THE CONCATENING
This patch does something I've been dreading since I started: it concatenates
the registers, stack, and heap into one single big-ass array called the store.
This is how the original WAM was laid out (actually the original WAM has
EVERYTHING in one giant block of memory, but let's not get carried away here).
I was hoping I wouldn't have to do this, because the code reads a lot nicer when
these things are separate, but after reading ahead in the book I think I'm
pretty sure it had to be done.
The upside here is that now dereferencing things can be done without caring
where they live -- it's all just pointers into this giant array. For example:
a register could refer to a stack cell, or a heap cell could point at a stack
cell. The downside is that the stack is no longer adjustable (and things are
a bit less safe).
| author |
Steve Losh <steve@stevelosh.com> |
| date |
Sun, 08 May 2016 21:25:08 +0000 |
| parents |
4d33f11b074f |
| children |
6f08985f19af |
(in-package #:bones.wam)
(defun registers-pointing-to (wam addr)
(loop
:for r :from 0 :below +register-count+
:for reg = (wam-local-register wam r)
:when (= reg addr)
:collect r))
(defun heap-debug (wam addr cell indent-p)
(format
nil "~A~A~{<-X~A ~}"
(if indent-p
" "
"")
(switch ((cell-type cell))
(+tag-reference+
(if (= addr (cell-value cell))
"unbound variable "
(format nil "var pointer to ~4,'0X " (cell-value cell))))
(+tag-structure+
(format nil "structure pointer to ~4,'0X " (cell-value cell)))
(+tag-functor+
(destructuring-bind (functor . arity)
(wam-functor-lookup wam (cell-functor-index cell))
(format nil "~A/~D " functor arity)))
(t ""))
(registers-pointing-to wam addr)))
(defun dump-heap (wam from to highlight)
;; This code is awful, sorry.
(let ((store (wam-store wam)))
(format t "HEAP~%")
(format t " +------+-----+----------+--------------------------------------+~%")
(format t " | ADDR | TYP | VALUE | DEBUG |~%")
(format t " +------+-----+----------+--------------------------------------+~%")
(when (> from +heap-start+)
(format t " | ⋮ | ⋮ | ⋮ | |~%"))
(flet ((print-cell (i cell indent)
(let ((hi (= i highlight)))
(format t "~A ~4,'0X | ~A | ~8,'0X | ~36A ~A~%"
(if hi "==>" " |")
i
(cell-type-short-name cell)
(cell-value cell)
(heap-debug wam i cell (> indent 0))
(if hi "<===" "|")))))
(loop :for i :from from :below to
:with indent = 0
:for cell = (aref store i)
:do
(progn
(print-cell i cell indent)
(if (cell-functor-p cell)
(setf indent (wam-functor-arity wam (cell-functor-index cell)))
(when (not (zerop indent))
(decf indent))))))
(when (< to (wam-heap-pointer wam))
(format t " | ⋮ | ⋮ | ⋮ | |~%"))
(format t " +------+-----+----------+--------------------------------------+~%")
(values)))
(defun dump-stack (wam)
(format t "STACK~%")
(format t " +------+----------+-------------------------------+~%")
(format t " | ADDR | VALUE | |~%")
(format t " +------+----------+-------------------------------+~%")
(with-accessors ((e wam-environment-pointer)
(b wam-backtrack-pointer))
wam
(when (not (= +stack-start+ e b))
(loop
:with nargs = nil
:with arg = 0
:with currently-in = nil
:for addr :from (1+ +stack-start+) :below (wam-stack-top wam)
:for cell = (wam-stack-word wam addr)
:for offset = 0 :then (1+ offset)
:do
(when (not (zerop addr))
(switch (addr :test #'=)
(e (setf currently-in :frame offset 0 arg 0))
(b (setf currently-in :choice offset 0 arg 0))))
(format t " | ~4,'0X | ~8,'0X | ~30A|~A~A~%"
addr
cell
(case currently-in ; jesus christ this needs to get fixed
(:frame
(cond
((= addr +stack-start+) "")
((= offset 0) "CE ===========================")
((= offset 1) "CP")
((= offset 2)
(if (zerop cell)
(progn
(setf currently-in nil)
"N: EMPTY")
(progn
(setf nargs cell)
(format nil "N: ~D" cell))))
((< arg nargs)
(prog1
(format nil " Y~D: ~8,'0X" arg cell)
(when (= nargs (incf arg))
(setf currently-in nil))))))
(:choice ; sweet lord make it stop
(cond
((= addr +stack-start+) "")
((= offset 0)
(if (zerop cell)
(progn
(setf currently-in nil)
"N: EMPTY =================")
(progn
(setf nargs cell)
(format nil "N: ~D =============" cell))))
((= offset 1) "CE saved env pointer")
((= offset 2) "CP saved cont pointer")
((= offset 3) "CB previous choice")
