--- Comment #11 from ams at gcc dot gnu dot org 2008-11-19 12:03 ---
The patch just committed should fix this issue.
The patch discussion is here:
http://gcc.gnu.org/ml/gcc-patches/2008-11/msg00641.html
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ams at gcc dot gnu dot org changed:
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--- Comment #10 from ams at gcc dot gnu dot org 2008-11-19 11:25 ---
Subject: Bug 36133
Author: ams
Date: Wed Nov 19 11:23:28 2008
New Revision: 141999
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=141999
Log:
2008-11-19 Andrew Stubbs <[EMAIL PROTECTED]>
gcc/
--- Comment #9 from ams at gcc dot gnu dot org 2008-11-10 13:01 ---
> > This tst instruction is unneeded as the LSR is setting the flags correctly
> > already.
>
> This is NOT correct. LSL does write to the condition codes, but not all of it.
> In particular, the bit involved in the not
--- Comment #8 from gunnar at greyhound-data dot com 2008-11-10 12:54
---
(In reply to comment #7)
> (In reply to comment #4)
> > There are two causes where GCC generates unneeded TST instructions.
> > A) General arithmetic
> > lsr.l #1,D0
> > tst.l d0
> > jbne ...
> >
> > This tst
--- Comment #7 from ams at gcc dot gnu dot org 2008-11-10 12:29 ---
(In reply to comment #4)
> There are two causes where GCC generates unneeded TST instructions.
> A) General arithmetic
> lsr.l #1,D0
> tst.l d0
> jbne ...
>
> This tst instruction is unneeded as the LSR is setting t
--- Comment #6 from gunnar at greyhound-data dot com 2008-06-12 14:26
---
Andreas,
Could you have a look at this?
Cheers
Gunnar
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gunnar at greyhound-data dot com changed:
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--- Comment #5 from gunnar at greyhound-data dot com 2008-06-05 12:07
---
Please find below a proposed patch.
The patch will making GCC aware that shift does set the CC already
and the TST is not needed in this case.
The same example could be used to used to make GCC aware of the CC set
--- Comment #4 from gunnar at greyhound-data dot com 2008-06-04 09:29
---
I want to add that this wrong behavior is partly related to the compile option
"-Os".
There are two causes where GCC generates unneeded TST instructions.
A) General arithmetic
lsr.l #1,D0
tst.l d0
jbne ...
--- Comment #3 from gunnar at greyhound-data dot com 2008-05-28 16:14
---
(In reply to comment #1)
> It would have been nice to check at least gcc 4.3 (or better current trunk).
>
I've verified with latest source gcc source "version 4.4.0 20080523
(experimental) (GCC)"
The problem th
--- Comment #2 from hp at gcc dot gnu dot org 2008-05-23 23:04 ---
This could be a duplicate of PR20211.
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hp at gcc dot gnu dot org changed:
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--- Comment #1 from rguenth at gcc dot gnu dot org 2008-05-07 19:33 ---
It would have been nice to check at least gcc 4.3 (or better current trunk).
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rguenth at gcc dot gnu dot org changed:
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