1 #line 2 "../src/kernel/none/cmp.c"
2 /* Copyright (C) 2002-2003 The PARI group.
3
4 This file is part of the PARI/GP package.
5
6 PARI/GP is free software; you can redistribute it and/or modify it under the
7 terms of the GNU General Public License as published by the Free Software
8 Foundation; either version 2 of the License, or (at your option) any later
9 version. It is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY WHATSOEVER.
11
12 Check the License for details. You should have received a copy of it, along
13 with the package; see the file 'COPYING'. If not, write to the Free Software
14 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
15
16
17 /********************************************************************/
18 /** **/
19 /** Comparison routines **/
20 /** **/
21 /********************************************************************/
22
23 /*They depend on cmpiispec and equaliispec in mp.c*/
24
25 int
equalii(GEN x,GEN y)26 equalii(GEN x, GEN y)
27 {
28 if ((x[1] & (LGBITS|SIGNBITS)) != (y[1] & (LGBITS|SIGNBITS))) return 0;
29 return equaliispec(x+2, y+2, lgefint(x)-2, lgefint(y)-2);
30 }
31
32 int
cmpii(GEN x,GEN y)33 cmpii(GEN x, GEN y)
34 {
35 const long sx = signe(x), sy = signe(y);
36 if (sx<sy) return -1;
37 if (sx>sy) return 1;
38 if (!sx) return 0;
39 if (sx>0)
40 return cmpiispec(x+2, y+2, lgefint(x)-2, lgefint(y)-2);
41 else
42 return -cmpiispec(x+2, y+2, lgefint(x)-2, lgefint(y)-2);
43 }
44
45 int
equalrr(GEN x,GEN y)46 equalrr(GEN x, GEN y)
47 {
48 long lx, ly, i;
49
50 if (!signe(x)) {
51 if (!signe(y)) return 1; /* all zeroes are equal */
52 return expo(x) >= expo(y);
53 }
54 if (!signe(y))
55 return expo(y) >= expo(x);
56
57 if (x[1] != y[1]) return 0;
58
59 lx = lg(x);
60 ly = lg(y);
61 if (lx < ly)
62 {
63 i=2; while (i<lx && x[i]==y[i]) i++;
64 if (i<lx) return 0;
65 for (; i < ly; i++) if (y[i]) return 0;
66 }
67 else
68 {
69 i=2; while (i<ly && x[i]==y[i]) i++;
70 if (i<ly) return 0;
71 for (; i < lx; i++) if (x[i]) return 0;
72 }
73 return 1;
74 }
75
76 int
cmprr(GEN x,GEN y)77 cmprr(GEN x, GEN y)
78 {
79 const long sx = signe(x), sy = signe(y);
80 long ex,ey,lx,ly,lz,i;
81
82 if (!sx) {
83 if (!sy || expo(x) >= expo(y)) return 0;
84 return sy > 0? -1: 1;
85 }
86 if (!sy) {
87 if (expo(y) >= expo(x)) return 0;
88 return sx > 0? 1: -1;
89 }
90 if (sx<sy) return -1;
91 if (sx>sy) return 1;
92
93 ex=expo(x); ey=expo(y);
94 if (ex>ey) return sx;
95 if (ex<ey) return -sx;
96
97 lx=lg(x); ly=lg(y); lz = (lx<ly)?lx:ly;
98 i=2; while (i<lz && x[i]==y[i]) i++;
99 if (i<lz) return ((ulong)x[i] > (ulong)y[i]) ? sx : -sx;
100 if (lx>=ly)
101 {
102 while (i<lx && !x[i]) i++;
103 return (i==lx) ? 0 : sx;
104 }
105 while (i<ly && !y[i]) i++;
106 return (i==ly) ? 0 : -sx;
107 }
108
109 /* x and y are integers. Return 1 if |x| == |y|, 0 otherwise */
110 int
absequalii(GEN x,GEN y)111 absequalii(GEN x, GEN y)
112 {
113 if (!signe(x)) return !signe(y);
114 if (!signe(y)) return 0;
115 return equaliispec(x+2, y+2, lgefint(x)-2, lgefint(y)-2);
116 }
117
118 /* x and y are integers. Return sign(|x| - |y|) */
119 int
abscmpii(GEN x,GEN y)120 abscmpii(GEN x, GEN y)
121 {
122 if (!signe(x)) return signe(y)? -1: 0;
123 if (!signe(y)) return 1;
124 return cmpiispec(x+2, y+2, lgefint(x)-2, lgefint(y)-2);
125 }
126
127 /* x and y are reals. Return sign(|x| - |y|) */
128 int
abscmprr(GEN x,GEN y)129 abscmprr(GEN x, GEN y)
130 {
131 long ex,ey,lx,ly,lz,i;
132
133 if (!signe(x)) return signe(y)? -1: 0;
134 if (!signe(y)) return 1;
135
136 ex=expo(x); ey=expo(y);
137 if (ex>ey) return 1;
138 if (ex<ey) return -1;
139
140 lx=lg(x); ly=lg(y); lz = (lx<ly)?lx:ly;
141 i=2; while (i<lz && x[i]==y[i]) i++;
142 if (i<lz) return ((ulong)x[i] > (ulong)y[i])? 1: -1;
143 if (lx>=ly)
144 {
145 while (i<lx && !x[i]) i++;
146 return (i==lx)? 0: 1;
147 }
148 while (i<ly && !y[i]) i++;
149 return (i==ly)? 0: -1;
150 }
151
152