--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2008-09-02  Simon Josefsson  <simon@josefsson.org>
+
+	* lib/bitrotate.h (rotl64, rotr64): Add.  Suggested by Bruce Korb
+	<bruce.korb@gmail.com> with ideas from Ben Pfaff
+	<blp@cs.stanford.edu> and Bruno Haible <bruno@clisp.org>.
+
+	* tests/test-bitrotate.c: Add more test vectors.
+
 2008-09-02  Eric Blake  <ebb9@byu.net>
 
 	vasnprintf-posix: handle large precision via %.*d

--- a/lib/bitrotate.h
+++ b/lib/bitrotate.h
@@ -21,6 +21,26 @@
 
 #include <stdint.h>
 
+#if defined UINT64_MAX && defined UINT64_C
+/* Given an unsigned 64-bit argument X, return the value corresponding
+   to rotating the bits N steps to the left.  N must be between 1 and
+   31 inclusive. */
+static inline uint64_t
+rotl64 (uint64_t x, int n)
+{
+  return ((x << n) | (x >> (64 - n))) & 0xFFFFFFFFFFFFFFFFULL;
+}
+
+/* Given an unsigned 64-bit argument X, return the value corresponding
+   to rotating the bits N steps to the right.  N must be between 1 to
+   31 inclusive.*/
+static inline uint64_t
+rotr64 (uint64_t x, int n)
+{
+  return ((x >> n) | (x << (64 - n))) & 0xFFFFFFFFFFFFFFFFULL;
+}
+#endif
+
 /* Given an unsigned 32-bit argument X, return the value corresponding
    to rotating the bits N steps to the left.  N must be between 1 and
    31 inclusive. */

--- a/tests/test-bitrotate.c
+++ b/tests/test-bitrotate.c
@@ -39,6 +39,22 @@
 int
 main (void)
 {
+  ASSERT (rotl8 (42, 1) == 84);
+  ASSERT (rotl8 (42, 2) == 168);
+  ASSERT (rotl8 (42, 3) == 81);
+  ASSERT (rotl8 (42, 4) == 162);
+  ASSERT (rotl8 (42, 5) == 69);
+  ASSERT (rotl8 (42, 6) == 138);
+  ASSERT (rotl8 (42, 7) == 21);
+
+  ASSERT (rotr8 (42, 1) == 21);
+  ASSERT (rotr8 (42, 2) == 138);
+  ASSERT (rotr8 (42, 3) == 69);
+  ASSERT (rotr8 (42, 4) == 162);
+  ASSERT (rotr8 (42, 5) == 81);
+  ASSERT (rotr8 (42, 6) == 168);
+  ASSERT (rotr8 (42, 7) == 84);
+
   ASSERT (rotl16 (43981, 1) == 22427);
   ASSERT (rotl16 (43981, 2) == 44854);
   ASSERT (rotl16 (43981, 3) == 24173);
@@ -55,6 +71,22 @@
   ASSERT (rotl16 (43981, 14) == 27379);
   ASSERT (rotl16 (43981, 15) == 54758);
 
+  ASSERT (rotr16 (43981, 1) == 54758);
+  ASSERT (rotr16 (43981, 2) == 27379);
+  ASSERT (rotr16 (43981, 3) == 46457);
+  ASSERT (rotr16 (43981, 4) == 55996);
+  ASSERT (rotr16 (43981, 5) == 27998);
+  ASSERT (rotr16 (43981, 6) == 13999);
+  ASSERT (rotr16 (43981, 7) == 39767);
+  ASSERT (rotr16 (43981, 8) == 52651);
+  ASSERT (rotr16 (43981, 9) == 59093);
+  ASSERT (rotr16 (43981, 10) == 62314);
+  ASSERT (rotr16 (43981, 11) == 31157);
+  ASSERT (rotr16 (43981, 12) == 48346);
+  ASSERT (rotr16 (43981, 13) == 24173);
+  ASSERT (rotr16 (43981, 14) == 44854);
+  ASSERT (rotr16 (43981, 15) == 22427);
+
   ASSERT (rotl32 (2309737967U, 1) == 324508639U);
   ASSERT (rotl32 (2309737967U, 2) == 649017278U);
   ASSERT (rotl32 (2309737967U, 3) == 1298034556U);
@@ -87,5 +119,168 @@
   ASSERT (rotl32 (2309737967U, 30) == 3798659963U);
   ASSERT (rotl32 (2309737967U, 31) == 3302352631U);
 
