Calculating relative jnz opcode sizes in a custom code generator

[redbull]

Hi Doug,

Agreed but the point is to actually make it right now.. My existing code generator works well and now I want to take it to the next level.


Here are some interesting arictles on this topic:

hxxp://compilers.iecc.com/comparch/article/97-05-281

hxxp://compilers.iecc.com/comparch/article/00-10-073

hxxp://compilers.iecc.com/crenshaw/

hxxp://www.pcengines.ch/tp3.htm

hxxp://www.etek.chalmers.se/~e8johan/compiler/

Generating instructions with variable length addresses is a well understood
problem. The PDP-11 Unix assembler did it in about 1973, and there was
a paper by Tom Szymanski in the CACM about that time. I always preferred
the other approach, start with everything long, then shorten until there's
nothing left to shorten, which has the advantage of being fail-safe, all
of the intermediate stages being valid code. -John