src/wam/constants.lisp @ 6138ec555cde
Change functor representation Functors are now (symbol . arity) pairs in the functor table, and the functor cells simply contain the address into the table and nothing more.
| author | Steve Losh <steve@stevelosh.com> |
|---|---|
| date | Tue, 05 Apr 2016 15:00:28 +0000 |
| parents | 6dc3f4e03454 |
| children | 564c709801aa |
(in-package #:bones.wam) (define-constant +cell-width+ 16 :documentation "Number of bits in each heap cell.") (define-constant +cell-tag-width+ 2 :documentation "Number of bits reserved for cell type tags.") (define-constant +cell-value-width+ (- +cell-width+ +cell-tag-width+) :documentation "Number of bits reserved for cell values.") (define-constant +cell-tag-bitmask+ #b11 :documentation "Bitmask for masking the cell type tags.") (define-constant +heap-limit+ (expt 2 +cell-value-width+) ;; We can only address 2^value-bits cells. :documentation "Maximum size of the WAM heap.") (define-constant +code-word-size+ 16 :documentation "Size (in bits) of each word in the code store.") (define-constant +code-limit+ (expt 2 +code-word-size+) :documentation "Maximum size of the WAM code store.") (define-constant +tag-null+ #b00 :documentation "An empty cell.") (define-constant +tag-structure+ #b01 :documentation "A structure cell.") (define-constant +tag-reference+ #b10 :documentation "A pointer to a cell.") (define-constant +tag-functor+ #b11 :documentation "A functor.") (define-constant +functor-arity-width+ 4 :documentation "Number of bits dedicated to functor arity.") (define-constant +functor-arity-bitmask+ #b1111 :documentation "Bitmask for the functor arity bits.") (define-constant +register-count+ 16 :documentation "The number of registers the WAM has available.") (define-constant +maximum-arity+ (1- (expt 2 +functor-arity-width+)) :documentation "The maximum allowed arity of functors.") ;;;; Opcodes ;;; Program (define-constant +opcode-get-structure+ 1) (define-constant +opcode-unify-variable+ 2) (define-constant +opcode-unify-value+ 3) (define-constant +opcode-get-variable+ 4) (define-constant +opcode-get-value+ 5) ;;; Query (define-constant +opcode-put-structure+ 6) (define-constant +opcode-set-variable+ 7) (define-constant +opcode-set-value+ 8) (define-constant +opcode-put-variable+ 9) (define-constant +opcode-put-value+ 10) ;;; Control (define-constant +opcode-call+ 11) (define-constant +opcode-proceed+ 12)