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| author | Lukas Larsson <[email protected]> | 2014-10-22 17:15:31 +0200 |
|---|---|---|
| committer | Lukas Larsson <[email protected]> | 2016-02-02 10:45:21 +0100 |
| commit | d76ee58c07f32dfc0652844ec2b513af2105ffa1 (patch) | |
| tree | ac6d50ec60414c7433508196410b22216493209d /erts/emulator/beam/sys.h | |
| parent | 1a6ec7c7eb20bb2b8300e7e59196c49ca63775b0 (diff) | |
| download | otp-d76ee58c07f32dfc0652844ec2b513af2105ffa1.tar.gz otp-d76ee58c07f32dfc0652844ec2b513af2105ffa1.tar.bz2 otp-d76ee58c07f32dfc0652844ec2b513af2105ffa1.zip | |
erts: Add ERTS_WRITE_UNLIKELY
ERTS_WRITE_UNLIKELY can be used to place global variables in
a specific section where only data that is very rarely modified
sits. This is used to improve cache locality.
Diffstat (limited to 'erts/emulator/beam/sys.h')
| -rw-r--r-- | erts/emulator/beam/sys.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h index 279e4db0af..e77b4b2dc8 100644 --- a/erts/emulator/beam/sys.h +++ b/erts/emulator/beam/sys.h @@ -136,6 +136,17 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType; # define ERTS_LIKELY(BOOL) (BOOL) # define ERTS_UNLIKELY(BOOL) (BOOL) #endif + +#if ERTS_AT_LEAST_GCC_VSN__(2, 96, 0) +#ifndef __llvm__ +# define ERTS_WRITE_UNLIKELY(X) X __attribute__ ((section ("ERTS_LOW_WRITE") )) +#else +# define ERTS_WRITE_UNLIKELY(X) X __attribute__ ((section ("__DATA,ERTS_LOW_WRITE") )) +#endif +#else +# define ERTS_WRITE_UNLIKELY(X) X +#endif + #ifdef __GNUC__ # if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 5) # define ERTS_DECLARE_DUMMY(X) X __attribute__ ((unused)) |