[committed,v4,4/5] Add support for target_version attribute

diff --git a/gcc/ada/gcc-interface/utils.cc b/gcc/ada/gcc-interface/utils.cc
index 3eabbec6bd34116910a0589b4ebf269b916cc607..17f6afd687d1dbd7648d52d86417414b04c0d896 100644
--- a/gcc/ada/gcc-interface/utils.cc
+++ b/gcc/ada/gcc-interface/utils.cc
@@ -146,14 +146,16 @@  static const struct attribute_spec::exclusions attr_noinline_exclusions[] =
 
 static const struct attribute_spec::exclusions attr_target_exclusions[] =
 {
-  { "target_clones", true, true, true },
+  { "target_clones", TARGET_HAS_FMV_TARGET_ATTRIBUTE,
+    TARGET_HAS_FMV_TARGET_ATTRIBUTE, TARGET_HAS_FMV_TARGET_ATTRIBUTE },
   { NULL, false, false, false },
 };
 
 static const struct attribute_spec::exclusions attr_target_clones_exclusions[] =
 {
   { "always_inline", true, true, true },
-  { "target", true, true, true },
+  { "target", TARGET_HAS_FMV_TARGET_ATTRIBUTE, TARGET_HAS_FMV_TARGET_ATTRIBUTE,
+    TARGET_HAS_FMV_TARGET_ATTRIBUTE },
   { NULL, false, false, false },
 };
 
diff --git a/gcc/attribs.cc b/gcc/attribs.cc
index 4e313d38f0f0608991c3267f55f43e3f0dd9d74a..0ca2779788569b7a02a79eab4db558df112aff87 100644
--- a/gcc/attribs.cc
+++ b/gcc/attribs.cc
@@ -675,7 +675,8 @@  decl_attributes (tree *node, tree attributes, int flags,
      options to the attribute((target(...))) list.  */
   if (TREE_CODE (*node) == FUNCTION_DECL
       && current_target_pragma
-      && targetm.target_option.valid_attribute_p (*node, NULL_TREE,
+      && targetm.target_option.valid_attribute_p (*node,
+						  get_identifier ("target"),
 						  current_target_pragma, 0))
     {
       tree cur_attr = lookup_attribute ("target", attributes);
@@ -1276,8 +1277,9 @@  make_dispatcher_decl (const tree decl)
   return func_decl;  
 }
 
-/* Returns true if decl is multi-versioned and DECL is the default function,
-   that is it is not tagged with target specific optimization.  */
+/* Returns true if DECL is multi-versioned using the target attribute, and this
+   is the default version.  This function can only be used for targets that do
+   not support the "target_version" attribute.  */
 
 bool
 is_function_default_version (const tree decl)
diff --git a/gcc/c-family/c-attribs.cc b/gcc/c-family/c-attribs.cc
index 9638848591fc82d3f7116cadf38b11237206ac0b..169c96a1397fce15365c1630767331392208f758 100644
--- a/gcc/c-family/c-attribs.cc
+++ b/gcc/c-family/c-attribs.cc
@@ -151,6 +151,7 @@  static tree handle_alloc_align_attribute (tree *, tree, tree, int, bool *);
 static tree handle_assume_aligned_attribute (tree *, tree, tree, int, bool *);
 static tree handle_assume_attribute (tree *, tree, tree, int, bool *);
 static tree handle_target_attribute (tree *, tree, tree, int, bool *);
+static tree handle_target_version_attribute (tree *, tree, tree, int, bool *);
 static tree handle_target_clones_attribute (tree *, tree, tree, int, bool *);
 static tree handle_optimize_attribute (tree *, tree, tree, int, bool *);
 static tree ignore_attribute (tree *, tree, tree, int, bool *);
@@ -233,14 +234,23 @@  static const struct attribute_spec::exclusions attr_noinline_exclusions[] =
 