+  ASSERT (rotr32 (2309737967U, 1) == 3302352631lU);
+  ASSERT (rotr32 (2309737967U, 2) == 3798659963lU);
+  ASSERT (rotr32 (2309737967U, 3) == 4046813629lU);
+  ASSERT (rotr32 (2309737967U, 4) == 4170890462lU);
+  ASSERT (rotr32 (2309737967U, 5) == 2085445231lU);
+  ASSERT (rotr32 (2309737967U, 6) == 3190206263lU);
+  ASSERT (rotr32 (2309737967U, 7) == 3742586779lU);
+  ASSERT (rotr32 (2309737967U, 8) == 4018777037lU);
+  ASSERT (rotr32 (2309737967U, 9) == 4156872166lU);
+  ASSERT (rotr32 (2309737967U, 10) == 2078436083lU);
+  ASSERT (rotr32 (2309737967U, 11) == 3186701689lU);
+  ASSERT (rotr32 (2309737967U, 12) == 3740834492lU);
+  ASSERT (rotr32 (2309737967U, 13) == 1870417246lU);
+  ASSERT (rotr32 (2309737967U, 14) == 935208623lU);
+  ASSERT (rotr32 (2309737967U, 15) == 2615087959lU);
+  ASSERT (rotr32 (2309737967U, 16) == 3455027627lU);
+  ASSERT (rotr32 (2309737967U, 17) == 3874997461lU);
+  ASSERT (rotr32 (2309737967U, 18) == 4084982378lU);
+  ASSERT (rotr32 (2309737967U, 19) == 2042491189lU);
+  ASSERT (rotr32 (2309737967U, 20) == 3168729242lU);
+  ASSERT (rotr32 (2309737967U, 21) == 1584364621lU);
+  ASSERT (rotr32 (2309737967U, 22) == 2939665958lU);
+  ASSERT (rotr32 (2309737967U, 23) == 1469832979lU);
+  ASSERT (rotr32 (2309737967U, 24) == 2882400137lU);
+  ASSERT (rotr32 (2309737967U, 25) == 3588683716lU);
+  ASSERT (rotr32 (2309737967U, 26) == 1794341858lU);
+  ASSERT (rotr32 (2309737967U, 27) == 897170929lU);
+  ASSERT (rotr32 (2309737967U, 28) == 2596069112lU);
+  ASSERT (rotr32 (2309737967U, 29) == 1298034556lU);
+  ASSERT (rotr32 (2309737967U, 30) == 649017278lU);
+  ASSERT (rotr32 (2309737967U, 31) == 324508639lU);
+
+#if defined(UINT64_MAX) && defined(UINT64_C)
+  ASSERT (rotl64 (16045690984503098046ULL, 1) == 13644637895296644477ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 2) == 8842531716883737339ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 3) == 17685063433767474678ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 4) == 16923382793825397741ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 5) == 15400021513941243867ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 6) == 12353298954172936119ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 7) == 6259853834636320623ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 8) == 12519707669272641246ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 9) == 6592671264835730877ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 10) == 13185342529671461754ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 11) == 7923940985633371893ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 12) == 15847881971266743786ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 13) == 13249019868823935957ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 14) == 8051295663938320299ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 15) == 16102591327876640598ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 16) == 13758438582043729581ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 17) == 9070133090377907547ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 18) == 18140266180755815094ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 19) == 17833788287802078573ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 20) == 17220832501894605531ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 21) == 15994920930079659447ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 22) == 13543097786449767279ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 23) == 8639451499189982943ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 24) == 17278902998379965886ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 25) == 16111061923050380157ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 26) == 13775379772391208699ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 27) == 9104015471072865783ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 28) == 18208030942145731566ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 29) == 17969317810581911517ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 30) == 17491891547454271419ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 31) == 16537039021198991223ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 32) == 14627333968688430831ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 33) == 10807923863667310047ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 34) == 3169103653625068479ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 35) == 6338207307250136958ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 36) == 12676414614500273916ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 37) == 6906085155290996217ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 38) == 13812170310581992434ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 39) == 9177596547454433253ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 40) == 18355193094908866506ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 41) == 18263642116108181397ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 42) == 18080540158506811179ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 43) == 17714336243304070743ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 44) == 16981928412898589871ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 45) == 15517112752087628127ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 46) == 12587481430465704639ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 47) == 6728218787221857663ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 48) == 13456437574443715326ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 49) == 8466131075177879037ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 50) == 16932262150355758074ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 51) == 15417780227001964533ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 52) == 12388816380294377451ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 53) == 6330888686879203287ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 54) == 12661777373758406574ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 55) == 6876810673807261533ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 56) == 13753621347614523066ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 57) == 9060498621519494517ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 58) == 18120997243038989034ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 59) == 17795250412368426453ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 60) == 17143756751027301291ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 61) == 15840769428345050967ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 62) == 13234794782980550319ULL);
