blob: 208e2052fb07f179e163d0580b9805bd43f05b6e (
plain)
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
|
(* TEST
flags += " -unsafe "
*)
(* Good test for loops. Best compiled with -unsafe. *)
let rec qsort lo hi (a : int array) =
if lo < hi then begin
let i = ref lo in
let j = ref hi in
let pivot = a.(hi) in
while !i < !j do
while !i < hi && a.(!i) <= pivot do incr i done;
while !j > lo && a.(!j) >= pivot do decr j done;
if !i < !j then begin
let temp = a.(!i) in a.(!i) <- a.(!j); a.(!j) <- temp
end
done;
let temp = a.(!i) in a.(!i) <- a.(hi); a.(hi) <- temp;
qsort lo (!i-1) a;
qsort (!i+1) hi a
end
(* Same but abstract over the comparison to force spilling *)
let cmp i j = i - j
let rec qsort2 lo hi (a : int array) =
if lo < hi then begin
let i = ref lo in
let j = ref hi in
let pivot = a.(hi) in
while !i < !j do
while !i < hi && cmp a.(!i) pivot <= 0 do incr i done;
while !j > lo && cmp a.(!j) pivot >= 0 do decr j done;
if !i < !j then begin
let temp = a.(!i) in a.(!i) <- a.(!j); a.(!j) <- temp
end
done;
let temp = a.(!i) in a.(!i) <- a.(hi); a.(hi) <- temp;
qsort2 lo (!i-1) a;
qsort2 (!i+1) hi a
end
(* Test *)
let seed = ref 0
let random() =
seed := !seed * 25173 + 17431; !seed land 0xFFF
exception Failed
let test_sort sort_fun size =
let a = Array.make size 0 in
let check = Array.make 4096 0 in
for i = 0 to size-1 do
let n = random() in a.(i) <- n; check.(n) <- check.(n)+1
done;
sort_fun 0 (size-1) a;
try
check.(a.(0)) <- check.(a.(0)) - 1;
for i = 1 to size-1 do
if a.(i-1) > a.(i) then raise Failed;
check.(a.(i)) <- check.(a.(i)) - 1
done;
for i = 0 to 4095 do
if check.(i) <> 0 then raise Failed
done;
print_string "OK"; print_newline()
with Failed ->
print_string "failed"; print_newline()
let main () =
test_sort qsort 50000;
test_sort qsort2 50000
let _ = main(); exit 0
|