 static const struct attribute_spec::exclusions attr_target_exclusions[] =
 {
-  ATTR_EXCL ("target_clones", true, true, true),
+  ATTR_EXCL ("target_clones", TARGET_HAS_FMV_TARGET_ATTRIBUTE,
+	     TARGET_HAS_FMV_TARGET_ATTRIBUTE, TARGET_HAS_FMV_TARGET_ATTRIBUTE),
   ATTR_EXCL (NULL, false, false, false),
 };
 
 static const struct attribute_spec::exclusions attr_target_clones_exclusions[] =
 {
   ATTR_EXCL ("always_inline", true, true, true),
-  ATTR_EXCL ("target", true, true, true),
+  ATTR_EXCL ("target", TARGET_HAS_FMV_TARGET_ATTRIBUTE,
+	     TARGET_HAS_FMV_TARGET_ATTRIBUTE, TARGET_HAS_FMV_TARGET_ATTRIBUTE),
+  ATTR_EXCL ("target_version", true, true, true),
+  ATTR_EXCL (NULL, false, false, false),
+};
+
+static const struct attribute_spec::exclusions attr_target_version_exclusions[] =
+{
+  ATTR_EXCL ("target_clones", true, true, true),
   ATTR_EXCL (NULL, false, false, false),
 };
 
@@ -512,6 +522,9 @@  const struct attribute_spec c_common_gnu_attributes[] =
   { "target",                 1, -1, true, false, false, false,
 			      handle_target_attribute,
 			      attr_target_exclusions },
+  { "target_version",         1, 1, true, false, false, false,
+			      handle_target_version_attribute,
+			      attr_target_version_exclusions },
   { "target_clones",          1, -1, true, false, false, false,
 			      handle_target_clones_attribute,
 			      attr_target_clones_exclusions },
@@ -5830,7 +5843,7 @@  static tree
 handle_target_attribute (tree *node, tree name, tree args, int flags,
 			 bool *no_add_attrs)
 {
-  /* Ensure we have a function type.  */
+  /* Ensure we have a function declaration.  */
   if (TREE_CODE (*node) != FUNCTION_DECL)
     {
       warning (OPT_Wattributes, "%qE attribute ignored", name);
@@ -5856,13 +5869,32 @@  handle_target_attribute (tree *node, tree name, tree args, int flags,
   return NULL_TREE;
 }
 
+/* Handle a "target_version" attribute.  */
+
+static tree
+handle_target_version_attribute (tree *node, tree name, tree args, int flags,
+				  bool *no_add_attrs)
+{
+  /* Ensure we have a function declaration.  */
+  if (TREE_CODE (*node) != FUNCTION_DECL)
+    {
+      warning (OPT_Wattributes, "%qE attribute ignored", name);
+      *no_add_attrs = true;
+    }
+  else if (!targetm.target_option.valid_version_attribute_p (*node, name, args,
+							     flags))
+    *no_add_attrs = true;
+
+  return NULL_TREE;
+}
+
 /* Handle a "target_clones" attribute.  */
 
