re PR target/63977 (r217769 caused many failures)

PR target/63977

 * config/i386/i386.c (ix86_static_chain): Reinstate the check
 for DECL_STATIC_CHAIN.

From-SVN: r217853

gcc/ChangeLog

+2014-11-20  Richard Henderson <rth@redhat.com>
+
+	PR target/63977
+	* config/i386/i386.c (ix86_static_chain): Reinstate the check
+	for DECL_STATIC_CHAIN.
+
 2014-11-20  Tejas Belagod  <tejas.belagod@arm.com>
 
 	* config/aarch64/aarch64-protos.h (aarch64_classify_symbol):

gcc/config/i386/i386.c

@@ -27360,6 +27360,12 @@ ix86_static_chain (const_tree fndecl_or_type, bool incoming_p)
 {
   unsigned regno;
 
+  /* While this function won't be called by the middle-end when a static
+     chain isn't needed, it's also used throughout the backend so it's
+     easiest to keep this check centralized.  */
+  if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
+    return NULL;
+
   if (TARGET_64BIT)
     {
       /* We always use R10 in 64-bit mode.  */