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From: Chung-Lin Tang <cltang@pllab.cs.nthu.edu.tw>
To: Thomas Schwinge <tschwinge@baylibre.com>,
	Tobias Burnus <tburnus@baylibre.com>,
	Chung-Lin Tang <cltang@baylibre.com>
Cc: gcc-patches@gcc.gnu.org, fortran@gcc.gnu.org
Subject: Re: [PATCH, OpenACC 2.7, v2] readonly modifier support in front-ends
Date: Thu, 7 Mar 2024 17:02:02 +0900	[thread overview]
Message-ID: <2f568f7d-807b-41d1-befb-40039e2edb74@pllab.cs.nthu.edu.tw> (raw)
In-Reply-To: <87ttqd7m8e.fsf@euler.schwinge.homeip.net>

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Hi Thomas, Tobias,

On 2023/10/26 6:43 PM, Thomas Schwinge wrote:
>>>>> +++ b/gcc/tree.h
>>>>> @@ -1813,6 +1813,14 @@ class auto_suppress_location_wrappers
>>>>>   #define OMP_CLAUSE_MAP_DECL_MAKE_ADDRESSABLE(NODE) \
>>>>>     (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_MAP)->base.addressable_flag)
>>>>>
>>>>> +/* Nonzero if OpenACC 'readonly' modifier set, used for 'copyin'.  */
>>>>> +#define OMP_CLAUSE_MAP_READONLY(NODE) \
>>>>> +  TREE_READONLY (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_MAP))
>>>>> +
>>>>> +/* Same as above, for use in OpenACC cache directives.  */
>>>>> +#define OMP_CLAUSE__CACHE__READONLY(NODE) \
>>>>> +  TREE_READONLY (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE__CACHE_))
>>>> I'm not sure if these special accessor functions are actually useful, or
>>>> we should just directly use 'TREE_READONLY' instead?  We're only using
>>>> them in contexts where it's clear that the 'OMP_CLAUSE_SUBCODE_CHECK' is
>>>> satisfied, for example.
>>> I find directly using TREE_READONLY confusing.
>>
>> FWIW, I've changed to use TREE_NOTHROW instead, if it can give a better sense of safety :P
> 
> I don't understand that, why not use 'TREE_READONLY'?
> 
>> I think there's a misunderstanding here anyways: we are not relying on a DECL marked
>> TREE_READONLY here. We merely need the OMP_CLAUSE_MAP to be marked as OMP_CLAUSE_MAP_READONLY == 1.
> 
> Yes, I understand that.  My question was why we don't just use
> 'TREE_READONLY (c)', where 'c' is the
> 'OMP_CLAUSE_MAP'/'OMP_CLAUSE__CACHE_' clause (not its decl), and avoid
> the indirection through
> '#define OMP_CLAUSE_MAP_READONLY'/'#define OMP_CLAUSE__CACHE__READONLY',
> given that we're only using them in contexts where it's clear that the
> 'OMP_CLAUSE_SUBCODE_CHECK' is satisfied.  I don't have a strong
> preference, though.

After further re-testing using TREE_NOTHROW, I have reverted to using TREE_READONLY, because TREE_NOTHROW clashes
with OMP_CLAUSE_RELEASE_DESCRIPTOR (which doesn't use the OMP_CLAUSE_MAP_* naming convention and is
not documented in gcc/tree-core.h either, hmmm...)

I have added the comment adjustments in gcc/tree-core.h for the new uses of TREE_READONLY/readonly_flag.

We basically all use OMP_CLAUSE_SUBCODE_CHECK macros for OpenMP clause expressions exclusively,
so I don't see a reason to diverge from that style (even when context is clear).

> Either way, you still need to document this:
> 
> | Also, for the new use for OMP clauses, update 'gcc/tree.h:TREE_READONLY',
> | and in 'gcc/tree-core.h' for 'readonly_flag' the
> | "table lists the uses of each of the above flags".

Okay, done as mentioned above.

> In addition to a few individual comments above and below, you've also not
> yet responded to my requests re test cases.

I have greatly expanded the test scan patterns to include parallel/kernels/serial/data/enter data,
as well as non-readonly copyin clause together with readonly.

Also added simple 'declare' tests, but there is not anything to scan in the 'tree-original' dump though.

>> +  tree nl = list;
>> +  bool readonly = false;
>> +  matching_parens parens;
>> +  if (parens.require_open (parser))
>> +    {
>> +      /* Turn on readonly modifier parsing for copyin clause.  */
>> +      if (c_kind == PRAGMA_OACC_CLAUSE_COPYIN)
>> +     {
>> +       c_token *token = c_parser_peek_token (parser);
>> +       if (token->type == CPP_NAME
>> +           && !strcmp (IDENTIFIER_POINTER (token->value), "readonly")
>> +           && c_parser_peek_2nd_token (parser)->type == CPP_COLON)
>> +         {
>> +           c_parser_consume_token (parser);
>> +           c_parser_consume_token (parser);
>> +           readonly = true;
>> +         }
>> +     }
>> +      location_t loc = c_parser_peek_token (parser)->location;
> 
> I suppose 'loc' here now points to after the opening '(' or after the
> 'readonly :'?  This is different from what 'c_parser_omp_var_list_parens'
> does, and indeed, 'c_parser_omp_variable_list' states that "CLAUSE_LOC is
> the location of the clause", not the location of the variable-list?  As
> this, I suppose, may change diagnostics, please restore the original
> behavior.  (This appears to be different in the C++ front end, huh.)

Thanks for catching this! Fixed.

>> --- a/gcc/fortran/openmp.cc
>> +++ b/gcc/fortran/openmp.cc
>> @@ -1197,7 +1197,7 @@ omp_inv_mask::omp_inv_mask (const omp_mask &m) : omp_mask (m)
>>
>>  static bool
>>  gfc_match_omp_map_clause (gfc_omp_namelist **list, gfc_omp_map_op map_op,
>> -                       bool allow_common, bool allow_derived)
>> +                       bool allow_common, bool allow_derived, bool readonly = false)
>>  {
>>    gfc_omp_namelist **head = NULL;
>>    if (gfc_match_omp_variable_list ("", list, allow_common, NULL, &head, true,
>> @@ -1206,7 +1206,10 @@ gfc_match_omp_map_clause (gfc_omp_namelist **list, gfc_omp_map_op map_op,
>>      {
>>        gfc_omp_namelist *n;
>>        for (n = *head; n; n = n->next)
>> -     n->u.map_op = map_op;
>> +     {
>> +       n->u.map.op = map_op;
>> +       n->u.map.readonly = readonly;
>> +     }
>>        return true;
>>      }
> 
> Didn't we conclude that "not doing it here is cleaner" (Tobias' words),
> and instead do this "Similar to 'c_parser_omp_var_list_parens'" (my
> words)?  That is, not add the 'bool readonly' formal parameter to
> 'gfc_match_omp_map_clause'.

