re PR tree-optimization/46583 (-fcompare-debug failure with -O -fno-inline -fipa-cp -fipa-cp-clone)

gcc/ChangeLog:
PR debug/46583
* tree-ssa-live.c (remove_unused_scope_block_p): Keep type decls.
gcc/testsuite/ChangeLog:
PR debug/46583
* g++.dg/debug/pr46583.C: New.

From-SVN: r169058

gcc/ChangeLog

+2011-01-20  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR debug/46583
+	* tree-ssa-live.c (remove_unused_scope_block_p): Keep type decls.
+
 2011-01-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/47283

gcc/testsuite/ChangeLog

+2011-01-20  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR debug/46583
+	* g++.dg/debug/pr46583.C: New.
+
 2011-01-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/47283

gcc/testsuite/g++.dg/debug/pr46583.C

+// PR debug/46583
+// { dg-do compile }
+// { dg-options "-O -fno-inline -fipa-cp -fipa-cp-clone -fcompare-debug" }
+
+template < typename = unsigned long >struct A
+{
+  unsigned long elems[3];
+  unsigned long *begin ()
+  {
+    return 0;
+  }
+};
+
+void
+bar (unsigned long *a1, unsigned long, unsigned long *a3, unsigned const &)
+{
+  *a3 = *a1;
+}
+
+A < >operatorM (A < >a1, unsigned long a2)
+{
+  typedef A < >G;
+  G a3;
+  bar (a1.begin (), a2, a3.begin (), 0);
+  return a3;
+}
+
+struct B
+{
+  B (A < >m):n (operatorM (m, 1))
+  {
+  }
+  A < >n;
+};
+
+void
+foo ()
+{
+  B (A < >());
+}

gcc/tree-ssa-live.c

@@ -490,11 +490,16 @@ remove_unused_scope_block_p (tree scope)
 	 can be considered dead.  We only want to keep around blocks user can
 	 breakpoint into and ask about value of optimized out variables.
 
-	 Similarly we need to keep around types at least until all variables of
-	 all nested blocks are gone.  We track no information on whether given
-	 type is used or not.  */
-
-      else if (debug_info_level == DINFO_LEVEL_NORMAL
+	 Similarly we need to keep around types at least until all
+	 variables of all nested blocks are gone.  We track no
+	 information on whether given type is used or not, so we have
+	 to keep them even when not emitting debug information,
+	 otherwise we may end up remapping variables and their (local)
+	 types in different orders depending on whether debug
+	 information is being generated.  */
+
+      else if (TREE_CODE (*t) == TYPE_DECL
+	       || debug_info_level == DINFO_LEVEL_NORMAL
 	       || debug_info_level == DINFO_LEVEL_VERBOSE)
 	;
       else