTX code will always do host fallback
> >anyway because of the incompatible PTX version, then why don't you just
> >do
> >   goacc_save_and_set_bind (acc_device_host);
> >   fn (hostaddrs);
> >   goacc_restore_bind ();
> >and nothing else in GOACC_parallel?
> 
> That was essentially my suggestion.
> 
> >Other than that, I think Bernd has covered all the issues I had.
> 
> What is your opinion on the forward compatibility issue? Is it something we
> care about?

For the (unlikely) case of using a newer GCC compiled binaries or libraries
with older libgomp, I'd prefer something other than silent crash.
Often it will not just start at all, because the binary needs newer symbols
from the library, if that is not the case, then supposedly ignoring some
newer features is fine, gomp_fatal is acceptable too though, but assert
failure is not.

	Jakub
Bernd Schmidt Sept. 24, 2015, 9:58 a.m. UTC | #7
On 09/24/2015 11:56 AM, Jakub Jelinek wrote:
> On Thu, Sep 24, 2015 at 11:50:56AM +0200, Bernd Schmidt wrote:
>> On 09/24/2015 10:40 AM, Jakub Jelinek wrote:
>>> Iff GCC 5 compiled offloaded OpenACC/PTX code will always do host fallback
>>> anyway because of the incompatible PTX version, then why don't you just
>>> do
>>>    goacc_save_and_set_bind (acc_device_host);
>>>    fn (hostaddrs);
>>>    goacc_restore_bind ();
>>> and nothing else in GOACC_parallel?
>>
>> That was essentially my suggestion.
>>
>>> Other than that, I think Bernd has covered all the issues I had.
>>
>> What is your opinion on the forward compatibility issue? Is it something we
>> care about?
>
> For the (unlikely) case of using a newer GCC compiled binaries or libraries
> with older libgomp, I'd prefer something other than silent crash.
> Often it will not just start at all, because the binary needs newer symbols
> from the library, if that is not the case, then supposedly ignoring some
> newer features is fine, gomp_fatal is acceptable too though, but assert
> failure is not.

In that case the patch is OK with the change suggested above.


Bernd
diff mbox

Patch

o2015-09-17  Nathan Sidwell  <nathan@codesourcery.com>

	inlude/
	* gomp-constants.h (GOMP_VERSION_NVIDIA_PTX): Increment.
	(GOMP_DIM_GANG, GOMP_DIM_WORKER, GOMP_DIM_VECTOR, GOMP_DIM_MAX,
	GOMP_DIM_MASK): New.
	(GOMP_LAUNCH_DIM, GOMP_LAUNCH_ASYNC, GOMP_LAUNCH_WAIT): New.
	(GOMP_LAUNCH_CODE_SHIFT, GOMP_LAUNCH_DEVICE_SHIFT,
	GOMP_LAUNCH_OP_SHIFT): New.
	(GOMP_LAUNCH_PACK, GOMP_LAUNCH_CODE, GOMP_LAUNCH_DEVICE,
	GOMP_LAUNCH_OP): New.
	(GOMP_LAUNCH_OP_MAX): New.

	libgomp/
	* libgomp.h (acc_dispatch_t): Replace separate geometry args with
	array.
	* libgomp.map (GOACC_parallel_keyed): New.
	* oacc-parallel.c (goacc_wait): Take pointer to va_list.  Adjust
	all callers.
	(GOACC_parallel_keyed): New interface.  Lose geometry arguments
	and take keyed varargs list.  Adjust call to exec_func.
	(GOACC_parallel): Forward to GACC_parallel_keyed.
	* libgomp_g.h (GOACC_parallel): Remove.
	(GOACC_parallel_keyed): Declare.
	* plugin/plugin-nvptx.c (struct targ_fn_launch): New struct.
	(stuct targ_gn_descriptor): Replace name field with launch field.
	(nvptx_exec): Lose separate geometry args, take array.  Process
	dynamic dimensions and adjust.
	(struct nvptx_tdata): Replace fn_names field with fn_descs.
	(GOMP_OFFLOAD_load_image): Adjust for change in function table
	data.
	(GOMP_OFFLOAD_openacc_parallel): Adjust for change in dimension
	passing.
	* oacc-host.c (host_openacc_exec): Adjust for change in dimension
	passing.

	gcc/
	* config/nvptx/nvptx.c: Include omp-low.h and gomp-constants.h.
	(nvptx_record_offload_symbol): Record function execution geometry.
	* config/nvptx/mkoffload.c (process): Include launch geometry in
	function data.
	* omp-low.c (oacc_launch_pack): New.
	(replace_oacc_fn_attrib): New.
	(set_oacc_fn_attrib): New.
	(get_oacc_fn_attrib): New.
	(expand_omp_target): Create keyed varargs for GOACC_parallel call
	generation.
	* omp-low.h (get_oacc_fn_attrib): Declare.
	* builtin-types.def (DEF_FUNCTION_TyPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_11): Delete.
	* tree.h (OMP_CLAUSE_EXPR): New.
	* omp-builtins.def (BUILT_IN_GOACC_PARALLEL): Change target fn name.

	gcc/lto/
	* lto-lang.c (DEF_FUNCTION_TYPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_11): Delete.

	gcc/c-family/
	* c-common.c (DEF_FUNCTION_TYPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_11): Delete.

	gcc/fortran/
	* f95-lang.c (DEF_FUNCTION_TYPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_11): Delete.
	* types.def (DEF_FUNCTION_TYPE_VAR_6): New.
	(DEF_FUNCTION_TYPE_VAR_11): Delete.

Index: include/gomp-constants.h
===================================================================
--- include/gomp-constants.h	(revision 227862)
+++ include/gomp-constants.h	(working copy)
@@ -115,11 +115,33 @@  enum gomp_map_kind
 
 /* Versions of libgomp and device-specific plugins.  */
 #define GOMP_VERSION	0
-#define GOMP_VERSION_NVIDIA_PTX 0
+#define GOMP_VERSION_NVIDIA_PTX 1
 #define GOMP_VERSION_INTEL_MIC 0
 
 #define GOMP_VERSION_PACK(LIB, DEV) (((LIB) << 16) | (DEV))
 #define GOMP_VERSION_LIB(PACK) (((PACK) >> 16) & 0xffff)
 #define GOMP_VERSION_DEV(PACK) ((PACK) & 0xffff)
 
