Add select-instructions pass

aarch64-hello.s

@@ -1,5 +1,6 @@
-.global _main
+.global start
 
-_main:
-    mov x0, 42  // exit code
-    ret
+start:
+    mov x0, 1
+    add x0, x0, 41
+    b conclusion

remove-complex-oper.rkt

@@ -6,10 +6,10 @@
 
 ; remove complex sub-expression
 ; the resulting code is either
-; - (read)
 ; - a number literal
 ; - a symbol
 ; the three above are called in the following "simple terms"
+; - (read)
 ; - (- x) where x is a simple term
 ; - (+ x y) where x and y are simple terms
 ; - (let ([var y]) z) where y and z are expressions
@@ -61,7 +61,13 @@
   (match exp
    [(? fixnum?) (values exp '() tmpcount)]
    [(? symbol?) (values exp '() tmpcount)]
-   [`(read) (values exp '() tmpcount)]
+   [`(read)
+    (begin
+      (define new-tmpcount (+ tmpcount 1))
+      (define tmpname (get-unique-symbol new-tmpcount))
+      (values tmpname
+              (list `(,tmpname (read)))
+              new-tmpcount))]
    [`(- ,e)
     (begin
      (define-values (new-exp assoc-list exp-tmpcount) (rco-arg e tmpcount))

runtime.s

@@ -1,5 +1,7 @@
-.global main
+.global main, conclusion
 main:
-    bl _main
+    b start
+
+conclusion:
 	mov x8, 93 	// sys_exit() is at index 93 in kernel functions table
 	svc #0 		// generate kernel call sys_exit(123);

select-instructions.rkt

@@ -0,0 +1,65 @@
+#lang racket
+
+(require racket/list)
+
+(provide select-instructions)
+
+(define (select-instructions p)
+  (match p
+    [`(program ,data ,body) `(AArch64VProgram ,data ,(select-instructions-section (car body)))]))
+
+(define (select-instructions-section sec)
+  (match sec
+    [`(,label . ,statement) `(,label . (Block `() ,(select-instructions-stmt statement)))]))
+
+(define (select-instructions-stmt stmt)
+  (match stmt
+    [`(return ,exp) (select-instructions-return exp)]
+    [`(seq (assign ,var ,exp) ,next-stmt) 
+      (append (select-instructions-assign var exp) 
+              (select-instructions-stmt next-stmt))]))
+
+(define (select-instructions-assign var exp)
+  (match exp
+         [(? symbol?) (list `(Instr mov ((Var ,var) (Var ,exp))))]
+         [(? fixnum?) (list `(Instr mov ((Var ,var) (Imm ,exp))))]
+         [`(read)     (select-instructions-read `(Var ,var))]
+         [`(- ,e)     (select-instructions-neg e `(Var ,var))]
+         [`(+ ,a ,b)  (select-instructions-add a b `(Var ,var))]))
+
+(define (select-instructions-return exp)
+  (append (match exp
+                [(? symbol?) (list `(Instr mov (x0 (Var ,exp))))]
+                [(? fixnum?) (list `(Instr mov (x0 (Imm ,exp))))]
+                [`(read)     (select-instructions-read 'x0)]
+                [`(- ,e)     (select-instructions-neg e 'x0)]
+                [`(+ ,a ,b)  (select-instructions-add a b 'x0)])
+          `[(Instr b (conclusion))]))
+
+(define (select-instructions-read dest)
+  (if (eq? dest 'x0)
+      (list `(Instr bl _builtin_read))
+      (list `(Instr bl _builtin_read) `(Instr mov (,dest x0)))))
+
+(define (select-instructions-neg exp dest)
+  (begin
+    (define var-exp (if (fixnum? exp)
+                        `(Imm ,exp)
+                        `(Var ,exp)))
+    (list `(Instr neg (,dest ,var-exp)))))
+
+(define (select-instructions-add a b dest)
+  (begin
+    ; if e1 is an imm, swap
+    (define-values (e1 e2) (imm-to-right a b))
+    (define num-imm (count fixnum? (list e1 e2)))
+    (match num-imm
+           [0 (list `(Instr add (,dest (Var ,e1) (Var ,e2))))]
+           [1 (list `(Instr add (,dest (Var ,e1) (Imm ,e2))))]
+           [2 (list `(Instr mov (,dest (Imm ,e1)))
+                    `(Instr add (,dest ,dest (Imm ,e2))))])))
+           
+(define (imm-to-right e1 e2)
+  (if (and (fixnum? e1) (not (fixnum? e2)))
+      (values e2 e1)
+      (values e1 e2)))

test-explicate-control.rkt

@@ -19,8 +19,6 @@
 
    `(program () (+ (let ([x (+ (- 1) 2)]) (+ x 2)) (+ 4 5)))))
 
