271 lines
6.7 KiB
Plaintext
271 lines
6.7 KiB
Plaintext
.BP
|
|
.AP "AN EXAMPLE PROGRAM"
|
|
.DS B
|
|
.ta 4n 8n 12n 16n 20n
|
|
1 program example(output);
|
|
2 {This program just demonstrates typical EM code.}
|
|
3 type rec = record r1: integer; r2:real; r3: boolean end;
|
|
4 var mi: integer; mx:real; r:rec;
|
|
5
|
|
6 function sum(a,b:integer):integer;
|
|
7 begin
|
|
8 sum := a + b
|
|
9 end;
|
|
10
|
|
11 procedure test(var r: rec);
|
|
12 label 1;
|
|
13 var i,j: integer;
|
|
14 x,y: real;
|
|
15 b: boolean;
|
|
16 c: char;
|
|
17 a: array[1..100] of integer;
|
|
18
|
|
19 begin
|
|
20 j := 1;
|
|
21 i := 3 * j + 6;
|
|
22 x := 4.8;
|
|
23 y := x/0.5;
|
|
24 b := true;
|
|
25 c := 'z';
|
|
26 for i:= 1 to 100 do a[i] := i * i;
|
|
27 r.r1 := j+27;
|
|
28 r.r3 := b;
|
|
29 r.r2 := x+y;
|
|
30 i := sum(r.r1, a[j]);
|
|
31 while i > 0 do begin j := j + r.r1; i := i - 1 end;
|
|
32 with r do begin r3 := b; r2 := x+y; r1 := 0 end;
|
|
33 goto 1;
|
|
34 1: writeln(j, i:6, x:9:3, b)
|
|
35 end; {test}
|
|
36 begin {main program}
|
|
37 mx := 15.96;
|
|
38 mi := 99;
|
|
39 test(r)
|
|
40 end.
|
|
.DE 0
|
|
.BP
|
|
The EM code as produced by the Pascal-VU compiler is given below. Comments
|
|
have been added manually. Note that this code has already been optimized.
|
|
.DS B
|
|
.ta 1n 24n
|
|
mes 2,2,2 ; wordsize 2, pointersize 2
|
|
.1
|
|
rom 't.p\e000' ; the name of the source file
|
|
hol 552,\-32768,0 ; externals and buf occupy 552 bytes
|
|
exp $sum ; sum can be called from other modules
|
|
pro $sum,2 ; procedure sum ; 2 bytes local storage
|
|
lin 8 ; code from source line 8
|
|
ldl 0 ; load two locals ( a and b )
|
|
adi 2 ; add them
|
|
ret 2 ; return the result
|
|
end 2 ; end of procedure ( still two bytes local storage )
|
|
.2
|
|
rom 1,99,2 ; descriptor of array a[]
|
|
exp $test ; the compiler exports all level 0 procedures
|
|
pro $test,226 ; procedure test, 226 bytes local storage
|
|
.3
|
|
rom 4.8F8 ; assemble Floating point 4.8 (8 bytes) in
|
|
.4 ; global storage
|
|
rom 0.5F8 ; same for 0.5
|
|
mes 3,\-226,2,2 ; compiler temporary not referenced by address
|
|
mes 3,\-24,2,0 ; the same is true for i, j, b and c in test
|
|
mes 3,\-22,2,0
|
|
mes 3,\-4,2,0
|
|
mes 3,\-2,2,0
|
|
mes 3,\-20,8,0 ; and for x and y
|
|
mes 3,\-12,8,0
|
|
lin 20 ; maintain source line number
|
|
loc 1
|
|
stl \-4 ; j := 1
|
|
lni ; lin 21 prior to optimization
|
|
lol \-4
|
|
loc 3
|
|
mli 2
|
|
loc 6
|
