[erlang-bugs] Crash on attempted use of float_to_binary/2

Mikael Pettersson <>
Tue Jan 27 17:29:54 CET 2009

Steve Davis writes:
 > Hi,
 > During my learning process I was trying to convert floats to binary, I 
 > inadvisedly tried the following:
 > to_binary(X) when is_float(X) -> erlang:float_to_binary(X, 64).
 > I do understand that this BIF has been removed, and it did throw an 
 > expected "erlang:float_to_binary/2 not defined" error BUT within 20 
 > seconds of running that code my PC "bluescreened" (for the first time in 
 > over 3 years).
 > I am not at all certain it's reproducible but I don't want to risk 
 > trying it again on my machine... but I do strongly suspect that the 
 > underlying c code for this bif remains, and this caused the observed result.
 > System details:
 > Erlang R12B-5/erts 5.6.5
 > Windows XP SP3
 > Acer Ferrari 3400 (a laptop)

I am unable to reproduce anything but the benign "not defined" error
with R12B-5 on Solaris 9, MacOSX 10.3, and Windows XP 64 Professional.

There is no float_to_binary of any kind in R12B-5, the only reference
to it is a documentation note that it has been removed.

A Windows bluescreen can happen due to any number of reasons, mostly
hardware or kernel/driver bugs, but a bug in the Erlang VM should not
be able to trigger it (that would in itself be a kernel bug).

IOW, I think this is pure coincidence.

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