in reply to Introspection into floats/NV
For curiosity and as i have a new license i asked ChatGPT:
#!/usr/bin/env perl + + + for m +y $val (qw(1 -1 2 -2 1/3 -1/3)) { my ($s, $e, $m) = double_to_bin_parts(eval $val); printf "%5s: sign=%s exp=%s mantissa=%s\n", $val, $s, $e, $m; } for my $expr (qw(1 -1 2 -2 1/3 -1/3)) { my $val = eval $expr; my ($s, $e, $m) = double_to_bin_parts($val); printf "%5s %.13a\n %s %s %s\n", $expr, $val, $s, $e, $m; } sub double_to_bin_parts { my $n = shift; my $bits = unpack "B64", pack "d>", $n; my $sign = substr $bits, 0, 1; my $exp = substr $bits, 1, 11; my $mantissa = substr $bits, 12, 52; return ($sign, $exp, $mantissa); } __END__ 1: sign=0 exp=01111111111 mantissa=00000000000000000000000000000000000 +00000000000000000 -1: sign=1 exp=01111111111 mantissa=0000000000000000000000000000000000 +000000000000000000 2: sign=0 exp=10000000000 mantissa=0000000000000000000000000000000000 +000000000000000000 -2: sign=1 exp=10000000000 mantissa=0000000000000000000000000000000000 +000000000000000000 1/3: sign=0 exp=01111111101 mantissa=010101010101010101010101010101010 +1010101010101010101 -1/3: sign=1 exp=01111111101 mantissa=01010101010101010101010101010101 +01010101010101010101 1 0x1.0000000000000p+0 0 01111111111 0000000000000000000000000000000000000000000000000000 -1 -0x1.0000000000000p+0 1 01111111111 0000000000000000000000000000000000000000000000000000 2 0x1.0000000000000p+1 0 10000000000 0000000000000000000000000000000000000000000000000000 -2 -0x1.0000000000000p+1 1 10000000000 0000000000000000000000000000000000000000000000000000 1/3 0x1.5555555555555p-2 0 01111111101 0101010101010101010101010101010101010101010101010101 -1/3 -0x1.5555555555555p-2 1 01111111101 0101010101010101010101010101010101010101010101010101
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Re^2: Introspection into floats/NV
by LanX (Saint) on Jun 04, 2025 at 14:09 UTC | |
by karlgoethebier (Abbot) on Jun 04, 2025 at 14:28 UTC | |
by LanX (Saint) on Jun 04, 2025 at 15:52 UTC | |
by ikegami (Patriarch) on Jun 04, 2025 at 17:50 UTC | |
by LanX (Saint) on Jun 04, 2025 at 19:03 UTC | |
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by karlgoethebier (Abbot) on Jun 04, 2025 at 17:00 UTC | |
by LanX (Saint) on Jun 04, 2025 at 17:29 UTC | |
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by ikegami (Patriarch) on Jun 04, 2025 at 18:05 UTC | |
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