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Re: Signed int overflow behavior in the security context
- From: Robert Dewar <dewar at adacore dot com>
- To: Paul Schlie <schlie at comcast dot net>
- Cc: Richard Guenther <richard dot guenther at gmail dot com>, Joe Buck <Joe dot Buck at synopsys dot com>, Andreas Bogk <andreas at andreas dot org>, gcc at gcc dot gnu dot org
- Date: Sun, 28 Jan 2007 00:03:43 -0500
- Subject: Re: Signed int overflow behavior in the security context
- References: <C1E180C7.FB0E%schlie@comcast.net>
Paul Schlie wrote:
I'm game; how might multiple specified references to the same non-volatileS
variable with no specified intervening assignments in a single threaded
language ever justifiably be interpreted to validly yield differing values?
Sorry, I'm not "game", it's something you should be able to figure out
if you know how compilers generate code and how typical compiler
optimization circuits propagate undefined information.
(any logically consistent concrete example absent reliance on undefined
hand-waving would be greatly appreciated; as any such interpretation or
implementation would seem clearly logically inconsistent and thereby
useless; as although the value of a variable may be undefined, variable
reference semantics are well defined and are independent of its value)
Nope, you are making this up again, if you reference an uninitialized
variables, the value is undefined, period.