diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index c058ac73a85ae069ea71bc95089aeadb08a2da86..99da8b588154d012daa61710870765e1e798213f 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,13 @@
+2007-12-24  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/tr1_impl/hashtable_policy.h (_Prime_rehash_policy::
+	_M_next_bkt, _M_bkt_for_elements, _M_need_rehash): Use __builtin_ceil.
+	* include/std/unordered_map: Do not include <cmath>; prefer
+	<bits/stringfwd.h> to <string>.
+	* include/std/unordered_set: Likewise.
+	* include/tr1/unordered_map: Likewise.
+	* include/tr1/unordered_set: Likewise.
+
 2007-12-24  Paolo Carlini  <pcarlini@suse.de>
 
 	* include/std/complex (complex<float>::complex(float, float)):
diff --git a/libstdc++-v3/include/std/unordered_map b/libstdc++-v3/include/std/unordered_map
index 226fea8b106685aa2e82e2c7b89850c497a80bad..4ce80514d686a2ce793577c3d31b700c2b8beea2 100644
--- a/libstdc++-v3/include/std/unordered_map
+++ b/libstdc++-v3/include/std/unordered_map
@@ -44,13 +44,12 @@
 #  error C++0x header cannot be included from TR1 header
 #endif
 
-#include <cmath>
-#include <string>
 #include <utility>
 #include <algorithm> // lower_bound
+#include <type_traits>
 #include <bits/allocator.h>
 #include <bits/stl_function.h> // equal_to, _Identity, _Select1st
-#include <type_traits>
+#include <bits/stringfwd.h>
 #include <bits/functional_hash.h>
 #include <bits/hashtable.h>
 
diff --git a/libstdc++-v3/include/std/unordered_set b/libstdc++-v3/include/std/unordered_set
index 3b0f22c341896861328e4efb201440ccc39d7874..3cc69372b6f74550cd1556e674d51f48ecb34814 100644
--- a/libstdc++-v3/include/std/unordered_set
+++ b/libstdc++-v3/include/std/unordered_set
@@ -44,13 +44,12 @@
 #  error C++0x header cannot be included from TR1 header
 #endif
 
-#include <cmath>
-#include <string>
 #include <utility>
 #include <algorithm> // lower_bound
+#include <type_traits>
 #include <bits/allocator.h>
 #include <bits/stl_function.h> // equal_to, _Identity, _Select1st
-#include <type_traits>
+#include <bits/stringfwd.h>
 #include <bits/functional_hash.h>
 #include <bits/hashtable.h>
 
diff --git a/libstdc++-v3/include/tr1/unordered_map b/libstdc++-v3/include/tr1/unordered_map
index 85e8f0015c475c756116a4994b12baa87d5e4d13..041eb9443cf8b4802cde2ae85127896604453811 100644
--- a/libstdc++-v3/include/tr1/unordered_map
+++ b/libstdc++-v3/include/tr1/unordered_map
@@ -40,12 +40,11 @@
 #  error TR1 header cannot be included from C++0x header
 #endif
 
-#include <cmath>
-#include <string>
 #include <utility>
 #include <algorithm> // lower_bound
 #include <bits/allocator.h>
 #include <bits/stl_function.h> // equal_to, _Identity, _Select1st
+#include <bits/stringfwd.h>
 #include <tr1/type_traits>
 #include <tr1/functional_hash.h>
 #include <tr1/hashtable.h>
diff --git a/libstdc++-v3/include/tr1/unordered_set b/libstdc++-v3/include/tr1/unordered_set
index 35c605ff681b376ada9fffbb1b8f8683deb90629..16181681f557f5d602b293c255365057542523db 100644
--- a/libstdc++-v3/include/tr1/unordered_set
+++ b/libstdc++-v3/include/tr1/unordered_set
@@ -40,12 +40,11 @@
 #  error TR1 header cannot be included from C++0x header
 #endif
 
-#include <cmath>
-#include <string>
 #include <utility>
 #include <algorithm> // lower_bound
 #include <bits/allocator.h>
 #include <bits/stl_function.h> // equal_to, _Identity, _Select1st
+#include <bits/stringfwd.h>
 #include <tr1/type_traits>
 #include <tr1/functional_hash.h>
 #include <tr1/hashtable.h>
diff --git a/libstdc++-v3/include/tr1_impl/hashtable_policy.h b/libstdc++-v3/include/tr1_impl/hashtable_policy.h
index 514d444420eb395964f1b6df7bbebc1f787a723b..b74531c2ddf8e2179a069cca50f8521d5ea43a2a 100644
--- a/libstdc++-v3/include/tr1_impl/hashtable_policy.h
+++ b/libstdc++-v3/include/tr1_impl/hashtable_policy.h
@@ -425,8 +425,8 @@ namespace __detail
   {
     const unsigned long* __p = std::lower_bound(__prime_list, __prime_list
 						+ _S_n_primes, __n);
-    _M_next_resize = static_cast<std::size_t>(std::ceil(*__p
-							* _M_max_load_factor));
+    _M_next_resize = 
+      static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor));
     return *__p;
   }
 
@@ -439,8 +439,8 @@ namespace __detail
     const float __min_bkts = __n / _M_max_load_factor;
     const unsigned long* __p = std::lower_bound(__prime_list, __prime_list
 						+ _S_n_primes, __min_bkts);
-    _M_next_resize = static_cast<std::size_t>(std::ceil(*__p
-							* _M_max_load_factor));
+    _M_next_resize =
+      static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor));
     return *__p;
   }
 
@@ -468,15 +468,14 @@ namespace __detail
 	    const unsigned long* __p =
 	      std::lower_bound(__prime_list, __prime_list + _S_n_primes,
 			       __min_bkts);
-	    _M_next_resize =
-	      static_cast<std::size_t>(std::ceil(*__p * _M_max_load_factor));
+	    _M_next_resize = static_cast<std::size_t>
+	      (__builtin_ceil(*__p * _M_max_load_factor));
 	    return std::make_pair(true, *__p);
 	  }
 	else 
 	  {
-	    _M_next_resize =
-	      static_cast<std::size_t>(std::ceil(__n_bkt
-						 * _M_max_load_factor));
+	    _M_next_resize = static_cast<std::size_t>
+	      (__builtin_ceil(__n_bkt * _M_max_load_factor));
 	    return std::make_pair(false, 0);
 	  }
       }