-
-
 (define (pass program) (explicate-control (remove-complex-opera* program)))
 
 (test-eq

test-remove-complex-opera.rkt

@@ -26,11 +26,21 @@
    `(program () (let ([x (let ([x 1]) x)]) (+ 2 x)))
    `(program ()
              (let ([y (let ([x 20])
-                        (+ x (let ([x 22]) x)))]) y))))
+                        (+ x (let ([x 22]) x)))]) y))
+   `(program ()
+             (+ (read) (read)))))
 
-(for ([program programs] [env (build-list (length programs) (lambda (_) '()))])
-  (test-eq ((interp-R1 env) program)
-           ((interp-R1 env) (remove-complex-opera* program))))
+(define inputs
+    (let ([empty-inputs (build-list (length programs) (lambda (_) ""))])
+      (list-set empty-inputs 13 "2\n3")))
+
+(for ([program programs]
+      [env (build-list (length programs) (lambda (_) '()))]
+      [input-string inputs])
+  (test-eq (with-input-from-string input-string
+               (lambda () ((interp-R1 env) program)))
+           (with-input-from-string input-string
+               (lambda () ((interp-R1 env) (remove-complex-opera* program))))))
 
 (test-eq
   (remove-complex-opera* (list-ref programs 0))
@@ -95,3 +105,7 @@
 (test-eq
   (remove-complex-opera* (list-ref programs 12))
   `(program () (let ((y.1 (let ((x.1 20)) (let ((x.2 22)) (+ x.1 x.2))))) y.1)))
+
+(test-eq
+  (remove-complex-opera* (list-ref programs 13))
+  `(program () (let ((tmp.1 (read))) (let ((tmp.2 (read))) (+ tmp.1 tmp.2)))))

test-select-instructions.rkt

@@ -0,0 +1,71 @@
+#lang racket
+
+(require "select-instructions.rkt")
+(require "test-util.rkt")
+
+(define programs
+    (list
+      `(program ()
+          ((start .
+            (return (+ 2 3)))))
+      `(program ()
+          ((start .
+            (seq (assign x 3)
+              (return (+ 2 x))))))
+      `(program ()
+          ((start .
+             (seq (assign tmp.1 (read))
+               (return (+ tmp.1 3))))))
+      `(program ()
+                ((start .
+                  (seq (assign tmp.1 (- 1))
+                       (seq (assign x.1 (+ tmp.1 2))
+                            (seq (assign tmp.2 (+ x.1 2))
+                                 (seq (assign tmp.3 (+ 4 5))
+                                      (return (+ tmp.2 tmp.3)))))))))))
+
+
+(test-eq (select-instructions (list-ref programs 0))
+         `(AArch64VProgram
+           ()
+           (start
+            Block
+            `()
+            ((Instr mov (x0 (Imm 2)))
+             (Instr add (x0 x0 (Imm 3)))
+             (Instr b (conclusion))))))
+
+(test-eq (select-instructions (list-ref programs 1))
+         `(AArch64VProgram
+           ()
+           (start
+            Block
+            `()
+            ((Instr mov ((Var x) (Imm 3)))
+             (Instr add (x0 (Var x) (Imm 2)))
+             (Instr b (conclusion))))))
+
+(test-eq (select-instructions (list-ref programs 2))
+         `(AArch64VProgram
+           ()
+           (start
+            Block
+            `()
+            ((Instr bl _builtin_read)
+             (Instr mov ((Var tmp.1) x0))
+             (Instr add (x0 (Var tmp.1) (Imm 3)))
+             (Instr b (conclusion))))))
+
+(test-eq (select-instructions (list-ref programs 3))
+         `(AArch64VProgram
+           ()
+           (start
+            Block
+            `()
+            ((Instr neg ((Var tmp.1) (Imm 1)))
+             (Instr add ((Var x.1) (Var tmp.1) (Imm 2)))
+             (Instr add ((Var tmp.2) (Var x.1) (Imm 2)))
+             (Instr mov ((Var tmp.3) (Imm 4)))
+             (Instr add ((Var tmp.3) (Var tmp.3) (Imm 5)))
+             (Instr add (x0 (Var tmp.2) (Var tmp.3)))
+             (Instr b (conclusion))))))