openmp: Do USM transform for omp_target_alloc

OpenMP 5.0 says that omp_target_alloc should return USM addresses.

gcc/ChangeLog:

	* omp-low.c (usm_transform): Transform omp_target_alloc and
	omp_target_free.

libgomp/ChangeLog:

	* testsuite/libgomp.c/usm-6.c: Add omp_target_alloc.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/usm-2.c: Add omp_target_alloc.
	* c-c++-common/gomp/usm-3.c: Add omp_target_alloc.

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 4e8ab9e4ca0..9235eafd1d7 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -15880,7 +15880,8 @@ usm_transform (gimple_stmt_iterator *gsi_p, bool *,
 	    if ((strcmp (name, "malloc") == 0)
 		 || (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)
 		     && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MALLOC)
-		 || DECL_IS_REPLACEABLE_OPERATOR_NEW_P (fndecl))
+		 || DECL_IS_REPLACEABLE_OPERATOR_NEW_P (fndecl)
+		 || strcmp (name, "omp_target_alloc") == 0)
 	      {
 		  tree omp_alloc_type
 		    = build_function_type_list (ptr_type_node, size_type_node,
@@ -15952,7 +15953,8 @@ usm_transform (gimple_stmt_iterator *gsi_p, bool *,
 		       || (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)
 			   && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_FREE)
 		       || (DECL_IS_OPERATOR_DELETE_P (fndecl)
-			   && DECL_IS_REPLACEABLE_OPERATOR (fndecl)))
+			   && DECL_IS_REPLACEABLE_OPERATOR (fndecl))
+		       || strcmp (name, "omp_target_free") == 0)
 	      {
 		tree omp_free_type
 		  = build_function_type_list (void_type_node, ptr_type_node,
diff --git a/gcc/testsuite/c-c++-common/gomp/usm-2.c b/gcc/testsuite/c-c++-common/gomp/usm-2.c
index 64dbb6be131..8c20ef94e69 100644
--- a/gcc/testsuite/c-c++-common/gomp/usm-2.c
+++ b/gcc/testsuite/c-c++-common/gomp/usm-2.c
@@ -12,6 +12,8 @@ void *aligned_alloc (__SIZE_TYPE__, __SIZE_TYPE__);
 void *calloc(__SIZE_TYPE__, __SIZE_TYPE__);
 void *realloc(void *, __SIZE_TYPE__);
 void free (void *);
+void *omp_target_alloc (__SIZE_TYPE__, int);
+void omp_target_free (void *, int);
 
 #ifdef __cplusplus
 }
@@ -24,16 +26,21 @@ foo ()
   void *p2 = realloc(p1, 30);
   void *p3 = calloc(4, 15);
   void *p4 = aligned_alloc(16, 40);
+  void *p5 = omp_target_alloc(50, 1);
   free (p2);
   free (p3);
   free (p4);
+  omp_target_free (p5, 1);
 }
 
 /* { dg-final { scan-tree-dump-times "omp_alloc \\(20, 10\\)" 1 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-times "omp_realloc \\(.*, 30, 10, 10\\)" 1 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-times "omp_calloc \\(4, 15, 10\\)" 1 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-times "omp_aligned_alloc \\(16, 40, 10\\)" 1 "usm_transform"  } } */
-/* { dg-final { scan-tree-dump-times "omp_free" 3 "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-times "omp_alloc \\(50, 10\\)" 1 "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-times "omp_free" 4 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-not " free"  "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-not " aligned_alloc"  "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-not " malloc"  "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-not " omp_target_alloc"  "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-not " omp_target_free"  "usm_transform"  } } */
diff --git a/gcc/testsuite/c-c++-common/gomp/usm-3.c b/gcc/testsuite/c-c++-common/gomp/usm-3.c
index 934582ea5fd..2b0cbb45e27 100644
--- a/gcc/testsuite/c-c++-common/gomp/usm-3.c
+++ b/gcc/testsuite/c-c++-common/gomp/usm-3.c
@@ -10,6 +10,8 @@ void *aligned_alloc (__SIZE_TYPE__, __SIZE_TYPE__);
 void *calloc(__SIZE_TYPE__, __SIZE_TYPE__);
 void *realloc(void *, __SIZE_TYPE__);
 void free (void *);
+void *omp_target_alloc (__SIZE_TYPE__, int);
+void omp_target_free (void *, int);
 
