(define wordsize 8)
+(define (stack-type? data-layouts type)
+ (if (assoc type data-layouts) #t #f))
+
+
(define (type-size data-layouts type)
(define (adt-size adt)
(error #f "unknown size" type)))]))
; returns the size of an expression's result in bytes
-(define (expr-size e)
+(define (expr-size dls e)
(if (eqv? (ast-type e) 'stack)
- (cadr e)
+ (type-size dls (cadr e))
wordsize))
(define (on-stack? 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)
;; (fold-left emit-binding (cons env '()) scc))))
; assoc map of binding name to size
+
+
+ (define dls (env-data-layouts env))
+
(define stack-sizes
- (map (lambda (binding) (cons (car binding) (expr-size (cadr binding))))
+ (map (lambda (binding) (cons (car binding) (expr-size dls (cadr binding))))
bindings))
; assoc map of binding name to offset
(for-each
(lambda (name)
(let* ([expr (cadr (assoc name bindings))]
- [size (expr-size expr)])
+ [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
(codegen-expr expr inner-si scc-env))
(if (on-stack? expr)
- (begin
; copy over whatevers on the stack
- (emit "leaq ~a(%rbp), %rsi" (- inner-si size))
- (emit "leaq ~a(%rbp), %rdi" (- (get-offset name) size))
- (emit "movq $~a, %rcx" (/ size wordsize))
- (emit "rep movsq"))
-
+ (emit-stack-copy inner-si (get-offset name) size)
(emit "movq %rax, ~a(%rbp)" (get-offset name)))))
comps)
scc-env))
body)))
(define (codegen-var e si env)
- (let* ([stack-size (on-stack? e)]
- [name (if (on-stack? e) (caddr e) e)]
- [stack-offset (cdr (assoc name (env-bindings env)))])
- (when (not stack-offset)
+ (let* ([stack-type (on-stack? e)]
+ [name (if stack-type (caddr e) e)]
+
+ [dls (env-data-layouts env)]
+
+ [singleton? (and stack-type
+ (assoc name
+ (cdr (assoc stack-type dls))))]
+
+ [stack-offset (assoc name (env-bindings env))])
+ (when (and (not stack-offset) (not singleton?))
(error #f (format "Variable ~a is not bound" name)))
(if (on-stack? e)
- (begin
- (emit "leaq ~a(%rbp), %rsi" (- stack-offset stack-size))
- (emit "leaq ~a(%rbp), %rdi" (- si stack-size))
- (emit "movq $~a, %rcx" (/ stack-size wordsize))
- (emit "rep movsq"))
- (emit "movq ~a(%rbp), %rax" stack-offset))))
+ (if singleton?
+ ; singletons don't need to be in the environment
+ ; just copy over the tag
+ (emit "movq $~a, ~a(%rbp)"
+ (data-sum-tag (env-data-layouts env)
+ stack-type
+ name)
+ si)
+ (emit-stack-copy (cdr stack-offset) si (type-size dls stack-type)))
+ (emit "movq ~a(%rbp), %rax" (cdr stack-offset)))))
(define cur-lambda 0)
(define (fresh-lambda)
(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))))))))
+
+
+ (let ([sums (assoc type dls)])
+ (if sums
+ (let* ([sum (if (list? x) (car x) x)] ; can sometimes be a singleton
+ [tag (data-sum-tag dls type 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 "cmp $~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)])
+ (emit "cmpq $~a, %rax" (car case))
+ (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 (eqv? 'stack (ast-type 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)
(if (not (list? e)) #f
(assoc (car e) (flat-map data-tors (env-data-layouts env)))))
(define (codegen-data-tor e si env)
+ (define dls (env-data-layouts env))
+
(define (codegen-destructor tor)
(let* ([res (codegen-expr (cadr e) si env)]
[info (cadr tor)]
- [index (caddr info)]
[type (car info)]
- [sum (cadr 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")
- (emit "movq ~a(%rbp), %rax"
- (- si (data-product-offset (env-data-layouts env) type sum index)))))
+
+ (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
sum)]
+ [inner-si (- si (type-size dls type))]
+
+ [product-types (cdr (assoc sum (cdr (assoc type dls))))]
+
[insert-product
- (lambda (expr i)
- (let ([res (codegen-expr expr si env)]
- [stack-offset (- si (data-product-offset (env-data-layouts env)
- type sum
- i))])
- (if (on-stack? res)
- (error #f "todo: handle stack-exprs in stack exprs")
- (emit "movq %rax, ~a(%rbp)" stack-offset))))])
+ (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)
-
- (for-each insert-product args (range 0 (length args)))
- (type-size (env-data-layouts env) type)))
+ ; 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)))])
('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))
['var (codegen-var e si env)]
[else (codegen-expr (caddr e) si env)]))
- (else (error #f "don't know how to codegen this"))))
+ (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
(let* ([e (ann-expr ann-e)]
[type (ann-type ann-e)])
(if (stack-type? type)
- `(stack ,(type-size data-layouts type) ,(ast-traverse strip e))
+ `(stack ,type
+ ,(ast-traverse (lambda (x) (annotate-stack-values data-layouts x)) e))
(ast-traverse (lambda (x)
(annotate-stack-values data-layouts x))
e))))
projects / scheme.git / blobdiff