Fixed in this v3 patch.

Again, tested on x86_64-linux + nvptx offloading. Okay for mainline?

Thanks,
Chung-Lin

gcc/c/ChangeLog:

	* c-parser.cc (c_parser_oacc_data_clause): Add parsing support for
	'readonly' modifier, set OMP_CLAUSE_MAP_READONLY if readonly modifier
	found, update comments.
	(c_parser_oacc_cache): Add parsing support for 'readonly' modifier,
	set OMP_CLAUSE__CACHE__READONLY if readonly modifier found, update
	comments.

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_oacc_data_clause): Add parsing support for
	'readonly' modifier, set OMP_CLAUSE_MAP_READONLY if readonly modifier
	found, update comments.
	(cp_parser_oacc_cache): Add parsing support for 'readonly' modifier,
	set OMP_CLAUSE__CACHE__READONLY if readonly modifier found, update
	comments.

gcc/fortran/ChangeLog:

	* dump-parse-tree.cc (show_omp_namelist): Print "readonly," for
	OMP_LIST_MAP and OMP_LIST_CACHE if n->u.map.readonly is set.
	Adjust 'n->u.map_op' to 'n->u.map.op'.
	* gfortran.h (typedef struct gfc_omp_namelist): Adjust map_op as
	'ENUM_BITFIELD (gfc_omp_map_op) op:8', add 'bool readonly' field,
	change to named struct field 'map'.

	* openmp.cc (gfc_match_omp_map_clause): Adjust 'n->u.map_op' to
	'n->u.map.op'.
	(gfc_match_omp_clause_reduction): Likewise.

	(gfc_match_omp_clauses): Add readonly modifier parsing for OpenACC
	copyin clause, set 'n->u.map.op' and 'n->u.map.readonly' for parsed
	clause. Adjust 'n->u.map_op' to 'n->u.map.op'.
	(gfc_match_oacc_declare): Adjust 'n->u.map_op' to 'n->u.map.op'.
	(gfc_match_oacc_cache): Add readonly modifier parsing for OpenACC
	cache directive.
	(resolve_omp_clauses): Adjust 'n->u.map_op' to 'n->u.map.op'.
	* trans-decl.cc (add_clause): Adjust 'n->u.map_op' to 'n->u.map.op'.
	(finish_oacc_declare): Likewise.
	* trans-openmp.cc (gfc_trans_omp_clauses): Set OMP_CLAUSE_MAP_READONLY,
	OMP_CLAUSE__CACHE__READONLY to 1 when readonly is set. Adjust
	'n->u.map_op' to 'n->u.map.op'.
	(gfc_add_clause_implicitly): Adjust 'n->u.map_op' to 'n->u.map.op'.

gcc/ChangeLog:
	* tree.h (OMP_CLAUSE_MAP_READONLY): New macro.
	(OMP_CLAUSE__CACHE__READONLY): New macro.
	* tree-core.h (struct GTY(()) tree_base): Adjust comments for new
	uses of readonly_flag bit in OMP_CLAUSE_MAP_READONLY and
	OMP_CLAUSE__CACHE__READONLY.
	* tree-pretty-print.cc (dump_omp_clause): Add support for printing
	OMP_CLAUSE_MAP_READONLY and OMP_CLAUSE__CACHE__READONLY.

gcc/testsuite/ChangeLog:

	* c-c++-common/goacc/readonly-1.c: New test.
	* gfortran.dg/goacc/readonly-1.f90: New test.






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diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 53e99aa29d9..00f8bf4376e 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -15627,7 +15627,11 @@ c_parser_omp_var_list_parens (c_parser *parser, enum omp_clause_code kind,
    OpenACC 2.6:
    no_create ( variable-list )
    attach ( variable-list )
-   detach ( variable-list ) */
+   detach ( variable-list )
+
+   OpenACC 2.7:
+   copyin (readonly : variable-list )
+ */
 
 static tree
 c_parser_oacc_data_clause (c_parser *parser, pragma_omp_clause c_kind,
@@ -15680,11 +15684,37 @@ c_parser_oacc_data_clause (c_parser *parser, pragma_omp_clause c_kind,
     default:
       gcc_unreachable ();
     }
-  tree nl, c;
-  nl = c_parser_omp_var_list_parens (parser, OMP_CLAUSE_MAP, list, false);
 
-  for (c = nl; c != list; c = OMP_CLAUSE_CHAIN (c))
-    OMP_CLAUSE_SET_MAP_KIND (c, kind);
+  tree nl = list;
+  bool readonly = false;
+  location_t open_loc = c_parser_peek_token (parser)->location;
+  matching_parens parens;
+  if (parens.require_open (parser))
+    {
+      /* Turn on readonly modifier parsing for copyin clause.  */
+      if (c_kind == PRAGMA_OACC_CLAUSE_COPYIN)
+	{
+	  c_token *token = c_parser_peek_token (parser);
+	  if (token->type == CPP_NAME
+	      && !strcmp (IDENTIFIER_POINTER (token->value), "readonly")
+	      && c_parser_peek_2nd_token (parser)->type == CPP_COLON)
+	    {
+	      c_parser_consume_token (parser);
+	      c_parser_consume_token (parser);
+	      readonly = true;
+	    }
+	}
+      nl = c_parser_omp_variable_list (parser, open_loc, OMP_CLAUSE_MAP, list,
+				       false);
+      parens.skip_until_found_close (parser);
+    }
+
+  for (tree c = nl; c != list; c = OMP_CLAUSE_CHAIN (c))
+    {
+      OMP_CLAUSE_SET_MAP_KIND (c, kind);
+      if (readonly)
+	OMP_CLAUSE_MAP_READONLY (c) = 1;
+    }
 
   return nl;
 }
@@ -19821,15 +19851,39 @@ c_parser_omp_structured_block (c_parser *parser, bool *if_p)
 /* OpenACC 2.0:
    # pragma acc cache (variable-list) new-line
 