 #ifdef __cplusplus
 }
@@ -22,16 +24,21 @@ foo ()
   void *p2 = realloc(p1, 30);
   void *p3 = calloc(4, 15);
   void *p4 = aligned_alloc(16, 40);
+  void *p5 = omp_target_alloc(50, 1);
   free (p2);
   free (p3);
   free (p4);
+  omp_target_free (p5, 1);
 }
 
 /* { dg-final { scan-tree-dump-times "omp_alloc \\(20, 10\\)" 1 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-times "omp_realloc \\(.*, 30, 10, 10\\)" 1 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-times "omp_calloc \\(4, 15, 10\\)" 1 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-times "omp_aligned_alloc \\(16, 40, 10\\)" 1 "usm_transform"  } } */
-/* { dg-final { scan-tree-dump-times "omp_free" 3 "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-times "omp_alloc \\(50, 10\\)" 1 "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-times "omp_free" 4 "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-not " free"  "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-not " aligned_alloc"  "usm_transform"  } } */
 /* { dg-final { scan-tree-dump-not " malloc"  "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-not " omp_target_alloc"  "usm_transform"  } } */
+/* { dg-final { scan-tree-dump-not " omp_target_free"  "usm_transform"  } } */
diff --git a/libgomp/testsuite/libgomp.c/usm-6.c b/libgomp/testsuite/libgomp.c/usm-6.c
index d2c828fdc9d..c207140092a 100644
--- a/libgomp/testsuite/libgomp.c/usm-6.c
+++ b/libgomp/testsuite/libgomp.c/usm-6.c
@@ -4,6 +4,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#include <omp.h>
+
 /* On old systems, the declaraition may not be present in stdlib.h which
    will generate a warning.  This function is going to be replaced with
    omp_aligned_alloc so the purpose of this declaration is to avoid that
@@ -19,7 +21,8 @@ main ()
   int *b = (int *) calloc(sizeof(int), 3);
   int *c = (int *) realloc(NULL, sizeof(int) * 4);
   int *d = (int *) aligned_alloc(32, sizeof(int));
-  if (!a || !b || !c || !d)
+  int *e = (int *) omp_target_alloc(sizeof(int), 1);
+  if (!a || !b || !c || !d || !e)
     __builtin_abort ();
 
   a[0] = 42;
@@ -36,6 +39,7 @@ main ()
   uintptr_t b_p = (uintptr_t)b;
   uintptr_t c_p = (uintptr_t)c;
   uintptr_t d_p = (uintptr_t)d;
+  uintptr_t e_p = (uintptr_t)e;
 
   if (d_p & 31 != 0)
     __builtin_abort ();
@@ -52,9 +56,12 @@ main ()
 	__builtin_abort ();
       if (d_p != (uintptr_t)d)
 	__builtin_abort ();
+      if (e_p != (uintptr_t)e)
+	__builtin_abort ();
       a[0] = 72;
       b[0] = 82;
       c[0] = 92;
+      e[0] = 102;
     }
 
 #pragma omp target
@@ -74,10 +81,12 @@ main ()
 
   if (a[0] != 72 || a[1] != 73
       || b[0] != 82 || b[1] != 83
-      || c[0] != 92 || c[1] != 93)
+      || c[0] != 92 || c[1] != 93
+      || e[0] != 102)
 	__builtin_abort ();
   free(a);
   free(b);
   free(c);
+  omp_target_free(e, 1);
   return 0;
 }