(load "typecheck.scm")
(load "ast.scm")
(load "platform.scm")
+(load "stdlib.scm")
(define target host-os)
(define wordsize 8)
+(define (stack-type? dls type)
+ (if (adt? dls type)
+ (> (type-size dls type) wordsize)
+ #f))
+
+(define (adt? data-layouts type) (assoc type data-layouts))
+
(define (type-size data-layouts type)
(define (adt-size adt)
(case type
['Int wordsize]
- ['Bool wordsize]
[else
(let ([adt (assoc type data-layouts)])
(if adt
(adt-size adt)
(error #f "unknown size" type)))]))
+(define (singletons dls)
+ (flat-map
+ (lambda (sums)
+ (fold-left append '()
+ (filter (lambda (x) (= 1 (length x))) sums)))
+ (map cdr dls)))
+
+(define (singleton? dls x)
+ (memv x (singletons dls)))
+
+ ; returns the size of an expression's result in bytes
+(define (expr-size dls e)
+ (if (eqv? (ast-type e) 'stack)
+ (type-size dls (cadr e))
+ wordsize))
+
(define (on-stack? expr)
(case (ast-type expr)
['stack (cadr expr)]
[else #f]))
+ ; does a movsq for something on the stack
+ ; src points to the start stack index, but not the top of that index
+ ; likewise for dst
+ ; | ... |
+ ; +------+ <-- to here
+ ; | tag0 |
+ ; +------+ <-- src (size = 16)
+ ; | 42 |
+ ; +------+ <-- start copying from here...
+(define (emit-stack-copy src dst size)
+ (let ([size-to-copy (- size wordsize)])
+ (emit "leaq ~a(%rbp), %rsi" (- src size-to-copy))
+ (emit "leaq ~a(%rbp), %rdi" (- dst size-to-copy))
+ (emit "movq $~a, %rcx" (/ size wordsize))
+ (emit "rep movsq")))
+
+
; an environment consists of adt layouts in scope,
; and any bound variables.
; bound variables are an assoc list with their stack offset
(define make-env list)
(define env-data-layouts car)
(define env-bindings cadr)
+(define (env-append-bindings env bindings)
+ (make-env (env-data-layouts env)
+ (append bindings (env-bindings env))))
(define (codegen-add xs si env)
(define (go ys)
(and (eqv? (ast-type expr) 'closure)
(memv name (caddr expr))))
-
;; (define (emit-scc scc env)
;; ; acc is a pair of the env and list of touchups
;; (define (emit-binding acc binding)
;; ))
;; (fold-left emit-binding (cons env '()) scc))))
-
- (let* ([stack-offsets (map (lambda (name x) ; assoc map of binding name to offset
- (cons name (- si (* x wordsize))))
- (map car bindings)
- (range 0 (length bindings)))]
- [inner-si (- si (* (length bindings) wordsize))]
+ ; assoc map of binding name to size
+
+
+ (define dls (env-data-layouts env))
+
+ (define stack-sizes
+ (map (lambda (binding) (cons (car binding) (expr-size dls (cadr binding))))
+ bindings))
+
+ ; assoc map of binding name to offset
+ (define stack-offsets
+ ; 2 4 2 8 6
+ (let* ([totals ; 2 6 8 16 22
+ (reverse (fold-left (lambda (acc x)
+ (if (null? acc)
+ (list x)
+ (cons (+ x (car acc)) acc)))
+ '()
+ (map cdr stack-sizes)))]
+ ; 0 2 6 8 16
+ [relative-offsets (map - totals (map cdr stack-sizes))]
+ [absolute-offsets (map (lambda (x) (- si x)) relative-offsets)])
+ (map cons (map car stack-sizes) absolute-offsets)))
+
+ (let* (
+ ; the stack index used when codegening binding body and main body
+ ; -> stack ->
+ ; [stack-offsets | inner-si]
+ [inner-si (- si (fold-left + 0 (map cdr stack-sizes)))]
[get-offset (lambda (n) (cdr (assoc n stack-offsets)))]
[scc-env (make-env (env-data-layouts env) scc-binding-offsets)])
(for-each
(lambda (name)
- (let ([expr (cadr (assoc name bindings))])
+ (let* ([expr (cadr (assoc name bindings))]
+ [size (expr-size dls expr)])
(emit "## generating ~a with scc-env ~a" name scc-env)
(if (self-captive-closure? name expr)
; if self-captive, insert a flag into the environment to let
(cons (cons name 'self-captive)
(env-bindings scc-env))))
(codegen-expr expr inner-si scc-env))
- (emit "movq %rax, ~a(%rbp)" (get-offset name))))
+
+ (if (on-stack? expr)
+ ; copy over whatevers on the stack
+ (emit-stack-copy inner-si (get-offset name) size)
+ (emit "movq %rax, ~a(%rbp)" (get-offset name)))))
comps)
scc-env))
env
(codegen-expr form inner-si inner-env))
body)))
-(define (codegen-var name si env)
- (let ([binding (assoc name (env-bindings env))])
- (if (not binding)
- (error #f (format "Variable ~a is not bound" name))
- (emit "movq ~a(%rbp), %rax" (cdr binding)))))
+(define (codegen-var e si env)
+ (let* ([stack-type (on-stack? e)]
+ [name (if stack-type (caddr e) e)]
+
+ [dls (env-data-layouts env)]
+
+
+ [stack-offset (assoc name (env-bindings env))])
+
+ (when (and (not stack-offset) (not singleton?))
