2013-02-04 Richard Guenther <rguenther@suse.de>

	PR lto/56168
	* lto-symtab.c (lto_symtab_merge_decls_1): Make non-builtin
	node prevail as last resort.
	(lto_symtab_merge_decls): Remove guard on LTRANS here.
	(lto_symtab_prevailing_decl): Builtins are their own prevailing
	decl.

	lto/
	* lto.c (read_cgraph_and_symbols): Do not call lto_symtab_merge_decls
	or lto_fixup_decls at LTRANS time.

	* gcc.dg/lto/pr56168_0.c: New testcase.
	* gcc.dg/lto/pr56168_1.c: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@195709 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 7 insertions, 8 deletions

diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index 546601d5eba..2b182ffaedf 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -439,12 +439,12 @@ lto_symtab_merge_decls_1 (symtab_node first)
 		&& COMPLETE_TYPE_P (TREE_TYPE (e->symbol.decl)))
 	      prevailing = e;
 	}
-      /* For variables prefer the builtin if one is available.  */
+      /* For variables prefer the non-builtin if one is available.  */
       else if (TREE_CODE (prevailing->symbol.decl) == FUNCTION_DECL)
 	{
 	  for (e = first; e; e = e->symbol.next_sharing_asm_name)
 	    if (TREE_CODE (e->symbol.decl) == FUNCTION_DECL
-		&& DECL_BUILT_IN (e->symbol.decl))
+		&& !DECL_BUILT_IN (e->symbol.decl))
 	      {
 		prevailing = e;
 		break;
@@ -507,12 +507,6 @@ lto_symtab_merge_decls (void)
 {
   symtab_node node;
 
-  /* In ltrans mode we read merged cgraph, we do not really need to care
-     about resolving symbols again, we only need to replace duplicated declarations
-     read from the callgraph and from function sections.  */
-  if (flag_ltrans)
-    return;
-
   /* Populate assembler name hash.   */
   symtab_initialize_asm_name_hash ();
 
@@ -598,6 +592,11 @@ lto_symtab_prevailing_decl (tree decl)
   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_ABSTRACT (decl))
     return decl;
 
+  /* Likewise builtins are their own prevailing decl.  This preserves
+     non-builtin vs. builtin uses from compile-time.  */
+  if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
+    return decl;
+
   /* Ensure DECL_ASSEMBLER_NAME will not set assembler name.  */
   gcc_assert (DECL_ASSEMBLER_NAME_SET_P (decl));