public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug target/52505] New: [avr]: __memx address space reading unintentionally from RAM
@ 2012-03-06 11:26 gjl at gcc dot gnu.org
  2012-03-06 11:27 ` [Bug target/52505] " gjl at gcc dot gnu.org
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: gjl at gcc dot gnu.org @ 2012-03-06 11:26 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52505

             Bug #: 52505
           Summary: [avr]: __memx address space reading unintentionally
                    from RAM
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gjl@gcc.gnu.org
            Target: avr


The __memx address space reader must determine at runtime from what memory area
to read and what instruction to use. To read one byte, ine sequence might look
like:

    ld   r24,Z
    sbrs r25,7
    lpm  r24,Z

This is not correct because if the read is fram flash memory but the address
taken as RAM address points to the I/O area, the read might have an effect on
I/O register, for example clear a latch or buffer.


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2012-03-22 15:30 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-03-06 11:26 [Bug target/52505] New: [avr]: __memx address space reading unintentionally from RAM gjl at gcc dot gnu.org
2012-03-06 11:27 ` [Bug target/52505] " gjl at gcc dot gnu.org
2012-03-07 10:36 ` gjl at gcc dot gnu.org
2012-03-22 15:15 ` gjl at gcc dot gnu.org
2012-03-22 15:31 ` gjl at gcc dot gnu.org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).