Messages in this thread Patch in this message | | | Subject | Re: [PATCH] 2.4.22pre10: {,un}likely_p() macros for pointers | From | Albert Cahalan <> | Date | 11 Aug 2003 09:09:59 -0400 |
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On Mon, 2003-08-11 at 01:42, Jamie Lokier wrote: > Willy Tarreau wrote: > > So in any case, the !!(x) construct should be valid. > > Yes, either of these is fine for pointers and integers alike: > > #define likely(x) __builtin_expect ((x) != 0, 1) > #define unlikely(x) __builtin_expect ((x) != 0, 0) > > #define likely(x) __builtin_expect (!!(x), 1) > #define unlikely(x) __builtin_expect (!!(x), 0)
Choosing the more familiar idiom for booleanizing a value, here we go:
diff -Naurd old/include/linux/compiler.h new/include/linux/compiler.h --- old/include/linux/compiler.h 2003-08-11 09:02:18.000000000 -0400 +++ new/include/linux/compiler.h 2003-08-11 09:04:58.000000000 -0400 @@ -24,8 +24,8 @@ #define __builtin_expect(x, expected_value) (x) #endif -#define likely(x) __builtin_expect((x),1) -#define unlikely(x) __builtin_expect((x),0) +#define likely(x) __builtin_expect(!!(x),1) +#define unlikely(x) __builtin_expect(!!(x),0) /* * Allow us to mark functions as 'deprecated' and have gcc emit a nice
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