((= offset 4) "BP next clause")
((= offset 5) "TR saved trail pointer")
((= offset 6) "H saved heap pointer")
((< arg nargs)
(prog1
(format nil " Y~D: ~8,'0X" arg cell)
(when (= nargs (incf arg))
(setf currently-in nil))))))
(t ""))
(if (= addr e) " <- E" "")
(if (= addr b) " <- B" "")))))
(format t " +------+----------+-------------------------------+~%"))
(defun pretty-functor (functor-index functor-list)
(when functor-list
(destructuring-bind (symbol . arity)
(elt functor-list functor-index)
(format nil "~A/~D" symbol arity))))
(defun pretty-arguments (arguments)
(format nil "~{ ~4,'0X~}" arguments))
(defgeneric instruction-details (opcode arguments functor-list))
(defmethod instruction-details ((opcode t) arguments functor-list)
(format nil "~A~A"
(opcode-short-name opcode)
(pretty-arguments arguments)))
(defmethod instruction-details ((opcode (eql +opcode-set-variable-local+)) arguments functor-list)
(format nil "SVAR~A ; X~A <- new unbound REF"
(pretty-arguments arguments)
(first arguments)))
(defmethod instruction-details ((opcode (eql +opcode-set-variable-stack+)) arguments functor-list)
(format nil "SVAR~A ; Y~A <- new unbound REF"
(pretty-arguments arguments)
(first arguments)))
(defmethod instruction-details ((opcode (eql +opcode-set-value-local+)) arguments functor-list)
(format nil "SVLU~A ; new REF to X~A"
(pretty-arguments arguments)
(first arguments)))
(defmethod instruction-details ((opcode (eql +opcode-set-value-stack+)) arguments functor-list)
(format nil "SVLU~A ; new REF to Y~A"
(pretty-arguments arguments)
(first arguments)))
(defmethod instruction-details ((opcode (eql +opcode-get-structure-local+)) arguments functor-list)
(format nil "GETS~A ; X~A = ~A"
(pretty-arguments arguments)
(second arguments)
(pretty-functor (first arguments) functor-list)))
(defmethod instruction-details ((opcode (eql +opcode-put-structure-local+)) arguments functor-list)
(format nil "PUTS~A ; X~A <- new ~A"
(pretty-arguments arguments)
(second arguments)
(pretty-functor (first arguments) functor-list)))
(defmethod instruction-details ((opcode (eql +opcode-get-variable-local+)) arguments functor-list)
(format nil "GVAR~A ; X~A <- A~A"
(pretty-arguments arguments)
(first arguments)
(second arguments)))
(defmethod instruction-details ((opcode (eql +opcode-get-variable-stack+)) arguments functor-list)
(format nil "GVAR~A ; Y~A <- A~A"
(pretty-arguments arguments)
(first arguments)
(second arguments)))
(defmethod instruction-details ((opcode (eql +opcode-get-value-local+)) arguments functor-list)
(format nil "GVLU~A ; X~A = A~A"
(pretty-arguments arguments)
(first arguments)
(second arguments)))
(defmethod instruction-details ((opcode (eql +opcode-get-value-stack+)) arguments functor-list)
(format nil "GVLU~A ; Y~A = A~A"
(pretty-arguments arguments)
(first arguments)
(second arguments)))
(defmethod instruction-details ((opcode (eql +opcode-put-variable-local+)) arguments functor-list)
(format nil "PVAR~A ; X~A <- A~A <- new unbound REF"
(pretty-arguments arguments)
(first arguments)
(second arguments)))
(defmethod instruction-details ((opcode (eql +opcode-put-variable-stack+)) arguments functor-list)
(format nil "PVAR~A ; Y~A <- A~A <- new unbound REF"
(pretty-arguments arguments)
(first arguments)
(second arguments)))
(defmethod instruction-details ((opcode (eql +opcode-put-value-local+)) arguments functor-list)
(format nil "PVLU~A ; A~A <- X~A"
(pretty-arguments arguments)
(second arguments)
(first arguments)))
(defmethod instruction-details ((opcode (eql +opcode-put-value-stack+)) arguments functor-list)
(format nil "PVLU~A ; A~A <- Y~A"
(pretty-arguments arguments)
(second arguments)
(first arguments)))
(defmethod instruction-details ((opcode (eql +opcode-call+)) arguments functor-list)
(format nil "CALL~A ; ~A"
(pretty-arguments arguments)
(pretty-functor (first arguments) functor-list)))
(defun dump-code-store (wam code-store
&optional
(from 0)
(to (length code-store)))
;; This is a little trickier than might be expected. We have to walk from
;; address 0 no matter what `from` we get, because instruction sizes vary and
;; aren't aligned. So if we just start at `from` we might start in the middle
;; of an instruction and everything would be fucked.
