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Re: Average swaps per word?

From Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem>
Newsgroups comp.lang.forth
Subject Re: Average swaps per word?
Date 2016-11-14 16:39 -0500
Organization Aioe.org NNTP Server
Message-ID <20161114163948.63e4da69@_> (permalink)
References (2 earlier) <o07bak$ru0$1@cherry.spenarnc.xs4all.nl> <2016Nov13.155518@mips.complang.tuwien.ac.at> <o0af90$5sf$1@cherry.spenarnc.xs4all.nl> <871syff9mv.fsf@nightsong.com> <2016Nov14.184256@mips.complang.tuwien.ac.at>

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On Mon, 14 Nov 2016 17:42:56 GMT
anton@mips.complang.tuwien.ac.at (Anton Ertl) wrote:

> Paul Rubin <no.email@nospam.invalid> writes:
> >albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) writes:  

> >>>and gcc therefore "optimized" the memset() away.  And
> >>>while the following read from that memory (due to a buffer
> >>>overflow)  
> >>
> >> They should have checked what happens while optimising. Failing
> >> that they shouldn't have optimised.  
> >
> >The right way to do that in C is with a volatile cast.  
> 
> Is it?

I haven't read the C specification on "volatile" in a while, but
"volatile" is supposed to prevent optimizing away reads or writes to
memory or ports.  "volatile" is used to tell the compiler that
something outside the context of the compiled C code is modifying
memory locations or updating values, e.g., ports, such as from hardware
or another program.  Of course, casting an integer to a memory or port
address is undefined behavior in C, or compiler defined behavior.


