MINOR: tools: add 64-bit rotate operators
This adds rotl64/rotr64 to rotate a 64-bit word by an arbitrary number
of bits. It's mainly aimed at being used with constants.
(cherry picked from commit 7a40909c00c13d2733bc1d41ddc7dc1d19e05da9)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 4deb8529fe01327ab23f18290cf7fdd2ef99090a)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/include/common/standard.h b/include/common/standard.h
index cdefc9f..b646ff7 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -61,6 +61,26 @@
* power of 2, and 0 otherwise */
#define POWEROF2(x) (((x) & ((x)-1)) == 0)
+/* rotate left a 64-bit integer by <bits:[0-5]> bits */
+static inline uint64_t rotl64(uint64_t v, uint8_t bits)
+{
+#if !defined(__ARM_ARCH_8A) && !defined(__x86_64__)
+ bits &= 63;
+#endif
+ v = (v << bits) | (v >> (-bits & 63));
+ return v;
+}
+
+/* rotate right a 64-bit integer by <bits:[0-5]> bits */
+static inline uint64_t rotr64(uint64_t v, uint8_t bits)
+{
+#if !defined(__ARM_ARCH_8A) && !defined(__x86_64__)
+ bits &= 63;
+#endif
+ v = (v >> bits) | (v << (-bits & 63));
+ return v;
+}
+
/* operators to compare values. They're ordered that way so that the lowest bit
* serves as a negation for the test and contains all tests that are not equal.
*/