+   OpenACC 2.7:
+   # pragma acc cache (readonly: variable-list) new-line
+
    LOC is the location of the #pragma token.
 */
 
 static tree
 c_parser_oacc_cache (location_t loc, c_parser *parser)
 {
-  tree stmt, clauses;
+  tree stmt, clauses = NULL_TREE;
+  bool readonly = false;
+  location_t open_loc = c_parser_peek_token (parser)->location;
+  matching_parens parens;
+  if (parens.require_open (parser))
+    {
+      c_token *token = c_parser_peek_token (parser);
+      if (token->type == CPP_NAME
+	  && !strcmp (IDENTIFIER_POINTER (token->value), "readonly")
+	  && c_parser_peek_2nd_token (parser)->type == CPP_COLON)
+	{
+	  c_parser_consume_token (parser);
+	  c_parser_consume_token (parser);
+	  readonly = true;
+	}
+      clauses = c_parser_omp_variable_list (parser, open_loc,
+					    OMP_CLAUSE__CACHE_, NULL_TREE);
+      parens.skip_until_found_close (parser);
+    }
+
+  if (readonly)
+    for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
+      OMP_CLAUSE__CACHE__READONLY (c) = 1;
 
-  clauses = c_parser_omp_var_list_parens (parser, OMP_CLAUSE__CACHE_, NULL);
   clauses = c_finish_omp_clauses (clauses, C_ORT_ACC);
 
   c_parser_skip_to_pragma_eol (parser);
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index e32acfc30a2..4fe27fb07b2 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -38544,7 +38544,11 @@ cp_parser_omp_var_list (cp_parser *parser, enum omp_clause_code kind, tree list,
    OpenACC 2.6:
    no_create ( variable-list )
    attach ( variable-list )
-   detach ( variable-list ) */
+   detach ( variable-list )
+
+   OpenACC 2.7:
+   copyin (readonly : variable-list )
+ */
 
 static tree
 cp_parser_oacc_data_clause (cp_parser *parser, pragma_omp_clause c_kind,
@@ -38597,11 +38601,34 @@ cp_parser_oacc_data_clause (cp_parser *parser, pragma_omp_clause c_kind,
     default:
       gcc_unreachable ();
     }
-  tree nl, c;
-  nl = cp_parser_omp_var_list (parser, OMP_CLAUSE_MAP, list, false);
 
-  for (c = nl; c != list; c = OMP_CLAUSE_CHAIN (c))
-    OMP_CLAUSE_SET_MAP_KIND (c, kind);
+  tree nl = list;
+  bool readonly = false;
+  if (cp_parser_require (parser, CPP_OPEN_PAREN, RT_OPEN_PAREN))
+    {
+      /* Turn on readonly modifier parsing for copyin clause.  */
+      if (c_kind == PRAGMA_OACC_CLAUSE_COPYIN)
+	{
+	  cp_token *token = cp_lexer_peek_token (parser->lexer);
+	  if (token->type == CPP_NAME
+	      && !strcmp (IDENTIFIER_POINTER (token->u.value), "readonly")
+	      && cp_lexer_peek_nth_token (parser->lexer, 2)->type == CPP_COLON)
+	    {
+	      cp_lexer_consume_token (parser->lexer);
+	      cp_lexer_consume_token (parser->lexer);
+	      readonly = true;
+	    }
+	}
+      nl = cp_parser_omp_var_list_no_open (parser, OMP_CLAUSE_MAP, list, NULL,
+					   false);
+    }
+
+  for (tree c = nl; c != list; c = OMP_CLAUSE_CHAIN (c))
+    {
+      OMP_CLAUSE_SET_MAP_KIND (c, kind);
+      if (readonly)
+	OMP_CLAUSE_MAP_READONLY (c) = 1;
+    }
 
   return nl;
 }
@@ -47178,6 +47205,9 @@ cp_parser_omp_target (cp_parser *parser, cp_token *pragma_tok,
 
 /* OpenACC 2.0:
    # pragma acc cache (variable-list) new-line
+
+   OpenACC 2.7:
+   # pragma acc cache (readonly: variable-list) new-line
 */
 
 static tree
@@ -47187,9 +47217,28 @@ cp_parser_oacc_cache (cp_parser *parser, cp_token *pragma_tok)
      clauses.  */
   auto_suppress_location_wrappers sentinel;
 
-  tree stmt, clauses;
+  tree stmt, clauses = NULL_TREE;
+  bool readonly = false;
+
+  if (cp_parser_require (parser, CPP_OPEN_PAREN, RT_OPEN_PAREN))
+    {
+      cp_token *token = cp_lexer_peek_token (parser->lexer);
+      if (token->type == CPP_NAME
+	  && !strcmp (IDENTIFIER_POINTER (token->u.value), "readonly")
+	  && cp_lexer_peek_nth_token (parser->lexer, 2)->type == CPP_COLON)
+	{
+	  cp_lexer_consume_token (parser->lexer);
+	  cp_lexer_consume_token (parser->lexer);
+	  readonly = true;
+	}
+      clauses = cp_parser_omp_var_list_no_open (parser, OMP_CLAUSE__CACHE_,
+						NULL, NULL);
+    }
+
+  if (readonly)
+    for (tree c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
+      OMP_CLAUSE__CACHE__READONLY (c) = 1;
 