 static tree
 handle_target_clones_attribute (tree *node, tree name, tree ARG_UNUSED (args),
 			  int ARG_UNUSED (flags), bool *no_add_attrs)
 {
-  /* Ensure we have a function type.  */
+  /* Ensure we have a function declaration.  */
   if (TREE_CODE (*node) == FUNCTION_DECL)
     {
       for (tree t = args; t != NULL_TREE; t = TREE_CHAIN (t))
diff --git a/gcc/cgraphclones.cc b/gcc/cgraphclones.cc
index 29d28ef895a73a223695cbb86aafbc845bbe7688..3ba5a4a2dd9fd4b7206d95f01c990818d0440334 100644
--- a/gcc/cgraphclones.cc
+++ b/gcc/cgraphclones.cc
@@ -78,6 +78,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "tree-eh.h"
 #include "tree-cfg.h"
 #include "tree-inline.h"
+#include "attribs.h"
 #include "dumpfile.h"
 #include "gimple-pretty-print.h"
 #include "alloc-pool.h"
@@ -1048,7 +1049,17 @@  cgraph_node::create_version_clone_with_body
       location_t saved_loc = input_location;
       tree v = TREE_VALUE (target_attributes);
       input_location = DECL_SOURCE_LOCATION (new_decl);
-      bool r = targetm.target_option.valid_attribute_p (new_decl, NULL, v, 1);
+      bool r;
+      tree name_id = get_attribute_name (target_attributes);
+      const char *name_str = IDENTIFIER_POINTER (name_id);
+      if (strcmp (name_str, "target") == 0)
+	r = targetm.target_option.valid_attribute_p (new_decl, name_id, v, 1);
+      else if (strcmp (name_str, "target_version") == 0)
+	r = targetm.target_option.valid_version_attribute_p (new_decl, name_id,
+							     v, 1);
+      else
+	gcc_unreachable();
+
       input_location = saved_loc;
       if (!r)
 	return NULL;
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index bee84879023f30145f4bbb5e0ace8fce871cd919..0850d3f5bce5d0db3f60f375c3da93d71b4587e3 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -834,8 +834,8 @@  check_classfn (tree ctype, tree function, tree template_parms)
       tree c2 = get_constraints (fndecl);
 
       /* While finding a match, same types and params are not enough
-	 if the function is versioned.  Also check version ("target")
-	 attributes.  */
+	 if the function is versioned.  Also check for different target
+	 specific attributes.  */
       if (same_type_p (TREE_TYPE (TREE_TYPE (function)),
 		       TREE_TYPE (TREE_TYPE (fndecl)))
 	  && compparms (p1, p2)
diff --git a/gcc/d/d-attribs.cc b/gcc/d/d-attribs.cc
index 3b69c530c1d29f880b7dcdd5b6e9188f07e4c2e8..52f3b27baa91dbf68d94dca5c3adaaaa32117a67 100644
--- a/gcc/d/d-attribs.cc
+++ b/gcc/d/d-attribs.cc
@@ -128,14 +128,16 @@  static const struct attribute_spec::exclusions attr_noinline_exclusions[] =
 
 static const struct attribute_spec::exclusions attr_target_exclusions[] =
 {
-  ATTR_EXCL ("target_clones", true, true, true),
+  ATTR_EXCL ("target_clones", TARGET_HAS_FMV_TARGET_ATTRIBUTE,
+	     TARGET_HAS_FMV_TARGET_ATTRIBUTE, TARGET_HAS_FMV_TARGET_ATTRIBUTE),
   ATTR_EXCL (NULL, false, false, false),
 };
 
 static const struct attribute_spec::exclusions attr_target_clones_exclusions[] =
 {
   ATTR_EXCL ("always_inline", true, true, true),
-  ATTR_EXCL ("target", true, true, true),
+  ATTR_EXCL ("target", TARGET_HAS_FMV_TARGET_ATTRIBUTE,
+	     TARGET_HAS_FMV_TARGET_ATTRIBUTE, TARGET_HAS_FMV_TARGET_ATTRIBUTE),
   ATTR_EXCL (NULL, false, false, false),
 };
 
diff --git a/gcc/defaults.h b/gcc/defaults.h
index dc6f09cacae8a85873c6d6685eea91fb749cc367..6f0959694102ca28fd993aaff7ec3f5d09334c39 100644
--- a/gcc/defaults.h
+++ b/gcc/defaults.h
@@ -877,6 +877,16 @@  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #endif
 #endif
 