+#define GOMP_DIM_GANG	0
+#define GOMP_DIM_WORKER	1
+#define GOMP_DIM_VECTOR	2
+#define GOMP_DIM_MAX	3
+#define GOMP_DIM_MASK(X) (1u << (X))
+
+/* Varadic launch arguments.  End of list is marked by a zero.  */
+#define GOMP_LAUNCH_DIM		1  /* Launch dimensions, op = mask */
+#define GOMP_LAUNCH_ASYNC	2  /* Async, op = cst val if not MAX  */
+#define GOMP_LAUNCH_WAIT	3  /* Waits, op = num waits.  */
+#define GOMP_LAUNCH_CODE_SHIFT	28
+#define GOMP_LAUNCH_DEVICE_SHIFT 16
+#define GOMP_LAUNCH_OP_SHIFT 0
+#define GOMP_LAUNCH_PACK(CODE,DEVICE,OP)	\
+  (((CODE) << GOMP_LAUNCH_CODE_SHIFT)		\
+   | ((DEVICE) << GOMP_LAUNCH_DEVICE_SHIFT)	\
+   | ((OP) << GOMP_LAUNCH_OP_SHIFT))
+#define GOMP_LAUNCH_CODE(X) (((X) >> GOMP_LAUNCH_CODE_SHIFT) & 0xf)
+#define GOMP_LAUNCH_DEVICE(X) (((X) >> GOMP_LAUNCH_DEVICE_SHIFT) & 0xfff)
+#define GOMP_LAUNCH_OP(X) (((X) >> GOMP_LAUNCH_OP_SHIFT) & 0xffff)
+#define GOMP_LAUNCH_OP_MAX 0xffff
+
 #endif
Index: libgomp/libgomp.h
===================================================================
--- libgomp/libgomp.h	(revision 227862)
+++ libgomp/libgomp.h	(working copy)
@@ -695,7 +695,7 @@  typedef struct acc_dispatch_t
 
   /* Execute.  */
   void (*exec_func) (void (*) (void *), size_t, void **, void **, size_t *,
-		     unsigned short *, int, int, int, int, void *);
+		     unsigned short *, int, unsigned *, void *);
 
   /* Async cleanup callback registration.  */
   void (*register_async_cleanup_func) (void *);
Index: libgomp/oacc-parallel.c
===================================================================
--- libgomp/oacc-parallel.c	(revision 227862)
+++ libgomp/oacc-parallel.c	(working copy)
@@ -49,14 +49,18 @@  find_pset (int pos, size_t mapnum, unsig
   return kind == GOMP_MAP_TO_PSET;
 }
 
-static void goacc_wait (int async, int num_waits, va_list ap);
+static void goacc_wait (int async, int num_waits, va_list *ap);
+
+
+/* Launch a possibly offloaded function on DEVICE.  FN is the host fn
+   address.  MAPNUM, HOSTADDRS, SIZES & KINDS  describe the memory
+   blocks to be copied to/from the device.  Varadic arguments are
+   keyed optional parameters terminated with a zero.  */
 
 void
-GOACC_parallel (int device, void (*fn) (void *),
-		size_t mapnum, void **hostaddrs, size_t *sizes,
-		unsigned short *kinds,
-		int num_gangs, int num_workers, int vector_length,
-		int async, int num_waits, ...)
+GOACC_parallel_keyed (int device, void (*fn) (void *),
+		      size_t mapnum, void **hostaddrs, size_t *sizes,
+		      unsigned short *kinds, ...)
 {
   bool host_fallback = device == GOMP_DEVICE_HOST_FALLBACK;
   va_list ap;
@@ -68,22 +72,16 @@  GOACC_parallel (int device, void (*fn) (
   struct splay_tree_key_s k;
   splay_tree_key tgt_fn_key;
   void (*tgt_fn);
-
-  if (num_gangs != 1)
-    gomp_fatal ("num_gangs (%d) different from one is not yet supported",
-		num_gangs);
-  if (num_workers != 1)
-    gomp_fatal ("num_workers (%d) different from one is not yet supported",
-		num_workers);
+  int async = GOMP_ASYNC_SYNC;
+  unsigned dims[GOMP_DIM_MAX];
+  unsigned tag;
 
 #ifdef HAVE_INTTYPES_H
-  gomp_debug (0, "%s: mapnum=%"PRIu64", hostaddrs=%p, size=%p, kinds=%p, "
-		 "async = %d\n",
-	      __FUNCTION__, (uint64_t) mapnum, hostaddrs, sizes, kinds, async);
+  gomp_debug (0, "%s: mapnum=%"PRIu64", hostaddrs=%p, size=%p, kinds=%p\n",
+	      __FUNCTION__, (uint64_t) mapnum, hostaddrs, sizes, kinds);
 #else
-  gomp_debug (0, "%s: mapnum=%lu, hostaddrs=%p, sizes=%p, kinds=%p, async=%d\n",
-	      __FUNCTION__, (unsigned long) mapnum, hostaddrs, sizes, kinds,
-	      async);
+  gomp_debug (0, "%s: mapnum=%lu, hostaddrs=%p, sizes=%p, kinds=%p\n",
+	      __FUNCTION__, (unsigned long) mapnum, hostaddrs, sizes, kinds);
 #endif
   goacc_lazy_initialize ();
 
@@ -105,12 +103,51 @@  GOACC_parallel (int device, void (*fn) (
       return;
     }
 
-  if (num_waits)
-    {
-      va_start (ap, num_waits);
-      goacc_wait (async, num_waits, ap);
-      va_end (ap);
+  va_start (ap, kinds);
+  /* TODO: This will need amending when device_type is implemented.  */
+  while ((tag = va_arg (ap, unsigned)) != 0)
+    {
+      if (GOMP_LAUNCH_DEVICE (tag))
+	gomp_fatal ("device_type '%d' offload parameters, libgomp is too old",
+		    GOMP_LAUNCH_DEVICE (tag));
+
+      switch (GOMP_LAUNCH_CODE (tag))
+	{
+	case GOMP_LAUNCH_DIM:
+	  {
+	    unsigned mask = GOMP_LAUNCH_OP (tag);
+
+	    for (i = 0; i != GOMP_DIM_MAX; i++)
+	      if (mask & GOMP_DIM_MASK (i))
+		dims[i] = va_arg (ap, unsigned);
+	  }
+	  break;
+
+	case GOMP_LAUNCH_ASYNC:
+	  {
+	    /* Small constant values are encoded in the operand.  */
+	    async = GOMP_LAUNCH_OP (tag);
+
+	    if (async == GOMP_LAUNCH_OP_MAX)
+	      async = va_arg (ap, unsigned);
+	    break;
+	  }
+
+	case GOMP_LAUNCH_WAIT:
+	  {
+	    unsigned num_waits = GOMP_LAUNCH_OP (tag);
+
+	    if (num_waits)
+	      goacc_wait (async, num_waits, &ap);
+	    break;
+	  }
+
+	default:
+	  gomp_fatal ("unrecognized offload code '%d',"
+		      " libgomp is too old", GOMP_LAUNCH_CODE (tag));
+	}
     }
+  va_end (ap);
   
   acc_dev->openacc.async_set_async_func (async);
 
@@ -138,9 +175,8 @@  GOACC_parallel (int device, void (*fn) (
     devaddrs[i] = (void *) (tgt->list[i]->tgt->tgt_start
 			    + tgt->list[i]->tgt_offset);
 
-  acc_dev->openacc.exec_func (tgt_fn, mapnum, hostaddrs, devaddrs, sizes, kinds,
-			      num_gangs, num_workers, vector_length, async,
-			      tgt);
+  acc_dev->openacc.exec_func (tgt_fn, mapnum, hostaddrs, devaddrs, sizes,
+			      kinds, async, dims, tgt);
 
   /* If running synchronously, unmap immediately.  */
   if (async < acc_async_noval)
@@ -154,6 +190,38 @@  GOACC_parallel (int device, void (*fn) (
   acc_dev->openacc.async_set_async_func (acc_async_sync);
 }
 
