(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)
[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)
- (emit "leaq ~a(%rbp), %rsi" (- src size))
- (emit "leaq ~a(%rbp), %rdi" (- 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"))
+ (emit "rep movsq")))
; an environment consists of adt layouts in scope,
;; (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
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)
- (emit-stack-copy stack-offset si stack-size)
- (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)
+
+ ; (foo a 2 (bar x)) -> ((2 Int 1) ((bar x) A 2))
+ ; sum: foo
+ (define (comparibles sum)
+ (if (not (list? sum))
+ '()
+ (let ([product-types (cdr (assoc sum (cdr (assoc type dls))))])
+ (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)))))))
+
+ (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)
+ (flat-map
+ (lambda (cmpx cmpt cmpi)
+ (check-equal jne-label
+ cmpt
+ (- inner-offset (data-product-offset dls type sum i))
+ cmpx))
+ (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 (append (check-equal next-section-label type si match)
+ env)])
+
+ (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)))))
('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))
(let* ([e (ann-expr ann-e)]
[type (ann-type ann-e)])
(if (stack-type? type)
- `(stack ,(type-size data-layouts type)
+ `(stack ,type
,(ast-traverse (lambda (x) (annotate-stack-values data-layouts x)) e))
(ast-traverse (lambda (x)
(annotate-stack-values data-layouts x))
projects / scheme.git / commitdiff