Re: [avr-gcc-list] avr-gcc (GCC) 3.4.5 Bug: copying structure through pointer will destroy the pointer

[hutchinsonandy]

The patch was to fix issue where GCC ran out of pointer regs.  The RTL 
level fix  should be safe - assuming GCC doesnt mess up on register 
allocation- so maybe this is just highlighting some other bug.



I cant add more without copy of assembler that clobbers pointers.


Andy Hutchinson

-----Original Message-----
From: Joerg Wunsch <address@hidden>
To: address@hidden
Cc: address@hidden; address@hidden; 
address@hidden; address@hidden
Sent: Wed,  1 Mar 2006 19:39:27 +0100 (MET)
Subject: Re: [avr-gcc-list] avr-gcc (GCC) 3.4.5 Bug: copying structure 
through pointer will destroy the pointer

 "Dmitry K." <address@hidden> wrote:

> > Here's the smallest reproducible test case:

> Avr-gcc 3.3.5 is correct:

By trial & error, I narrowed it down to be a change between GCC 3.4.3
and GCC 3.4.4.  After reviewing the ChangeLog, the following caught my
attention:

2005-03-19  Andy Hutchinson  <address@hidden>

      PR target/18251
      * config/avr/avr.md (movstrhi): Rewrite as RTL loop.
      (*movstrqi_insn): Delete.
      (*movstrhi): Delete.

It corresponds to the following SVN log entry:

Revision 96732 - (view) (download) - [select for diffs]
Modified Sat Mar 19 15:45:41 2005 UTC (11 months, 1 week ago) by marekm
File length: 79688 byte(s)
Diff to previous 96394 (colored)

   PR target/18251
   * config/avr/avr.md (movstrhi): Rewrite as RTL loop.
   (*movstrqi_insn): Delete.
   (*movstrhi): Delete.

I'm attaching the diff that caused it.  If I unpatch a GCC 3.4.4
(using patch -p2 -R < avr.md.patch -- remember you have to revert the
original change, thus the -R), it generates the correct code again.

--
J"org Wunsch                                           Unix support 
engineer
address@hidden        
http://www.interface-systems.de/~j/


___________________________________________________
Try the New Netscape Mail Today!
Virtually Spam-Free | More Storage | Import Your Contact List
http://mail.netscape.com