Before this patch, function multiversioning determines that two functions

are different by comparing the arch type and isa flags that are set
after the target string is processed. This leads to cases where  the
versions become identical when the command-line target options are
altered.

This patch modifies the function version determination to
just compare the target string.


2012-12-27  Sriraman Tallam  <tmsriram@google.com>

	* doc/tm.texi.in (TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS): Document
	new target hook.
	* doc/tm.texi: Regenerate.
	* c-family/c-common.c (handle_target_attribute): Retain target attribute
	for targets that support versioning.
	* target.def (supports_function_versions): New hook.
	* cp/class.c (add_method): Remove calls
	to DECL_FUNCTION_SPECIFIC_TARGET.
	* config/i386/i386.c (ix86_function_versions): Use target string
	to check for function versions instead of target flags.
	* (ix86_supports_function_versions): New function.
	* (is_function_default_version): Check target string.
	* TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS: New macro.

2012-12-27  Sriraman Tallam  <tmsriram@google.com>

	* testsuite/g++.dg/mv1.C: Remove target options.
	* testsuite/g++.dg/mv2.C: Ditto.
	* testsuite/g++.dg/mv3.C: Ditto.
	* testsuite/g++.dg/mv4.C: Ditto.
	* testsuite/g++.dg/mv5.C: Ditto.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@194730 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 1 deletions

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 872a6a0feed..012751330f3 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -8742,8 +8742,12 @@ handle_target_attribute (tree *node, tree name, tree args, int flags,
       warning (OPT_Wattributes, "%qE attribute ignored", name);
       *no_add_attrs = true;
     }
+  /* Do not strip invalid target attributes for targets which support function
+     multiversioning as the target string is used to determine versioned
+     functions.  */
   else if (! targetm.target_option.valid_attribute_p (*node, name, args,
-						      flags))
+						      flags)
+	   && ! targetm.target_option.supports_function_versions ())
     *no_add_attrs = true;
 
   return NULL_TREE;