Re eating one's own dogfood: We have the same term in our workplace (granted, only because I introduced it). My code is peppered with comments that say "TODO" and indicate something that ought to be done eventually, but a comment saying "DOGFOOD" (both keywords are always at the beginning of the comment, in all caps) means something that must be done before this program can be used even internally. It's a handy thing to search for, as the word "dogfood" is never going to appear in a quoted string - if it does, I can always just say "dog-food" or something - so even a case-insensitive search will come up with the right results.

Regarding zeroing the accumulator: I've done exactly the same thing when programming an Intel 80x86 (I started on the 8086 and moved up from there into the modern Pentiums). XORing a register with itself is the quickest and tightest way to clear it. Using "MOV AX,0" requires three bytes (opcode and two bytes of literal 16-bit zero), whereas "XOR AX,AX" is only two; it's even more noticeable with the 386-and-higher extended registers, where "MOV EAX,0" requires five bytes (four bytes of 32-bit zero). My C/C++ compiler always zeroes registers this way, so I'd assume it's still the best way (although I haven't studied opcode timing tables in ages, and probably both XOR reg,reg and MOV reg,imm take one clock).

/* Look not upon this file lest your eyes be burnt from your head. */

我能说什么呢?我当时是实习生，夏天快结束了。我们可以说，我对我的文件责任缺乏认真的承诺。

try {

} finally { // should never happen 

}

这一点对其他人来说很有趣，但对我来说就不那么有趣了。我从一个开发人员那里继承了代码(ASP)，而他自己也继承了它。第一个程序员编写了一些很难理解的代码。第二个开发者添加了如下评论(为了保护不那么无辜的人，名字被隐藏了):

'This code was written by **************.
'I haven't a clue what it does. He hasn't a clue what it does.
'Nobody else has a clue what it does or how it does it.
'It is something to do with data but **** knows what.
'The ******* still works so please do not change this code,
'even though it is a complete pile of ****.

那我为什么不觉得有趣呢?嗯，这是一个客户内部网的ASP代码。

.．.正是那位顾客向我强调了这条评论。

:-(

// Any maintenance developer who can't quote entire Monty Python
// movies from memory has no business being a developer. 
const string LancelotsFavoriteColor = "$0204FB"

'Do not optimize these next two lines. Compiler bugs lurk.

他们做到了。将变量压缩到第二行表达式中会导致跳到堆中间并尝试执行数据。