Assorted internals tidbits

Compiler backend

VINSN   Virtual instruction (probably akin to SBCL's VOPs)

VINSN macros

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

(from compiler/X86/X862.lisp)

Operand syntax

(% x)    register
($ x)    immediate
(@ x)    memory operand
x        labelref
(:rcontext x)   memory operand, using segment register or gpr
(:self fn)      self-reference

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