1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
; (include-book "m1")
; (certify-book "compile" 1)
(in-package "M1")
(defun collect-at-end (x e)
(if (member e x)
x
(append x (cons e nil))))
(defun collect-vars-in-expr (vars expr)
(if (atom expr)
(if (symbolp expr)
(collect-at-end vars expr)
vars)
(collect-vars-in-expr
(collect-vars-in-expr vars
(nth 0 expr))
(nth 2 expr))))
(mutual-recursion
(defun collect-vars-in-stmt* (vars stmt-list)
(if (endp stmt-list)
vars
(collect-vars-in-stmt*
(collect-vars-in-stmt vars (car stmt-list))
(cdr stmt-list))))
(defun collect-vars-in-stmt (vars stmt)
(if (equal (nth 1 stmt) '=)
(collect-vars-in-expr
(collect-at-end vars (nth 0 stmt))
(nth 2 stmt))
(if (equal (nth 0 stmt) 'WHILE)
(collect-vars-in-stmt*
(collect-vars-in-expr vars (nth 1 stmt))
(cdr (cdr stmt)))
(if (equal (nth 0 stmt) 'RETURN)
(collect-vars-in-expr vars (nth 1 stmt))
vars))))
)
(defun index (vars var)
(if (endp vars)
0
(if (equal var (car vars))
0
(+ 1 (index (cdr vars) var)))))
(defun OP! (op)
(if (equal op '+)
'((ADD))
(if (equal op '-)
'((SUB))
(if (equal op '*)
'((MUL))
'((ILLEGAL))))))
(defun LOAD! (vars var)
(cons (cons 'LOAD (cons (index vars var) nil))
nil))
(defun PUSH! (n)
(cons (cons 'PUSH (cons n nil))
nil))
(defun expr! (vars expr)
(if (atom expr)
(if (symbolp expr)
(LOAD! vars expr)
(PUSH! expr))
(append (expr! vars (nth 0 expr))
(append (expr! vars (nth 2 expr))
(OP! (nth 1 expr))))))
(defun IFLE! (offset)
(cons (cons 'IFLE (cons offset nil))
nil))
(defun GOTO! (offset)
(cons (cons 'GOTO (cons offset nil))
nil))
(defun while! (test-code body-code)
(append test-code
(append (IFLE! (+ 2 (len body-code)))
(append body-code
(GOTO! (- (+ (len test-code)
1
(len body-code))))))))
(defun test! (vars test)
(if (equal (nth 1 test) '>)
(if (equal (nth 2 test) 0)
(expr! vars (nth 0 test))
(append (expr! vars (nth 0 test))
(append (expr! vars (nth 2 test))
'((SUB)))))
'((ILLEGAL))))
(defun STORE! (vars var)
(cons (cons 'STORE (cons (index vars var) nil))
nil))
(mutual-recursion
(defun stmt*! (vars stmt-list)
(if (endp stmt-list)
nil
(append (stmt! vars (car stmt-list))
(stmt*! vars (cdr stmt-list)))))
(defun stmt! (vars stmt)
(if (equal (nth 1 stmt) '=)
(append (expr! vars (nth 2 stmt))
(STORE! vars (nth 0 stmt)))
(if (equal (nth 0 stmt) 'WHILE)
(while!
(test! vars (nth 1 stmt))
(stmt*! vars (cdr (cdr stmt))))
(if (equal (nth 0 stmt) 'RETURN)
(append (expr! vars (nth 1 stmt))
'((RETURN)))
'((ILLEGAL))))))
)
(defun compile (formals stmt-list)
(stmt*! (collect-vars-in-stmt* formals stmt-list)
stmt-list))
(defthm example-compilation-1
(equal (compile '(n)
'((a = 1)
(while (n > 0)
(a = (n * a))
(n = (n - 1)))
(return a)))
'((PUSH 1)
(STORE 1)
(LOAD 0)
(IFLE 10)
(LOAD 0)
(LOAD 1)
(MUL)
(STORE 1)
(LOAD 0)
(PUSH 1)
(SUB)
(STORE 0)
(GOTO -10)
(LOAD 1)
(RETURN)))
:rule-classes nil)
|
