re PR middle-end/41261 (ice with -O2 -fprofile-arcs when compiling Linux kernel)

2009-09-06  Richard Guenther  <rguenther@suse.de>

	PR middle-end/41261
	* tree-ssa-alias.c (refs_may_alias_p_1): Bail out for function decls.

	* gcc.dg/torture/pr41261.c: New testcase.

From-SVN: r151460

gcc/ChangeLog

+2009-09-06  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/41261
+	* tree-ssa-alias.c (refs_may_alias_p_1): Bail out for function decls.
+
 2009-09-05  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/41181

gcc/testsuite/ChangeLog

+2009-09-06  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/41261
+	* gcc.dg/torture/pr41261.c: New testcase.
+
 2009-09-05  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/41181

gcc/testsuite/gcc.dg/torture/pr41261.c

+/* { dg-do compile } */
+/* { dg-options "-fprofile-arcs" } */
+
+extern void relocate_kernel();
+void machine_kexec(void *control_page)
+{ 
+  __builtin_memcpy(control_page, relocate_kernel, 2048);
+}

gcc/tree-ssa-alias.c

@@ -784,6 +784,12 @@ refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
       || is_gimple_min_invariant (base2))
     return false;
 
+  /* We can end up refering to code via function decls.  As we likely
+     do not properly track code aliases conservatively bail out.  */
+  if (TREE_CODE (base1) == FUNCTION_DECL
+      || TREE_CODE (base2) == FUNCTION_DECL)
+    return true;
+
   /* Defer to simple offset based disambiguation if we have
      references based on two decls.  Do this before defering to
      TBAA to handle must-alias cases in conformance with the