+/* Legacy entry point.  */
+void
+GOACC_parallel (int device, void (*fn) (void *),
+		size_t mapnum, void **hostaddrs, size_t *sizes,
+		unsigned short *kinds,
+		int num_gangs, int num_workers, int vector_length,
+		int async, int num_waits, ...)
+{
+  int waits[9];
+  unsigned ix;
+  va_list ap;
+
+  if (num_waits > 8)
+    gomp_fatal ("too many waits for legacy interface");
+  
+  va_start (ap, num_waits);
+  for (ix = 0; ix != num_waits; ix++)
+    waits[ix] = va_arg (ap, int);
+  waits[ix] = 0;
+  va_end (ap);
+
+  GOACC_parallel_keyed (device, fn, mapnum, hostaddrs, sizes, kinds,
+			GOMP_LAUNCH_PACK (GOMP_LAUNCH_DIM, 0,
+					  GOMP_DIM_MASK (GOMP_DIM_MAX) - 1),
+			num_gangs, num_workers, vector_length,
+			GOMP_LAUNCH_PACK (GOMP_LAUNCH_ASYNC, 0,
+					  GOMP_LAUNCH_OP_MAX), async,
+			GOMP_LAUNCH_PACK (GOMP_LAUNCH_WAIT, 0, num_waits),
+			async, waits[0], waits[1], waits[2], waits[3],
+			waits[4], waits[5], waits[6], waits[7], waits[8]);
+}
+
 void
 GOACC_data_start (int device, size_t mapnum,
 		  void **hostaddrs, size_t *sizes, unsigned short *kinds)
@@ -230,7 +298,7 @@  GOACC_enter_exit_data (int device, size_
       va_list ap;
 
       va_start (ap, num_waits);
-      goacc_wait (async, num_waits, ap);
+      goacc_wait (async, num_waits, &ap);
       va_end (ap);
     }
 
@@ -344,15 +412,15 @@  GOACC_enter_exit_data (int device, size_
 }
 
 static void
-goacc_wait (int async, int num_waits, va_list ap)
+goacc_wait (int async, int num_waits, va_list *ap)
 {
   struct goacc_thread *thr = goacc_thread ();
   struct gomp_device_descr *acc_dev = thr->dev;
 
   while (num_waits--)
     {
-      int qid = va_arg (ap, int);
-
+      int qid = va_arg (*ap, int);
+      
       if (acc_async_test (qid))
 	continue;
 
@@ -389,7 +457,7 @@  GOACC_update (int device, size_t mapnum,
       va_list ap;
 
       va_start (ap, num_waits);
-      goacc_wait (async, num_waits, ap);
+      goacc_wait (async, num_waits, &ap);
       va_end (ap);
     }
 
@@ -430,7 +498,7 @@  GOACC_wait (int async, int num_waits, ..
       va_list ap;
 
       va_start (ap, num_waits);
-      goacc_wait (async, num_waits, ap);
+      goacc_wait (async, num_waits, &ap);
       va_end (ap);
     }
   else if (async == acc_async_sync)
Index: libgomp/libgomp_g.h
===================================================================
--- libgomp/libgomp_g.h	(revision 227862)
+++ libgomp/libgomp_g.h	(working copy)
@@ -222,9 +222,8 @@  extern void GOACC_data_start (int, size_
 extern void GOACC_data_end (void);
 extern void GOACC_enter_exit_data (int, size_t, void **,
 				   size_t *, unsigned short *, int, int, ...);
-extern void GOACC_parallel (int, void (*) (void *), size_t,
-			    void **, size_t *, unsigned short *, int, int, int,
-			    int, int, ...);
+extern void GOACC_parallel_2 (int, void (*) (void *), size_t,
+			      void **, size_t *, unsigned short *, ...);
 extern void GOACC_update (int, size_t, void **, size_t *,
 			  unsigned short *, int, int, ...);
 extern void GOACC_wait (int, int, ...);
Index: libgomp/libgomp.map
===================================================================
--- libgomp/libgomp.map	(revision 227862)
+++ libgomp/libgomp.map	(working copy)
@@ -332,6 +332,11 @@  GOACC_2.0 {
 	GOACC_get_num_threads;
 };
 
+GOACC_2.0.1 {
+  global:
+	GOACC_parallel_keyed;
+} GOACC_2.0;
+
 GOMP_PLUGIN_1.0 {
   global:
 	GOMP_PLUGIN_malloc;
Index: libgomp/plugin/plugin-nvptx.c
===================================================================
--- libgomp/plugin/plugin-nvptx.c	(revision 227862)
+++ libgomp/plugin/plugin-nvptx.c	(working copy)
@@ -282,12 +282,20 @@  map_push (struct ptx_stream *s, int asyn
   return;
 }
 
+/* Target data function launch information.  */
+
+struct targ_fn_launch
+{
+  const char *fn;
+  unsigned short dim[3];
+};
+
 /* Descriptor of a loaded function.  */
 
 struct targ_fn_descriptor
 {
   CUfunction fn;
-  const char *name;
+  const struct targ_fn_launch *launch;
 };
 
 /* A loaded PTX image.  */
@@ -929,8 +937,8 @@  event_add (enum ptx_event_type type, CUe
 
 void
 nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs,
-	  size_t *sizes, unsigned short *kinds, int num_gangs, int num_workers,
-	  int vector_length, int async, void *targ_mem_desc)
+	    size_t *sizes, unsigned short *kinds, int async, unsigned *dims,
+	    void *targ_mem_desc)
 {
   struct targ_fn_descriptor *targ_fn = (struct targ_fn_descriptor *) fn;
   CUfunction function;
@@ -939,7 +947,6 @@  nvptx_exec (void (*fn), size_t mapnum, v
   struct ptx_stream *dev_str;
   void *kargs[1];
   void *hp, *dp;
-  unsigned int nthreads_in_block;
   struct nvptx_thread *nvthd = nvptx_thread ();
   const char *maybe_abort_msg = "(perhaps abort was called)";
 
@@ -948,6 +955,20 @@  nvptx_exec (void (*fn), size_t mapnum, v
   dev_str = select_stream_for_async (async, pthread_self (), false, NULL);
   assert (dev_str == nvthd->current_stream);
 
+  /* Initialize the launch dimensions.  Typically this is constant,
+     provided by the device compiler, but we must permit runtime
+     values.  */
+  for (i = 0; i != 3; i++)
+    if (targ_fn->launch->dim[i])
+      dims[i] = targ_fn->launch->dim[i];
+
+  if (dims[GOMP_DIM_GANG] != 1)
+    GOMP_PLUGIN_fatal ("non-unity num_gangs (%d) not supported",
+		       dims[GOMP_DIM_GANG]);
+  if (dims[GOMP_DIM_WORKER] != 1)
+    GOMP_PLUGIN_fatal ("non-unity num_workers (%d) not supported",
+		       dims[GOMP_DIM_WORKER]);
+
   /* This reserves a chunk of a pre-allocated page of memory mapped on both
      the host and the device. HP is a host pointer to the new chunk, and DP is
      the corresponding device pointer.  */
@@ -965,35 +986,21 @@  nvptx_exec (void (*fn), size_t mapnum, v
   if (r != CUDA_SUCCESS)
     GOMP_PLUGIN_fatal ("cuMemcpy failed: %s", cuda_error (r));
 
