🚀 go-pugleaf

In article <GJR.92Dec10233620@chamarti.ai.mit.edu>, gjr@zurich.ai.mit.edu (Guillermo J. Rozas) writes:
|> In article <1g8ub1INN8it@agate.berkeley.edu> jbuck@forney.berkeley.edu (Joe Buck) writes:
|> 
|> |   From: jbuck@forney.berkeley.edu (Joe Buck)
|> |   Newsgroups: comp.arch
|> |   Date: 11 Dec 1992 02:27:45 GMT
|> |
|> |   They are used heavily in VMS, since it encodes error status returns
|> |   that way (the LSB determines whether there is an error or not).  The
|> |   Vax had an instruction that could do this, so so must the Alpha for
|> |   efficient VMS implementatation.
|> 
|> Isn't this in fact how booleans are represented in BLISS, the language
|> in which a lot of VMS was/is written?


Since many programs use boolean variables for control flow but use integers
as the boolean variable, I could see how this could be useful.  However,
if a int value is being used as a single boolean variable it would make
more sense to use/have an instruction like branch on zero.  It's more general
purpose and useful.  You can use it to test boolean values as well as
count down (to zero) loops.

/jack