Feeds

We only use above average programmers here...

Floating point and legacy

Boost IT visibility and business value

A number of people have commented that "nobody" uses Floating Point in financial calculations, for all the reasons Dan Clarke went into in his recent article on Floating Point and rounding issues.

But it seems to me that this misses the point. Yes, I'm old enough to remember when IBM mainframes, and its COBOL, supported BCD (binary coded decimal) and, since I was working for a bank, our coding standards warned you about Floating Point and rounding/truncation effects generally.

So, lots of languages and hardware today support decimal arithmetic and other relatively safe ways of doing financial calculations - but who tells programmers to employ them? Who, for that matter, reads (or writes) coding standards manuals?

Well, some people do and some places will (possibly more sensibly) see training courses as a more effective alternative to standards manuals, but floating point arithmetic, in the wrong place, is still a bug waiting to happen.

Surely, the common assumptions that "all our programmers are above average" (really? are you sure? do you have any metrics for this?) and "no-one competent enough to be employed here would ever do that" are exactly what give rise to the sort of expensive bugs that pop up in the Risks Digests and embarrass everyone?

I once worked for a bank that only employed above average people. One of them decided to write a new date routine using 9s complement arithmetic, so that dates were stored/retrieved in some "right" order - but he couldn't do 9s complement arithmetic himself reliably.

Then, there was the guy that could write database locks more efficiently than IBM could - but forgot to issue any unlocks. I doubt either of these people lasted long, they were pretty much "below average", but some people can write a lot of code in three months or so - I wonder how much of it is still there in this bank's systems...

Although, perhaps it is pretty safe by now. That is one of the good things about legacy systems – like old houses, if they haven’t already fallen over and been abandoned, they’ve settled into rock-solid stability over the years. Although, like old houses, they can be tricky to maintain...®

Build a business case: developing custom apps

More from The Register

next story
KDE releases ice-cream coloured Plasma 5 just in time for summer
Melty but refreshing - popular rival to Mint's Cinnamon's still a work in progress
Leaked Windows Phone 8.1 Update specs tease details of Nokia's next mobes
New screen sizes, dual SIMs, voice over LTE, and more
Mozilla keeps its Beard, hopes anti-gay marriage troubles are now over
Plenty on new CEO's todo list – starting with Firefox's slipping grasp
Apple: We'll unleash OS X Yosemite beta on the MASSES on 24 July
Starting today, regular fanbois will be guinea pigs, it tells Reg
Another day, another Firefox: Version 31 is upon us ALREADY
Web devs, Mozilla really wants you to like this one
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
Cloudy CoreOS Linux distro declares itself production-ready
Lightweight, container-happy Linux gets first Stable release
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Maximize storage efficiency across the enterprise
The HP StoreOnce backup solution offers highly flexible, centrally managed, and highly efficient data protection for any enterprise.