Sponsoring The Perl Toolchain Summit 2025: Help make this important event another success Learn more

SISYPHUS / Math-MPFR-4.35 / t / overload_shift.t 

            

              
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

              
# Performing shift operations on floating-point types is not
# permitted under IEEE standards.
# Here, we simply overload the '<<' and '>>' operators to
# increase/decrease the exponent by the given "shift" amount.
# Effectively, we are multiplying/dividing the value held in
# the Math::MPFR object by 2**$hift.
# This is precisely what happens when we left-shift/right-shift
# an integer value.
use strict;
use warnings;
use Math::MPFR qw(:mpfr);
use Math::BigFloat; # Aiming to emulate Math::BigFloat in Math::MPFR.
use Config;
use Test::More;
my $f = Math::MPFR->new() << 10;
cmp_ok(Rmpfr_nan_p($f), '!=', 0, "NaN << returns NaN");
$f = Math::MPFR->new() >> 10;
cmp_ok(Rmpfr_nan_p($f), '!=', 0, "NaN >> returns NaN");
$f <<= 10;
cmp_ok(Rmpfr_nan_p($f), '!=', 0, "NaN <<= returns NaN");
$f >>= 10;
cmp_ok(Rmpfr_nan_p($f), '!=', 0, "NaN <<= returns NaN");
Rmpfr_set_inf($f, 0);
my $n = $f << 10;
cmp_ok(Rmpfr_inf_p($n), '!=', 0, "+Inf << returns Inf");
cmp_ok($n, '>', 0, "+Inf << returns +Inf");
$n = $f >> 10;
cmp_ok(Rmpfr_inf_p($n), '!=', 0, "+Inf >> returns Inf");
cmp_ok($n, '>', 0, "+Inf >> returns +Inf");
$f <<= 10;
cmp_ok(Rmpfr_inf_p($f), '!=', 0, "+Inf <<= returns Inf");
cmp_ok($f, '>', 0, "+Inf <<= returns +Inf");
$f >>= 10;
cmp_ok(Rmpfr_inf_p($f), '!=', 0, "+Inf >>= returns Inf");
cmp_ok($f, '>', 0, "-Inf >>= returns +Inf");
my $fneg = Math::MPFR->new();
Rmpfr_set_inf($fneg, -1);
##########################
$n = $fneg << 10;
cmp_ok(Rmpfr_inf_p($n), '!=', 0, "-Inf << returns Inf");
cmp_ok($n, '<', 0, "-Inf << returns -Inf");
$n = $fneg >> 10;
cmp_ok(Rmpfr_inf_p($n), '!=', 0, "-Inf >> returns Inf");
cmp_ok($n, '<', 0, "-Inf >> returns -Inf");
$fneg <<= 10;
cmp_ok(Rmpfr_inf_p($f), '!=', 0, "-Inf <<= returns Inf");
cmp_ok($fneg, '<', 0, "-Inf <<= returns -Inf");
$fneg >>= 10;
cmp_ok(Rmpfr_inf_p($f), '!=', 0, "-Inf >>= returns Inf");
cmp_ok($fneg, '<', 0, "-Inf >>= returns -Inf");
Rmpfr_set_NV($f, 0.0, MPFR_RNDN);
$n = $f << 10;
cmp_ok(Rmpfr_zero_p($f), '!=', 0, "'<<' 0 results in 0");
$n = $f >> 10;
cmp_ok(Rmpfr_zero_p($f), '!=', 0, "'>>' 0 results in 0");
my $samples = 10;
my($mpfr_res, $mbf_res);
my @values;
for(1 .. $samples) {push @values, rand(10000)}
my @shifts;
for(1 .. $samples) {push @shifts, int(rand(40)) - 20}
$samples--;
for my $i(0 .. $samples) {
  my $obj = Math::MPFR->new($values[$i]);
  my $mbf = Math::BigFloat->new($values[$i]);
  my $shift = $shifts[$i];
  cmp_ok($obj << $shift, '==', $obj >> -$shift, "A: $obj: handled consistently by << and >>");
  cmp_ok($obj << -$shift, '==', $obj >> $shift, "B: $obj: handled consistently by << and >>");
  if($] >= 5.04) {
    $mpfr_res = $obj << $shift;
    $mbf_res = $mbf << $shift;
    cmp_ok("$mpfr_res", '==', "$mbf_res", "<<: Math::BigFloat and Math::MPFR concur");
    $mpfr_res = $obj >> $shift;
    $mbf_res = $mbf >> $shift;
    cmp_ok("$mpfr_res", '==', "$mbf_res", ">>: Math::BigFloat and Math::MPFR concur");
  }
  my($x, $y) = ($obj + 10, $obj + 10);
  $x <<= $shift;
  $y >>= -$shift;
  cmp_ok($x, '==', $y, "A: $obj: handled consistently by <<= and >>=");
  $x <<= -$shift;
  $y >>= $shift;
   cmp_ok($x, '==', $y, "B: $obj: handled consistently by <<= and >>=");
 }
cmp_ok(Math::MPFR->new(-401.3) >> 1.8, '==', -201, "-401.3 >> 1.8 == -201");
cmp_ok(Math::MPFR->new(-401.3) >> 1.8, '==', -201, "-401.3 << -1.8 == -201");
eval { my $discard = 2 >> Math::MPFR->new(7);};
like($@, qr/argument that specifies the number of bits to be/, "switched overload throws expected error");
eval {my $discard = $f >> Math::BigFloat->new(7);};
like($@, qr/argument that specifies the number of bits to be/, "Math::BigFloat shift arg throws expected error with '>>'");
eval {$f <<= Math::BigInt->new(7);};
like($@, qr/argument that specifies the number of bits to be/, "Math::BigFloat shift arg throws expected error with '<<='");
if($Config{longsize} < $Config{ivsize}) {
  eval { my $discard = $f >> ~0;};
  like ( $@, qr/In Math::MPFR overloading of '>>' operator,/, "mp_bitcnt_t overflow is caught in '>>'");
  eval { my $discard = $f << ~0;};
  like ( $@, qr/In Math::MPFR overloading of '<<' operator,/, "mp_bitcnt_t overflow is caught in '<<'");
  eval { $f >>= ~0;};
  like ( $@, qr/In Math::MPFR overloading of '>>=' operator,/, "mp_bitcnt_t overflow is caught in '>>='");
  eval { $f <<= ~0;};
  like ( $@, qr/In Math::MPFR overloading of '<<=' operator,/, "mp_bitcnt_t overflow is caught in '<<='");
}
done_testing();