RE: Memory corruption due to word sharing

From: Bernd Petrovitsch
Date: Thu Feb 02 2012 - 04:30:08 EST


On Mit, 2012-02-01 at 21:04 +0000, Boehm, Hans wrote:
[...]
> The C11 memory model potentially adds overhead in only two cases:
>
> 1. When current code involves touching a field that wouldn't otherwise
> be touched. There are odd cases in which this measurably slows down
> code, but I think all agree that we need it. In addition to
> bitfields, it can affect speculatively promoting a value to a register
> in a loop, which at least older versions of gcc also do.

Just adding an -f option for this and/or activating it only for -O5 (or
whatever the highest level is) and - in case that feature is activated -
emit warnings if bitfields (and/or any other data types that might be
affected)?

Kind regards,
Bernd
--
Bernd Petrovitsch Email : bernd@xxxxxxxxxxxxxxxxxxx
LUGA : http://www.luga.at

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