+/* Indicate whether the target uses "target" attributes for function
+   multiversioning.  This is used to choose between the "target" and
+   "target_version" attributes when expanding a "target_clones" attribute, and
+   determine whether the "target" and "target_clones" attributes are mutually
+   exclusive.  */
+#ifndef TARGET_HAS_FMV_TARGET_ATTRIBUTE
+#define TARGET_HAS_FMV_TARGET_ATTRIBUTE 1
+#endif
+
+
 /* Select a format to encode pointers in exception handling data.  We
    prefer those that result in fewer dynamic relocations.  Assume no
    special support here and encode direct references.  */
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 0bb6da080f8492629537b6c0160674edb425de9c..22a1bebc0f432497d59318ca9ca6a7d9da528d2e 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -10741,6 +10741,18 @@  the function declaration to hold a pointer to a target-specific
 @code{struct cl_target_option} structure.
 @end deftypefn
 
+@deftypefn {Target Hook} bool TARGET_OPTION_VALID_VERSION_ATTRIBUTE_P (tree @var{fndecl}, tree @var{name}, tree @var{args}, int @var{flags})
+This hook is called to parse @code{attribute(target_version("..."))},
+which allows setting target-specific options on individual function versions.
+These function-specific options may differ
+from the options specified on the command line.  The hook should return
+@code{true} if the options are valid.
+
+The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in
+the function declaration to hold a pointer to a target-specific
+@code{struct cl_target_option} structure.
+@end deftypefn
+
 @deftypefn {Target Hook} void TARGET_OPTION_SAVE (struct cl_target_option *@var{ptr}, struct gcc_options *@var{opts}, struct gcc_options *@var{opts_set})
 This hook is called to save any additional target-specific information
 in the @code{struct cl_target_option} structure for function-specific
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 4fe0805394ea4d45dfa6ffb41eb052fd32649a0d..f92cb7678784613e1d192c0eb12e1cf67084f16e 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -7066,6 +7066,8 @@  on this implementation detail.
 
 @hook TARGET_OPTION_VALID_ATTRIBUTE_P
 
+@hook TARGET_OPTION_VALID_VERSION_ATTRIBUTE_P
+
 @hook TARGET_OPTION_SAVE
 
 @hook TARGET_OPTION_RESTORE
diff --git a/gcc/multiple_target.cc b/gcc/multiple_target.cc
index a2ed048d7dd28ec470953fcd8a0dc86817e4b7dc..a832d1e8ff83d99acd7579c276b083141102f3e1 100644
--- a/gcc/multiple_target.cc
+++ b/gcc/multiple_target.cc
@@ -66,10 +66,6 @@  create_dispatcher_calls (struct cgraph_node *node)
 {
   ipa_ref *ref;
 
-  if (!DECL_FUNCTION_VERSIONED (node->decl)
-      || !is_function_default_version (node->decl))
-    return;
-
   if (!targetm.has_ifunc_p ())
     {
       error_at (DECL_SOURCE_LOCATION (node->decl),
@@ -377,6 +373,8 @@  expand_target_clones (struct cgraph_node *node, bool definition)
       return false;
     }
 
+  const char *new_attr_name = (TARGET_HAS_FMV_TARGET_ATTRIBUTE
+			       ? "target" : "target_version");
   cgraph_function_version_info *decl1_v = NULL;
   cgraph_function_version_info *decl2_v = NULL;
   cgraph_function_version_info *before = NULL;
@@ -392,7 +390,7 @@  expand_target_clones (struct cgraph_node *node, bool definition)
       char *attr = attrs[i];
 
       /* Create new target clone.  */
-      tree attributes = make_attribute ("target", attr,
+      tree attributes = make_attribute (new_attr_name, attr,
 					DECL_ATTRIBUTES (node->decl));
 
       char *suffix = XNEWVEC (char, strlen (attr) + 1);
@@ -430,7 +428,7 @@  expand_target_clones (struct cgraph_node *node, bool definition)
   XDELETEVEC (attr_str);
 
