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From: "torvalds@linux-foundation.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/49095] Horrible code generation for trivial decrement with test
Date: Fri, 27 May 2011 16:52:00 -0000	[thread overview]
Message-ID: <bug-49095-4-GiUTMsBgSU@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-49095-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49095

--- Comment #10 from Linus Torvalds <torvalds@linux-foundation.org> 2011-05-27 16:48:52 UTC ---
(In reply to comment #9)
> 
>         32-bit before    32-bit after    64-bit before    64-bit after
> libstdc++.so.6    0x71708        0x716e8        0x67ee6        0x67ec6
> libgcj.so.12    0xa3ec58    0xa3eb98    0x90cd68    0x90cce8
> cc1plus        0xe8a29c    0xe8a25c    0xdccf98    0xdccf08

Ok, that's much less noticeable than I was hoping for.

That said, even for the kernel, the only reason I noticed this problem was not
because I've seen a lot of them per se, but because the pattern showed up in a
very hot function. In fact, it's the same __rcu_read_unlock() function that I
made the otherwise unrelated bugzilla entry for inlining: 

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49194

so it's quite possible that we don't have that many of them in the kernel
either.


  parent reply	other threads:[~2011-05-27 16:49 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-21  3:46 [Bug other/49095] New: " torvalds@linux-foundation.org
2011-05-21 10:12 ` [Bug rtl-optimization/49095] " rguenth at gcc dot gnu.org
2011-05-21 19:22 ` torvalds@linux-foundation.org
2011-05-21 21:33 ` torvalds@linux-foundation.org
2011-05-27 10:50 ` jakub at gcc dot gnu.org
2011-05-27 12:30 ` jakub at gcc dot gnu.org
2011-05-27 14:22 ` torvalds@linux-foundation.org
2011-05-27 14:55 ` jakub at gcc dot gnu.org
2011-05-27 16:02 ` torvalds@linux-foundation.org
2011-05-27 16:36 ` jakub at gcc dot gnu.org
2011-05-27 16:52 ` torvalds@linux-foundation.org [this message]
2011-05-29 18:53 ` jakub at gcc dot gnu.org
2011-05-29 18:57 ` jakub at gcc dot gnu.org
2011-05-29 19:09 ` torvalds@linux-foundation.org

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