comment on

Hello all monks,

In the following code rand() doesn't even give me 52bit of data;
both MSB and LSBs are fixed !

what is the best way to get 64bit numbers ?

0000000000000000010111100101110000011011100101010001000000001111 00005
+E5C1B95100F
0000000000001100111011111010100001011001101001100011011101111111 000CE
+FA859A6377F
0000000000000011001010100001010110101011101000101010001000101111 00032
+A15ABA2A22F
0000000000000110110100001111000101010110001101100010111100011111 0006D
+0F156362F1F
0000000000001101001011001010011110010100111010001101000101001111 000D2
+CA794E8D14F
0000000000000101110101011101011111101000111011101111111110111111 0005D
+5D7E8EEFFBF
0000000000000001000001010001000100101100100010010110010101101111 00010
+5112C89656F
0000000000001111110001100010010000001010111000101101000101011111 000FC
+6240AE2D15F
0000000000000100100100001010101010101111001011110110011010001111 00049
+0AAAF2F668F
0000000000001100100011011000010010011010000101000000101111111111 000C8
+D849A140BFF
0000000000001101000011001100011010101101010100010001110010101111 000D0
+CC6AD511CAF
0000000000000010100111010110010110111101100011110101011110011111 00029
+D65BD8F579F
0000000000000000001100001110001000000110010000100000111111001111 00003
+0E206420FCF
0000000000000101001111111000100011111000000101011001110000111111 00053
+F88F8159C3F
0000000000000100100110101110000010010110100101010000011111101111 00049
+AE0969507EF
0000000000000100111011101101111101110011110101100000000111011111 0004E
+EDF73D601DF
0000000000000110110111111000000010010010010011100000110100001111 0006D
+F80924E0D0F
0000000000000111011111011100100001010101101101111111000001111111 00077
+DC855B7F07F
0000000000001110110001011111000001110111011001000110011100101111 000EC
+5F07764672F
0000000000001101011110001010000111001010101101010001000000011111 000D7
+8A1CAB5101F
[download]

#!/usr/bin/perl
$|++;
srand(54321);
for (1 .. 20) {
    my $n = int rand(0xF_FFFF_FFFF_FFFF);
  printf "\r%064b %016X\n",$n,$n;
}
exit $?;
[download]

In reply to how to get a 64bit random number with rand() ? by iglake

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