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| author | David Kalnischkies <kalnischkies@gmail.com> | 2010-01-22 08:27:20 +0100 |
|---|---|---|
| committer | David Kalnischkies <kalnischkies@gmail.com> | 2010-01-22 08:27:20 +0100 |
| commit | 3d43e5390d83a95b08d09e8b811523f2d99a092c (patch) | |
| tree | 3dedea7cc43708d102bdbaeb39e9a72459b294a2 /apt-pkg | |
| parent | d16aade9b781538ad5d6d79eda7b69ff075aad85 (diff) | |
add a few gcc helpers, including [un]likely() and __deprecated
Diffstat (limited to 'apt-pkg')
| -rw-r--r-- | apt-pkg/contrib/system.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/apt-pkg/contrib/system.h b/apt-pkg/contrib/system.h index 7ec3d7feb..b57093b93 100644 --- a/apt-pkg/contrib/system.h +++ b/apt-pkg/contrib/system.h @@ -55,4 +55,26 @@ #define CLRFLAG(v,f) ((v) &=~FLAG(f)) #define CHKFLAG(v,f) ((v) & FLAG(f) ? true : false) +// some nice optional GNUC features +#if __GNUC__ >= 3 + #define __must_check __attribute__ ((warn_unused_result)) + #define __deprecated __attribute__ ((deprecated)) + /* likely() and unlikely() can be used to mark boolean expressions + as (not) likely true which will help the compiler to optimise */ + #define likely(x) __builtin_expect (!!(x), 1) + #define unlikely(x) __builtin_expect (!!(x), 0) +#else + #define __must_check /* no warn_unused_result */ + #define __deprecated /* no deprecated */ + #define likely(x) (x) + #define unlikely(x) (x) +#endif + +// cold functions are unlikely() to be called +#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4 + #define __cold __attribute__ ((__cold__)) +#else + #define __cold /* no cold marker */ +#endif + #endif |