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From: "rearnsha at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/64774] [ARM/thumb] missed optimization: pc relative ldr used when constant can be derived from register
Date: Wed, 28 Jan 2015 16:14:00 -0000	[thread overview]
Message-ID: <bug-64774-4-rQGGd0YcaJ@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-64774-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64774

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |arm
           Priority|P3                          |P5
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-01-28
     Ever confirmed|0                           |1

--- Comment #1 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
Although the compiler tries to find some common cases, it is generally
infeasible to detect all the possible permutations that exist.  Furthermore, in
real code generating common expressions in this way can increase register
pressure and have additional impact on some optimization passes.

I don't hold out much hope of this sort of problem ever being entirely fixed.


  reply	other threads:[~2015-01-28 16:14 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-24 16:00 [Bug target/64774] New: " bruck.michael at googlemail dot com
2015-01-28 16:14 ` rearnsha at gcc dot gnu.org [this message]
2015-01-29  2:03 ` [Bug target/64774] " bruck.michael at googlemail dot com

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