+  ASSERT (rotl64 (16045690984503098046ULL, 63) == 8022845492251549023ULL);
+
+  ASSERT (rotr64 (16045690984503098046ULL, 0) == 16045690984503098046ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 1) == 8022845492251549023ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 2) == 13234794782980550319ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 3) == 15840769428345050967ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 4) == 17143756751027301291ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 5) == 17795250412368426453ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 6) == 18120997243038989034ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 7) == 9060498621519494517ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 8) == 13753621347614523066ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 9) == 6876810673807261533ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 10) == 12661777373758406574ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 11) == 6330888686879203287ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 12) == 12388816380294377451ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 13) == 15417780227001964533ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 14) == 16932262150355758074ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 15) == 8466131075177879037ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 16) == 13456437574443715326ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 17) == 6728218787221857663ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 18) == 12587481430465704639ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 19) == 15517112752087628127ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 20) == 16981928412898589871ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 21) == 17714336243304070743ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 22) == 18080540158506811179ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 23) == 18263642116108181397ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 24) == 18355193094908866506ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 25) == 9177596547454433253ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 26) == 13812170310581992434ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 27) == 6906085155290996217ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 28) == 12676414614500273916ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 29) == 6338207307250136958ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 30) == 3169103653625068479ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 31) == 10807923863667310047ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 32) == 14627333968688430831ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 33) == 16537039021198991223ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 34) == 17491891547454271419ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 35) == 17969317810581911517ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 36) == 18208030942145731566ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 37) == 9104015471072865783ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 38) == 13775379772391208699ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 39) == 16111061923050380157ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 40) == 17278902998379965886ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 41) == 8639451499189982943ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 42) == 13543097786449767279ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 43) == 15994920930079659447ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 44) == 17220832501894605531ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 45) == 17833788287802078573ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 46) == 18140266180755815094ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 47) == 9070133090377907547ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 48) == 13758438582043729581ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 49) == 16102591327876640598ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 50) == 8051295663938320299ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 51) == 13249019868823935957ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 52) == 15847881971266743786ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 53) == 7923940985633371893ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 54) == 13185342529671461754ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 55) == 6592671264835730877ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 56) == 12519707669272641246ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 57) == 6259853834636320623ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 58) == 12353298954172936119ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 59) == 15400021513941243867ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 60) == 16923382793825397741ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 61) == 17685063433767474678ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 62) == 8842531716883737339ULL);
+  ASSERT (rotr64 (16045690984503098046ULL, 63) == 13644637895296644477ULL);
+#endif
+
   return 0;
 }