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Reading indeterminate contents might as well be undefined
Pascal Cuoq on 13 March 2013

Warning: on a punctiliousness scale ranging from zero to ten, this post is a good nine-and-a-half. There was no tag for that, so I tagged it both “C99” and “C11”. The faithful reader will know what to expect. There is a bit of C90, too. To summarize, it may appear...

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Correct rounding or mathematically-correct rounding?
Pascal Cuoq on 3 March 2013

CRlibm is a high-quality library of floating-point elementary functions. We used it as reference a long time ago in this blog while looking at lesser elementary function implementations and the even lesser properties we could verify about them. A bold choice The CRlibm documentation contains this snippet: […] it may...

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Portable modulo signed arithmetic operations
Pascal Cuoq on 26 February 2013

In a recent post, John Regehr reports on undefined behaviors in Coq! In Coq! Coq! Exclamation point! Coq is a proof assistant. It looks over your shoulder and tells you what remains to be done while you are elaborating a mathematical proof. Coq has been used to check that the...

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From Facebook to Silent Circle, through the “metrics” Frama-C plug-in
Pascal Cuoq on 16 February 2013

From Facebook to Silent Circle Some computers at Facebook were recently compromised because of a zero-day in Java. Nothing unexpected. Last december instead of writing a full blog post I lazily linked to Robert Graham predicting this sort of thing for the year 2013. Speaking of Facebook do you know...

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ENSL seminar
Pascal Cuoq on 1 February 2013

Seminar As anticipated, I was at my alma mater's student seminar last tuesday. School and seminar were very much like I remembered them. The latter was improved by orange juice and biscuits to chat around after the talk, that I do not think were part of the protocol when I...

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