ru.unix.bsd

 
 - RU.UNIX.BSD ------------------------------------------------------------------
 From : Slawa Olhovchenkov                   2:5030/500     07 Jul 2004  13:34:06
 To : Eugen
 Subject : gcc & -O2
 -------------------------------------------------------------------------------- 
 

 
 07 Jul 04, Eugene Grosbein writes to Eugene Grosbein:
 
  EG>> Забавно: src/lib/libalias/alias.c,1.47 в репозитории FreeBSD.
 
  EG> Хотел это в ru.unix.prog, но промахнулся. Впрочем, ладно.
  EG> Есть мнение, что теперь в 5-CURRENT не осталось багов, связанных с -O2.
 
 Щаз.
 
 From: David Schultz <das@freebsd.org>
 
 FWIW, I've been compiling most things with -O2 for a while (to
 find -O2 bugs, not for speed) and haven't noticed many problems.
 The only significant one I know of is that -O2 breaks
 floating-point exceptions in libm because gcc doesn't support the
 FENV_ACCESS pragma.  I think for some routines like rint(3), it
 may even give the wrong answer due to incorrect optimizations, but
 I'd have to check that again.
 
 AFAIK, the necessary functionality to make gcc's optimizer treat
 floating-point code in a sane manner isn't on the horizon, so
 maybe -O2 should be automatically turned off while compiling libm
 (and perhaps libalias as well).  That would make it more
 easily justifiable to make -O2 the default at some future point.
 
 ... Это опять-таки случай так называемого вранья, бумажки, граждане, настоящие!
 --- GoldED+/BSD 1.1.5
  * Origin:  (2:5030/500)
 
 

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Тема:    Автор:    Дата:    gcc & -O2   Eugene Grosbein   07 Jul 2004 16:56:12   Re: gcc & -O2   Eugene Grosbein   07 Jul 2004 17:00:00   gcc & -O2   Slawa Olhovchenkov   07 Jul 2004 13:34:06   Re: gcc & -O2   Eugene Grosbein   07 Jul 2004 18:17:57