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| author | Ingo Molnar <mingo@elte.hu> | 2008-03-03 14:38:52 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-26 19:44:55 +0400 |
| commit | 60a3cdd0639473c79c253bc08c8ef8f882cca107 (patch) | |
| tree | e72a5ca87873b286b02966a390277f828139d350 /include/linux/compiler-gcc.h | |
| parent | b1721d0da266b4af8cb4419473b4ca36206ab200 (diff) | |
| download | linux-60a3cdd0639473c79c253bc08c8ef8f882cca107.tar.xz | |
x86: add optimized inlining
add CONFIG_OPTIMIZE_INLINING=y.
allow gcc to optimize the kernel image's size by uninlining
functions that have been marked 'inline'. Previously gcc was
forced by Linux to always-inline these functions via a gcc
attribute:
#define inline inline __attribute__((always_inline))
Especially when the user has already selected
CONFIG_OPTIMIZE_FOR_SIZE=y this can make a huge difference in
kernel image size (using a standard Fedora .config):
text data bss dec hex filename
5613924 562708 3854336 10030968 990f78 vmlinux.before
5486689 562708 3854336 9903733 971e75 vmlinux.after
that's a 2.3% text size reduction (!).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/compiler-gcc.h')
| -rw-r--r-- | include/linux/compiler-gcc.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index fe23792f05c1..340bc5d92772 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -28,9 +28,15 @@ #define __must_be_array(a) \ BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0]))) -#define inline inline __attribute__((always_inline)) -#define __inline__ __inline__ __attribute__((always_inline)) -#define __inline __inline __attribute__((always_inline)) +/* + * Force always-inline if the user requests it so via the .config: + */ +#if !defined(CONFIG_OPTIMIZE_INLINING) && (__GNUC__ >= 4) +# define inline inline __attribute__((always_inline)) +# define __inline__ __inline__ __attribute__((always_inline)) +# define __inline __inline __attribute__((always_inline)) +#endif + #define __deprecated __attribute__((deprecated)) #define __packed __attribute__((packed)) #define __weak __attribute__((weak)) |