While drunk, probably very little. I used to when I was a lot younger. In fact about 8 years ago I wrote the smallest /bin/sh execve shellcode for x86 I'd ever seen while completely out of my tree. I was amazed it worked.
These days I generally find that a beer is fine, two can give a temporary boost in productivity (as I find it easier to focus) but more than that and I have to stop.
Alcohol's probably the wrong substance to code on. Something like caffeine is probably better.