+ (error #f (format "Variable ~a is not bound" name)))
+
+ (cond
+ [(singleton? dls name)
+ ; singletons don't need to be in the environment
+ ; just store the tag
+ (let ([tag (data-sum-tag (env-data-layouts env) name)])
+ (if (on-stack? e)
+ (emit "movq $~a, ~a(%rbp)" tag si)
+ (emit "movq $~a, %rax" tag)))]
+ [(on-stack? e) (emit-stack-copy (cdr stack-offset) si (type-size dls stack-type))]
+ [else (emit "movq ~a(%rbp), %rax" (cdr stack-offset))])))
(define cur-lambda 0)
(define (fresh-lambda)
(define (codegen-lambda l)
(let* ((label (car l))
(stuff (cdr l))
- (captives (car stuff))
- (args (cadr stuff))
- (body (caddr stuff))
+ (dls (car stuff))
+ (captives (cadr stuff))
+ (args (caddr stuff))
+ (body (cadddr stuff))
; params = what actually gets passed
(params (append captives args))
(range 0 (length params))))
[bindings (map cons params stack-offsets)]
- [env (make-env '() bindings)])
+ [env (make-env dls bindings)])
(emit "~a:" label)
(display "## lambda captives: ")
(codegen-expr else si env)
(emit "~a:" exit-label)))
+(define (codegen-case switch cases si env)
+ (define dls (env-data-layouts env))
+ (define exit-label (fresh-label))
+
+
+ ; checks if equal and returns assoc list of bindings
+ (define (check-equal jne-label type inner-offset x)
+
+ ; TODO: tidy this up! comparibles and binds could be merged
+ ; (foo a 2 (bar x)) -> ((2 Int 1) ((bar x) A 2))
+ ; sum: foo
+ (define (comparibles sum)
+ (let ([product-types (cdr (assoc sum (cdr (assoc type dls))))])
+ (if (null? product-types)
+ '()
+ (filter (lambda (x) (not (eqv? 'var (ast-type (car x)))))
+ (map (lambda (x t i) (list x t i))
+ (cdr x)
+ product-types
+ (range 0 (length product-types)))))))
+
+ (define (binds sum)
+ (let ([product-types (cdr (assoc sum (cdr (assoc type dls))))])
+ (if (null? product-types)
+ '()
+ (filter (lambda (x) (eqv? 'var (ast-type (car x))))
+ (map (lambda (x i)
+ (cons x
+ (- inner-offset
+ (data-product-offset dls type sum i))))
+ (cdr x)
+ (range 0 (length (cdr x))))))))
+
+
+ (if (adt? dls type)
+ (let* ([sum (if (list? x) (car x) x)] ; can sometimes be a singleton
+ [tag (data-sum-tag dls sum)])
+ ; the tag is at the top (beginning) of the adt on the stack
+ (emit "cmpq $~a, ~a(%rbp)" tag inner-offset)
+ (emit "jne ~a" jne-label)
+
+ (append (binds sum)
+ (flat-map
+ (lambda (cmp) ; cmp = (x type index)
+ (check-equal jne-label
+ (cadr cmp)
+ (- inner-offset (data-product-offset dls type sum (caddr cmp)))
+ (car cmp)))
+ (comparibles sum))))
+ (if (eqv? 'var (ast-type x))
+ (list (cons x inner-offset))
+ (begin
+ (emit "cmpq $~a, ~a(%rbp)" x inner-offset)
+ (emit "jne ~a" jne-label)
+ '() ))))
+
+ (define (codegen-adt-match type case)
+ (let* ([match (car case)]
+ [expr (cadr case)]
+ [next-section-label (fresh-label)]
+ [inner-si (- si (type-size dls type))]
+ [new-env (env-append-bindings env
+ (check-equal next-section-label type si match))])
+
+