-  clauses = cp_parser_omp_var_list (parser, OMP_CLAUSE__CACHE_, NULL_TREE);
   clauses = finish_omp_clauses (clauses, C_ORT_ACC);
 
   cp_parser_require_pragma_eol (parser, cp_lexer_peek_token (parser->lexer));
diff --git a/gcc/fortran/dump-parse-tree.cc b/gcc/fortran/dump-parse-tree.cc
index 7b154eb3ca7..db84b06289b 100644
--- a/gcc/fortran/dump-parse-tree.cc
+++ b/gcc/fortran/dump-parse-tree.cc
@@ -1400,6 +1400,9 @@ show_omp_namelist (int list_type, gfc_omp_namelist *n)
 	    fputs (") ALLOCATE(", dumpfile);
 	  continue;
 	}
+      if ((list_type == OMP_LIST_MAP || list_type == OMP_LIST_CACHE)
+	  && n->u.map.readonly)
+	fputs ("readonly,", dumpfile);
       if (list_type == OMP_LIST_REDUCTION)
 	switch (n->u.reduction_op)
 	  {
@@ -1467,7 +1470,7 @@ show_omp_namelist (int list_type, gfc_omp_namelist *n)
 	  default: break;
 	  }
       else if (list_type == OMP_LIST_MAP)
-	switch (n->u.map_op)
+	switch (n->u.map.op)
 	  {
 	  case OMP_MAP_ALLOC: fputs ("alloc:", dumpfile); break;
 	  case OMP_MAP_TO: fputs ("to:", dumpfile); break;
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index ebba2336e12..32b792f85fb 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -1363,7 +1363,11 @@ typedef struct gfc_omp_namelist
     {
       gfc_omp_reduction_op reduction_op;
       gfc_omp_depend_doacross_op depend_doacross_op;
-      gfc_omp_map_op map_op;
+      struct
+        {
+	  ENUM_BITFIELD (gfc_omp_map_op) op:8;
+	  bool readonly;
+        } map;
       gfc_expr *align;
       struct
 	{
diff --git a/gcc/fortran/openmp.cc b/gcc/fortran/openmp.cc
index 38de60238c0..5c44e666eb9 100644
--- a/gcc/fortran/openmp.cc
+++ b/gcc/fortran/openmp.cc
@@ -1210,7 +1210,7 @@ gfc_match_omp_map_clause (gfc_omp_namelist **list, gfc_omp_map_op map_op,
     {
       gfc_omp_namelist *n;
       for (n = *head; n; n = n->next)
-	n->u.map_op = map_op;
+	n->u.map.op = map_op;
       return true;
     }
 
@@ -1524,7 +1524,7 @@ gfc_match_omp_clause_reduction (char pc, gfc_omp_clauses *c, bool openacc,
 	    gfc_omp_namelist *p = gfc_get_omp_namelist (), **tl;
 	    p->sym = n->sym;
 	    p->where = p->where;
-	    p->u.map_op = OMP_MAP_ALWAYS_TOFROM;
+	    p->u.map.op = OMP_MAP_ALWAYS_TOFROM;
 
 	    tl = &c->lists[OMP_LIST_MAP];
 	    while (*tl)
@@ -2181,11 +2181,25 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
 	    {
 	      if (openacc)
 		{
-		  if (gfc_match ("copyin ( ") == MATCH_YES
-		      && gfc_match_omp_map_clause (&c->lists[OMP_LIST_MAP],
-						   OMP_MAP_TO, true,
-						   allow_derived))
-		    continue;
+		  if (gfc_match ("copyin ( ") == MATCH_YES)
+		    {
+		      bool readonly = gfc_match ("readonly : ") == MATCH_YES;
+		      head = NULL;
+		      if (gfc_match_omp_variable_list ("",
+						       &c->lists[OMP_LIST_MAP],
+						       true, NULL, &head, true,
+						       allow_derived)
+			  == MATCH_YES)
+			{
+			  gfc_omp_namelist *n;
+			  for (n = *head; n; n = n->next)
+			    {
+			      n->u.map.op = OMP_MAP_TO;
+			      n->u.map.readonly = readonly;
+			    }
+			  continue;
+			}
+		    }
 		}
 	      else if (gfc_match_omp_variable_list ("copyin (",
 						    &c->lists[OMP_LIST_COPYIN],
@@ -3134,7 +3148,7 @@ gfc_match_omp_clauses (gfc_omp_clauses **cp, const omp_mask mask,
 		{
 		  gfc_omp_namelist *n;
 		  for (n = *head; n; n = n->next)
-		    n->u.map_op = map_op;
+		    n->u.map.op = map_op;
 		  continue;
 		}
 	      gfc_current_locus = old_loc;
@@ -4002,7 +4016,7 @@ gfc_match_oacc_declare (void)
       if (gfc_current_ns->proc_name
 	  && gfc_current_ns->proc_name->attr.flavor == FL_MODULE)
 	{
-	  if (n->u.map_op != OMP_MAP_ALLOC && n->u.map_op != OMP_MAP_TO)
+	  if (n->u.map.op != OMP_MAP_ALLOC && n->u.map.op != OMP_MAP_TO)
 	    {
 	      gfc_error ("Invalid clause in module with !$ACC DECLARE at %L",
 			 &where);
@@ -4036,7 +4050,7 @@ gfc_match_oacc_declare (void)
 	  return MATCH_ERROR;
 	}
 
-      switch (n->u.map_op)
+      switch (n->u.map.op)
 	{
 	  case OMP_MAP_FORCE_ALLOC:
 	  case OMP_MAP_ALLOC:
@@ -4151,21 +4165,36 @@ gfc_match_oacc_wait (void)
 match
 gfc_match_oacc_cache (void)
 {
+  bool readonly = false;
   gfc_omp_clauses *c = gfc_get_omp_clauses ();
   /* The OpenACC cache directive explicitly only allows "array elements or
      subarrays", which we're currently not checking here.  Either check this
      after the call of gfc_match_omp_variable_list, or add something like a
      only_sections variant next to its allow_sections parameter.  */
-  match m = gfc_match_omp_variable_list (" (",
-					 &c->lists[OMP_LIST_CACHE], true,
-					 NULL, NULL, true);
+  match m = gfc_match (" ( ");
   if (m != MATCH_YES)
     {
       gfc_free_omp_clauses(c);
       return m;
     }
 
