OpenACC – support "if" + "if_present" clauses with "host_data"

2020-01-10  Gergö Barany  <gergo@codesourcery.com>
	    Thomas Schwinge <thomas@codesourcery.com>
	    Julian Brown  <julian@codesourcery.com>
	    Tobias Burnus  <tobias@codesourcery.com>

        gcc/c/
        * c-parser.c (OACC_HOST_DATA_CLAUSE_MASK): Add PRAGMA_OACC_CLAUSE_IF
        and PRAGMA_OACC_CLAUSE_IF_PRESENT.

        gcc/cp/
        * parser.c (OACC_HOST_DATA_CLAUSE_MASK): Add PRAGMA_OACC_CLAUSE_IF
        and PRAGMA_OACC_CLAUSE_IF_PRESENT.

        gcc/fortran/
        * openmp.c (OACC_HOST_DATA_CLAUSES): Add PRAGMA_OACC_CLAUSE_IF
        and PRAGMA_OACC_CLAUSE_IF_PRESENT.

	gcc/
	* omp-low.c (lower_omp_target): Use GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT
	if PRAGMA_OACC_CLAUSE_IF_PRESENT exist.

	gcc/testsuite/
	* c-c++-common/goacc/host_data-1.c: Added tests of if and if_present
	clauses on host_data.
	* gfortran.dg/goacc/host_data-tree.f95: Likewise.

	include/
	* gomp-constants.h (enum gomp_map_kind): New enumeration constant
	GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT.
        
	libgomp/
	* oacc-parallel.c (GOACC_data_start): Handle
	GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT.
	* target.c (gomp_map_vars_async): Likewise.
	* testsuite/libgomp.oacc-c-c++-common/host_data-7.c: New.
	* testsuite/libgomp.oacc-fortran/host_data-5.F90: New.

