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* Using __builtin_expect (likely/unlikely macros)
@ 2019-04-15  0:15 Alex Gramiak
  2019-04-15  1:18 ` Paul Eggert
  0 siblings, 1 reply; 45+ messages in thread
From: Alex Gramiak @ 2019-04-15  0:15 UTC (permalink / raw)
  To: emacs-devel

Would using these, if available, be acceptable? I noticed that some code
in configure.ac already defines HAVE___BUILTIN_EXPECT, though I couldn't
see what part of autoconf does this.

Good candidates here include the conditionals around emacs_abort/fatal,
and possibly in cases like the *alloc procedures and xfree.

Even if there's no noticeable speedup, I think that the likely/unlikely
macros are a nice way to indicate that a branch is exceedingly
rare/common.

  #define unlikely(expr) __builtin_expect(!!(expr), 0)
  #define likely(expr) __builtin_expect(!!(expr), 1)



^ permalink raw reply	[flat|nested] 45+ messages in thread

end of thread, other threads:[~2020-04-15  3:14 UTC | newest]

Thread overview: 45+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-04-15  0:15 Using __builtin_expect (likely/unlikely macros) Alex Gramiak
2019-04-15  1:18 ` Paul Eggert
2019-04-15  3:11   ` Alex Gramiak
2019-04-15  4:41     ` Paul Eggert
2019-04-16  0:16       ` Alex Gramiak
2019-04-16  2:34         ` Eli Zaretskii
2019-04-16  5:33           ` Alex Gramiak
2019-04-16 15:23             ` Eli Zaretskii
2019-04-16 15:47               ` Alex Gramiak
2019-04-16  3:42         ` Paul Eggert
2019-04-16 13:05           ` Stefan Monnier
2019-04-16 15:22             ` Paul Eggert
2019-04-16 16:10               ` Alex Gramiak
2019-04-16 17:54                 ` Paul Eggert
2019-04-16 20:50                   ` Alex Gramiak
2019-04-16 21:11                     ` Alex Gramiak
2019-04-16 21:27                     ` Stefan Monnier
2019-04-16 21:27                     ` Konstantin Kharlamov
2019-04-18  8:25                       ` Paul Eggert
2019-04-18  8:43                         ` Konstantin Kharlamov
2019-04-18 13:47                         ` Andy Moreton
2019-04-18 17:27                           ` Paul Eggert
2019-04-18 17:56                             ` Andy Moreton
2019-04-18 19:32                               ` Paul Eggert
2019-04-19 13:45                         ` Alex Gramiak
2019-04-19 13:58                           ` Konstantin Kharlamov
2019-04-19 14:45                             ` Alex Gramiak
2019-04-19 17:33                           ` Paul Eggert
2019-04-19 20:53                             ` Alex Gramiak
2019-04-20  0:05                               ` Alan Mackenzie
2019-04-20  0:42                                 ` Paul Eggert
2019-04-20 19:46                                   ` Alan Mackenzie
2019-04-20 15:29                             ` Andy Moreton
2019-04-20 15:57                               ` Paul Eggert
2019-04-20 16:03                                 ` Eli Zaretskii
2019-04-20 16:11                                   ` Paul Eggert
2019-04-20 16:18                                     ` Eli Zaretskii
2019-04-20 16:57                                       ` Paul Eggert
2019-04-20 17:22                                         ` Eli Zaretskii
2019-04-20 19:13                                           ` Paul Eggert
2019-04-20 16:28                                 ` Óscar Fuentes
2019-04-20 18:58                                   ` Paul Eggert
2019-04-20 19:35                                     ` Óscar Fuentes
2019-04-20 22:54                                       ` Paul Eggert
2020-04-15  3:14   ` John Carter

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