-  GOMP_PLUGIN_debug (0, "  %s: kernel %s: launch\n", __FUNCTION__, targ_fn->name);
+  GOMP_PLUGIN_debug (0, "  %s: kernel %s: launch"
+		     " gangs=%u, workers=%u, vectors=%u\n",
+		     __FUNCTION__, targ_fn->launch->fn,
+		     dims[0], dims[1], dims[2]);
 
   // OpenACC		CUDA
   //
-  // num_gangs		blocks
-  // num_workers	warps (where a warp is equivalent to 32 threads)
-  // vector length	threads
-  //
-
-  /* The openacc vector_length clause 'determines the vector length to use for
-     vector or SIMD operations'.  The question is how to map this to CUDA.
-
-     In CUDA, the warp size is the vector length of a CUDA device.  However, the
-     CUDA interface abstracts away from that, and only shows us warp size
-     indirectly in maximum number of threads per block, which is a product of
-     warp size and the number of hyperthreads of a multiprocessor.
-
-     We choose to map openacc vector_length directly onto the number of threads
-     in a block, in the x dimension.  This is reflected in gcc code generation
-     that uses ThreadIdx.x to access vector elements.
-
-     Attempting to use an openacc vector_length of more than the maximum number
-     of threads per block will result in a cuda error.  */
-  nthreads_in_block = vector_length;
+  // num_gangs		nctaid.x
+  // num_workers	ntid.y
+  // vector length	ntid.x
 
   kargs[0] = &dp;
   r = cuLaunchKernel (function,
-		      num_gangs, 1, 1,
-		      nthreads_in_block, 1, 1,
+		      dims[GOMP_DIM_GANG], 1, 1,
+		      dims[GOMP_DIM_VECTOR], dims[GOMP_DIM_WORKER], 1,
 		      0, dev_str->stream, kargs, 0);
   if (r != CUDA_SUCCESS)
     GOMP_PLUGIN_fatal ("cuLaunchKernel error: %s", cuda_error (r));
@@ -1039,7 +1046,7 @@  nvptx_exec (void (*fn), size_t mapnum, v
 #endif
 
   GOMP_PLUGIN_debug (0, "  %s: kernel %s: finished\n", __FUNCTION__,
-		     targ_fn->name);
+		     targ_fn->launch->fn);
 
 #ifndef DISABLE_ASYNC
   if (async < acc_async_noval)
@@ -1567,7 +1574,7 @@  typedef struct nvptx_tdata
   const char *const *var_names;
   size_t var_num;
 
-  const char *const *fn_names;
+  const struct targ_fn_launch *fn_descs;
   size_t fn_num;
 } nvptx_tdata_t;
 
@@ -1588,7 +1595,8 @@  GOMP_OFFLOAD_load_image (int ord, unsign
 			 struct addr_pair **target_table)
 {
   CUmodule module;
-  const char *const *fn_names, *const *var_names;
+  const char *const *var_names;
+  const struct targ_fn_launch *fn_descs;
   unsigned int fn_entries, var_entries, i, j;
   CUresult r;
   struct targ_fn_descriptor *targ_fns;
@@ -1617,7 +1625,7 @@  GOMP_OFFLOAD_load_image (int ord, unsign
   var_entries = img_header->var_num;
   var_names = img_header->var_names;
   fn_entries = img_header->fn_num;
-  fn_names = img_header->fn_names;
+  fn_descs = img_header->fn_descs;
 
   targ_tbl = GOMP_PLUGIN_malloc (sizeof (struct addr_pair)
 				 * (fn_entries + var_entries));
@@ -1640,12 +1648,12 @@  GOMP_OFFLOAD_load_image (int ord, unsign
     {
       CUfunction function;
 
-      r = cuModuleGetFunction (&function, module, fn_names[i]);
+      r = cuModuleGetFunction (&function, module, fn_descs[i].fn);
       if (r != CUDA_SUCCESS)
 	GOMP_PLUGIN_fatal ("cuModuleGetFunction error: %s", cuda_error (r));
 
       targ_fns->fn = function;
-      targ_fns->name = (const char *) fn_names[i];
+      targ_fns->launch = &fn_descs[i];
 
       targ_tbl->start = (uintptr_t) targ_fns;
       targ_tbl->end = targ_tbl->start + 1;
@@ -1724,13 +1732,12 @@  void (*device_run) (int n, void *fn_ptr,
 
 void
 GOMP_OFFLOAD_openacc_parallel (void (*fn) (void *), size_t mapnum,
-			       void **hostaddrs, void **devaddrs, size_t *sizes,
-			       unsigned short *kinds, int num_gangs,
-			       int num_workers, int vector_length, int async,
-			       void *targ_mem_desc)
+			       void **hostaddrs, void **devaddrs,
+			       size_t *sizes, unsigned short *kinds,
+			       int async, unsigned *dims, void *targ_mem_desc)
 {
-  nvptx_exec (fn, mapnum, hostaddrs, devaddrs, sizes, kinds, num_gangs,
-	    num_workers, vector_length, async, targ_mem_desc);
+  nvptx_exec (fn, mapnum, hostaddrs, devaddrs, sizes, kinds,
+	      async, dims, targ_mem_desc);
 }
 
 void
Index: libgomp/oacc-host.c
===================================================================
--- libgomp/oacc-host.c	(revision 227862)
+++ libgomp/oacc-host.c	(working copy)
@@ -137,10 +137,8 @@  host_openacc_exec (void (*fn) (void *),
 		   void **devaddrs __attribute__ ((unused)),
 		   size_t *sizes __attribute__ ((unused)),
 		   unsigned short *kinds __attribute__ ((unused)),
-		   int num_gangs __attribute__ ((unused)),
-		   int num_workers __attribute__ ((unused)),
-		   int vector_length __attribute__ ((unused)),
 		   int async __attribute__ ((unused)),
+		   unsigned *dims __attribute ((unused)),
 		   void *targ_mem_desc __attribute__ ((unused)))
 {
   fn (hostaddrs);
Index: gcc/config/nvptx/nvptx.c
===================================================================
--- gcc/config/nvptx/nvptx.c	(revision 227862)
+++ gcc/config/nvptx/nvptx.c	(working copy)
@@ -56,6 +56,8 @@ 
 #include "cfgrtl.h"
 #include "stor-layout.h"
 #include "builtins.h"
+#include "omp-low.h"
+#include "gomp-constants.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -2066,9 +2068,51 @@  nvptx_vector_alignment (const_tree type)
 static void
 nvptx_record_offload_symbol (tree decl)
 {
-  fprintf (asm_out_file, "//:%s_MAP %s\n",
-	   TREE_CODE (decl) == VAR_DECL ? "VAR" : "FUNC",
-	   IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
+  switch (TREE_CODE (decl))
+    {
+    case VAR_DECL:
+      fprintf (asm_out_file, "//:VAR_MAP \"%s\"\n",
+	       IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
+      break;
+
+    case FUNCTION_DECL:
+      {
+	tree attr = get_oacc_fn_attrib (decl);
+	tree dims = NULL_TREE;
+	unsigned ix;
+
+	if (attr)
+	  dims = TREE_VALUE (attr);
+	fprintf (asm_out_file, "//:FUNC_MAP \"%s\"",
+		 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
+
+	for (ix = 0; ix != GOMP_DIM_MAX; ix++)
+	  {
+	    int size = 1;
+
+	    /* TODO: This check can go away once the dimension default
+	       machinery is merged to trunk.  */
+	    if (dims)
+	      {
+		tree dim = TREE_VALUE (dims);
+
+		if (dim)
+		  size = TREE_INT_CST_LOW (dim);
+
+		gcc_assert (!TREE_PURPOSE (dims));
+		dims = TREE_CHAIN (dims);
+	      }
+	    
+	    fprintf (asm_out_file, ", %#x", size);
+	  }
+	
+	fprintf (asm_out_file, "\n");
+      }
+      break;
+  
+    default:
+      gcc_unreachable ();
+    }
 }
 