|
adi 2
|
|
stl \-2 ; i := 3 * j + 6
|
|
lni ; lin 22 prior to optimization
|
|
lae .3
|
|
loi 8
|
|
lal \-12
|
|
sti 8 ; x := 4.8
|
|
lni ; lin 23 prior to optimization
|
|
lal \-12
|
|
loi 8
|
|
lae .4
|
|
loi 8
|
|
dvf 8
|
|
lal \-20
|
|
sti 8 ; y := x / 0.5
|
|
lni ; lin 24 prior to optimization
|
|
loc 1
|
|
stl \-22 ; b := true
|
|
lni ; lin 25 prior to optimization
|
|
loc 122
|
|
stl \-24 ; c := 'z'
|
|
lni ; lin 26 prior to optimization
|
|
loc 1
|
|
stl \-2 ; for i:= 1
|
|
2
|
|
lol \-2
|
|
dup 2
|
|
mli 2 ; i*i
|
|
lal \-224
|
|
lol \-2
|
|
lae .2
|
|
sar 2 ; a[i] :=
|
|
lol \-2
|
|
loc 100
|
|
beq *3 ; to 100 do
|
|
inl \-2 ; increment i and loop
|
|
bra *2
|
|
3
|
|
lin 27
|
|
lol \-4
|
|
loc 27
|
|
adi 2 ; j + 27
|
|
sil 0 ; r.r1 :=
|
|
lni ; lin 28 prior to optimization
|
|
lol \-22 ; b
|
|
lol 0
|
|
stf 10 ; r.r3 :=
|
|
lni ; lin 29 prior to optimization
|
|
lal \-20
|
|
loi 16
|
|
adf 8 ; x + y
|
|
lol 0
|
|
adp 2
|
|
sti 8 ; r.r2 :=
|
|
lni ; lin 23 prior to optimization
|
|
lal \-224
|
|
lol \-4
|
|
lae .2
|
|
lar 2 ; a[j]
|
|
lil 0 ; r.r1
|
|
cal $sum ; call now
|
|
asp 4 ; remove parameters from stack
|
|
lfr 2 ; get function result
|
|
stl \-2 ; i :=
|
|
4
|
|
lin 31
|
|
lol \-2
|
|
zle *5 ; while i > 0 do
|
|
lol \-4
|
|
lil 0
|
|
adi 2
|
|
stl \-4 ; j := j + r.r1
|
|
del \-2 ; i := i - 1
|
|
bra *4 ; loop
|
|
5
|
|
lin 32
|
|
lol 0
|
|
stl \-226 ; make copy of address of r
|
|
lol \-22
|
|
lol \-226
|
|
stf 10 ; r3 := b
|
|
lal \-20
|
|
loi 16
|
|
adf 8
|
|
lol \-226
|
|
adp 2
|
|
sti 8 ; r2 := x + y
|
|
loc 0
|
|
sil \-226 ; r1 := 0
|
|
lin 34 ; note the abscence of the unnecesary jump
|
|
lae 22 ; address of output structure
|
|
lol \-4
|
|
cal $_wri ; write integer with default width
|
|
asp 4 ; pop parameters
|
|
lae 22
|
|
lol \-2
|
|
loc 6
|
|
cal $_wsi ; write integer width 6
|
|
asp 6
|
|
lae 22
|
|
lal \-12
|
|
loi 8
|
|
loc 9
|
|
loc 3
|
|
cal $_wrf ; write fixed format real, width 9, precision 3
|
|
asp 14
|
|
lae 22
|
|
lol \-22
|
|
cal $_wrb ; write boolean, default width
|
|
asp 4
|
|
lae 22
|
|
cal $_wln ; writeln
|
|
asp 2
|
|
ret 0 ; return, no result
|
|
end 226
|
|
exp $_main
|
|
pro $_main,0 ; main program
|
|
.6
|
|
con 2,\-1,22 ; description of external files
|
|
.5
|
|
rom 15.96F8
|
|
fil .1 ; maintain source file name
|
|
lae .6 ; description of external files
|
|
lae 0 ; base of hol area to relocate buffer addresses
|
|
cal $_ini ; initialize files, etc...