-  if (gfc_current_state() != COMP_DO 
+  if (gfc_match ("readonly : ") == MATCH_YES)
+    readonly = true;
+
+  gfc_omp_namelist **head = NULL;
+  m = gfc_match_omp_variable_list ("", &c->lists[OMP_LIST_CACHE], true,
+				   NULL, &head, true);
+  if (m != MATCH_YES)
+    {
+      gfc_free_omp_clauses(c);
+      return m;
+    }
+
+  if (readonly)
+    for (gfc_omp_namelist *n = *head; n; n = n->next)
+      n->u.map.readonly = true;
+
+  if (gfc_current_state() != COMP_DO
       && gfc_current_state() != COMP_DO_CONCURRENT)
     {
       gfc_error ("ACC CACHE directive must be inside of loop %C");
@@ -8436,8 +8465,8 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 		  }
 		if (openacc
 		    && list == OMP_LIST_MAP
-		    && (n->u.map_op == OMP_MAP_ATTACH
-			|| n->u.map_op == OMP_MAP_DETACH))
+		    && (n->u.map.op == OMP_MAP_ATTACH
+			|| n->u.map.op == OMP_MAP_DETACH))
 		  {
 		    symbol_attribute attr;
 		    if (n->expr)
@@ -8447,7 +8476,7 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 		    if (!attr.pointer && !attr.allocatable)
 		      gfc_error ("%qs clause argument must be ALLOCATABLE or "
 				 "a POINTER at %L",
-				 (n->u.map_op == OMP_MAP_ATTACH) ? "attach"
+				 (n->u.map.op == OMP_MAP_ATTACH) ? "attach"
 				 : "detach", &n->where);
 		  }
 		if (lastref
@@ -8518,7 +8547,7 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 		else if (openacc)
 		  {
 		    if (list == OMP_LIST_MAP
-			&& n->u.map_op == OMP_MAP_FORCE_DEVICEPTR)
+			&& n->u.map.op == OMP_MAP_FORCE_DEVICEPTR)
 		      resolve_oacc_deviceptr_clause (n->sym, n->where, name);
 		    else
 		      resolve_oacc_data_clauses (n->sym, n->where, name);
@@ -8540,7 +8569,7 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 		    {
 		    case EXEC_OMP_TARGET:
 		    case EXEC_OMP_TARGET_DATA:
-		      switch (n->u.map_op)
+		      switch (n->u.map.op)
 			{
 			case OMP_MAP_TO:
 			case OMP_MAP_ALWAYS_TO:
@@ -8567,7 +8596,7 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 			}
 		      break;
 		    case EXEC_OMP_TARGET_ENTER_DATA:
-		      switch (n->u.map_op)
+		      switch (n->u.map.op)
 			{
 			case OMP_MAP_TO:
 			case OMP_MAP_ALWAYS_TO:
@@ -8577,16 +8606,16 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 			case OMP_MAP_PRESENT_ALLOC:
 			  break;
 			case OMP_MAP_TOFROM:
-			  n->u.map_op = OMP_MAP_TO;
+			  n->u.map.op = OMP_MAP_TO;
 			  break;
 			case OMP_MAP_ALWAYS_TOFROM:
-			  n->u.map_op = OMP_MAP_ALWAYS_TO;
+			  n->u.map.op = OMP_MAP_ALWAYS_TO;
 			  break;
 			case OMP_MAP_PRESENT_TOFROM:
-			  n->u.map_op = OMP_MAP_PRESENT_TO;
+			  n->u.map.op = OMP_MAP_PRESENT_TO;
 			  break;
 			case OMP_MAP_ALWAYS_PRESENT_TOFROM:
-			  n->u.map_op = OMP_MAP_ALWAYS_PRESENT_TO;
+			  n->u.map.op = OMP_MAP_ALWAYS_PRESENT_TO;
 			  break;
 			default:
 			  gfc_error ("TARGET ENTER DATA with map-type other "
@@ -8596,7 +8625,7 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 			}
 		      break;
 		    case EXEC_OMP_TARGET_EXIT_DATA:
-		      switch (n->u.map_op)
+		      switch (n->u.map.op)
 			{
 			case OMP_MAP_FROM:
 			case OMP_MAP_ALWAYS_FROM:
@@ -8606,16 +8635,16 @@ resolve_omp_clauses (gfc_code *code, gfc_omp_clauses *omp_clauses,
 			case OMP_MAP_DELETE:
 			  break;
 			case OMP_MAP_TOFROM:
-			  n->u.map_op = OMP_MAP_FROM;
+			  n->u.map.op = OMP_MAP_FROM;
 			  break;
 			case OMP_MAP_ALWAYS_TOFROM:
-			  n->u.map_op = OMP_MAP_ALWAYS_FROM;
+			  n->u.map.op = OMP_MAP_ALWAYS_FROM;
 			  break;
 			case OMP_MAP_PRESENT_TOFROM:
-			  n->u.map_op = OMP_MAP_PRESENT_FROM;
+			  n->u.map.op = OMP_MAP_PRESENT_FROM;
 			  break;
 			case OMP_MAP_ALWAYS_PRESENT_TOFROM:
-			  n->u.map_op = OMP_MAP_ALWAYS_PRESENT_FROM;
+			  n->u.map.op = OMP_MAP_ALWAYS_PRESENT_FROM;
 			  break;
 			default:
 			  gfc_error ("TARGET EXIT DATA with map-type other "
diff --git a/gcc/fortran/trans-decl.cc b/gcc/fortran/trans-decl.cc
index 6d463036966..b7dea11461f 100644
--- a/gcc/fortran/trans-decl.cc
+++ b/gcc/fortran/trans-decl.cc
@@ -6744,7 +6744,7 @@ add_clause (gfc_symbol *sym, gfc_omp_map_op map_op)
 
   n = gfc_get_omp_namelist ();
   n->sym = sym;
-  n->u.map_op = map_op;
+  n->u.map.op = map_op;
 
   if (!module_oacc_clauses)
     module_oacc_clauses = gfc_get_omp_clauses ();
@@ -6846,10 +6846,10 @@ finish_oacc_declare (gfc_namespace *ns, gfc_symbol *sym, bool block)
 
   for (n = omp_clauses->lists[OMP_LIST_MAP]; n; n = n->next)
     {
-      switch (n->u.map_op)
+      switch (n->u.map.op)
 	{
 	  case OMP_MAP_DEVICE_RESIDENT:
-	    n->u.map_op = OMP_MAP_FORCE_ALLOC;
+	    n->u.map.op = OMP_MAP_FORCE_ALLOC;
 	    break;
 
 	  default:
diff --git a/gcc/fortran/trans-openmp.cc b/gcc/fortran/trans-openmp.cc
index a2bf15665b3..fa1bfd41380 100644
--- a/gcc/fortran/trans-openmp.cc
+++ b/gcc/fortran/trans-openmp.cc
@@ -3139,7 +3139,10 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		      || (n->expr && gfc_expr_attr (n->expr).pointer)))
 		always_modifier = true;
 