 /* Implement TARGET_ASM_FILE_START.  Write the kinds of things ptxas expects
Index: gcc/config/nvptx/mkoffload.c
===================================================================
--- gcc/config/nvptx/mkoffload.c	(revision 227862)
+++ gcc/config/nvptx/mkoffload.c	(working copy)
@@ -842,6 +842,8 @@  process (FILE *in, FILE *out)
 {
   const char *input = read_file (in);
   Token *tok = tokenize (input);
+  const char *comma;
+  id_map const *id;
 
   do
     tok = parse_file (tok);
@@ -853,21 +855,25 @@  process (FILE *in, FILE *out)
   write_stmts (out, rev_stmts (fns));
   fprintf (out, ";\n\n");
 
-  fprintf (out, "static const char *const var_mappings[] = {\n");
-  for (id_map *id = var_ids; id; id = id->next)
-    fprintf (out, "\t\"%s\"%s\n", id->ptx_name, id->next ? "," : "");
-  fprintf (out, "};\n\n");
-  fprintf (out, "static const char *const func_mappings[] = {\n");
-  for (id_map *id = func_ids; id; id = id->next)
-    fprintf (out, "\t\"%s\"%s\n", id->ptx_name, id->next ? "," : "");
-  fprintf (out, "};\n\n");
+  fprintf (out, "static const char *const var_mappings[] = {");
+  for (comma = "", id = var_ids; id; comma = ",", id = id->next)
+    fprintf (out, "%s\n\t%s", comma, id->ptx_name);
+  fprintf (out, "\n};\n\n");
+
+  fprintf (out, "static const struct nvptx_fn {\n"
+	   "  const char *name;\n"
+	   "  unsigned short dim[3];\n"
+	   "} func_mappings[] = {\n");
+  for (comma = "", id = func_ids; id; comma = ",", id = id->next)
+    fprintf (out, "%s\n\t{%s}", comma, id->ptx_name);
+  fprintf (out, "\n};\n\n");
 
   fprintf (out,
 	   "static const struct nvptx_tdata {\n"
 	   "  const char *ptx_src;\n"
 	   "  const char *const *var_names;\n"
 	   "  __SIZE_TYPE__ var_num;\n"
-	   "  const char *const *fn_names;\n"
+	   "  const struct nvptx_fn *fn_names;\n"
 	   "  __SIZE_TYPE__ fn_num;\n"
 	   "} target_data = {\n"
 	   "  ptx_code,\n"
Index: gcc/omp-low.c
===================================================================
--- gcc/omp-low.c	(revision 227862)
+++ gcc/omp-low.c	(working copy)
@@ -82,7 +82,6 @@  along with GCC; see the file COPYING3.
 #include "lto-section-names.h"
 #include "gomp-constants.h"
 
-
 /* Lowering of OMP parallel and workshare constructs proceeds in two
    phases.  The first phase scans the function looking for OMP statements
    and then for variables that must be replaced to satisfy data sharing
@@ -8861,6 +8860,110 @@  expand_omp_atomic (struct omp_region *re
 }
 
 
+/* Encode an oacc launc argument.  This matches the GOMP_LAUNCH_PACK
+   macro on gomp-constants.h.  We do not check for overflow.  */
+
+static tree
+oacc_launch_pack (unsigned code, tree device, unsigned op)
+{
+  tree res;
+  
+  res = build_int_cst (unsigned_type_node, GOMP_LAUNCH_PACK (code, 0, op));
+  if (device)
+    {
+      device = fold_build2 (LSHIFT_EXPR, unsigned_type_node,
+			    device, build_int_cst (unsigned_type_node,
+						   GOMP_LAUNCH_DEVICE_SHIFT));
+      res = fold_build2 (BIT_IOR_EXPR, unsigned_type_node, res, device);
+    }
+  return res;
+}
+
+/* Look for compute grid dimension clauses and convert to an attribute
+   attached to FN.  This permits the target-side code to (a) massage
+   the dimensions, (b) emit that data and (c) optimize.  Non-constant
+   dimensions are pushed onto ARGS.
+
+   The attribute value is a TREE_LIST.  A set of dimensions is
+   represented as a list of INTEGER_CST.  Those that are runtime
+   expres are represented as an INTEGER_CST of zero.
+
+   TOOO. Normally the attribute will just contain a single such list.  If
+   however it contains a list of lists, this will represent the use of
+   device_type.  Each member of the outer list is an assoc list of
+   dimensions, keyed by the device type.  The first entry will be the
+   default.  Well, that's the plan.  */
+
+#define OACC_FN_ATTRIB "oacc function"
+
+/* Replace any existing oacc fn attribute with updated dimensions.  */
+
+void
+replace_oacc_fn_attrib (tree fn, tree dims)
+{
+  tree ident = get_identifier (OACC_FN_ATTRIB);
+  tree attribs = DECL_ATTRIBUTES (fn);
+
+  /* If we happen to be present as the first attrib, drop it.  */
+  if (attribs && TREE_PURPOSE (attribs) == ident)
+    attribs = TREE_CHAIN (attribs);
+  DECL_ATTRIBUTES (fn) = tree_cons (ident, dims, attribs);
+}
+
+/* Scan CLAUSES for launch dimensions and attach them to the oacc
+   function attribute.  Push any that are non-constant onto the ARGS
+   list, along with an appropriate GOMP_LAUNCH_DIM tag.  */
+
+static void
+set_oacc_fn_attrib (tree fn, tree clauses, vec<tree> *args)
+{
+  /* Must match GOMP_DIM ordering.  */
+  static const omp_clause_code ids[]
+    = { OMP_CLAUSE_NUM_GANGS, OMP_CLAUSE_NUM_WORKERS,
+	OMP_CLAUSE_VECTOR_LENGTH };
+  unsigned ix;
+  tree dims[GOMP_DIM_MAX];
+  tree attr = NULL_TREE;
+  unsigned non_const = 0;
+
+  for (ix = GOMP_DIM_MAX; ix--;)
+    {
+      tree clause = find_omp_clause (clauses, ids[ix]);
+      tree dim = NULL_TREE;
+
+      if (clause)
+	dim = OMP_CLAUSE_EXPR (clause, ids[ix]);
+      dims[ix] = dim;
+      if (dim && TREE_CODE (dim) != INTEGER_CST)
+	{
+	  dim = integer_zero_node;
+	  non_const |= GOMP_DIM_MASK (ix);
+	}
+      attr = tree_cons (NULL_TREE, dim, attr);
+    }
+
+  replace_oacc_fn_attrib (fn, attr);
+
+  if (non_const)
+    {
+      /* Push a dynamic argument set.  */
+      args->safe_push (oacc_launch_pack (GOMP_LAUNCH_DIM,
+					 NULL_TREE, non_const));
+      for (unsigned ix = 0; ix != GOMP_DIM_MAX; ix++)
+	if (non_const & GOMP_DIM_MASK (ix))
+	  args->safe_push (dims[ix]);
+    }
+}
+
+/* Retrieve the oacc function attrib and return it.  Non-oacc
+   functions will return NULL.  */
+
+tree
+get_oacc_fn_attrib (tree fn)
+{
+  return lookup_attribute (OACC_FN_ATTRIB, DECL_ATTRIBUTES (fn));
+}
+
 /* Expand the GIMPLE_OMP_TARGET starting at REGION.  */
 
