re PR lto/60404 (wrong code by LTO on x86_64-linux-gnu)

	PR lto/60404
	* cfgexpand.c (expand_used_vars): Do not assume all SSA_NAMEs
	of PARM/RESULT_DECLs must be coalesced with optimize && in_lto_p.
	* tree-ssa-coalesce.c (coalesce_ssa_name): Use MUST_COALESCE_COST - 1
	cost for in_lto_p.

	* gcc.dg/lto/pr60404_0.c: New test.
	* gcc.dg/lto/pr60404_1.c: New file.
	* gcc.dg/lto/pr60404_2.c: New file.

From-SVN: r208340

gcc/ChangeLog

+2014-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR lto/60404
+	* cfgexpand.c (expand_used_vars): Do not assume all SSA_NAMEs
+	of PARM/RESULT_DECLs must be coalesced with optimize && in_lto_p.
+	* tree-ssa-coalesce.c (coalesce_ssa_name): Use MUST_COALESCE_COST - 1
+	cost for in_lto_p.
+
 2014-03-04  Heiher  <r@hev.cc>
 
 	* config/mips/mips-cpus.def (loongson3a): Mark as a MIPS64r2 processor.

gcc/cfgexpand.c

@@ -1652,10 +1652,12 @@ expand_used_vars (void)
 	 debug info, there is no need to do so if optimization is disabled
 	 because all the SSA_NAMEs based on these DECLs have been coalesced
 	 into a single partition, which is thus assigned the canonical RTL
-	 location of the DECLs.  */
+	 location of the DECLs.  If in_lto_p, we can't rely on optimize,
+	 a function could be compiled with -O1 -flto first and only the
+	 link performed at -O0.  */
       if (TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL)
 	expand_one_var (var, true, true);
-      else if (DECL_IGNORED_P (SSA_NAME_VAR (var)) || optimize)
+      else if (DECL_IGNORED_P (SSA_NAME_VAR (var)) || optimize || in_lto_p)
 	{
 	  /* This is a PARM_DECL or RESULT_DECL.  For those partitions that
 	     contain the default def (representing the parm or result itself)

gcc/testsuite/ChangeLog

+2014-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR lto/60404
+	* gcc.dg/lto/pr60404_0.c: New test.
+	* gcc.dg/lto/pr60404_1.c: New file.
+	* gcc.dg/lto/pr60404_2.c: New file.
+
 2014-03-04  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* gcc.dg/vmx/extract-vsx.c: Replace "vector long" with "vector

gcc/testsuite/gcc.dg/lto/pr60404_0.c

+/* { dg-lto-do run } */
+/* { dg-lto-options { { -O1 -flto } } } */
+/* { dg-extra-ld-options { -O0 } } */
+
+extern void fn2 (int);
+int a[1], b;
+
+int
+main ()
+{
+  fn2 (0);
+  if (b != 0 || a[b] != 0)
+    __builtin_abort ();
+  return 0;
+}

gcc/testsuite/gcc.dg/lto/pr60404_1.c

+void
+fn1 (int p)
+{
+}

gcc/testsuite/gcc.dg/lto/pr60404_2.c

+extern int b;
+extern void fn1 (int);
+
+void
+fn2 (int p)
+{
+  b = p++;
+  fn1 (p);
+}

gcc/tree-ssa-coalesce.c

@@ -1289,9 +1289,12 @@ coalesce_ssa_name (void)
 		     _require_ that all the names originating from it be
 		     coalesced, because there must be a single partition
 		     containing all the names so that it can be assigned
-		     the canonical RTL location of the DECL safely.  */
+		     the canonical RTL location of the DECL safely.
+		     If in_lto_p, a function could have been compiled
+		     originally with optimizations and only the link
+		     performed at -O0, so we can't actually require it.  */
 		  const int cost
-		    = TREE_CODE (SSA_NAME_VAR (a)) == VAR_DECL
+		    = (TREE_CODE (SSA_NAME_VAR (a)) == VAR_DECL || in_lto_p)
 		      ? MUST_COALESCE_COST - 1 : MUST_COALESCE_COST;
 		  add_coalesce (cl, SSA_NAME_VERSION (a),
 				SSA_NAME_VERSION (*slot), cost);