rs6000.c (rs6000_get_function_versions_dispatcher): Add warning if GCC was not configured to link against a GLIBC that exports the...

[gcc]
2017-07-07  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config/rs6000/rs6000.c (rs6000_get_function_versions_dispatcher):
	Add warning if GCC was not configured to link against a GLIBC that
	exports the hardware capability bits.
	(make_resolver_func): Make resolver function private and not a
	COMDAT function.  Create the name with clone_function_name instead
	of make_unique_name.

[gcc/testsuite]
2017-07-07  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* gcc.target/powerpc/clone1.c: Add check to make sure the
	__builtin_cpu_supports function is fully supported.
	* gcc.target/powerpc/clone2.c: New runtime test for
	target_clones.

From-SVN: r250055

1 files changed, 12 insertions, 25 deletions

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 200f43a..10c5521 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -37283,6 +37283,12 @@ rs6000_get_function_versions_dispatcher (void *decl)
 
   default_node = default_version_info->this_node;
 
+#ifndef TARGET_LIBC_PROVIDES_HWCAP_IN_TCB
+  warning_at (DECL_SOURCE_LOCATION (default_node->decl), 0,
+	      "target_clone needs GLIBC (2.23 and newer) to export hardware "
+	      "capability bits");
+#endif
+
   if (targetm.has_ifunc_p ())
     {
       struct cgraph_function_version_info *it_v = NULL;
@@ -37328,29 +37334,19 @@ make_resolver_func (const tree default_decl,
 		    const tree dispatch_decl,
 		    basic_block *empty_bb)
 {
-  /* IFUNC's have to be globally visible.  So, if the default_decl is
-     not, then the name of the IFUNC should be made unique.  */
-  bool is_uniq = (TREE_PUBLIC (default_decl) == 0);
-
-  /* Append the filename to the resolver function if the versions are
-     not externally visible.  This is because the resolver function has
-     to be externally visible for the loader to find it.  So, appending
-     the filename will prevent conflicts with a resolver function from
-     another module which is based on the same version name.  */
-  char *resolver_name = make_unique_name (default_decl, "resolver", is_uniq);
-
-  /* The resolver function should return a (void *).  */
+  /* Make the resolver function static.  The resolver function returns
+     void *.  */
+  tree decl_name = clone_function_name (default_decl, "resolver");
+  const char *resolver_name = IDENTIFIER_POINTER (decl_name);
   tree type = build_function_type_list (ptr_type_node, NULL_TREE);
   tree decl = build_fn_decl (resolver_name, type);
-  tree decl_name = get_identifier (resolver_name);
   SET_DECL_ASSEMBLER_NAME (decl, decl_name);
 
   DECL_NAME (decl) = decl_name;
   TREE_USED (decl) = 1;
   DECL_ARTIFICIAL (decl) = 1;
   DECL_IGNORED_P (decl) = 0;
-  /* IFUNC resolvers have to be externally visible.  */
-  TREE_PUBLIC (decl) = 1;
+  TREE_PUBLIC (decl) = 0;
   DECL_UNINLINABLE (decl) = 1;
 
   /* Resolver is not external, body is generated.  */
@@ -37361,15 +37357,6 @@ make_resolver_func (const tree default_decl,
   DECL_INITIAL (decl) = make_node (BLOCK);
   DECL_STATIC_CONSTRUCTOR (decl) = 0;
 
-  if (DECL_COMDAT_GROUP (default_decl) || TREE_PUBLIC (default_decl))
-    {
-      /* In this case, each translation unit with a call to this
-	 versioned function will put out a resolver.  Ensure it
-	 is comdat to keep just one copy.  */
-      DECL_COMDAT (decl) = 1;
-      make_decl_one_only (decl, DECL_ASSEMBLER_NAME (decl));
-    }
-
   /* Build result decl and add to function_decl.  */
   tree t = build_decl (UNKNOWN_LOCATION, RESULT_DECL, NULL_TREE, ptr_type_node);
   DECL_ARTIFICIAL (t) = 1;
@@ -37391,7 +37378,7 @@ make_resolver_func (const tree default_decl,
     = make_attribute ("ifunc", resolver_name, DECL_ATTRIBUTES (dispatch_decl));
 
   cgraph_node::create_same_body_alias (dispatch_decl, decl);
-  XDELETEVEC (resolver_name);
+
   return decl;
 }