 static void
@@ -8881,10 +8984,10 @@  expand_omp_target (struct omp_region *re
   offloaded = is_gimple_omp_offloaded (entry_stmt);
   switch (gimple_omp_target_kind (entry_stmt))
     {
-    case GF_OMP_TARGET_KIND_REGION:
-    case GF_OMP_TARGET_KIND_UPDATE:
     case GF_OMP_TARGET_KIND_OACC_PARALLEL:
     case GF_OMP_TARGET_KIND_OACC_KERNELS:
+    case GF_OMP_TARGET_KIND_REGION:
+    case GF_OMP_TARGET_KIND_UPDATE:
     case GF_OMP_TARGET_KIND_OACC_UPDATE:
     case GF_OMP_TARGET_KIND_OACC_ENTER_EXIT_DATA:
       data_region = false;
@@ -9216,6 +9319,7 @@  expand_omp_target (struct omp_region *re
     }
 
   gimple g;
+  bool tagging = false;
   /* The maximum number used by any start_ix, without varargs.  */
   auto_vec<tree, 11> args;
   args.quick_push (device);
@@ -9251,88 +9355,87 @@  expand_omp_target (struct omp_region *re
       break;
     case BUILT_IN_GOACC_PARALLEL:
       {
-	tree t_num_gangs, t_num_workers, t_vector_length;
-
-	/* Default values for num_gangs, num_workers, and vector_length.  */
-	t_num_gangs = t_num_workers = t_vector_length
-	  = fold_convert_loc (gimple_location (entry_stmt),
-			      integer_type_node, integer_one_node);
-	/* ..., but if present, use the value specified by the respective
-	   clause, making sure that are of the correct type.  */
-	c = find_omp_clause (clauses, OMP_CLAUSE_NUM_GANGS);
-	if (c)
-	  t_num_gangs = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
-					  integer_type_node,
-					  OMP_CLAUSE_NUM_GANGS_EXPR (c));
-	c = find_omp_clause (clauses, OMP_CLAUSE_NUM_WORKERS);
-	if (c)
-	  t_num_workers = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
-					    integer_type_node,
-					    OMP_CLAUSE_NUM_WORKERS_EXPR (c));
-	c = find_omp_clause (clauses, OMP_CLAUSE_VECTOR_LENGTH);
-	if (c)
-	  t_vector_length = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
-					      integer_type_node,
-					      OMP_CLAUSE_VECTOR_LENGTH_EXPR (c));
-	args.quick_push (t_num_gangs);
-	args.quick_push (t_num_workers);
-	args.quick_push (t_vector_length);
+	set_oacc_fn_attrib (child_fn, clauses, &args);
+	tagging = true;
       }
       /* FALLTHRU */
     case BUILT_IN_GOACC_ENTER_EXIT_DATA:
     case BUILT_IN_GOACC_UPDATE:
       {
-	tree t_async;
-	int t_wait_idx;
+	tree t_async = NULL_TREE;
 
-	/* Default values for t_async.  */
-	t_async = fold_convert_loc (gimple_location (entry_stmt),
-				    integer_type_node,
-				    build_int_cst (integer_type_node,
-						   GOMP_ASYNC_SYNC));
-	/* ..., but if present, use the value specified by the respective
+	/* If present, use the value specified by the respective
 	   clause, making sure that is of the correct type.  */
 	c = find_omp_clause (clauses, OMP_CLAUSE_ASYNC);
 	if (c)
 	  t_async = fold_convert_loc (OMP_CLAUSE_LOCATION (c),
 				      integer_type_node,
 				      OMP_CLAUSE_ASYNC_EXPR (c));
-
-	args.quick_push (t_async);
-	/* Save the index, and... */
-	t_wait_idx = args.length ();
-	/* ... push a default value.  */
-	args.quick_push (fold_convert_loc (gimple_location (entry_stmt),
-					   integer_type_node,
-					   integer_zero_node));
-	c = find_omp_clause (clauses, OMP_CLAUSE_WAIT);
-	if (c)
+	else if (!tagging)
+	  /* Default values for t_async.  */
+	  t_async = fold_convert_loc (gimple_location (entry_stmt),
+				      integer_type_node,
+				      build_int_cst (integer_type_node,
+						     GOMP_ASYNC_SYNC));
+	if (tagging && t_async)
 	  {
-	    int n = 0;
+	    unsigned HOST_WIDE_INT i_async;
 
-	    for (; c; c = OMP_CLAUSE_CHAIN (c))
+	    if (TREE_CODE (t_async) == INTEGER_CST)
 	      {
-		if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_WAIT)
-		  {
-		    args.safe_push (fold_convert_loc (OMP_CLAUSE_LOCATION (c),
-						      integer_type_node,
-						      OMP_CLAUSE_WAIT_EXPR (c)));
-		    n++;
-		  }
+		/* See if we can pack the async arg in to the tag's
+		   operand.  */
+		i_async = TREE_INT_CST_LOW (t_async);
+
+		if (i_async < GOMP_LAUNCH_OP_MAX)
+		  t_async = NULL_TREE;
 	      }
+	    if (t_async)
+	      i_async = GOMP_LAUNCH_OP_MAX;
+	    args.safe_push (oacc_launch_pack
+			    (GOMP_LAUNCH_ASYNC, NULL_TREE, i_async));
+	  }
+	if (t_async)
+	  args.safe_push (t_async);
 
-	    /* Now that we know the number, replace the default value.  */
-	    args.ordered_remove (t_wait_idx);
-	    args.quick_insert (t_wait_idx,
-			       fold_convert_loc (gimple_location (entry_stmt),
-						 integer_type_node,
-						 build_int_cst (integer_type_node, n)));
+	/* Save the argument index, and ... */
+	unsigned t_wait_idx = args.length ();
+	unsigned num_waits = 0;
+	c = find_omp_clause (clauses, OMP_CLAUSE_WAIT);
+	if (!tagging || c)
+	  /* ... push a placeholder.  */
+	  args.safe_push (integer_zero_node);
+
+	for (; c; c = OMP_CLAUSE_CHAIN (c))
+	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_WAIT)
+	    {
+	      args.safe_push (fold_convert_loc (OMP_CLAUSE_LOCATION (c),
+						integer_type_node,
+						OMP_CLAUSE_WAIT_EXPR (c)));
+	      num_waits++;
+	    }
+
+	if (!tagging || num_waits)
+	  {
+	    tree len;
+
+	    /* Now that we know the number, update the placeholder.  */
+	    if (tagging)
+	      len = oacc_launch_pack (GOMP_LAUNCH_WAIT, NULL_TREE, num_waits);
+	    else
+	      len = build_int_cst (integer_type_node, num_waits);
+	    len = fold_convert_loc (gimple_location (entry_stmt),
+				    unsigned_type_node, len);
+	    args[t_wait_idx] = len;
 	  }
       }
       break;
     default:
       gcc_unreachable ();
     }
+  if (tagging)
+    /*  Push terminal marker - zero.  */
+    args.safe_push (oacc_launch_pack (0, NULL_TREE, 0));
 
