diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 164bd56b48b..36097607bf9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2010-08-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/44485
+	* calls.c (flags_from_decl_or_type): For const or pure
+	noreturn functions return ECF_LOOPING_CONST_OR_PURE|ECF_NORETURN
+	together with ECF_CONST resp. ECF_PURE.
+	* builtins.c (expand_builtin): Use flags_from_decl_or_type
+	instead of querying flags directly.
+	* tree-ssa-loop-niter.c (finite_loop_p): Likewise.
+	* tree-ssa-dce.c (find_obviously_necessary_stmts): Likewise.
+
 2010-08-26  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45255
diff --git a/gcc/builtins.c b/gcc/builtins.c
index e8974e1bbc2..6d755a1b5c7 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -5748,6 +5748,7 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
   tree fndecl = get_callee_fndecl (exp);
   enum built_in_function fcode = DECL_FUNCTION_CODE (fndecl);
   enum machine_mode target_mode = TYPE_MODE (TREE_TYPE (exp));
+  int flags;
 
   if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD)
     return targetm.expand_builtin (exp, target, subtarget, mode, ignore);
@@ -5770,8 +5771,8 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
      none of its arguments are volatile, we can avoid expanding the
      built-in call and just evaluate the arguments for side-effects.  */
   if (target == const0_rtx
-      && (DECL_PURE_P (fndecl) || TREE_READONLY (fndecl))
-      && !DECL_LOOPING_CONST_OR_PURE_P (fndecl))
+      && ((flags = flags_from_decl_or_type (fndecl)) & (ECF_CONST | ECF_PURE))
+      && !(flags & ECF_LOOPING_CONST_OR_PURE))
     {
       bool volatilep = false;
       tree arg;
diff --git a/gcc/calls.c b/gcc/calls.c
index cd0d9c593f3..c50a79265f0 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -601,7 +601,7 @@ flags_from_decl_or_type (const_tree exp)
 	flags |= ECF_RETURNS_TWICE;
 
       /* Process the pure and const attributes.  */
-      if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
+      if (TREE_READONLY (exp))
 	flags |= ECF_CONST;
       if (DECL_PURE_P (exp))
 	flags |= ECF_PURE;
@@ -616,11 +616,15 @@ flags_from_decl_or_type (const_tree exp)
 
       flags = special_function_p (exp, flags);
     }
-  else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
+  else if (TYPE_P (exp) && TYPE_READONLY (exp))
     flags |= ECF_CONST;
 
   if (TREE_THIS_VOLATILE (exp))
-    flags |= ECF_NORETURN;
+    {
+      flags |= ECF_NORETURN;
+      if (flags & (ECF_CONST|ECF_PURE))
+	flags |= ECF_LOOPING_CONST_OR_PURE;
+    }
 
   return flags;
 }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d27a2e2cf3c..8eb2f3a322f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-08-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/44485
+	* gcc.dg/pr44485.c: New test.
+
 2010-08-26  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* gcc.dg/tls/thr-init-2.c: Use dg-add-options tls.
diff --git a/gcc/testsuite/gcc.dg/pr44485.c b/gcc/testsuite/gcc.dg/pr44485.c
new file mode 100644
index 00000000000..82f05f8ce6a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr44485.c
@@ -0,0 +1,31 @@
+/* PR tree-optimization/44485 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -funsafe-math-optimizations" } */
+
+unsigned short b;
+int bar (unsigned);
+
+void
+baz (void)
+{
+  if (bar (0))
+    for (b = 0; b < 30; b++)
+      ;
+}
+
+int
+bar (unsigned z)
+{
+  unsigned short c;
+  for (; ; z += 1)
+l1:
+    if (z)
+      goto l2;
+l2:
+  for (z = 0; z < 9; z++)
+    if (z)
+      goto l1;
+  for (c = 0; c; c = (__UINTPTR_TYPE__) baz)
+    ;
+  return 0;
+}
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index edec49d374f..a1a51914fa6 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -433,6 +433,7 @@ find_obviously_necessary_stmts (struct edge_list *el)
   gimple_stmt_iterator gsi;
   edge e;
   gimple phi, stmt;
+  int flags;
 
   FOR_EACH_BB (bb)
     {
@@ -454,9 +455,8 @@ find_obviously_necessary_stmts (struct edge_list *el)
 
   /* Pure and const functions are finite and thus have no infinite loops in
      them.  */
-  if ((TREE_READONLY (current_function_decl)
-       || DECL_PURE_P (current_function_decl))
-      && !DECL_LOOPING_CONST_OR_PURE_P (current_function_decl))
+  flags = flags_from_decl_or_type (current_function_decl);
+  if ((flags & (ECF_CONST|ECF_PURE)) && !(flags & ECF_LOOPING_CONST_OR_PURE))
     return;
 
   /* Prevent the empty possibly infinite loops from being removed.  */
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 2630faf02fa..d23592dfa53 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -1970,12 +1970,12 @@ finite_loop_p (struct loop *loop)
   edge ex;
   struct tree_niter_desc desc;
   bool finite = false;
+  int flags;
 
   if (flag_unsafe_loop_optimizations)
     return true;
-  if ((TREE_READONLY (current_function_decl)
-       || DECL_PURE_P (current_function_decl))
-      && !DECL_LOOPING_CONST_OR_PURE_P (current_function_decl))
+  flags = flags_from_decl_or_type (current_function_decl);
+  if ((flags & (ECF_CONST|ECF_PURE)) && !(flags & ECF_LOOPING_CONST_OR_PURE))
     {
       if (dump_file && (dump_flags & TDF_DETAILS))
 	fprintf (dump_file, "Found loop %i to be finite: it is within pure or const function.\n",