(let ((addr 0)
(lbls (bones.utils::invert-hash-table (wam-code-labels wam)))) ; oh god
(while (< addr to)
(let ((instruction (retrieve-instruction code-store addr)))
(when (>= addr from)
(let ((lbl (gethash addr lbls))) ; forgive me
(when lbl
(format t ";;;; BEGIN ~A~%"
(pretty-functor lbl (wam-functors wam)))))
(format t ";~A~4,'0X: "
(if (= (wam-program-counter wam) addr)
">>"
" ")
addr)
(format t "~A~%" (instruction-details (aref instruction 0)
(rest (coerce instruction 'list))
(wam-functors wam))))
(incf addr (length instruction))))))
(defun dump-code
(wam
&optional
(from (max (- (wam-program-counter wam) 8) ; wow
0)) ; this
(to (min (+ (wam-program-counter wam) 8) ; is
(length (wam-code wam))))) ; bad
(format t "CODE~%")
(dump-code-store wam (wam-code wam) from to))
(defun dump-wam-registers (wam)
(format t "REGISTERS:~%")
(format t "~5@A -> ~8@A~%" "S" (wam-subterm wam))
(loop :for i :from 0 :to +register-count+
:for reg :across (wam-store wam)
:for contents = (when (not (zerop reg))
(wam-heap-cell wam reg))
:when contents
:do (format t "~5@A -> ~8,'0X ~10A ~A~%"
(format nil "X~D" i)
reg
(cell-aesthetic contents)
(format nil "; ~A" (first (extract-things wam (list reg)))))))
(defun dump-wam-functors (wam)
(format t " FUNCTORS: ~S~%" (wam-functors wam)))
(defun dump-wam-trail (wam)
(format t " TRAIL: ")
(loop :for addr :across (wam-trail wam) :do
(format t "~4,'0X ~A //"
addr
(cell-aesthetic (wam-heap-cell wam addr))))
(format t "~%"))
(defun dump-labels (wam)
(format t "LABELS:~%~{ ~A -> ~4,'0X~^~%~}~%"
(loop :for functor-index
:being :the :hash-keys :of (wam-code-labels wam)
:using (hash-value address)
:nconc (list (pretty-functor functor-index
(wam-functors wam))
address))))
(defun dump-wam (wam from to highlight)
(format t " FAIL: ~A~%" (wam-fail wam))
(format t " MODE: ~S~%" (wam-mode wam))
(dump-wam-functors wam)
(format t " HEAP SIZE: ~A~%" (- (wam-heap-pointer wam) +heap-start+))
(format t " PROGRAM COUNTER: ~4,'0X~%" (wam-program-counter wam))
(format t "CONTINUATION PTR: ~4,'0X~%" (wam-continuation-pointer wam))
(format t " ENVIRONMENT PTR: ~4,'0X~%" (wam-environment-pointer wam))
(format t " BACKTRACK PTR: ~4,'0X~%" (wam-backtrack-pointer wam))
(format t "HEAP BCKTRCK PTR: ~4,'0X~%" (wam-heap-backtrack-pointer wam))
(dump-wam-trail wam)
(dump-wam-registers wam)
(format t "~%")
(dump-heap wam from to highlight)
(format t "~%")
(dump-stack wam)
(format t "~%")
(dump-labels wam)
(dump-code wam))
(defun dump-wam-query-code (wam)
(with-slots (code) wam
(dump-code-store wam code 0 +maximum-query-size+)))
(defun dump-wam-code (wam)
(with-slots (code) wam
(dump-code-store wam code +maximum-query-size+ (length code))))
(defun dump-wam-full (wam)
(dump-wam wam +heap-start+ (wam-heap-pointer wam) -1))
(defun dump-wam-around (wam addr width)
(dump-wam wam
(max +heap-start+ (- addr width))
(min (wam-heap-pointer wam)
(+ addr width 1))
addr))