   g = gimple_build_call_vec (builtin_decl_explicit (start_ix), args);
   gimple_set_location (g, gimple_location (entry_stmt));
Index: gcc/omp-low.h
===================================================================
--- gcc/omp-low.h	(revision 227862)
+++ gcc/omp-low.h	(working copy)
@@ -28,6 +28,7 @@  extern void free_omp_regions (void);
 extern tree omp_reduction_init (tree, tree);
 extern bool make_gimple_omp_edges (basic_block, struct omp_region **, int *);
 extern void omp_finish_file (void);
+extern tree get_oacc_fn_attrib (tree);
 
 extern GTY(()) vec<tree, va_gc> *offload_funcs;
 extern GTY(()) vec<tree, va_gc> *offload_vars;
Index: gcc/builtin-types.def
===================================================================
--- gcc/builtin-types.def	(revision 227862)
+++ gcc/builtin-types.def	(working copy)
@@ -590,15 +590,14 @@  DEF_FUNCTION_TYPE_VAR_5 (BT_FN_INT_STRIN
 DEF_FUNCTION_TYPE_VAR_5 (BT_FN_INT_INT_INT_INT_INT_INT_VAR,
 			 BT_INT, BT_INT, BT_INT, BT_INT, BT_INT, BT_INT)
 
+DEF_FUNCTION_TYPE_VAR_6 (BT_FN_VOID_INT_OMPFN_SIZE_PTR_PTR_PTR_VAR,
+			 BT_VOID, BT_INT, BT_PTR_FN_VOID_PTR, BT_SIZE,
+			 BT_PTR, BT_PTR, BT_PTR)
+
 DEF_FUNCTION_TYPE_VAR_7 (BT_FN_VOID_INT_SIZE_PTR_PTR_PTR_INT_INT_VAR,
 			 BT_VOID, BT_INT, BT_SIZE, BT_PTR, BT_PTR,
 			 BT_PTR, BT_INT, BT_INT)
 
-DEF_FUNCTION_TYPE_VAR_11 (BT_FN_VOID_INT_OMPFN_SIZE_PTR_PTR_PTR_INT_INT_INT_INT_INT_VAR,
-			  BT_VOID, BT_INT, BT_PTR_FN_VOID_PTR, BT_SIZE,
-			  BT_PTR, BT_PTR, BT_PTR, BT_INT, BT_INT, BT_INT,
-			  BT_INT, BT_INT)
-
 DEF_POINTER_TYPE (BT_PTR_FN_VOID_VAR, BT_FN_VOID_VAR)
 DEF_FUNCTION_TYPE_3 (BT_FN_PTR_PTR_FN_VOID_VAR_PTR_SIZE,
 		     BT_PTR, BT_PTR_FN_VOID_VAR, BT_PTR, BT_SIZE)
Index: gcc/tree.h
===================================================================
--- gcc/tree.h	(revision 227862)
+++ gcc/tree.h	(working copy)
@@ -1369,6 +1370,8 @@  extern void protected_set_expr_location
   OMP_CLAUSE_OPERAND (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_SCHEDULE), 0)
 
 /* OpenACC clause expressions  */
+#define OMP_CLAUSE_EXPR(NODE, CLAUSE) \
+  OMP_CLAUSE_OPERAND (OMP_CLAUSE_SUBCODE_CHECK (NODE, CLAUSE), 0)
 #define OMP_CLAUSE_GANG_EXPR(NODE) \
   OMP_CLAUSE_OPERAND ( \
     OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_GANG), 0)
Index: gcc/omp-builtins.def
===================================================================
--- gcc/omp-builtins.def	(revision 227862)
+++ gcc/omp-builtins.def	(working copy)
@@ -38,8 +38,8 @@  DEF_GOACC_BUILTIN (BUILT_IN_GOACC_DATA_E
 DEF_GOACC_BUILTIN (BUILT_IN_GOACC_ENTER_EXIT_DATA, "GOACC_enter_exit_data",
 		   BT_FN_VOID_INT_SIZE_PTR_PTR_PTR_INT_INT_VAR,
 		   ATTR_NOTHROW_LIST)
-DEF_GOACC_BUILTIN (BUILT_IN_GOACC_PARALLEL, "GOACC_parallel",
-		   BT_FN_VOID_INT_OMPFN_SIZE_PTR_PTR_PTR_INT_INT_INT_INT_INT_VAR,
+DEF_GOACC_BUILTIN (BUILT_IN_GOACC_PARALLEL, "GOACC_parallel_keyed",
+		   BT_FN_VOID_INT_OMPFN_SIZE_PTR_PTR_PTR_VAR,
 		   ATTR_NOTHROW_LIST)
 DEF_GOACC_BUILTIN (BUILT_IN_GOACC_UPDATE, "GOACC_update",
 		   BT_FN_VOID_INT_SIZE_PTR_PTR_PTR_INT_INT_VAR,
Index: gcc/lto/lto-lang.c
===================================================================
--- gcc/lto/lto-lang.c	(revision 227862)
+++ gcc/lto/lto-lang.c	(working copy)
@@ -160,10 +160,10 @@  enum lto_builtin_type
 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \
 				NAME,
+#define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				 ARG6) NAME,
 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
 				ARG6, ARG7) NAME,
-#define DEF_FUNCTION_TYPE_VAR_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
 #include "builtin-types.def"
 #undef DEF_PRIMITIVE_TYPE
@@ -182,8 +182,8 @@  enum lto_builtin_type
 #undef DEF_FUNCTION_TYPE_VAR_3
 #undef DEF_FUNCTION_TYPE_VAR_4
 #undef DEF_FUNCTION_TYPE_VAR_5
+#undef DEF_FUNCTION_TYPE_VAR_6
 #undef DEF_FUNCTION_TYPE_VAR_7
-#undef DEF_FUNCTION_TYPE_VAR_11
 #undef DEF_POINTER_TYPE
   BT_LAST
 };
@@ -668,13 +668,12 @@  lto_define_builtins (tree va_list_ref_ty
   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
+#define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				 ARG6)	\
+  def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
 				ARG6, ARG7)				\
   def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
-#define DEF_FUNCTION_TYPE_VAR_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11)	\
-  def_fn_type (ENUM, RETURN, 1, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6,	\
-	       ARG7, ARG8, ARG9, ARG10, ARG11);
 #define DEF_POINTER_TYPE(ENUM, TYPE) \
   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
 
@@ -696,8 +695,8 @@  lto_define_builtins (tree va_list_ref_ty
 #undef DEF_FUNCTION_TYPE_VAR_3
 #undef DEF_FUNCTION_TYPE_VAR_4
 #undef DEF_FUNCTION_TYPE_VAR_5
+#undef DEF_FUNCTION_TYPE_VAR_6
 #undef DEF_FUNCTION_TYPE_VAR_7
-#undef DEF_FUNCTION_TYPE_VAR_11
 #undef DEF_POINTER_TYPE
   builtin_types[(int) BT_LAST] = NULL_TREE;
 
