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[avr-gcc-list] Re: optimizer removes volatile pin access code. why?
From: |
Joerg Desch |
Subject: |
[avr-gcc-list] Re: optimizer removes volatile pin access code. why? |
Date: |
Wed, 28 Oct 2009 07:22:19 +0100 |
On Tue, 27 Oct 2009 20:17:46 +0100 (MET)
address@hidden (Joerg Wunsch) wrote:
> How did you verify it?
First I can't see the pulse on the oscilloscope ;-)
Than I had a look in the list file.
> I don't believe the compiler removed the code. (If you really think
> it does, please supply a compilable code example.)
Give me some time. I try to put it in a simple snippet. Is it OK to
attach it as tgz to this mailing list?
> However, the
> optimized code will just toggle the pin for a single CPU cycles only,
> while the pin will stay a little longer at high in the non-optimized
> example. So if your oscilloscope is too slow, you might not notice
> the pin actually becoming high for one clock period.
Tektroniks TDS784 with 4GS/s ;-)
--
Email: Joerg Desch <jd DOT vvd AT web DOT de>
- [avr-gcc-list] optimizer removes volatile pin access code. why?, Joerg Desch, 2009/10/27
- Re: [avr-gcc-list] optimizer removes volatile pin access code. why?, Joerg Wunsch, 2009/10/27
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?,
Joerg Desch <=
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, David Brown, 2009/10/28
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, Joerg Desch, 2009/10/28
- Re: [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, Erik Christiansen, 2009/10/28
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, Joerg Desch, 2009/10/31
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, Erik Christiansen, 2009/10/28
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, David Brown, 2009/10/28
- RE: [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, Stu Bell, 2009/10/28
- [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, David Brown, 2009/10/29
- RE: [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, Stu Bell, 2009/10/30
- Re: [avr-gcc-list] Re: optimizer removes volatile pin access code. why?, df_welch, 2009/10/28