+ (codegen-expr expr inner-si new-env)
+ (emit "jmp ~a" exit-label)
+
+ (emit "~a:" next-section-label)))
+
+ (define (codegen-literal-match case)
+ (let* ([next-section-label (fresh-label)]
+ [match (car case)]
+ [val (if (singleton? dls match)
+ (data-sum-tag dls match)
+ match)])
+ (emit "cmpq $~a, %rax" val)
+ (emit "jne ~a" next-section-label)
+ (codegen-expr (cadr case) si env)
+ (emit "jmp ~a" exit-label)
+ (emit "~a:" next-section-label)))
+
+ ; generate the switch
+ ; (and store it on the stack if not a stack value)
+ (codegen-expr switch si env)
+
+ (if (on-stack? switch)
+ ; adt pattern match
+ (for-each (lambda (x) (codegen-adt-match (cadr switch) x)) cases)
+ (for-each codegen-literal-match cases))
+ (emit "~a:" exit-label))
+
+
(define (data-tor env e)
- (and (list? e)
+ (if (not (list? e)) #f
(assoc (car e) (flat-map data-tors (env-data-layouts env)))))
+ ; returns the internal offset in bytes of a product within an ADT
+ ; given the constructor layout
+ ; constructor-layout: (foo (Int Bool))
+(define (data-product-offset data-layouts type sum index)
+ (let* ([products (cdr (assoc sum (cdr (assoc type data-layouts))))]
+ [to-traverse (list-head products index)])
+ (fold-left
+ (lambda (acc t) (+ acc (type-size data-layouts t)))
+ wordsize ; skip the tag in the first word
+ to-traverse)))
+
+(define (data-sum-tag data-layouts sum)
+
+ (define (go acc sums)
+ (when (null? sums) (error #f "data-sum-tag no sum for type" sum type))
+ (if (eqv? sum (car sums))
+ acc
+ (go (+ 1 acc) (cdr sums))))
+ (let* ([all-sum-names (flat-map (lambda (x) (map (lambda (y) (cons (car y) (car x))) (cdr x))) data-layouts)]
+ [type (cdr (assoc sum all-sum-names))]
+ [type-sums (cdr (assoc type data-layouts))])
+ (go 0 (map car type-sums))))
+
(define (codegen-data-tor e si env)
+ (define dls (env-data-layouts env))
+
(define (codegen-destructor tor)
- (codegen-expr (cadr e) si env)
- (let ([index (cadr tor)]
- [products 2]
- [to-traverse (list-head products index)]
- [offset (fold-left
- (lambda (acc t) (+ acc (type-size t)))
- wordsize ; skip tag in first word
- to-traverse)])
- 3
- ))
-
- (let ([tor (data-tor env e)]
- [constructor (eqv? 'constructor (cadr tor))])
+ (let* ([res (codegen-expr (cadr e) si env)]
+ [info (cadr tor)]
+ [type (car info)]
+ [sum (cadr info)]
+ [index (caddr info)]
+ [product-type (cadddr info)]
+ [product-type-size (type-size dls product-type)]
+
+ [safe-space-offset (- si (type-size dls type))]
+
+ [inner-offset (- si (data-product-offset dls type sum index))])
+
+ (when (not (on-stack? (cadr e)))
+ (error #f "trying to destruct something that isn't a stack expression"))
+ (emit "# deconstructing")
+
+ (if (stack-type? (env-data-layouts env) product-type)
+ ; if copying from the stack, need to first copy
+ ; to a safe space above to avoid overwriting
+ ; the original result on the stack
+ ; this is bad. please remove this in the rewrite.
