Frama-C news and ideas

To content | To menu | To search | Frama-C Home

Big round numbers, and a book review

Nearly 15 months ago, according to a past article, this blog celebrated its 15-month anniversary, and celebrated with the announcement of minor milestones having been reached: 100 articles and 50 comments.

Fifteen months after that, the current count is nearly 200 articles and 200 comments. Also, the blog managed to get 100 subscribers in Google's centralized service for never having to mark the same post as read twice, Reader. This was a close call.

A lot of recent posts have been related to floating-point arithmetic. I would like to reassure everyone that this was only a fluke. Floating-point correctness became one of the Frama-C tenets with our involvement in two collaborative projects, U3CAT and Hisseo, now both completed. Very recently, something must have clicked for me and I became quite engrossed by the subject.

As a result of this recent passion, in the last few days, I started reading the “Handbook of Floating-Point Arithmetic”, by Jean-Michel Muller et al. This book is both thick and dense, but fortunately well organized, so that it is easy to skip over sections you do not feel concerned with, such as decimal floating-point or hardware implementation details. This book is an amazing overview. It contains cristal-clear explanations of floating-point idioms that I was until then painstakingly reverse-engineering from library code. Fifteen years from now, people will say, “… and you should read the Handbook of Floating-Point Arithmetic. It is a bit dated now, but it is still the best reference, just complete it with this one and that one”, just like people might say now about Aho, Sethi and Ullman's Dragon book for compilation.

Except that right now, the book is current. The references to hardware are references to hardware that you might still have, or certainly remember having had. The open questions are still open. If you were offered the chance to read the Dragon book when it came out and was all shiny and new, would you pass? If not, and if there is the slightest chance that you might hold an interest in the mysteries of floating-point computation in the foreseeable future, read this book now, for the bragging rights.

In addition, the book goes down to the lowest levels of detail, with occasional snippets of programs to make it clear what is meant. The snippets are C code, and irreproachable C code.