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* [Bug target/50447] New: [avr] Better support of AND, OR, XOR and PLUS with constant integers for 16- and 32-bit values
@ 2011-09-18 13:12 gjl at gcc dot gnu.org
  2011-09-18 13:23 ` [Bug target/50447] " gjl at gcc dot gnu.org
                   ` (6 more replies)
  0 siblings, 7 replies; 8+ messages in thread
From: gjl at gcc dot gnu.org @ 2011-09-18 13:12 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50447

             Bug #: 50447
           Summary: [avr] Better support of AND, OR, XOR and PLUS with
                    constant integers for 16- and 32-bit values
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gjl@gcc.gnu.org
            Target: avr


The current implementation sometimes leads to poor code for several reasons:

o Insn "*iorsi3_clobber" is hidden behind "iorsi3" and thus will never
  be used.

o There are no such insn for AND, XOR, PLUS so that the constant gets 
  reloaded to a same-width register where a QI was sufficient.

o If a clobber is needed, the value in the clobber reg is not reused.

o Work out if a clobber is actually needed.


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2011-10-19 15:00 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2011-09-18 13:12 [Bug target/50447] New: [avr] Better support of AND, OR, XOR and PLUS with constant integers for 16- and 32-bit values gjl at gcc dot gnu.org
2011-09-18 13:23 ` [Bug target/50447] " gjl at gcc dot gnu.org
2011-09-22 10:00 ` gjl at gcc dot gnu.org
2011-09-23 17:09 ` gjl at gcc dot gnu.org
2011-09-23 17:11 ` gjl at gcc dot gnu.org
2011-09-23 17:21 ` gjl at gcc dot gnu.org
2011-10-11 18:29 ` gjl at gcc dot gnu.org
2011-10-19 15:00 ` gjl at gcc dot gnu.org

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