-	      switch (n->u.map_op)
+	      if (n->u.map.readonly)
+		OMP_CLAUSE_MAP_READONLY (node) = 1;
+
+	      switch (n->u.map.op)
 		{
 		case OMP_MAP_ALLOC:
 		  OMP_CLAUSE_SET_MAP_KIND (node, GOMP_MAP_ALLOC);
@@ -3266,8 +3269,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		      && n->sym->attr.omp_declare_target
 		      && (always_modifier || n->sym->attr.pointer)
 		      && op != EXEC_OMP_TARGET_EXIT_DATA
-		      && n->u.map_op != OMP_MAP_DELETE
-		      && n->u.map_op != OMP_MAP_RELEASE)
+		      && n->u.map.op != OMP_MAP_DELETE
+		      && n->u.map.op != OMP_MAP_RELEASE)
 		    {
 		      gcc_assert (n->sym->ts.u.cl->backend_decl);
 		      node5 = build_omp_clause (input_location, OMP_CLAUSE_MAP);
@@ -3333,7 +3336,7 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			{
 			  enum gomp_map_kind gmk = GOMP_MAP_POINTER;
 			  if (op == EXEC_OMP_TARGET_EXIT_DATA
-			      && n->u.map_op == OMP_MAP_DELETE)
+			      && n->u.map.op == OMP_MAP_DELETE)
 			    gmk = GOMP_MAP_DELETE;
 			  else if (op == EXEC_OMP_TARGET_EXIT_DATA)
 			    gmk = GOMP_MAP_RELEASE;
@@ -3356,7 +3359,7 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			{
 			  enum gomp_map_kind gmk;
 			  if (op == EXEC_OMP_TARGET_EXIT_DATA
-			      && n->u.map_op == OMP_MAP_DELETE)
+			      && n->u.map.op == OMP_MAP_DELETE)
 			    gmk = GOMP_MAP_DELETE;
 			  else if (op == EXEC_OMP_TARGET_EXIT_DATA)
 			    gmk = GOMP_MAP_RELEASE;
@@ -3388,18 +3391,18 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		      node2 = build_omp_clause (input_location, OMP_CLAUSE_MAP);
 		      OMP_CLAUSE_DECL (node2) = decl;
 		      OMP_CLAUSE_SIZE (node2) = TYPE_SIZE_UNIT (type);
-		      if (n->u.map_op == OMP_MAP_DELETE)
+		      if (n->u.map.op == OMP_MAP_DELETE)
 			map_kind = GOMP_MAP_DELETE;
 		      else if (op == EXEC_OMP_TARGET_EXIT_DATA
-			       || n->u.map_op == OMP_MAP_RELEASE)
+			       || n->u.map.op == OMP_MAP_RELEASE)
 			map_kind = GOMP_MAP_RELEASE;
 		      else
 			map_kind = GOMP_MAP_TO_PSET;
 		      OMP_CLAUSE_SET_MAP_KIND (node2, map_kind);
 
 		      if (op != EXEC_OMP_TARGET_EXIT_DATA
-			  && n->u.map_op != OMP_MAP_DELETE
-			  && n->u.map_op != OMP_MAP_RELEASE)
+			  && n->u.map.op != OMP_MAP_DELETE
+			  && n->u.map.op != OMP_MAP_RELEASE)
 			{
 			  node3 = build_omp_clause (input_location,
 						    OMP_CLAUSE_MAP);
@@ -3417,7 +3420,7 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			      = gfc_conv_descriptor_data_get (decl);
 			  OMP_CLAUSE_SIZE (node3) = size_int (0);
 
