Re: snag of G_LIKELY()

[Mark Mielke <mark mark mielke cc>]

On Sat, Nov 23, 2002 at 08:38:06PM +0100, Daniel Elstner wrote:
> > #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
> > #define _G_BOOLEAN_EXPR(expr)                   \
> >  __extension__ ({                               \
> >    int _g_boolean_var_;                         \
> >    if (expr)                                    \
> >       _g_boolean_var_ = 1;                      \
> >    else                                         \
> >       _g_boolean_var_ = 0;                      \
> >    _g_boolean_var_;                             \
> > })
> > #define G_LIKELY(expr) __builtin_expect (_G_BOOLEAN_EXPR(expr), 1)
> > #define G_UNLIKELY(expr) __builtin_expect (_G_BOOLEAN_EXPR(expr), 0)
> > #else
> > #define G_LIKELY(expr) expr
> > #define G_UNLIKELY(expr) expr
> > #endif

I think I missed the point... why shouldn't it be:

  #define G_LIKELY(expr) __builtin_expect(!(expr), 0)
  #define G_UNLIKELY(expr) __builtin_expect((expr), 0)

mark

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