From-SVN: r280115

4 files changed, 173 insertions, 2 deletions

diff --git a/libgomp/oacc-parallel.c b/libgomp/oacc-parallel.c
index edfc6067ee9..c7e46e35bd6 100644
--- a/libgomp/oacc-parallel.c
+++ b/libgomp/oacc-parallel.c
@@ -415,7 +415,8 @@ GOACC_data_start (int flags_m, size_t mapnum,
 	= _ACC_OTHER_EVENT_INFO_VALID_BYTES;
       enter_data_event_info.other_event.parent_construct = acc_construct_data;
       for (int i = 0; i < mapnum; ++i)
-	if ((kinds[i] & 0xff) == GOMP_MAP_USE_DEVICE_PTR)
+	if ((kinds[i] & 0xff) == GOMP_MAP_USE_DEVICE_PTR
+	    || (kinds[i] & 0xff) == GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT)
 	  {
 	    /* If there is one such data mapping kind, then this is actually an
 	       OpenACC 'host_data' construct.  (GCC maps the OpenACC
diff --git a/libgomp/target.c b/libgomp/target.c
index 617baec8b40..522b69e6d5d 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -720,7 +720,8 @@ gomp_map_vars_internal (struct gomp_device_descr *devicep,
 	  tgt->list[i].offset = OFFSET_INLINED;
 	  continue;
 	}
-      else if ((kind & typemask) == GOMP_MAP_USE_DEVICE_PTR)
+      else if ((kind & typemask) == GOMP_MAP_USE_DEVICE_PTR
+	       || (kind & typemask) == GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT)
 	{
 	  tgt->list[i].key = NULL;
 	  if (!not_found_cnt)
@@ -741,6 +742,12 @@ gomp_map_vars_internal (struct gomp_device_descr *devicep,
 	      splay_tree_key n = gomp_map_lookup (mem_map, &cur_node);
 	      if (n == NULL)
 		{
+		  if ((kind & typemask) == GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT)
+		    {
+		      /* If not present, continue using the host address.  */
+		      tgt->list[i].offset = 0;
+		      continue;
+		    }
 		  gomp_mutex_unlock (&devicep->lock);
 		  gomp_fatal ("use_device_ptr pointer wasn't mapped");
 		}
@@ -974,6 +981,7 @@ gomp_map_vars_internal (struct gomp_device_descr *devicep,
 	      case GOMP_MAP_ZERO_LEN_ARRAY_SECTION:
 		continue;
 	      case GOMP_MAP_USE_DEVICE_PTR:
+	      case GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT:
 		if (tgt->list[i].offset == 0)
 		  {
 		    cur_node.host_start = (uintptr_t) hostaddrs[i];
@@ -981,6 +989,10 @@ gomp_map_vars_internal (struct gomp_device_descr *devicep,
 		    n = gomp_map_lookup (mem_map, &cur_node);
 		    if (n == NULL)
 		      {
+			if ((kind & typemask)
+			    == GOMP_MAP_USE_DEVICE_PTR_IF_PRESENT)
+			  /* If not present, continue using the host address.  */
+			  continue;
 			gomp_mutex_unlock (&devicep->lock);
 			gomp_fatal ("use_device_ptr pointer wasn't mapped");
 		      }
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/host_data-7.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/host_data-7.c
new file mode 100644
index 00000000000..6830ef1e7ed
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/host_data-7.c
@@ -0,0 +1,66 @@
+/* { dg-do run } */
+
+/* Test if, if_present clauses on host_data construct.  */
+/* C/C++ variant of 'libgomp.oacc-fortran/host_data-5.F90' */
+
+#include <assert.h>
+#include <stdint.h>
+
+void
+foo (float *p, intptr_t host_p, int cond)
+{
+  assert (p == (float *) host_p);
+
+#pragma acc data copyin(host_p)
+  {
+#pragma acc host_data use_device(p) if_present
+    /* p not mapped yet, so it will be equal to the host pointer.  */
+    assert (p == (float *) host_p);
+
+#pragma acc data copy(p[0:100])
+    {
+      /* Not inside a host_data construct, so p is still the host pointer.  */
+      assert (p == (float *) host_p);
+
+#pragma acc host_data use_device(p)
+      {
+#if ACC_MEM_SHARED
+	assert (p == (float *) host_p);
+#else
+	/* The device address is different from host address.  */
+	assert (p != (float *) host_p);
+#endif
+      }
+
+#pragma acc host_data use_device(p) if_present
+      {
+#if ACC_MEM_SHARED
+	assert (p == (float *) host_p);
+#else
+	/* p is present now, so this is the same as above.  */
+	assert (p != (float *) host_p);
+#endif
+      }
+
+#pragma acc host_data use_device(p) if(cond)
+      {
+#if ACC_MEM_SHARED
+	assert (p == (float *) host_p);
+#else
+	/* p is the device pointer iff cond is true.  */
+	assert ((p != (float *) host_p) == cond);
+#endif
+      }
+    }
+  }
+}
+
+int
+main (void)
+{
+  float arr[100];
+  foo (arr, (intptr_t) arr, 0);
+  foo (arr, (intptr_t) arr, 1);
+
+  return 0;
+}
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90 b/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90
new file mode 100644
index 00000000000..483ac3fb668
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90
@@ -0,0 +1,92 @@
+! { dg-do run }
+!
+! Test if, if_present clauses on host_data construct.
+!
+! Fortran variant of 'libgomp.oacc-c-c++-common/host_data-7.c'.
+!
+program main
+  use iso_c_binding
+  implicit none
+  real, target :: var, arr(100)
+  integer(c_intptr_t) :: host_p, host_parr
+  host_p = transfer(c_loc(var), host_p)
+  host_parr = transfer(c_loc(arr), host_parr)
+  call foo (var, arr, host_p, host_parr, .false.)
+  call foo (var, arr, host_p, host_parr, .true.)
+
+contains
+
+subroutine foo (p2, parr, host_p, host_parr, cond)
+  use openacc
+  implicit none
+  real, target, intent(in) :: parr(:), p2
+  integer(c_intptr_t), value, intent(in) :: host_p, host_parr
+  logical, value, intent(in) :: cond
+  real, pointer :: p
+  p => p2
+
+  if (host_p /= transfer(c_loc(p), host_p)) stop 1
+  if (host_parr /= transfer(c_loc(parr), host_parr)) stop 2
+#if !ACC_MEM_SHARED
+  if (acc_is_present(p, c_sizeof(p))) stop 3
+  if (acc_is_present(parr, 1)) stop 4
+#endif
+  
+  !$acc data copyin(host_p, host_parr)
+#if !ACC_MEM_SHARED
+    if (acc_is_present(p, c_sizeof(p))) stop 5
+    if (acc_is_present(parr, 1)) stop 6
+#endif
+    !$acc host_data use_device(p, parr) if_present
+      ! not mapped yet, so it will be equal to the host pointer.
+      if (transfer(c_loc(p), host_p) /= host_p) stop 7
+      if (transfer(c_loc(parr), host_parr) /= host_parr) stop 8
+    !$acc end host_data
+#if !ACC_MEM_SHARED
+    if (acc_is_present(p, c_sizeof(p))) stop 9
+    if (acc_is_present(parr, 1)) stop 10
+#endif
+
+    !$acc data copy(p, parr)
+      if (.not. acc_is_present(p, c_sizeof(p))) stop 11
+      if (.not. acc_is_present(parr, 1)) stop 12
+      ! Not inside a host_data construct, so still the host pointer.
+      if (transfer(c_loc(p), host_p) /= host_p) stop 13
+      if (transfer(c_loc(parr), host_parr) /= host_parr) stop 14
+      
+      !$acc host_data use_device(p, parr)
+#if ACC_MEM_SHARED
+        if (transfer(c_loc(p), host_p) /= host_p) stop 15
+        if (transfer(c_loc(parr), host_parr) /= host_parr) stop 16
+#else
+        ! The device address is different from host address.
+        if (transfer(c_loc(p), host_p) == host_p) stop 17
+        if (transfer(c_loc(parr), host_parr) == host_parr) stop 18
+#endif
+      !$acc end host_data
+
+      !$acc host_data use_device(p, parr) if_present
+#if ACC_MEM_SHARED
+        if (transfer(c_loc(p), host_p) /= host_p) stop 19
+        if (transfer(c_loc(parr), host_parr) /= host_parr) stop 20
+#else
+        ! is present now, so this is the same as above.
+        if (transfer(c_loc(p), host_p) == host_p) stop 21
+        if (transfer(c_loc(parr), host_parr) == host_parr) stop 22
+#endif
+      !$acc end host_data
+
+      !$acc host_data use_device(p, parr) if(cond)
+#if ACC_MEM_SHARED
+        if (transfer(c_loc(p), host_p) /= host_p) stop 23
+        if (transfer(c_loc(parr), host_parr) /= host_parr) stop 24
+#else
+        ! is the device pointer iff cond is true.
+        if ((transfer(c_loc(p), host_p) /= host_p) .neqv. cond) stop 25
+        if ((transfer(c_loc(parr), host_parr) /= host_parr) .neqv. cond) stop 26
+#endif
+      !$acc end host_data
+    !$acc end data
+  !$acc end data
+end subroutine foo
+end