-			  if (n->u.map_op == OMP_MAP_ATTACH)
+			  if (n->u.map.op == OMP_MAP_ATTACH)
 			    {
 			      /* Standalone attach clauses used with arrays with
 				 descriptors must copy the descriptor to the
@@ -3433,7 +3436,7 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			      node3 = NULL;
 			      goto finalize_map_clause;
 			    }
-			  else if (n->u.map_op == OMP_MAP_DETACH)
+			  else if (n->u.map.op == OMP_MAP_DETACH)
 			    {
 			      OMP_CLAUSE_SET_MAP_KIND (node3, GOMP_MAP_DETACH);
 			      /* Similarly to above, we don't want to unmap PTR
@@ -3626,8 +3629,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			 to perform a single attach/detach operation, of the
 			 pointer itself, not of the pointed-to object.  */
 		      if (openacc
-			  && (n->u.map_op == OMP_MAP_ATTACH
-			      || n->u.map_op == OMP_MAP_DETACH))
+			  && (n->u.map.op == OMP_MAP_ATTACH
+			      || n->u.map.op == OMP_MAP_DETACH))
 			{
 			  OMP_CLAUSE_DECL (node)
 			    = build_fold_addr_expr (OMP_CLAUSE_DECL (node));
@@ -3656,7 +3659,7 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 					       se.string_length),
 					   TYPE_SIZE_UNIT (tmp));
 			  gomp_map_kind kind;
-			  if (n->u.map_op == OMP_MAP_DELETE)
+			  if (n->u.map.op == OMP_MAP_DELETE)
 			    kind = GOMP_MAP_DELETE;
 			  else if (op == EXEC_OMP_TARGET_EXIT_DATA)
 			    kind = GOMP_MAP_RELEASE;
@@ -3713,8 +3716,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			     to perform a single attach/detach operation, of the
 			     pointer itself, not of the pointed-to object.  */
 			  if (openacc
-			      && (n->u.map_op == OMP_MAP_ATTACH
-				  || n->u.map_op == OMP_MAP_DETACH))
+			      && (n->u.map.op == OMP_MAP_ATTACH
+				  || n->u.map.op == OMP_MAP_DETACH))
 			    {
 			      OMP_CLAUSE_DECL (node)
 				= build_fold_addr_expr (inner);
@@ -3806,8 +3809,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		    {
 		      /* Bare attach and detach clauses don't want any
 			 additional nodes.  */
-		      if ((n->u.map_op == OMP_MAP_ATTACH
-			   || n->u.map_op == OMP_MAP_DETACH)
+		      if ((n->u.map.op == OMP_MAP_ATTACH
+			   || n->u.map.op == OMP_MAP_DETACH)
 			  && (POINTER_TYPE_P (TREE_TYPE (inner))
 			      || GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (inner))))
 			{
@@ -3840,8 +3843,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			    map_kind = ((GOMP_MAP_ALWAYS_P (map_kind)
 					 || gfc_expr_attr (n->expr).pointer)
 					? GOMP_MAP_ALWAYS_TO : GOMP_MAP_TO);
-			  else if (n->u.map_op == OMP_MAP_RELEASE
-				   || n->u.map_op == OMP_MAP_DELETE)
+			  else if (n->u.map.op == OMP_MAP_RELEASE
+				   || n->u.map.op == OMP_MAP_DELETE)
 			    ;
 			  else if (op == EXEC_OMP_TARGET_EXIT_DATA
 				   || op == EXEC_OACC_EXIT_DATA)
@@ -4088,6 +4091,8 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		}
 	      if (n->u.present_modifier)
 		OMP_CLAUSE_MOTION_PRESENT (node) = 1;
+	      if (list == OMP_LIST_CACHE && n->u.map.readonly)
+		OMP_CLAUSE__CACHE__READONLY (node) = 1;
 	      omp_clauses = gfc_trans_add_clause (node, omp_clauses);
 	    }
 	  break;
@@ -6561,7 +6566,7 @@ gfc_add_clause_implicitly (gfc_omp_clauses *clauses_out,
 	  n2->where = n->where;
 	  n2->sym = n->sym;
 	  if (is_target)
-	    n2->u.map_op = OMP_MAP_TOFROM;
+	    n2->u.map.op = OMP_MAP_TOFROM;
 	  if (tail)
 	    {
 	      tail->next = n2;
diff --git a/gcc/testsuite/c-c++-common/goacc/readonly-1.c b/gcc/testsuite/c-c++-common/goacc/readonly-1.c
new file mode 100644
index 00000000000..34fc92c24d5
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/readonly-1.c
@@ -0,0 +1,59 @@
+/* { dg-additional-options "-fdump-tree-original" } */
+
+struct S
+{
+  int *ptr;
+  float f;
+};
+
+int a[32], b[32];
+#pragma acc declare copyin(readonly: a) copyin(b)
+
+int main (void)
+{
+  int x[32], y[32];
+  struct S s = {x, 0};
+
+  #pragma acc parallel copyin(readonly: x[:32], s.ptr[:16]) copyin(y[:32])
+  {
+    #pragma acc cache (readonly: x[:32])
+    #pragma acc cache (y[:32])
+  }
+
+  #pragma acc kernels copyin(readonly: x[:32], s.ptr[:16]) copyin(y[:32])
+  {
+    #pragma acc cache (readonly: x[:32])
+    #pragma acc cache (y[:32])
+  }
+
+  #pragma acc serial copyin(readonly: x[:32], s.ptr[:16]) copyin(y[:32])
+  {
+    #pragma acc cache (readonly: x[:32])
+    #pragma acc cache (y[:32])
+  }
+
+  #pragma acc data copyin(readonly: x[:32], s.ptr[:16]) copyin(y[:32])
+  {
+    #pragma acc cache (readonly: x[:32])
+    #pragma acc cache (y[:32])
+  }
+
+  #pragma acc enter data copyin(readonly: x[:32], s.ptr[:16]) copyin(y[:32])
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc parallel map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:\\*s.ptr \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc kernels map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:\\*s.ptr \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc serial map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:\\*s.ptr \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc data map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) map\\(readonly,to:\\*s.ptr \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc enter data map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) map\\(readonly,to:\\*s.ptr \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c } } } } */
+
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc parallel map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:\\*NON_LVALUE_EXPR <s.ptr> \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c++ } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc kernels map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:\\*NON_LVALUE_EXPR <s.ptr> \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c++ } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc serial map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:\\*NON_LVALUE_EXPR <s.ptr> \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c++ } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc data map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) map\\(readonly,to:\\*NON_LVALUE_EXPR <s.ptr> \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c++ } } } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc enter data map\\(to:y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\) map\\(readonly,to:\\*NON_LVALUE_EXPR <s.ptr> \\\[len: \[0-9\]+\\\]\\) .+ map\\(readonly,to:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\)" 1 "original" { target { c++ } } } } */
+
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc cache \\(readonly:x\\\[0\\\] \\\[len: \[0-9\]+\\\]\\);$" 4 "original" } } */
+/* { dg-final { scan-tree-dump-times "(?n)#pragma acc cache \\(y\\\[0\\\] \\\[len: \[0-9\]+\\\]\\);$" 4 "original" } } */
diff --git a/gcc/testsuite/gfortran.dg/goacc/readonly-1.f90 b/gcc/testsuite/gfortran.dg/goacc/readonly-1.f90
new file mode 100644
index 00000000000..696ebd08321
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/goacc/readonly-1.f90
@@ -0,0 +1,89 @@
+! { dg-additional-options "-fdump-tree-original" }
+
+subroutine foo (a, n)
+  integer :: n, a(:)
+  integer :: i, b(n), c(n)
+  !$acc parallel copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end parallel
+
+  !$acc kernels copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end kernels
+
+  !$acc serial copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end serial
+
+  !$acc data copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end data
+
+  !$acc enter data copyin(readonly: a(:), b(:n)) copyin(c(:))
+
+end subroutine foo
+
+program main
+  integer :: g(32), h(32)
+  integer :: i, n = 32, a(32)
+  integer :: b(32), c(32)
+
+  !$acc declare copyin(readonly: g), copyin(h)
+
+  !$acc parallel copyin(readonly: a(:32), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end parallel
+
+  !$acc kernels copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end kernels
+
+  !$acc serial copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end serial
+
+  !$acc data copyin(readonly: a(:), b(:n)) copyin(c(:))
+  do i = 1,32
+     !$acc cache (readonly: a(:), b(:n))
+     !$acc cache (c(:))
+  enddo
+  !$acc end data
+
+  !$acc enter data copyin(readonly: a(:), b(:n)) copyin(c(:))
+
+end program main
+
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc parallel map\\(readonly,to:\\*.+ map\\(alloc:a.+ map\\(readonly,to:\\*.+ map\\(alloc:b.+ map\\(to:\\*.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc parallel map\\(readonly,to:a.+ map\\(alloc:a.+ map\\(readonly,to:b.+ map\\(alloc:b.+ map\\(to:c.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc kernels map\\(readonly,to:\\*.+ map\\(alloc:a.+ map\\(readonly,to:\\*.+ map\\(alloc:b.+ map\\(to:\\*.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc kernels map\\(readonly,to:a.+ map\\(alloc:a.+ map\\(readonly,to:b.+ map\\(alloc:b.+ map\\(to:c.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc serial map\\(readonly,to:\\*.+ map\\(alloc:a.+ map\\(readonly,to:\\*.+ map\\(alloc:b.+ map\\(to:\\*.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc serial map\\(readonly,to:a.+ map\\(alloc:a.+ map\\(readonly,to:b.+ map\\(alloc:b.+ map\\(to:c.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc data map\\(readonly,to:\\*.+ map\\(alloc:a.+ map\\(readonly,to:\\*.+ map\\(alloc:b.+ map\\(to:\\*.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc data map\\(readonly,to:a.+ map\\(alloc:a.+ map\\(readonly,to:b.+ map\\(alloc:b.+ map\\(to:c.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc enter data map\\(readonly,to:\\*.+ map\\(alloc:a.+ map\\(readonly,to:\\*.+ map\\(alloc:b.+ map\\(to:\\*.+ map\\(alloc:c.+" 1 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc enter data map\\(readonly,to:a.+ map\\(alloc:a.+ map\\(readonly,to:b.+ map\\(alloc:b.+ map\\(to:c.+ map\\(alloc:c.+" 1 "original" } }
+
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc cache \\(readonly:\\*\\(integer\\(kind=4\\)\\\[0:\\\] \\*\\) parm.*data \\\[len: .+\\\]\\) \\(readonly:\\*\\(integer\\(kind=4\\)\\\[0:\\\] \\*\\) parm.*data \\\[len: .+\\\]\\);" 8 "original" } }
+! { dg-final { scan-tree-dump-times "(?n)#pragma acc cache \\(\\*\\(integer\\(kind=4\\)\\\[0:\\\] \\*\\) parm.*data \\\[len: .+\\\]\\);" 8 "original" } }
diff --git a/gcc/tree-core.h b/gcc/tree-core.h
index 8a89462bd7e..d529712306d 100644
--- a/gcc/tree-core.h
+++ b/gcc/tree-core.h
@@ -1344,6 +1344,12 @@ struct GTY(()) tree_base {
        TYPE_READONLY in
            all types
 
