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From: "roger at eyesopen dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/11259] [avr] gcc Double 'andi' missed optimization
Date: Tue, 11 Nov 2003 04:23:00 -0000	[thread overview]
Message-ID: <20031111042331.7854.qmail@sources.redhat.com> (raw)
In-Reply-To: <20030619231538.11259.chris@westnet.com>


------- Additional Comments From roger at eyesopen dot com  2003-11-11 04:23 -------
The AVR backend defines its lshrqi3 patterns as opaque "macro" sequences,
hence the fact that "x >> 4" is implemented as a swap/rotate followed by
an and instruction is never exposed to GCC's RTL optimizers.  If it were,
the two ands would be optimized away by CSE, combine or peephole, as they
are for other targets.

As there's nothing the middle-end can do unless the AVR backend is rewritten
to use RTL expanders, I'm changing this PR's component to target/11259.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|optimization                |target


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11259


  parent reply	other threads:[~2003-11-11  4:23 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-06-19 23:33 [Bug optimization/11259] New: " chris at westnet dot com
2003-07-06  1:32 ` [Bug optimization/11259] " pinskia at physics dot uc dot edu
2003-07-06  2:13 ` chris at westnet dot com
2003-07-06  2:16 ` pinskia at physics dot uc dot edu
2003-07-06  3:03 ` chris at westnet dot com
2003-07-06  3:11 ` pinskia at physics dot uc dot edu
2003-08-04 20:59 ` pinskia at physics dot uc dot edu
2003-08-11 18:19 ` pinskia at gcc dot gnu dot org
2003-11-11  4:23 ` roger at eyesopen dot com [this message]
     [not found] <bug-11259-6346@http.gcc.gnu.org/bugzilla/>
2007-07-25  0:04 ` [Bug target/11259] " eweddington at cso dot atmel dot com
2007-11-28 22:07 ` rask at gcc dot gnu dot org
2008-08-22 21:27 ` aesok at gcc dot gnu dot org
2008-08-22 23:07 ` eric dot weddington at atmel dot com

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