== Frontend ==
See files in compiler/ with nx in their name.

== Backend ==
=== VINSNs ===
VINSN means ''Virtual Instruction''.

Those likely belong to the same category of SBCL's Virtual Operations (VOPs).

{{{
<-    copy register
@     label
@=    label (aligned)
->    jump to label
^     branch
?     register (unwired)
$     register (wired)
}}}

(from compiler/X86/x862.lisp)

=== LAP ===
LAP means ''Lisp Assembly Parser'' (probably). It's a DSL that compiles into opcodes.

==== Operand syntax ====
{{{
(% x)    register
($ x)    immediate
(@ x)    memory operand; x ~ ([seg] [disp] [base] [index] [scale])
x        labelref
(:rcontext x)   memory operand, using segment register or gpr; see @ for syntax of x.
(:self fn)      self-reference
}}}

(from compiler/X86/x86-lap.lisp)