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
|
/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License. */
/* */
/***********************************************************************/
/* $Id$ */
#include "fail.h"
#include "memory.h"
#include "misc.h"
#include "mlvalues.h"
/* Structural comparison on trees.
May loop on cyclic structures. */
static long compare_val(value v1, value v2)
{
tag_t t1, t2;
tailcall:
if (v1 == v2) return 0;
if (Is_long(v1)) {
if (Is_long(v2))
return Long_val(v1) - Long_val(v2);
else
return -1;
}
if (Is_long(v2)) return 1;
/* If one of the objects is outside the heap (but is not an atom),
use address comparison. Since both addresses are 2-aligned,
shift lsb off to avoid overflow in subtraction. */
if ((!Is_atom(v1) && !Is_young(v1) && !Is_in_heap(v1)) ||
(!Is_atom(v2) && !Is_young(v2) && !Is_in_heap(v2)))
return (v1 >> 1) - (v2 >> 1);
t1 = Tag_val(v1);
t2 = Tag_val(v2);
if (t1 != t2) return (long)t1 - (long)t2;
switch(t1) {
case String_tag: {
mlsize_t len1, len2, len;
unsigned char * p1, * p2;
len1 = string_length(v1);
len2 = string_length(v2);
for (len = (len1 <= len2 ? len1 : len2),
p1 = (unsigned char *) String_val(v1),
p2 = (unsigned char *) String_val(v2);
len > 0;
len--, p1++, p2++)
if (*p1 != *p2) return (long)*p1 - (long)*p2;
return len1 - len2;
}
case Double_tag: {
double d1 = Double_val(v1);
double d2 = Double_val(v2);
if (d1 < d2) return -1; else if (d1 > d2) return 1; else return 0;
}
case Double_array_tag: {
mlsize_t sz1 = Wosize_val(v1) / Double_wosize;
mlsize_t sz2 = Wosize_val(v2) / Double_wosize;
mlsize_t i;
if (sz1 != sz2) return sz1 - sz2;
for (i = 0; i < sz1; i++) {
double d1 = Double_field(v1, i);
double d2 = Double_field(v2, i);
if (d1 < d2) return -1; else if (d1 > d2) return 1;
}
return 0;
}
case Abstract_tag:
case Final_tag:
invalid_argument("equal: abstract value");
case Closure_tag:
case Infix_tag:
invalid_argument("equal: functional value");
case Object_tag:
return (Oid_val(v1) - Oid_val(v2));
default: {
mlsize_t sz1 = Wosize_val(v1);
mlsize_t sz2 = Wosize_val(v2);
value * p1, * p2;
long res;
if (sz1 != sz2) return sz1 - sz2;
if (sz1 == 0) return 0;
for(p1 = Op_val(v1), p2 = Op_val(v2);
sz1 > 1;
sz1--, p1++, p2++) {
res = compare_val(*p1, *p2);
if (res != 0) return res;
}
v1 = *p1;
v2 = *p2;
goto tailcall;
}
}
}
value compare(value v1, value v2) /* ML */
{
long res = compare_val(v1, v2);
if (res < 0)
return Val_int(-1);
else if (res > 0)
return Val_int(1);
else
return Val_int(0);
}
value equal(value v1, value v2) /* ML */
{
return Val_int(compare_val(v1, v2) == 0);
}
value notequal(value v1, value v2) /* ML */
{
return Val_int(compare_val(v1, v2) != 0);
}
value lessthan(value v1, value v2) /* ML */
{
return Val_int(compare_val(v1, v2) < 0);
}
value lessequal(value v1, value v2) /* ML */
{
return Val_int(compare_val(v1, v2) <= 0);
}
value greaterthan(value v1, value v2) /* ML */
{
return Val_int(compare_val(v1, v2) > 0);
}
value greaterequal(value v1, value v2) /* ML */
{
return Val_int(compare_val(v1, v2) >= 0);
}
|