|
|
asp 4
|
|
lin 37
|
|
lae .5
|
|
loi 8
|
|
lae 2
|
|
sti 8 ; mx := 15.96
|
|
lni ; lin 38 prior to optimization
|
|
loc 99
|
|
ste 0 ; mi := 99
|
|
lni ; lin 39 prior to optimization
|
|
lae 10 ; address of r
|
|
cal $test
|
|
asp 2
|
|
loc 0 ; normal exit
|
|
cal $_hlt ; cleanup and finish
|
|
asp 2
|
|
end 0
|
|
mes 5 ; reals were used
|
|
.DE 0
|
|
The compact code corresponding to the above program is listed below.
|
|
Read it horizontally, line by line, not column by column.
|
|
Each number represents a byte of compact code, printed in decimal.
|
|
The first two bytes form the magic word.
|
|
.N 1
|
|
.IS 3
|
|
.Dr 33
|
|
173 0 159 122 122 122 255 242 1 161 250 124 116 46 112 0
|
|
255 156 245 40 2 245 0 128 120 155 249 123 115 117 109 160
|
|
249 123 115 117 109 122 67 128 63 120 3 122 88 122 152 122
|
|
242 2 161 121 219 122 255 155 249 124 116 101 115 116 160 249
|
|
124 116 101 115 116 245 226 0 242 3 161 253 128 123 52 46
|
|
56 255 242 4 161 253 128 123 48 46 53 255 159 123 245 30
|
|
255 122 122 255 159 123 96 122 120 255 159 123 98 122 120 255
|
|
159 123 116 122 120 255 159 123 118 122 120 255 159 123 100 128
|
|
120 255 159 123 108 128 120 255 67 140 69 121 113 116 68 73
|
|
116 69 123 81 122 69 126 3 122 113 118 68 57 242 3 72
|
|
128 58 108 112 128 68 58 108 72 128 57 242 4 72 128 44
|
|
128 58 100 112 128 68 69 121 113 98 68 69 245 122 0 113
|
|
96 68 69 121 113 118 182 73 118 42 122 81 122 58 245 32
|
|
255 73 118 57 242 2 94 122 73 118 69 220 10 123 54 118
|
|
18 122 183 67 147 73 116 69 147 3 122 104 120 68 73 98
|
|
73 120 111 130 68 58 100 72 136 2 128 73 120 4 122 112
|
|
128 68 58 245 32 255 73 116 57 242 2 59 122 65 120 20
|
|
249 123 115 117 109 8 124 64 122 113 118 184 67 151 73 118
|
|
128 125 73 116 65 120 3 122 113 116 41 118 18 124 185 67
|
|
152 73 120 113 245 30 255 73 98 73 245 30 255 111 130 58
|
|
100 72 136 2 128 73 245 30 255 4 122 112 128 69 120 104
|
|
245 30 255 67 154 57 142 73 116 20 249 124 95 119 114 105
|
|
8 124 57 142 73 118 69 126 20 249 124 95 119 115 105 8
|
|
126 57 142 58 108 72 128 69 129 69 123 20 249 124 95 119
|
|
114 102 8 134 57 142 73 98 20 249 124 95 119 114 98 8
|
|
124 57 142 20 249 124 95 119 108 110 8 122 88 120 152 245
|
|
226 0 155 249 125 95 109 97 105 110 160 249 125 95 109 97
|
|
105 110 120 242 6 151 122 119 142 255 242 5 161 253 128 125
|
|
49 53 46 57 54 255 50 242 1 57 242 6 57 120 20 249
|
|
124 95 105 110 105 8 124 67 157 57 242 5 72 128 57 122
|
|
112 128 68 69 219 110 120 68 57 130 20 249 124 116 101 115
|
|
116 8 122 69 120 20 249 124 95 104 108 116 8 122 152 120
|
|
159 124 160 255 159 125 255
|
|
.De
|
|
.IE
|