   /* Setting new attribute to initial function.  */
-  tree attributes = make_attribute ("target", "default",
+  tree attributes = make_attribute (new_attr_name, "default",
 				    DECL_ATTRIBUTES (node->decl));
   DECL_ATTRIBUTES (node->decl) = attributes;
   node->local = false;
diff --git a/gcc/target.def b/gcc/target.def
index ca030abab6c6694ded178a62dbc4e1dbd20540ca..0509e07d6b80bc2fddcb12ccfd3d5bcb7eb16d57 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -6635,6 +6635,23 @@  the function declaration to hold a pointer to a target-specific\n\
  bool, (tree fndecl, tree name, tree args, int flags),
  default_target_option_valid_attribute_p)
 
+/* Function to validate the attribute((target_version(...))) strings.  If
+   the option is validated, the hook should also fill in
+   DECL_FUNCTION_SPECIFIC_TARGET in the function decl node.  */
+DEFHOOK
+(valid_version_attribute_p,
+ "This hook is called to parse @code{attribute(target_version(\"...\"))},\n\
+which allows setting target-specific options on individual function versions.\n\
+These function-specific options may differ\n\
+from the options specified on the command line.  The hook should return\n\
+@code{true} if the options are valid.\n\
+\n\
+The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in\n\
+the function declaration to hold a pointer to a target-specific\n\
+@code{struct cl_target_option} structure.",
+ bool, (tree fndecl, tree name, tree args, int flags),
+ default_target_option_valid_version_attribute_p)
+
 /* Function to save any extra target state in the target options structure.  */
 DEFHOOK
 (save,
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
index 5a39e8e6d540714678f912340fb35b65e88757a2..7996cb4433662d5fd76c0eeef2e146802ca9d055 100644
--- a/gcc/targhooks.h
+++ b/gcc/targhooks.h
@@ -193,6 +193,7 @@  extern bool default_hard_regno_scratch_ok (unsigned int);
 extern bool default_mode_dependent_address_p (const_rtx, addr_space_t);
 extern bool default_new_address_profitable_p (rtx, rtx_insn *, rtx);
 extern bool default_target_option_valid_attribute_p (tree, tree, tree, int);
+extern bool default_target_option_valid_version_attribute_p (tree, tree, tree, int);
 extern bool default_target_option_pragma_parse (tree, tree);
 extern bool default_target_can_inline_p (tree, tree);
 extern bool default_update_ipa_fn_target_info (unsigned int &, const gimple *);
diff --git a/gcc/targhooks.cc b/gcc/targhooks.cc
index afe91fe1d17a2dd263a6864bd15bc61c08954b36..1cc0895ceab4b431aebcec9bbebc79cd68af2696 100644
--- a/gcc/targhooks.cc
+++ b/gcc/targhooks.cc
@@ -1799,7 +1799,19 @@  default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
 					 int ARG_UNUSED (flags))
 {
   warning (OPT_Wattributes,
-	   "target attribute is not supported on this machine");
+	   "%<target%> attribute is not supported on this machine");
+
+  return false;
+}
+
+bool
+default_target_option_valid_version_attribute_p (tree ARG_UNUSED (fndecl),
+						 tree ARG_UNUSED (name),
+						 tree ARG_UNUSED (args),
+						 int ARG_UNUSED (flags))
+{
+  warning (OPT_Wattributes,
+	   "%<target_version%> attribute is not supported on this machine");
 
   return false;
 }
diff --git a/gcc/tree.h b/gcc/tree.h
index cec9f6c54a7a53148e5114140356a6a94b6e9746..4829f84c975f7f4e75fb7937a7338e3d9323a50e 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3510,8 +3510,8 @@  extern vec<tree, va_gc> **decl_debug_args_insert (tree);
    (FUNCTION_DECL_CHECK (NODE)->function_decl.function_specific_optimization)
 
 /* In FUNCTION_DECL, this is set if this function has other versions generated
-   using "target" attributes.  The default version is the one which does not
-   have any "target" attribute set. */
+   to support different architecture feature sets, e.g. using "target" or
+   "target_version" attributes.  */
 #define DECL_FUNCTION_VERSIONED(NODE)\
    (FUNCTION_DECL_CHECK (NODE)->function_decl.versioned_function)