From 7a40909c00c13d2733bc1d41ddc7dc1d19e05da9 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Sun, 8 Mar 2020 00:41:00 +0100 Subject: [PATCH] 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. --- include/common/standard.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/include/common/standard.h b/include/common/standard.h index a78083318..f9eed961f 100644 --- a/include/common/standard.h +++ b/include/common/standard.h @@ -66,6 +66,26 @@ * power of 2, and 0 otherwise */ #define POWEROF2(x) (((x) & ((x)-1)) == 0) +/* rotate left a 64-bit integer by 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 */ +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; +} + /* DEFNULL() returns either the argument as-is, or NULL if absent. This is for * use in macros arguments. */