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c	(revision 227862)
+++ gcc/c-family/c-common.c	(working copy)
@@ -5545,10 +5545,10 @@  enum c_builtin_type
 #define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME,
 #define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
 				NAME,
+#define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				ARG6) NAME,
 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
 				ARG6, ARG7) NAME,
-#define DEF_FUNCTION_TYPE_VAR_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
 #include "builtin-types.def"
 #undef DEF_PRIMITIVE_TYPE
@@ -5567,8 +5567,8 @@  enum c_builtin_type
 #undef DEF_FUNCTION_TYPE_VAR_3
 #undef DEF_FUNCTION_TYPE_VAR_4
 #undef DEF_FUNCTION_TYPE_VAR_5
+#undef DEF_FUNCTION_TYPE_VAR_6
 #undef DEF_FUNCTION_TYPE_VAR_7
-#undef DEF_FUNCTION_TYPE_VAR_11
 #undef DEF_POINTER_TYPE
   BT_LAST
 };
@@ -5661,13 +5661,12 @@  c_define_builtins (tree va_list_ref_type
   def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4);
 #define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \
   def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5);
+#define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				ARG6) \
+  def_fn_type (ENUM, RETURN, 1, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6);
 #define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
 				ARG6, ARG7)				\
   def_fn_type (ENUM, RETURN, 1, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7);
-#define DEF_FUNCTION_TYPE_VAR_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) \
-  def_fn_type (ENUM, RETURN, 1, 11, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6,      \
-	       ARG7, ARG8, ARG9, ARG10, ARG11);
 #define DEF_POINTER_TYPE(ENUM, TYPE) \
   builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]);
 
@@ -5689,8 +5688,8 @@  c_define_builtins (tree va_list_ref_type
 #undef DEF_FUNCTION_TYPE_VAR_3
 #undef DEF_FUNCTION_TYPE_VAR_4
 #undef DEF_FUNCTION_TYPE_VAR_5
+#undef DEF_FUNCTION_TYPE_VAR_6
 #undef DEF_FUNCTION_TYPE_VAR_7
-#undef DEF_FUNCTION_TYPE_VAR_11
 #undef DEF_POINTER_TYPE
   builtin_types[(int) BT_LAST] = NULL_TREE;
 
Index: gcc/fortran/f95-lang.c
===================================================================
--- gcc/fortran/f95-lang.c	(revision 227862)
+++ gcc/fortran/f95-lang.c	(working copy)
@@ -635,10 +635,10 @@  gfc_init_builtin_functions (void)
 			    ARG6, ARG7, ARG8) NAME,
 #define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME,
 #define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME,
+#define DEF_FUNCTION_TYPE_VAR_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				 ARG6) NAME,
 #define DEF_FUNCTION_TYPE_VAR_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
 				ARG6, ARG7) NAME,
-#define DEF_FUNCTION_TYPE_VAR_11(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11) NAME,
 #define DEF_POINTER_TYPE(NAME, TYPE) NAME,
 #include "types.def"
 #undef DEF_PRIMITIVE_TYPE
@@ -653,8 +653,8 @@  gfc_init_builtin_functions (void)
 #undef DEF_FUNCTION_TYPE_8
 #undef DEF_FUNCTION_TYPE_VAR_0
 #undef DEF_FUNCTION_TYPE_VAR_2
+#undef DEF_FUNCTION_TYPE_VAR_6
 #undef DEF_FUNCTION_TYPE_VAR_7
-#undef DEF_FUNCTION_TYPE_VAR_11
 #undef DEF_POINTER_TYPE
     BT_LAST
   };
@@ -1096,8 +1096,8 @@  gfc_init_builtin_functions (void)
 					builtin_types[(int) ARG1],     	\
 					builtin_types[(int) ARG2],     	\
 					NULL_TREE);
-#define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				ARG6, ARG7)				\
+#define DEF_FUNCTION_TYPE_VAR_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				ARG6)	\
   builtin_types[(int) ENUM]						\
     = build_varargs_function_type_list (builtin_types[(int) RETURN],   	\
 					builtin_types[(int) ARG1],     	\
@@ -1106,10 +1106,9 @@  gfc_init_builtin_functions (void)
 					builtin_types[(int) ARG4],	\
 					builtin_types[(int) ARG5],	\
 					builtin_types[(int) ARG6],	\
-					builtin_types[(int) ARG7],	\
 					NULL_TREE);
-#define DEF_FUNCTION_TYPE_VAR_11(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
-				 ARG6, ARG7, ARG8, ARG9, ARG10, ARG11)	\
+#define DEF_FUNCTION_TYPE_VAR_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \
+				ARG6, ARG7)				\
   builtin_types[(int) ENUM]						\
     = build_varargs_function_type_list (builtin_types[(int) RETURN],   	\
 					builtin_types[(int) ARG1],     	\
@@ -1119,10 +1118,6 @@  gfc_init_builtin_functions (void)
 					builtin_types[(int) ARG5],	\
 					builtin_types[(int) ARG6],	\
 					builtin_types[(int) ARG7],	\
-					builtin_types[(int) ARG8],	\
-					builtin_types[(int) ARG9],	\
-					builtin_types[(int) ARG10],	\
-					builtin_types[(int) ARG11],	\
 					NULL_TREE);
 #define DEF_POINTER_TYPE(ENUM, TYPE)			\
   builtin_types[(int) ENUM]				\
@@ -1140,8 +1135,8 @@  gfc_init_builtin_functions (void)
 #undef DEF_FUNCTION_TYPE_8
 #undef DEF_FUNCTION_TYPE_VAR_0
 #undef DEF_FUNCTION_TYPE_VAR_2
+#undef DEF_FUNCTION_TYPE_VAR_6
 #undef DEF_FUNCTION_TYPE_VAR_7
-#undef DEF_FUNCTION_TYPE_VAR_11
 #undef DEF_POINTER_TYPE
   builtin_types[(int) BT_LAST] = NULL_TREE;
 
Index: gcc/fortran/types.def
===================================================================
--- gcc/fortran/types.def	(revision 227862)
+++ gcc/fortran/types.def	(working copy)
@@ -219,7 +219,6 @@  DEF_FUNCTION_TYPE_VAR_7 (BT_FN_VOID_INT_
 			 BT_VOID, BT_INT, BT_SIZE, BT_PTR, BT_PTR,
 			 BT_PTR, BT_INT, BT_INT)
 
-DEF_FUNCTION_TYPE_VAR_11 (BT_FN_VOID_INT_OMPFN_SIZE_PTR_PTR_PTR_INT_INT_INT_INT_INT_VAR,
+DEF_FUNCTION_TYPE_VAR_6 (BT_FN_VOID_INT_OMPFN_SIZE_PTR_PTR_PTR_VAR,
 			  BT_VOID, BT_INT, BT_PTR_FN_VOID_PTR, BT_SIZE,
-			  BT_PTR, BT_PTR, BT_PTR, BT_INT, BT_INT, BT_INT,
-			  BT_INT, BT_INT)
+			  BT_PTR, BT_PTR, BT_PTR)