+       OMP_CLAUSE_MAP_READONLY in
+           OMP_CLAUSE_MAP
+
+       OMP_CLAUSE__CACHE__READONLY in
+           OMP_CLAUSE__CACHE_
+
    constant_flag:
 
        TREE_CONSTANT in
diff --git a/gcc/tree-pretty-print.cc b/gcc/tree-pretty-print.cc
index 654f5247e3a..926f7e006a7 100644
--- a/gcc/tree-pretty-print.cc
+++ b/gcc/tree-pretty-print.cc
@@ -913,6 +913,8 @@ dump_omp_clause (pretty_printer *pp, tree clause, int spc, dump_flags_t flags)
 
     case OMP_CLAUSE_MAP:
       pp_string (pp, "map(");
+      if (OMP_CLAUSE_MAP_READONLY (clause))
+	pp_string (pp, "readonly,");
       switch (OMP_CLAUSE_MAP_KIND (clause))
 	{
 	case GOMP_MAP_ALLOC:
@@ -1095,6 +1097,8 @@ dump_omp_clause (pretty_printer *pp, tree clause, int spc, dump_flags_t flags)
 
     case OMP_CLAUSE__CACHE_:
       pp_string (pp, "(");
+      if (OMP_CLAUSE__CACHE__READONLY (clause))
+	pp_string (pp, "readonly:");
       dump_generic_node (pp, OMP_CLAUSE_DECL (clause),
 			 spc, flags, false);
       goto print_clause_size;
diff --git a/gcc/tree.h b/gcc/tree.h
index e1fc6c2221d..b67a37d6522 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1841,6 +1841,14 @@ class auto_suppress_location_wrappers
 #define OMP_CLAUSE_MAP_DECL_MAKE_ADDRESSABLE(NODE) \
   (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_MAP)->base.addressable_flag)
 
+/* Nonzero if OpenACC 'readonly' modifier set, used for 'copyin'.  */
+#define OMP_CLAUSE_MAP_READONLY(NODE) \
+  TREE_READONLY (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_MAP))
+
+/* Same as above, for use in OpenACC cache directives.  */
+#define OMP_CLAUSE__CACHE__READONLY(NODE) \
+  TREE_READONLY (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE__CACHE_))
+
 /* True on an OMP_CLAUSE_USE_DEVICE_PTR with an OpenACC 'if_present'
    clause.  */
 #define OMP_CLAUSE_USE_DEVICE_PTR_IF_PRESENT(NODE) \

  reply	other threads:[~2024-03-07  8:02 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <d0e6013f-ca38-b98d-dc01-b30adbd5901a@siemens.com>
     [not found] ` <87lefaaesb.fsf@euler.schwinge.homeip.net>
     [not found]   ` <b45bd2bb-a306-5e42-7c84-53433e8d06a2@codesourcery.com>
     [not found]     ` <b5af4407-1538-802f-92ca-aae843258c15@siemens.com>
2023-10-26  9:43       ` Thomas Schwinge
2024-03-07  8:02         ` Chung-Lin Tang [this message]
2024-03-13  9:12           ` Thomas Schwinge
2024-03-14 15:09             ` OpenACC 2.7: front-end support for readonly modifier: Add basic OpenACC 'declare' testing (was: [PATCH, OpenACC 2.7, v2] readonly modifier support in front-ends) Thomas Schwinge
2024-03-14 16:55               ` OpenACC 2.7: front-end support for readonly modifier: Add basic OpenACC 'declare' testing Tobias Burnus
2024-03-14 16:55               ` Tobias Burnus
     [not found] ` <5196826c-e81a-ab5c-63e9-bd8509232da0@siemens.com>
2023-10-27 14:28   ` [PATCH, OpenACC 2.7] Connect readonly modifier to points-to analysis Thomas Schwinge
2023-10-30 12:46     ` Richard Biener

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