Re: Short blocking delay in Cortex-M0+

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From	Hans-Bernhard Bröker <HBBroeker@t-online.de>
Newsgroups	comp.arch.embedded
Subject	Re: Short blocking delay in Cortex-M0+
Date	Wed, 22 Mar 2017 22:02:54 +0100
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Am 22.03.2017 um 17:48 schrieb mrfirmware:

> Gah! I forgot about optimizers. Yes the -O2 flag will remove the for
> loop. It's not correct C though to do that.

Actually in the case at hand, it can still be considered correct, 
depending how you interpret some rather involved wording in the standard.

> The port read is immune to optimizer magic.

If there were one in the code under consideration, it might be.  But 
there isn't, so the entire loop is fair game.

Thread

Short blocking delay in Cortex-M0+ pozz <pozzugno@gmail.com> - 2017-02-23 17:15 +0100
  Re: Short blocking delay in Cortex-M0+ John Speth <johnspeth@yahoo.com> - 2017-02-23 09:00 -0800
    Re: Short blocking delay in Cortex-M0+ Tim Wescott <tim@seemywebsite.com> - 2017-02-23 13:15 -0600
    Re: Short blocking delay in Cortex-M0+ pozz <pozzugno@gmail.com> - 2017-02-24 09:51 +0100
      Re: Short blocking delay in Cortex-M0+ rickman <gnuarm@gmail.com> - 2017-02-24 04:26 -0500
      Re: Short blocking delay in Cortex-M0+ Tim Wescott <seemywebsite@myfooter.really> - 2017-02-24 14:22 -0600
    Re: Short blocking delay in Cortex-M0+ Jack <jack4747@gmail.com> - 2017-02-24 02:22 -0800
    Re: Short blocking delay in Cortex-M0+ Don Y <blockedofcourse@foo.invalid> - 2017-02-24 10:51 -0700
    Re: Short blocking delay in Cortex-M0+ Stefan Reuther <stefan.news@arcor.de> - 2017-02-24 18:29 +0100
      Re: Short blocking delay in Cortex-M0+ Dave Nadler <drn@nadler.com> - 2017-02-24 13:03 -0800
    Re: Short blocking delay in Cortex-M0+ mrfirmware <mrfirmware@gmail.com> - 2017-03-22 09:29 -0700
      Re: Short blocking delay in Cortex-M0+ mrfirmware <mrfirmware@gmail.com> - 2017-03-22 09:48 -0700
        Re: Short blocking delay in Cortex-M0+ Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2017-03-22 22:02 +0100
        Re: Short blocking delay in Cortex-M0+ David Brown <david.brown@hesbynett.no> - 2017-03-23 10:05 +0100
          Re: Short blocking delay in Cortex-M0+ Tim Wescott <seemywebsite@myfooter.really> - 2017-03-23 12:54 -0500
            Re: Short blocking delay in Cortex-M0+ mrfirmware <mrfirmware@gmail.com> - 2017-03-23 12:52 -0700
  Re: Short blocking delay in Cortex-M0+ Don Y <blockedofcourse@foo.invalid> - 2017-02-23 13:54 -0700
  Re: Short blocking delay in Cortex-M0+ Paul <paul@pcserviceselectronics.co.uk> - 2017-02-24 10:36 +0000
  Re: Short blocking delay in Cortex-M0+ pozz <pozzugno@gmail.com> - 2017-03-24 12:23 +0100
    Re: Short blocking delay in Cortex-M0+ David Brown <david.brown@hesbynett.no> - 2017-03-24 12:57 +0100
      Re: Short blocking delay in Cortex-M0+ pozz <pozzugno@gmail.com> - 2017-03-24 13:54 +0100
        Re: Short blocking delay in Cortex-M0+ David Brown <david.brown@hesbynett.no> - 2017-03-24 15:21 +0100
          Re: Short blocking delay in Cortex-M0+ Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-24 21:26 +0200
            Re: Short blocking delay in Cortex-M0+ David Brown <david.brown@hesbynett.no> - 2017-03-25 01:11 +0100

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