diff options
| author | Vadim Yanitskiy <vyanitskiy@sysmocom.de> | 2022-02-02 01:17:45 +0600 |
|---|---|---|
| committer | Vadim Yanitskiy <vyanitskiy@sysmocom.de> | 2022-02-08 12:48:28 +0600 |
| commit | e59e839dd949136d2f1b63c59df141e1b01f4763 (patch) | |
| tree | 4e44e45007edea0dbaf1a4c1971813bb9e19afb4 /include/osmocom/core | |
| parent | 1790f1763adcb71c6c2efd22ca733c6caff52949 (diff) | |
core/utils.h: add OSMO_LIKELY / OSMO_UNLIKELY macros
These macros are built on top of the __builtin_expect() function [1],
which provides the compiler with branch prediction information.
Similar macros exist in the Linux kernel: likely() / unlikely().
[1] https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
Change-Id: I0b029654ba050f079eed4a0574a3fa8019677067
Diffstat (limited to 'include/osmocom/core')
| -rw-r--r-- | include/osmocom/core/utils.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h index eda0e399..7625da16 100644 --- a/include/osmocom/core/utils.h +++ b/include/osmocom/core/utils.h @@ -38,6 +38,15 @@ /*! Copy a C-string into a sized buffer using sizeof to detect buffer's size */ #define OSMO_STRLCPY_ARRAY(array, src) osmo_strlcpy(array, src, sizeof(array)) +/*! Branch prediction optimizations */ +#if defined(__GNUC__) +#define OSMO_LIKELY(exp) __builtin_expect(!!(exp), 1) +#define OSMO_UNLIKELY(exp) __builtin_expect(!!(exp), 0) +#else +#define OSMO_LIKELY(exp) exp +#define OSMO_UNLIKELY(exp) exp +#endif + /*! A mapping between human-readable string and numeric value */ struct value_string { uint32_t value; /*!< numeric value */ |