+ (begin
+ (emit-stack-copy inner-offset safe-space-offset product-type-size)
+ (emit-stack-copy safe-space-offset si product-type-size))
+ (emit "movq ~a(%rbp), %rax" inner-offset))))
+
+ (define (codegen-constructor tor)
+ (let* ([info (cadr tor)]
+ [type (car info)]
+ [sum (cadr info)]
+ [constructor (car e)]
+
+ [args (cdr e)]
+
+ [tag (data-sum-tag (env-data-layouts env)
+ sum)]
+
+ [inner-si (- si (type-size dls type))]
+
+ [product-types (cdr (assoc sum (cdr (assoc type dls))))]
+
+ [insert-product
+ (lambda (expr i product-type)
+ (let ([dest-offset
+ (- si (data-product-offset dls type sum i))]
+ [product-size (type-size dls product-type)])
+ (codegen-expr expr inner-si env)
+ (if (on-stack? expr)
+ (emit-stack-copy inner-si dest-offset product-size)
+ (emit "movq %rax, ~a(%rbp)" dest-offset))))])
+
+ ; emit the tag
+ (emit "movq $~a, ~a(%rbp)" tag si)
+ ; generate products
+ (for-each insert-product args (range 0 (length args)) product-types)))
+
+ (let* ([tor (data-tor env e)]
+ [constructor (eqv? 'constructor (caddr (cadr tor)))])
(if constructor
(codegen-constructor tor)
(codegen-destructor tor))))
('var (codegen-var e si env))
('if (codegen-if (cadr e) (caddr e) (cadddr e) si env))
+ ('case (codegen-case (case-switch e) (case-cases e) si env))
('bool-literal (emit "movq $~a, %rax" (if e 1 0)))
('int-literal (emit "movq $~a, %rax" e))
('static-string (emit "movq ~a@GOTPCREL(%rip), %rax"
(cadr e)))
- (else (error #f "don't know how to codegen this"))))
+ ('stack (case (ast-type (caddr e))
+ ['var (codegen-var e si env)]
+ [else (codegen-expr (caddr e) si env)]))
+
+ (else (error #f "don't know how to codegen this")))
+ (emit "# done ~a" e))
; takes in a expr annotated with types and returns a type-less AST
; with stack values wrapped
-(define (annotate-stack-values data-layout ann-e)
- (define (struct-type? type)
- (assoc type data-layout))
+(define (annotate-stack-values data-layouts ann-e)
(define (strip e)
(ast-traverse strip (ann-expr e)))
(let* ([e (ann-expr ann-e)]
[type (ann-type ann-e)])
- (if (struct-type? type)
- `(struct ,(type-size data-layout type) ,(ast-traverse strip e))
+ (if (stack-type? data-layouts type)
+ `(stack ,type
+ ,(ast-traverse (lambda (x) (annotate-stack-values data-layouts x)) e))
(ast-traverse (lambda (x)
- (annotate-stack-values data-layout x))
+ (annotate-stack-values data-layouts x))
e))))
-(define (free-vars prog)
- (define bound '())
+(define (free-vars dls prog)
+ (define bound (singletons dls))
(define (collect e)
(case (ast-type e)
('builtin '()) ; do nothing
; outside of an immediate app
; but only one closure for each builtin
-(define (extract-lambdas program)
+(define (extract-lambdas dls program)
(define lambdas '())
(define (add-lambda e)
(let* ((label (fresh-lambda))
(args (lambda-args e))
- (captured (free-vars e))
+ (captured (free-vars dls e))
(body (extract (lambda-body e)))
- (new-lambda (cons label (list captured args body))))
+ (new-lambda (cons label (list dls captured args body))))
(set! lambdas (cons new-lambda lambdas))
`(closure ,label ,captured))) ; todo: should we string->symbol?
(captured '())
(args (builtin-args e))
(body `(,e ,@args))
- (new-lambda (cons label (list captured args body)))]
+ (new-lambda (cons label (list dls captured args body)))]
(set! lambdas (cons new-lambda lambdas))
`(closure ,label ,captured)))
(emit "movq heap_start@GOTPCREL(%rip), %rsi")
(emit "movq %rax, (%rsi)")))
-(define (codegen program)
+(define (codegen program-without-stdlib)
(set! cur-label 0)
(set! cur-lambda 0)
- (let* ([data-layouts (program-data-layouts program)]
+ (let* ([program (append stdlib program-without-stdlib)]
+ [data-layouts (program-data-layouts program)]
- [type-annotated (annotate-types program)]
+ [pattern-matched (expand-pattern-matches program)]
+ [type-annotated (annotate-types pattern-matched)]
[stack-annotated (annotate-stack-values data-layouts
type-annotated)]
(strings-res (extract-strings stack-annotated))
(strings (car strings-res))
- (lambdas-res (extract-lambdas (cdr strings-res)))
+ (lambdas-res (extract-lambdas data-layouts (cdr strings-res)))
(lambdas (car lambdas-res))
(xform-prog (cdr lambdas-res)))
+ ; verify pattern matches are total
+ (verify-cases data-layouts type-annotated)
+
(emit "\t.global _start")
(emit "\t.text")
- ; (emit ".p2align 4,,15") is this needed?
(for-each codegen-lambda lambdas)
(initialize-heap)
(emit "movq %rsp, %rbp") ; set up the base pointer
-
(codegen-expr xform-prog (- wordsize) (make-env data-layouts '()))
; exit syscall
projects / scheme.git / blobdiff