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From: "vvv at ru dot ru" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/40171] GCC does not pass -mtune and -march options to assembler!
Date: Mon, 25 May 2009 19:54:00 -0000	[thread overview]
Message-ID: <20090525195425.19329.qmail@sourceware.org> (raw)
In-Reply-To: <bug-40171-17483@http.gcc.gnu.org/bugzilla/>



------- Comment #4 from vvv at ru dot ru  2009-05-25 19:54 -------
(In reply to comment #2)
> This is very odd?  What is the assembler doing that the compiler isn't?

There are exist some optimizations impossible without exact knowledge of
address and opcodes,
One example avoiding of branch mispredicts -
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39942
Other example - Ensure instructions using 0xF7 opcode byte does not start at
offset 14 of a fetch line...

Unfortunately, current version GNU AS cat't do this optimizations.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40171


  parent reply	other threads:[~2009-05-25 19:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-16 14:18 [Bug c/40171] New: " vvv at ru dot ru
2009-05-24 21:17 ` [Bug target/40171] " rguenth at gcc dot gnu dot org
2009-05-25  0:46 ` sabre at nondot dot org
2009-05-25  0:55 ` pinskia at gcc dot gnu dot org
2009-05-25 19:54 ` vvv at ru dot ru [this message]
     [not found] <bug-40171-4@http.gcc.gnu.org/bugzilla/>
2010-11-07 16:16 ` mahatma at eu dot by
2010-11-17 19:26 ` mahatma at eu dot by
2010-11-18 12:38 ` mahatma at eu dot by
2011-04-15 16:33 ` mahatma at eu dot by

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