Rod Pemberton

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Thread

Average swaps per word? trans <transfire@gmail.com> - 2016-11-08 22:03 -0800
  Re: Average swaps per word? "Elizabeth D. Rather" <erather@forth.com> - 2016-11-08 20:20 -1000
  Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-09 08:16 +0000
  Re: Average swaps per word? Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-11-09 03:34 -0500
    Re: Average swaps per word? trans <transfire@gmail.com> - 2016-11-09 02:53 -0800
      Re: Average swaps per word? rickman <gnuarm@gmail.com> - 2016-11-09 11:50 -0500
        Re: Average swaps per word? stephen@mpeforth.com (Stephen Pelc) - 2016-11-09 18:37 +0000
          Re: Average swaps per word? Harold <hzrabbie@gmail.com> - 2016-11-10 16:28 -0800
            Re: Average swaps per word? stephen@mpeforth.com (Stephen Pelc) - 2016-11-11 17:51 +0000
            Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-12 12:23 +0000
              Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-12 16:09 +0100
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-13 14:55 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-13 20:34 +0100
                Re: Average swaps per word? Paul Rubin <no.email@nospam.invalid> - 2016-11-13 11:43 -0800
                Re: Average swaps per word? hughaguilar96@gmail.com - 2016-11-13 16:58 -0800
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-14 16:41 +0100
                Re: Average swaps per word? hughaguilar96@gmail.com - 2016-11-14 16:38 -0800
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-14 17:42 +0000
                Re: Average swaps per word? Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-11-14 16:39 -0500
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-17 12:40 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-17 14:10 +0100
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-18 15:14 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-20 18:16 +0100
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-22 10:29 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-22 15:54 +0100
                Re: Average swaps per word? James Kuyper <jameskuyper@verizon.net> - 2016-11-22 11:50 -0500
                Re: Average swaps per word? raltbos@xs4all.nl (Richard Bos) - 2016-11-24 17:27 +0000
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-15 03:55 -0600
                Re: Average swaps per word? Rod Pemberton <NeedNotReplyHere@xrsevnneqk.cem> - 2016-11-15 17:49 -0500
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-16 02:59 -0600
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-17 13:07 +0000
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-16 22:57 +0000
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-17 03:12 -0600
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-17 12:32 +0100
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-18 15:02 +0000
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-17 13:23 +0000
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-17 08:54 -0600
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-18 15:54 +0000
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-18 12:37 -0600
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-14 17:32 +0000
                Re: Average swaps per word? Mark Wills <markwills1970@gmail.com> - 2016-11-15 02:09 -0800
                Re: Average swaps per word? jim <anon@example.com> - 2016-11-15 10:44 +0000
                Re: Average swaps per word? Mark Wills <markwills1970@gmail.com> - 2016-11-15 03:12 -0800
                Re: Average swaps per word? Alex <alex@rivadpm.com> - 2016-11-15 13:01 +0000
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-17 12:51 +0000
                Re: Average swaps per word? Alex <alex@rivadpm.com> - 2016-11-17 14:02 +0000
                Re: Average swaps per word? Alex <alex@rivadpm.com> - 2016-11-17 14:06 +0000
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-18 15:26 +0000
                Re: Average swaps per word? Alex <alex@rivadpm.com> - 2016-11-18 18:33 +0000
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-19 03:32 -0600
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-17 14:29 +0100
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-15 13:51 +0100
                Re: Average swaps per word? jim <anon@example.com> - 2016-11-15 13:01 +0000
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-17 12:46 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-17 14:16 +0100
              Re: Average swaps per word? Harold <hzrabbie@gmail.com> - 2016-11-13 11:08 -0800
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-14 17:08 +0000
                Re: Average swaps per word? Mark Wills <markwills1970@gmail.com> - 2016-11-15 02:04 -0800
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-15 14:04 +0100
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-15 14:05 +0100
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-17 12:58 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-17 15:16 +0100
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-18 15:41 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-20 18:12 +0100
  Re: Average swaps per word? minforth@arcor.de - 2016-11-09 03:15 -0800
    Re: Average swaps per word? trans <transfire@gmail.com> - 2016-11-09 11:22 -0800
    Re: Average swaps per word? "HAA" <someone@microsoft.com> - 2016-11-10 12:20 +1100
      Re: Average swaps per word? "Elizabeth D. Rather" <erather@forth.com> - 2016-11-09 21:04 -1000
      Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-10 03:45 -0600
        Re: Average swaps per word? rickman <gnuarm@gmail.com> - 2016-11-10 11:52 -0500
          Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-10 11:42 -0600
            Re: Average swaps per word? rickman <gnuarm@gmail.com> - 2016-11-10 13:34 -0500
              Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-10 12:54 -0600
                Re: Average swaps per word? rickman <gnuarm@gmail.com> - 2016-11-10 16:33 -0500
                Re: Average swaps per word? "Elizabeth D. Rather" <erather@forth.com> - 2016-11-10 15:56 -1000
                Re: Average swaps per word? rickman <gnuarm@gmail.com> - 2016-11-10 21:30 -0500
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-11 03:04 -0600
                Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-12 13:25 +0000
                Re: Average swaps per word? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-11-14 03:34 -0600
                Re: Average swaps per word? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-11-11 10:41 +0000
                Re: Average swaps per word? hughaguilar96@gmail.com - 2016-11-11 16:45 -0800
      Re: Average swaps per word? jim <anon@example.com> - 2016-11-10 11:17 +0000
        Re: Average swaps per word? Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-11-10 04:34 -0800
          Re: Average swaps per word? jim <anon@example.com> - 2016-11-10 12:44 +0000
            Re: Average swaps per word? Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-11-10 07:27 -0800
              Re: Average swaps per word? Ron Aaron <rambamist@gmail.com> - 2016-11-10 18:26 +0200
              Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-10 16:05 +0000
        Re: Average swaps per word? stephen@mpeforth.com (Stephen Pelc) - 2016-11-10 14:55 +0000
          Re: Average swaps per word? "HAA" <someone@microsoft.com> - 2016-11-12 11:36 +1100
            Re: Average swaps per word? hughaguilar96@gmail.com - 2016-11-11 16:56 -0800
            Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-12 16:14 +0100
          Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-12 12:14 +0000
            Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-12 16:16 +0100
              Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-13 14:51 +0000
                Re: Average swaps per word? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-11-13 20:41 +0100
      Re: Average swaps per word? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-10 14:42 +0000
  Re: Average swaps per word? hughaguilar96@gmail.com - 2016-11-11 15:54 -0800

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